Awesome

Gatus is a developer-oriented health dashboard that gives you the ability to monitor your services using HTTP, ICMP, TCP, and even DNS queries as well as evaluate the result of said queries by using a list of conditions on values like the status code, the response time, the certificate expiration, the body and many others. The icing on top is that each of these health checks can be paired with alerting via Slack, Teams, PagerDuty, Discord, Twilio and many more.

I personally deploy it in my Kubernetes cluster and let it monitor the status of my core applications: https://status.twin.sh/

Looking for a managed solution? Check out Gatus.io.

docker run -p 8080:8080 --name gatus twinproduction/gatus

You can also use GitHub Container Registry if you prefer:

docker run -p 8080:8080 --name gatus ghcr.io/twin/gatus

For more details, see Usage

❤ Like this project? Please consider sponsoring me.

Have any feedback or questions? Create a discussion.

Table of Contents

• Table of Contents
• Why Gatus?
• Features
• Usage
• Configuration
  • Endpoints
  • External Endpoints
  • Conditions
    • Placeholders
    • Functions
  • Storage
  • Client configuration
  • Alerting
    • Configuring Discord alerts
    • Configuring Email alerts
    • Configuring GitHub alerts
    • Configuring GitLab alerts
    • Configuring Google Chat alerts
    • Configuring Gotify alerts
    • Configuring JetBrains Space alerts
    • Configuring Matrix alerts
    • Configuring Mattermost alerts
    • Configuring Messagebird alerts
    • Configuring Ntfy alerts
    • Configuring Opsgenie alerts
    • Configuring PagerDuty alerts
    • Configuring Pushover alerts
    • Configuring Slack alerts
    • Configuring Teams alerts
    • Configuring Telegram alerts
    • Configuring Twilio alerts
    • Configuring AWS SES alerts
    • Configuring custom alerts
    • Setting a default alert
  • Maintenance
  • Security
    • Basic Authentication
    • OIDC
  • TLS Encryption
  • Metrics
  • Connectivity
  • Remote instances (EXPERIMENTAL)
• Deployment
  • Docker
  • Helm Chart
  • Terraform
• Running the tests
• Using in Production
• FAQ
  • Sending a GraphQL request
  • Recommended interval
  • Default timeouts
  • Monitoring a TCP endpoint
  • Monitoring a UDP endpoint
  • Monitoring a SCTP endpoint
  • Monitoring a WebSocket endpoint
  • Monitoring an endpoint using ICMP
  • Monitoring an endpoint using DNS queries
  • Monitoring an endpoint using SSH
  • Monitoring an endpoint using STARTTLS
  • Monitoring an endpoint using TLS
  • Monitoring domain expiration
  • disable-monitoring-lock
  • Reloading configuration on the fly
  • Endpoint groups
  • Exposing Gatus on a custom path
  • Exposing Gatus on a custom port
  • Configuring a startup delay
  • Keeping your configuration small
  • Proxy client configuration
  • Badges
    • Uptime
    • Health
    • Health (Shields.io)
    • Response time
      • How to change the color thresholds of the response time badge
  • API
  • Installing as binary
  • High level design overview

Why Gatus?

Before getting into the specifics, I want to address the most common question:

Why would I use Gatus when I can just use Prometheus’ Alertmanager, Cloudwatch or even Splunk?

Neither of these can tell you that there’s a problem if there are no clients actively calling the endpoint. In other words, it's because monitoring metrics mostly rely on existing traffic, which effectively means that unless your clients are already experiencing a problem, you won't be notified.

Gatus, on the other hand, allows you to configure health checks for each of your features, which in turn allows it to monitor these features and potentially alert you before any clients are impacted.

A sign you may want to look into Gatus is by simply asking yourself whether you'd receive an alert if your load balancer was to go down right now. Will any of your existing alerts be triggered? Your metrics won’t report an increase in errors if no traffic makes it to your applications. This puts you in a situation where your clients are the ones that will notify you about the degradation of your services rather than you reassuring them that you're working on fixing the issue before they even know about it.

Features

The main features of Gatus are:

• Highly flexible health check conditions: While checking the response status may be enough for some use cases, Gatus goes much further and allows you to add conditions on the response time, the response body and even the IP address.
• Ability to use Gatus for user acceptance tests: Thanks to the point above, you can leverage this application to create automated user acceptance tests.
• Very easy to configure: Not only is the configuration designed to be as readable as possible, it's also extremely easy to add a new service or a new endpoint to monitor.
• Alerting: While having a pretty visual dashboard is useful to keep track of the state of your application(s), you probably don't want to stare at it all day. Thus, notifications via Slack, Mattermost, Messagebird, PagerDuty, Twilio, Google chat and Teams are supported out of the box with the ability to configure a custom alerting provider for any needs you might have, whether it be a different provider or a custom application that manages automated rollbacks.
• Metrics
• Low resource consumption: As with most Go applications, the resource footprint that this application requires is negligibly small.
• Badges:
• Dark mode

Usage

docker run -p 8080:8080 --name gatus twinproduction/gatus

You can also use GitHub Container Registry if you prefer:

docker run -p 8080:8080 --name gatus ghcr.io/twin/gatus

If you want to create your own configuration, see Docker for information on how to mount a configuration file.

Here's a simple example:

endpoints:
  - name: website                 # Name of your endpoint, can be anything
    url: "https://twin.sh/health"
    interval: 5m                  # Duration to wait between every status check (default: 60s)
    conditions:
      - "[STATUS] == 200"         # Status must be 200
      - "[BODY].status == UP"     # The json path "$.status" must be equal to UP
      - "[RESPONSE_TIME] < 300"   # Response time must be under 300ms

  - name: make-sure-header-is-rendered
    url: "https://example.org/"
    interval: 60s
    conditions:
      - "[STATUS] == 200"                          # Status must be 200
      - "[BODY] == pat(*<h1>Example Domain</h1>*)" # Body must contain the specified header

This example would look similar to this:

By default, the configuration file is expected to be at config/config.yaml.

