Awesome
Cadence Web UI
Cadence is a distributed, scalable, durable, and highly available orchestration engine we developed at Uber Engineering to execute asynchronous long-running business logic in a scalable and resilient way.
This web UI is used to view workflows from Cadence, see what's running, and explore and debug workflow executions.
Getting Started
Configuration
Set these environment variables if you need to change their defaults
Variable | Description | Default |
---|---|---|
CADENCE_TCHANNEL_PEERS | Comma-delmited list of tchannel peers | 127.0.0.1:7933 |
CADENCE_TCHANNEL_SERVICE | Name of the cadence tchannel service to call | cadence-frontend |
CADENCE_WEB_PORT | HTTP port to serve on | 8088 |
CADENCE_EXTERNAL_SCRIPTS | Addtional JavaScript tags to serve in the UI | |
ENABLE_AUTH | Enable auth feature | false |
AUTH_TYPE | supports ADMIN_JWT and OIDC | '' |
AUTH_ADMIN_JWT_PRIVATE_KEY | JWT signing private key for ADMIN_JWT type | '' |
OPENID_CLIENT_ID | Client ID for OIDC type authentication | '' |
OPENID_CLIENT_SECRET | Client secret for OIDC type authentication | '' |
OPENID_CALLBACK_URL | URL redirect to Cadence WEB after OIDC auth | '' |
OPENID_DISCOVER_URL | Link to provider .well-known configuration | '' |
OPENID_SCOPE | Scope to request from idp | openid |
Running locally
cadence-web
requires node v10.22.1
or greater to be able to run correctly. cadence-web
uses all the standard npm scripts to install dependencies, run the
server, and run tests.
To provide a consistent environment we recommend using docker in development. We provide a default configuration for remote containers using docker-compose.
Using VSCode Dev Containers
- Set up the Remote Containers plugin in VSCode.
- Open the cadence-web directory in VSCode.
- Use the Command Palette to select the 'Reopen folder in Container' option.
npm install
should run automatically in the container upon doing so. - Run the app in the container with
npm run dev
. - Open
localhost:8088
(or the custom Cadence Web port you have defined) to load the webapp.
Using docker-compose to start the dev container
To start local server with live reload on code change you can run docker-compose up
.
For development and contributing to cadence-web
, please see the contributing guide.
You may also use docker by pulling ubercadence/web. It is also included in the Cadence server's local docker setup.
API
If you need to extend cadence-web
to add middleware to the server, you can install cadence-web
as a dependecy, and it will export the Koa web server that has not yet been started or configured. It includes an additional init
function that will then compose the built-in middleware. This gives you an option to add middleware before or after you call init
so it will add the middleware at the beginning or the end of the chain, respectively.
init(options)
All options are optional.
useWebpack
: If true
, starts webpack and adds the middleware, otherwise if false
, it assumes the UI bundle was already built and serves it statically. Defaults to process.env.NODE_ENV === 'production'
.
logErrors
: If true
, thrown errors are logged to console.error
. Defaults to true
.
For example, here is how you would add a request count metric using uber-statsd-client
:
var app = require('cadence-web');
var createStatsd = require('uber-statsd-client');
var sdc = createStatsd({
host: 'statsd.example.com',
});
app
.use(async function(ctx, next) {
sdc.increment('http.request');
await next();
})
.init()
.listen(7000);
The webpack configuration is also exported as webpackConfig
, and can be modified before calling init()
.
Licence
MIT License, please see LICENSE for details.