You can specify a custom path by setting the GATUS_CONFIG_PATH environment variable.

If GATUS_CONFIG_PATH points to a directory, all *.yaml and *.yml files inside said directory and its subdirectories are merged like so:

• All maps/objects are deep merged (i.e. you could define alerting.slack in one file and alerting.pagerduty in another file)
• All slices/arrays are appended (i.e. you can define endpoints in multiple files and each endpoint will be added to the final list of endpoints)
• Parameters with a primitive value (e.g. debug, metrics, alerting.slack.webhook-url, etc.) may only be defined once to forcefully avoid any ambiguity
  • To clarify, this also means that you could not define alerting.slack.webhook-url in two files with different values. All files are merged into one before they are processed. This is by design.

💡 You can also use environment variables in the configuration file (e.g. $DOMAIN, ${DOMAIN})

See examples/docker-compose-postgres-storage/config/config.yaml for an example.

If you want to test it locally, see Docker.

Configuration

Endpoints

Endpoints are URLs, applications, or services that you want to monitor. Each endpoint has a list of conditions that are evaluated on an interval that you define. If any condition fails, the endpoint is considered as unhealthy. You can then configure alerts to be triggered when an endpoint is unhealthy once a certain threshold is reached.

External Endpoints

Unlike regular endpoints, external endpoints are not monitored by Gatus, but they are instead pushed programmatically. This allows you to monitor anything you want, even when what you want to check lives in an environment that would not normally be accessible by Gatus.

For instance:

• You can create your own agent that lives in a private network and pushes the status of your services to a publicly-exposed Gatus instance
• You can monitor services that are not supported by Gatus
• You can implement your own monitoring system while using Gatus as the dashboard

Example:

external-endpoints:
  - name: ext-ep-test
    group: core
    token: "potato"
    alerts:
      - type: discord
        description: "healthcheck failed"
        send-on-resolved: true

To push the status of an external endpoint, the request would have to look like this:

POST /api/v1/endpoints/{key}/external?success={success}

Where:

• {key} has the pattern <GROUP_NAME>_<ENDPOINT_NAME> in which both variables have , /, _, , and . replaced by -.
  • Using the example configuration above, the key would be core_ext-ep-test.
• {success} is a boolean (true or false) value indicating whether the health check was successful or not.

You must also pass the token as a Bearer token in the Authorization header.

Conditions

Here are some examples of conditions you can use:

Placeholders

Functions

💡 Use pat only when you need to. [STATUS] == pat(2*) is a lot more expensive than [STATUS] < 300.

Storage

The results for each endpoint health check as well as the data for uptime and the past events must be persisted so that they can be displayed on the dashboard. These parameters allow you to configure the storage in question.

• If storage.type is memory (default):

# Note that this is the default value, and you can omit the storage configuration altogether to achieve the same result.
# Because the data is stored in memory, the data will not survive a restart.
storage:
  type: memory

• If storage.type is sqlite, storage.path must not be blank:

storage:
  type: sqlite
  path: data.db

See examples/docker-compose-sqlite-storage for an example.

• If storage.type is postgres, storage.path must be the connection URL:

storage:
  type: postgres
  path: "postgres://user:password@127.0.0.1:5432/gatus?sslmode=disable"

See examples/docker-compose-postgres-storage for an example.

Client configuration

In order to support a wide range of environments, each monitored endpoint has a unique configuration for the client used to send the request.

📝 Some of these parameters are ignored based on the type of endpoint. For instance, there's no certificate involved in ICMP requests (ping), therefore, setting client.insecure to true for an endpoint of that type will not do anything.

This default configuration is as follows:

client:
  insecure: false
  ignore-redirect: false
  timeout: 10s

Note that this configuration is only available under endpoints[], alerting.mattermost and alerting.custom.

Here's an example with the client configuration under endpoints[]:

endpoints:
  - name: website
    url: "https://twin.sh/health"
    client:
      insecure: false
      ignore-redirect: false
      timeout: 10s
    conditions:
      - "[STATUS] == 200"

This example shows how you can specify a custom DNS resolver:

endpoints:
  - name: with-custom-dns-resolver
    url: "https://your.health.api/health"
    client:
      dns-resolver: "tcp://8.8.8.8:53"
    conditions:
      - "[STATUS] == 200"

This example shows how you can use the client.oauth2 configuration to query a backend API with Bearer token:

endpoints:
  - name: with-custom-oauth2
    url: "https://your.health.api/health"
    client:
      oauth2:
        token-url: https://your-token-server/token
        client-id: 00000000-0000-0000-0000-000000000000
        client-secret: your-client-secret
        scopes: ['https://your.health.api/.default']
    conditions:
      - "[STATUS] == 200"

This example shows how you can use the client.identity-aware-proxy configuration to query a backend API with Bearer token using Google Identity-Aware-Proxy:

endpoints:
  - name: with-custom-iap
    url: "https://my.iap.protected.app/health"
    client:
      identity-aware-proxy:
        audience: "XXXXXXXX-XXXXXXXXXXXX.apps.googleusercontent.com"
    conditions:
      - "[STATUS] == 200"

📝 Note that Gatus will use the gcloud default credentials within its environment to generate the token.

This example shows you how you cna use the client.tls configuration to perform an mTLS query to a backend API:

endpoints:
  - name: website
    url: "https://your.mtls.protected.app/health"
    client:
      tls:
        certificate-file: /path/to/user_cert.pem
        private-key-file: /path/to/user_key.pem
        renegotiation: once
    conditions:
      - "[STATUS] == 200"

📝 Note that if running in a container, you must volume mount the certificate and key into the container.

Alerting

Gatus supports multiple alerting providers, such as Slack and PagerDuty, and supports different alerts for each individual endpoints with configurable descriptions and thresholds.

Alerts are configured at the endpoint level like so:

Here's an example of what an alert configuration might look like at the endpoint level:

endpoints:
  - name: example
    url: "https://example.org"
    conditions:
      - "[STATUS] == 200"
    alerts:
      - type: slack
        description: "healthcheck failed"
        send-on-resolved: true

📝 If an alerting provider is not properly configured, all alerts configured with the provider's type will be ignored.

Configuring Discord alerts

alerting:
  discord:
    webhook-url: "https://discord.com/api/webhooks/**********/**********"

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 5m
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: discord
        description: "healthcheck failed"
        send-on-resolved: true

Configuring Email alerts

alerting:
  email:
    from: "from@example.com"
    username: "from@example.com"
    password: "hunter2"
    host: "mail.example.com"
    port: 587
    to: "recipient1@example.com,recipient2@example.com"
    client:
      insecure: false
    # You can also add group-specific to keys, which will
    # override the to key above for the specified groups
    overrides:
      - group: "core"
        to: "recipient3@example.com,recipient4@example.com"

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 5m
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: email
        description: "healthcheck failed"
        send-on-resolved: true

  - name: back-end
    group: core
    url: "https://example.org/"
    interval: 5m
    conditions:
      - "[STATUS] == 200"
      - "[CERTIFICATE_EXPIRATION] > 48h"
    alerts:
      - type: email
        description: "healthcheck failed"
        send-on-resolved: true

⚠ Some mail servers are painfully slow.

Configuring GitHub alerts

The GitHub alerting provider creates an issue prefixed with alert(gatus): and suffixed with the endpoint's display name for each alert. If send-on-resolved is set to true on the endpoint alert, the issue will be automatically closed when the alert is resolved.

alerting:
  github:
    repository-url: "https://github.com/TwiN/test"
    token: "github_pat_12345..."

endpoints:
  - name: example
    url: "https://twin.sh/health"
    interval: 5m
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 75"
    alerts:
      - type: github
        failure-threshold: 2
        success-threshold: 3
        send-on-resolved: true
        description: "Everything's burning AAAAAHHHHHHHHHHHHHHH"

Configuring GitLab alerts

The GitLab alerting provider creates an alert prefixed with alert(gatus): and suffixed with the endpoint's display name for each alert. If send-on-resolved is set to true on the endpoint alert, the alert will be automatically closed when the alert is resolved. See https://docs.gitlab.com/ee/operations/incident_management/integrations.html#configuration to configure the endpoint.

alerting:
  gitlab:
    webhook-url: "https://gitlab.com/hlidotbe/example/alerts/notify/gatus/xxxxxxxxxxxxxxxx.json"
    authorization-key: "12345"

endpoints:
  - name: example
    url: "https://twin.sh/health"
    interval: 5m
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 75"
    alerts:
      - type: gitlab
        failure-threshold: 2
        success-threshold: 3
        send-on-resolved: true
        description: "Everything's burning AAAAAHHHHHHHHHHHHHHH"

Configuring Google Chat alerts

alerting:
  googlechat:
    webhook-url: "https://chat.googleapis.com/v1/spaces/*******/messages?key=**********&token=********"

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 5m
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: googlechat
        description: "healthcheck failed"
        send-on-resolved: true

Configuring Gotify alerts

alerting:
  gotify:
    server-url: "https://gotify.example"
    token: "**************"

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 5m
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: gotify
        description: "healthcheck failed"
        send-on-resolved: true

Here's an example of what the notifications look like:

Configuring JetBrains Space alerts

alerting:
  jetbrainsspace:
    project: myproject
    channel-id: ABCDE12345
    token: "**************"

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 5m
    conditions:
      - "[STATUS] == 200"
    alerts:
      - type: jetbrainsspace
        description: "healthcheck failed"
        send-on-resolved: true

Here's an example of what the notifications look like:

Configuring Matrix alerts

alerting:
  matrix:
    server-url: "https://matrix-client.matrix.org"
    access-token: "123456"
    internal-room-id: "!example:matrix.org"

endpoints:
  - name: website
    interval: 5m
    url: "https://twin.sh/health"
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: matrix
        send-on-resolved: true
        description: "healthcheck failed"

Configuring Mattermost alerts

alerting:
  mattermost:
    webhook-url: "http://**********/hooks/**********"
    client:
      insecure: true

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 5m
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: mattermost
        description: "healthcheck failed"
        send-on-resolved: true

Here's an example of what the notifications look like:

Configuring Messagebird alerts

Example of sending SMS text message alert using Messagebird:

alerting:
  messagebird:
    access-key: "..."
    originator: "31619191918"
    recipients: "31619191919,31619191920"

endpoints:
  - name: website
    interval: 5m
    url: "https://twin.sh/health"
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: messagebird
        failure-threshold: 3
        send-on-resolved: true
        description: "healthcheck failed"

Configuring Ntfy alerts

ntfy is an amazing project that allows you to subscribe to desktop and mobile notifications, making it an awesome addition to Gatus.

Example:

alerting:
  ntfy:
    topic: "gatus-test-topic"
    priority: 2
    token: faketoken
    default-alert:
      failure-threshold: 3
      send-on-resolved: true

endpoints:
  - name: website
    interval: 5m
    url: "https://twin.sh/health"
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: ntfy

Configuring Opsgenie alerts

Opsgenie provider will automatically open and close alerts.

alerting:
  opsgenie:
    api-key: "00000000-0000-0000-0000-000000000000"

Configuring PagerDuty alerts

It is highly recommended to set endpoints[].alerts[].send-on-resolved to true for alerts of type pagerduty, because unlike other alerts, the operation resulting from setting said parameter to true will not create another incident but mark the incident as resolved on PagerDuty instead.

Behavior:

• By default, alerting.pagerduty.integration-key is used as the integration key
• If the endpoint being evaluated belongs to a group (endpoints[].group) matching the value of alerting.pagerduty.overrides[].group, the provider will use that override's integration key instead of alerting.pagerduty.integration-key's

alerting:
  pagerduty:
    integration-key: "********************************"
    # You can also add group-specific integration keys, which will
    # override the integration key above for the specified groups
    overrides:
      - group: "core"
        integration-key: "********************************"

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 30s
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: pagerduty
        failure-threshold: 3
        success-threshold: 5
        send-on-resolved: true
        description: "healthcheck failed"

  - name: back-end
    group: core
    url: "https://example.org/"
    interval: 5m
    conditions:
      - "[STATUS] == 200"
      - "[CERTIFICATE_EXPIRATION] > 48h"
    alerts:
      - type: pagerduty
        failure-threshold: 3
        success-threshold: 5
        send-on-resolved: true
        description: "healthcheck failed"

Configuring Pushover alerts

alerting:
  pushover:
    application-token: "******************************"
    user-key: "******************************"

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 30s
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: pushover
        failure-threshold: 3
        success-threshold: 5
        send-on-resolved: true
        description: "healthcheck failed"

Configuring Slack alerts

alerting:
  slack:
    webhook-url: "https://hooks.slack.com/services/**********/**********/**********"

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 30s
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: slack
        description: "healthcheck failed 3 times in a row"
        send-on-resolved: true
      - type: slack
        failure-threshold: 5
        description: "healthcheck failed 5 times in a row"
        send-on-resolved: true

Here's an example of what the notifications look like:

Configuring Teams alerts

alerting:
  teams:
    webhook-url: "https://********.webhook.office.com/webhookb2/************"
    # You can also add group-specific to keys, which will
    # override the to key above for the specified groups
    overrides:
      - group: "core"
        webhook-url: "https://********.webhook.office.com/webhookb3/************"

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 30s
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: teams
        description: "healthcheck failed"
        send-on-resolved: true

  - name: back-end
    group: core
    url: "https://example.org/"
    interval: 5m
    conditions:
      - "[STATUS] == 200"
      - "[CERTIFICATE_EXPIRATION] > 48h"
    alerts:
      - type: teams
        description: "healthcheck failed"
        send-on-resolved: true

Here's an example of what the notifications look like:

Configuring Telegram alerts

alerting:
  telegram:
    token: "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11"
    id: "0123456789"

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 30s
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
    alerts:
      - type: telegram
        send-on-resolved: true

Here's an example of what the notifications look like:

Configuring Twilio alerts

alerting:
  twilio:
    sid: "..."
    token: "..."
    from: "+1-234-567-8901"
    to: "+1-234-567-8901"

endpoints:
  - name: website
    interval: 30s
    url: "https://twin.sh/health"
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: twilio
        failure-threshold: 5
        send-on-resolved: true
        description: "healthcheck failed"

Configuring AWS SES alerts

alerting:
  aws-ses:
    access-key-id: "..."
    secret-access-key: "..."
    region: "us-east-1"
    from: "status@example.com"
    to: "user@example.com"

endpoints:
  - name: website
    interval: 30s
    url: "https://twin.sh/health"
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: aws-ses
        failure-threshold: 5
        send-on-resolved: true
        description: "healthcheck failed"

If the access-key-id and secret-access-key are not defined Gatus will fall back to IAM authentication.

Make sure you have the ability to use ses:SendEmail.

Configuring custom alerts

While they're called alerts, you can use this feature to call anything.

For instance, you could automate rollbacks by having an application that keeps tracks of new deployments, and by leveraging Gatus, you could have Gatus call that application endpoint when an endpoint starts failing. Your application would then check if the endpoint that started failing was part of the recently deployed application, and if it was, then automatically roll it back.

Furthermore, you may use the following placeholders in the body (alerting.custom.body) and in the url (alerting.custom.url):

• [ALERT_DESCRIPTION] (resolved from endpoints[].alerts[].description)
• [ENDPOINT_NAME] (resolved from endpoints[].name)
• [ENDPOINT_GROUP] (resolved from endpoints[].group)
• [ENDPOINT_URL] (resolved from endpoints[].url)

If you have an alert using the custom provider with send-on-resolved set to true, you can use the [ALERT_TRIGGERED_OR_RESOLVED] placeholder to differentiate the notifications. The aforementioned placeholder will be replaced by TRIGGERED or RESOLVED accordingly, though it can be modified (details at the end of this section).

For all intents and purposes, we'll configure the custom alert with a Slack webhook, but you can call anything you want.

alerting:
  custom:
    url: "https://hooks.slack.com/services/**********/**********/**********"
    method: "POST"
    body: |
      {
        "text": "[ALERT_TRIGGERED_OR_RESOLVED]: [ENDPOINT_GROUP] - [ENDPOINT_NAME] - [ALERT_DESCRIPTION]"
      }
endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 30s
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: custom
        failure-threshold: 10
        success-threshold: 3
        send-on-resolved: true
        description: "health check failed"

Note that you can customize the resolved values for the [ALERT_TRIGGERED_OR_RESOLVED] placeholder like so:

alerting:
  custom:
    placeholders:
      ALERT_TRIGGERED_OR_RESOLVED:
        TRIGGERED: "partial_outage"
        RESOLVED: "operational"

As a result, the [ALERT_TRIGGERED_OR_RESOLVED] in the body of first example of this section would be replaced by partial_outage when an alert is triggered and operational when an alert is resolved.

Setting a default alert

⚠ You must still specify the type of the alert in the endpoint configuration even if you set the default alert of a provider.

While you can specify the alert configuration directly in the endpoint definition, it's tedious and may lead to a very long configuration file.

To avoid such problem, you can use the default-alert parameter present in each provider configuration:

alerting:
  slack:
    webhook-url: "https://hooks.slack.com/services/**********/**********/**********"
    default-alert:
      description: "health check failed"
      send-on-resolved: true
      failure-threshold: 5
      success-threshold: 5

As a result, your Gatus configuration looks a lot tidier:

endpoints:
  - name: example
    url: "https://example.org"
    conditions:
      - "[STATUS] == 200"
    alerts:
      - type: slack

  - name: other-example
    url: "https://example.com"
    conditions:
      - "[STATUS] == 200"
    alerts:
      - type: slack

It also allows you to do things like this:

endpoints:
  - name: example
    url: "https://example.org"
    conditions:
      - "[STATUS] == 200"
    alerts:
      - type: slack
        failure-threshold: 5
      - type: slack
        failure-threshold: 10
      - type: slack
        failure-threshold: 15

Of course, you can also mix alert types:

alerting:
  slack:
    webhook-url: "https://hooks.slack.com/services/**********/**********/**********"
    default-alert:
      failure-threshold: 3
  pagerduty:
    integration-key: "********************************"
    default-alert:
      failure-threshold: 5

endpoints:
  - name: endpoint-1
    url: "https://example.org"
    conditions:
      - "[STATUS] == 200"
    alerts:
      - type: slack
      - type: pagerduty

  - name: endpoint-2
    url: "https://example.org"
    conditions:
      - "[STATUS] == 200"
    alerts:
      - type: slack
      - type: pagerduty

Maintenance

If you have maintenance windows, you may not want to be annoyed by alerts. To do that, you'll have to use the maintenance configuration:

Here's an example:

maintenance:
  start: 23:00
  duration: 1h
  timezone: "Europe/Amsterdam"
  every: [Monday, Thursday]

Note that you can also specify each day on separate lines:

maintenance:
  start: 23:00
  duration: 1h
  timezone: "Europe/Amsterdam"
  every:
    - Monday
    - Thursday

Security

Basic Authentication

The example below will require that you authenticate with the username john.doe and the password hunter2:

security:
  basic:
    username: "john.doe"
    password-bcrypt-base64: "JDJhJDEwJHRiMnRFakxWazZLdXBzRERQazB1TE8vckRLY05Yb1hSdnoxWU0yQ1FaYXZRSW1McmladDYu"

⚠ Make sure to carefully select to cost of the bcrypt hash. The higher the cost, the longer it takes to compute the hash, and basic auth verifies the password against the hash on every request. As of 2023-01-06, I suggest a cost of 9.

OIDC

security:
  oidc:
    issuer-url: "https://example.okta.com"
    redirect-url: "https://status.example.com/authorization-code/callback"
    client-id: "123456789"
    client-secret: "abcdefghijk"
    scopes: ["openid"]
    # You may optionally specify a list of allowed subjects. If this is not specified, all subjects will be allowed.
    #allowed-subjects: ["johndoe@example.com"]

Confused? Read Securing Gatus with OIDC using Auth0.

TLS Encryption

Gatus supports basic encryption with TLS. To enable this, certificate files in PEM format have to be provided.

The example below shows an example configuration which makes gatus respond on port 4443 to HTTPS requests:

web:
  port: 4443
  tls:
    certificate-file: "certificate.crt"
    private-key-file: "private.key"

Metrics

To enable metrics, you must set metrics to true. Doing so will expose Prometheus-friendly metrics at the /metrics endpoint on the same port your application is configured to run on (web.port).

See examples/docker-compose-grafana-prometheus for further documentation as well as an example.

Connectivity

While Gatus is used to monitor other services, it is possible for Gatus itself to lose connectivity to the internet. In order to prevent Gatus from reporting endpoints as unhealthy when Gatus itself is unhealthy, you may configure Gatus to periodically check for internet connectivity.

All endpoint executions are skipped while the connectivity checker deems connectivity to be down.

connectivity:
  checker:
    target: 1.1.1.1:53
    interval: 60s

Remote instances (EXPERIMENTAL)

This feature allows you to retrieve endpoint statuses from a remote Gatus instance.

There are two main use cases for this:

• You have multiple Gatus instances running on different machines, and you wish to visually expose the statuses through a single dashboard
• You have one or more Gatus instances that are not publicly accessible (e.g. behind a firewall), and you wish to retrieve

This is an experimental feature. It may be removed or updated in a breaking manner at any time. Furthermore, there are known issues with this feature. If you'd like to provide some feedback, please write a comment in #64. Use at your own risk.

remote:
  instances:
    - endpoint-prefix: "status.example.org-"
      url: "https://status.example.org/api/v1/endpoints/statuses"

Deployment

Many examples can be found in the .examples folder, but this section will focus on the most popular ways of deploying Gatus.

Docker

To run Gatus locally with Docker:

docker run -p 8080:8080 --name gatus twinproduction/gatus

Other than using one of the examples provided in the .examples folder, you can also try it out locally by creating a configuration file, we'll call it config.yaml for this example, and running the following command:

docker run -p 8080:8080 --mount type=bind,source="$(pwd)"/config.yaml,target=/config/config.yaml --name gatus twinproduction/gatus

If you're on Windows, replace "$(pwd)" by the absolute path to your current directory, e.g.:

docker run -p 8080:8080 --mount type=bind,source=C:/Users/Chris/Desktop/config.yaml,target=/config/config.yaml --name gatus twinproduction/gatus

To build the image locally:

docker build . -t twinproduction/gatus

Helm Chart

Helm must be installed to use the chart. Please refer to Helm's documentation to get started.

Once Helm is set up properly, add the repository as follows:

helm repo add minicloudlabs https://minicloudlabs.github.io/helm-charts

To get more details, please check chart's configuration and helm file example

Terraform

Gatus can be deployed on Terraform by using the following module: terraform-kubernetes-gatus.

Running the tests

go test -v ./...

Using in Production

See the Deployment section.

FAQ

Sending a GraphQL request

By setting endpoints[].graphql to true, the body will automatically be wrapped by the standard GraphQL query parameter.

For instance, the following configuration:

endpoints:
  - name: filter-users-by-gender
    url: http://localhost:8080/playground
    method: POST
    graphql: true
    body: |
      {
        users(gender: "female") {
          id
          name
          gender
          avatar
        }
      }
    conditions:
      - "[STATUS] == 200"
      - "[BODY].data.users[0].gender == female"

will send a POST request to http://localhost:8080/playground with the following body:

{"query":"      {\n        users(gender: \"female\") {\n          id\n          name\n          gender\n          avatar\n        }\n      }"}

Recommended interval

📝 This does not apply if disable-monitoring-lock is set to true, as the monitoring lock is what tells Gatus to only evaluate one endpoint at a time.

To ensure that Gatus provides reliable and accurate results (i.e. response time), Gatus only evaluates one endpoint at a time In other words, even if you have multiple endpoints with the same interval, they will not execute at the same time.

You can test this yourself by running Gatus with several endpoints configured with a very short, unrealistic interval, such as 1ms. You'll notice that the response time does not fluctuate - that is because while endpoints are evaluated on different goroutines, there's a global lock that prevents multiple endpoints from running at the same time.

Unfortunately, there is a drawback. If you have a lot of endpoints, including some that are very slow or prone to timing out (the default timeout is 10s), then it means that for the entire duration of the request, no other endpoint can be evaluated.

The interval does not include the duration of the request itself, which means that if an endpoint has an interval of 30s and the request takes 2s to complete, the timestamp between two evaluations will be 32s, not 30s.

While this does not prevent Gatus' from performing health checks on all other endpoints, it may cause Gatus to be unable to respect the configured interval, for instance:

• Endpoint A has an interval of 5s, and times out after 10s to complete
• Endpoint B has an interval of 5s, and takes 1ms to complete
• Endpoint B will be unable to run every 5s, because endpoint A's health evaluation takes longer than its interval

To sum it up, while Gatus can handle any interval you throw at it, you're better off having slow requests with higher interval.

As a rule of thumb, I personally set the interval for more complex health checks to 5m (5 minutes) and simple health checks used for alerting (PagerDuty/Twilio) to 30s.

Default timeouts

To modify the timeout, see Client configuration.

Monitoring a TCP endpoint

By prefixing endpoints[].url with tcp:\\, you can monitor TCP endpoints at a very basic level:

endpoints:
  - name: redis
    url: "tcp://127.0.0.1:6379"
    interval: 30s
    conditions:
      - "[CONNECTED] == true"

Placeholders [STATUS] and [BODY] as well as the fields endpoints[].body, endpoints[].headers, endpoints[].method and endpoints[].graphql are not supported for TCP endpoints.

This works for applications such as databases (Postgres, MySQL, etc.) and caches (Redis, Memcached, etc.).

📝 [CONNECTED] == true does not guarantee that the endpoint itself is healthy - it only guarantees that there's something at the given address listening to the given port, and that a connection to that address was successfully established.

Monitoring a UDP endpoint

By prefixing endpoints[].url with udp:\\, you can monitor UDP endpoints at a very basic level:

endpoints:
  - name: example
    url: "udp://example.org:80"
    conditions:
      - "[CONNECTED] == true"

Placeholders [STATUS] and [BODY] as well as the fields endpoints[].body, endpoints[].headers, endpoints[].method and endpoints[].graphql are not supported for UDP endpoints.

This works for UDP based application.

Monitoring a SCTP endpoint

By prefixing endpoints[].url with sctp:\\, you can monitor Stream Control Transmission Protocol (SCTP) endpoints at a very basic level:

endpoints:
  - name: example
    url: "sctp://127.0.0.1:38412"
    conditions:
      - "[CONNECTED] == true"

Placeholders [STATUS] and [BODY] as well as the fields endpoints[].body, endpoints[].headers, endpoints[].method and endpoints[].graphql are not supported for SCTP endpoints.

This works for SCTP based application.

Monitoring a WebSocket endpoint

By prefixing endpoints[].url with ws:// or wss://, you can monitor WebSocket endpoints at a very basic level:

endpoints:
  - name: example
    url: "wss://example.com/"
    body: "status"
    conditions:
      - "[CONNECTED] == true"
      - "[BODY].result >= 0"

The [BODY] placeholder contains the output of the query, and [CONNECTED] shows whether the connection was successfully established.

Monitoring an endpoint using ICMP

By prefixing endpoints[].url with icmp:\\, you can monitor endpoints at a very basic level using ICMP, or more commonly known as "ping" or "echo":

endpoints:
  - name: ping-example
    url: "icmp://example.com"
    conditions:
      - "[CONNECTED] == true"

Only the placeholders [CONNECTED], [IP] and [RESPONSE_TIME] are supported for endpoints of type ICMP. You can specify a domain prefixed by icmp://, or an IP address prefixed by icmp://.

If you run Gatus on Linux, please read the Linux section on https://github.com/prometheus-community/pro-bing#linux if you encounter any problems.

Monitoring an endpoint using DNS queries

Defining a dns configuration in an endpoint will automatically mark said endpoint as an endpoint of type DNS:

endpoints:
  - name: example-dns-query
    url: "8.8.8.8" # Address of the DNS server to use
    dns:
      query-name: "example.com"
      query-type: "A"
    conditions:
      - "[BODY] == 93.184.215.14"
      - "[DNS_RCODE] == NOERROR"

There are two placeholders that can be used in the conditions for endpoints of type DNS:

• The placeholder [BODY] resolves to the output of the query. For instance, a query of type A would return an IPv4.
• The placeholder [DNS_RCODE] resolves to the name associated to the response code returned by the query, such as NOERROR, FORMERR, SERVFAIL, NXDOMAIN, etc.

Monitoring an endpoint using SSH

You can monitor endpoints using SSH by prefixing endpoints[].url with ssh:\\:

endpoints:
  - name: ssh-example
    url: "ssh://example.com:22" # port is optional. Default is 22.
    ssh:
      username: "username"
      password: "password"
    body: |
      {
        "command": "uptime"
      }
    interval: 1m
    conditions:
      - "[CONNECTED] == true"
      - "[STATUS] == 0"

The following placeholders are supported for endpoints of type SSH:

• [CONNECTED] resolves to true if the SSH connection was successful, false otherwise
• [STATUS] resolves the exit code of the command executed on the remote server (e.g. 0 for success)

Monitoring an endpoint using STARTTLS

If you have an email server that you want to ensure there are no problems with, monitoring it through STARTTLS will serve as a good initial indicator:

endpoints:
  - name: starttls-smtp-example
    url: "starttls://smtp.gmail.com:587"
    interval: 30m
    client:
      timeout: 5s
    conditions:
      - "[CONNECTED] == true"
      - "[CERTIFICATE_EXPIRATION] > 48h"

Monitoring an endpoint using TLS

Monitoring endpoints using SSL/TLS encryption, such as LDAP over TLS, can help detect certificate expiration:

endpoints:
  - name: tls-ldaps-example
    url: "tls://ldap.example.com:636"
    interval: 30m
    client:
      timeout: 5s
    conditions:
      - "[CONNECTED] == true"
      - "[CERTIFICATE_EXPIRATION] > 48h"

Monitoring domain expiration

You can monitor the expiration of a domain with all endpoint types except for DNS by using the [DOMAIN_EXPIRATION] placeholder:

endpoints:
  - name: check-domain-and-certificate-expiration
    url: "https://example.org"
    interval: 1h
    conditions:
      - "[DOMAIN_EXPIRATION] > 720h"
      - "[CERTIFICATE_EXPIRATION] > 240h"

⚠ The usage of the [DOMAIN_EXPIRATION] placeholder requires Gatus to send a request to the official IANA WHOIS service through a library and in some cases, a secondary request to a TLD-specific WHOIS server (e.g. whois.nic.sh). To prevent the WHOIS service from throttling your IP address if you send too many requests, Gatus will prevent you from using the [DOMAIN_EXPIRATION] placeholder on an endpoint with an interval of less than 5m.

disable-monitoring-lock

Setting disable-monitoring-lock to true means that multiple endpoints could be monitored at the same time.

While this behavior wouldn't generally be harmful, conditions using the [RESPONSE_TIME] placeholder could be impacted by the evaluation of multiple endpoints at the same time, therefore, the default value for this parameter is false.

There are three main reasons why you might want to disable the monitoring lock:

• You're using Gatus for load testing (each endpoint are periodically evaluated on a different goroutine, so technically, if you create 100 endpoints with a 1 seconds interval, Gatus will send 100 requests per second)
• You have a lot of endpoints to monitor
• You want to test multiple endpoints at very short intervals (< 5s)

Reloading configuration on the fly

For the sake of convenience, Gatus automatically reloads the configuration on the fly if the loaded configuration file is updated while Gatus is running.

By default, the application will exit if the updating configuration is invalid, but you can configure Gatus to continue running if the configuration file is updated with an invalid configuration by setting skip-invalid-config-update to true.

Keep in mind that it is in your best interest to ensure the validity of the configuration file after each update you apply to the configuration file while Gatus is running by looking at the log and making sure that you do not see the following message:

The configuration file was updated, but it is not valid. The old configuration will continue being used.

Failure to do so may result in Gatus being unable to start if the application is restarted for whatever reason.

I recommend not setting skip-invalid-config-update to true to avoid a situation like this, but the choice is yours to make.

If you are not using a file storage, updating the configuration while Gatus is running is effectively the same as restarting the application.

📝 Updates may not be detected if the config file is bound instead of the config folder. See #151.

Endpoint groups

Endpoint groups are used for grouping multiple endpoints together on the dashboard.

endpoints:
  - name: frontend
    group: core
    url: "https://example.org/"
    interval: 5m
    conditions:
      - "[STATUS] == 200"

  - name: backend
    group: core
    url: "https://example.org/"
    interval: 5m
    conditions:
      - "[STATUS] == 200"

  - name: monitoring
    group: internal
    url: "https://example.org/"
    interval: 5m
    conditions:
      - "[STATUS] == 200"

  - name: nas
    group: internal
    url: "https://example.org/"
    interval: 5m
    conditions:
      - "[STATUS] == 200"

  - name: random endpoint that is not part of a group
    url: "https://example.org/"
    interval: 5m
    conditions:
      - "[STATUS] == 200"

The configuration above will result in a dashboard that looks like this:

Exposing Gatus on a custom path

Currently, you can expose the Gatus UI using a fully qualified domain name (FQDN) such as status.example.org. However, it does not support path-based routing, which means you cannot expose it through a URL like example.org/status/.

For more information, see https://github.com/TwiN/gatus/issues/88.

Exposing Gatus on a custom port

By default, Gatus is exposed on port 8080, but you may specify a different port by setting the web.port parameter:

web:
  port: 8081

If you're using a PaaS like Heroku that doesn't let you set a custom port and exposes it through an environment variable instead, you can use that environment variable directly in the configuration file:

web:
  port: ${PORT}

Configuring a startup delay

If, for any reason, you need Gatus to wait for a given amount of time before monitoring the endpoints on application start, you can use the GATUS_DELAY_START_SECONDS environment variable to make Gatus sleep on startup.

Keeping your configuration small

While not specific to Gatus, you can leverage YAML anchors to create a default configuration. If you have a large configuration file, this should help you keep things clean.

default-endpoint: &defaults
  group: core
  interval: 5m
  client:
    insecure: true
    timeout: 30s
  conditions:
    - "[STATUS] == 200"

endpoints:
  - name: anchor-example-1
    <<: *defaults               # This will merge the configuration under &defaults with this endpoint
    url: "https://example.org"

  - name: anchor-example-2
    <<: *defaults
    group: example              # This will override the group defined in &defaults
    url: "https://example.com"

  - name: anchor-example-3
    <<: *defaults
    url: "https://twin.sh/health"
    conditions:                # This will override the conditions defined in &defaults
      - "[STATUS] == 200"
      - "[BODY].status == UP"

Proxy client configuration

You can configure a proxy for the client to use by setting the proxy-url parameter in the client configuration.

endpoints:
  - name: website
    url: "https://twin.sh/health"
    client:
      proxy-url: http://proxy.example.com:8080
    conditions:
      - "[STATUS] == 200"

Proxy client configuration

You can configure a proxy for the client to use by setting the proxy-url parameter in the client configuration.

endpoints:
  - name: website
    url: "https://twin.sh/health"
    client:
      proxy-url: http://proxy.example.com:8080
    conditions:
      - "[STATUS] == 200"

How to fix 431 Request Header Fields Too Large error

Depending on where your environment is deployed and what kind of middleware or reverse proxy sits in front of Gatus, you may run into this issue. This could be because the request headers are too large, e.g. big cookies.

By default, web.read-buffer-size is set to 8192, but increasing this value like so will increase the read buffer size:

web:
  read-buffer-size: 32768

Badges

Uptime

Gatus can automatically generate an SVG badge for one of your monitored endpoints. This allows you to put badges in your individual applications' README or even create your own status page if you desire.

The path to generate a badge is the following:

/api/v1/endpoints/{key}/uptimes/{duration}/badge.svg

Where:

• {duration} is 7d, 24h or 1h
• {key} has the pattern <GROUP_NAME>_<ENDPOINT_NAME> in which both variables have , /, _, , and . replaced by -.

For instance, if you want the uptime during the last 24 hours from the endpoint frontend in the group core, the URL would look like this:

https://example.com/api/v1/endpoints/core_frontend/uptimes/7d/badge.svg

If you want to display an endpoint that is not part of a group, you must leave the group value empty:

https://example.com/api/v1/endpoints/_frontend/uptimes/7d/badge.svg

Example:

![Uptime 24h](https://status.twin.sh/api/v1/endpoints/core_blog-external/uptimes/24h/badge.svg)

If you'd like to see a visual example of each badge available, you can simply navigate to the endpoint's detail page.

Health

The path to generate a badge is the following:

/api/v1/endpoints/{key}/health/badge.svg

Where:

• {key} has the pattern <GROUP_NAME>_<ENDPOINT_NAME> in which both variables have , /, _, , and . replaced by -.

For instance, if you want the current status of the endpoint frontend in the group core, the URL would look like this:

https://example.com/api/v1/endpoints/core_frontend/health/badge.svg

Health (Shields.io)

The path to generate a badge is the following:

/api/v1/endpoints/{key}/health/badge.shields

Where:

• {key} has the pattern <GROUP_NAME>_<ENDPOINT_NAME> in which both variables have , /, _, , and . replaced by -.

For instance, if you want the current status of the endpoint frontend in the group core, the URL would look like this:

https://example.com/api/v1/endpoints/core_frontend/health/badge.shields

See more information about the Shields.io badge endpoint here.

Response time

The endpoint to generate a badge is the following:

/api/v1/endpoints/{key}/response-times/{duration}/badge.svg

Where:

• {duration} is 7d, 24h or 1h
• {key} has the pattern <GROUP_NAME>_<ENDPOINT_NAME> in which both variables have , /, _, , and . replaced by -.

How to change the color thresholds of the response time badge

To change the response time badges' threshold, a corresponding configuration can be added to an endpoint. The values in the array correspond to the levels [Awesome, Great, Good, Passable, Bad] All five values must be given in milliseconds (ms).

endpoints:
- name: nas
  group: internal
  url: "https://example.org/"
  interval: 5m
  conditions:
    - "[STATUS] == 200"
  ui:
    badge:
      response-time:
        thresholds: [550, 850, 1350, 1650, 1750]

API

Gatus provides a simple read-only API that can be queried in order to programmatically determine endpoint status and history.

All endpoints are available via a GET request to the following endpoint:

/api/v1/endpoints/statuses

Example: https://status.twin.sh/api/v1/endpoints/statuses

Specific endpoints can also be queried by using the following pattern:

/api/v1/endpoints/{group}_{endpoint}/statuses

Example: https://status.twin.sh/api/v1/endpoints/core_blog-home/statuses

Gzip compression will be used if the Accept-Encoding HTTP header contains gzip.

The API will return a JSON payload with the Content-Type response header set to application/json. No such header is required to query the API.

Installing as binary

You can download Gatus as a binary using the following command:

go install github.com/TwiN/gatus/v5@latest

High level design overview