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rabtap - RabbitMQ wire tap

Swiss army knife for RabbitMQ. Tap/Pub/Sub messages, create/delete/bind queues and exchanges, inspect broker.

Features
Screenshots
Installation
Usage
JSON message format
Filtering output of info command
- Filtering expressions
  - Evaluation context
  - Examples
- Type reference
Build from source
Test data generator
Contributing
Author
Copyright and license

Features

tap to messages being sent to exchanges using RabbitMQ exchange-to-exchange bindings without affecting actual message delivery (aka tapping)
display broker related information using the RabbitMQ REST management API
save messages and meta data for later analysis and replay
publish messages to exchanges
consume messages from queues and streams (subscribe)
supports TLS
no runtime dependencies (statically linked golang single file binary)
simple to use command line tool
runs on Linux, Windows, Mac and wherever you can compile go

Screenshots

Show broker topology

Output of rabtap info command:

info mode

Output of rabtap info --stats command, showing additional statistics:

info mode

Visualize broker topology with graphviz

Using the --format=dot option, the info command can generate output in the dot format, which can be visualized using graphviz, e.g. rabtap info --show-default --format dot | dot -T svg > mybroker.svg. The resulting SVG file can be visualized with a web browser.

info mode

Tap messages

Output of rabtap in tap mode, showing message meta data and the message body:

info mode

Installation

Docker image

A docker image is provided so rabtap can be used as a docker container, e.g.

$ docker run --rm -ti ghcr.io/jandelgado/rabtap:latest

Pre-compiled binaries

Pre-compiled binaries can be downloaded for multiple platforms from the releases page.

Arch Linux

Rabtap can be installed from the Arch Linux User Repository (AUR):

$ yay -S rabtap

Installation from source

See the build from source section if you prefer to compile from source.

Usage


rabtap - RabbitMQ wire tap.                    github.com/jandelgado/rabtap

Usage:
  rabtap -h|--help
  rabtap info [--api=APIURI] [--consumers] [--stats] [--filter=EXPR] [--omit-empty]
              [--show-default] [--mode=MODE] [--format=FORMAT] [-kncv]
              [(--tls-cert-file=CERTFILE --tls-key-file=KEYFILE)] [--tls-ca-file=CAFILE]
  rabtap tap EXCHANGES [--uri=URI] [--saveto=DIR]
              [--format=FORMAT]  [--limit=NUM] [--idle-timeout=DURATION] [-jkncsv]
              [(--tls-cert-file=CERTFILE --tls-key-file=KEYFILE)] [--tls-ca-file=CAFILE]
  rabtap (tap --uri=URI EXCHANGES)... [--saveto=DIR]
              [--format=FORMAT]  [--limit=NUM] [--idle-timeout=DURATION] [-jkncsv]
              [(--tls-cert-file=CERTFILE --tls-key-file=KEYFILE)] [--tls-ca-file=CAFILE]
  rabtap sub QUEUE [--uri URI] [--saveto=DIR] [--format=FORMAT] [--limit=NUM]
              [--offset=OFFSET] [--args=KV]... [(--reject [--requeue])] [-jkcsvn]
			  [--idle-timeout=DURATION]
              [(--tls-cert-file=CERTFILE --tls-key-file=KEYFILE)] [--tls-ca-file=CAFILE]
  rabtap pub  [--uri=URI] [SOURCE] [--exchange=EXCHANGE] [--format=FORMAT]
              [--routingkey=KEY | (--header=KV)...]
              [--confirms] [--mandatory] [--delay=DELAY | --speed=FACTOR] [-jkv]
              [(--tls-cert-file=CERTFILE --tls-key-file=KEYFILE)] [--tls-ca-file=CAFILE]
  rabtap exchange create EXCHANGE [--uri=URI] [--type=TYPE] [--args=KV]... [-kv]
              [--autodelete] [--durable]
              [(--tls-cert-file=CERTFILE --tls-key-file=KEYFILE)] [--tls-ca-file=CAFILE]
  rabtap exchange bind EXCHANGE to DESTEXCHANGE [--uri=URI] [-kv]
              (--bindingkey=KEY | (--header=KV)... (--all|--any))
              [(--tls-cert-file=CERTFILE --tls-key-file=KEYFILE)] [--tls-ca-file=CAFILE]
  rabtap exchange rm EXCHANGE [--uri=URI] [-kv]
              [(--tls-cert-file=CERTFILE --tls-key-file=KEYFILE)] [--tls-ca-file=CAFILE]
  rabtap queue create QUEUE [--uri=URI] [--queue-type=TYPE] [--args=KV]... [-kv]
              [--autodelete] [--durable] [--lazy]
              [(--tls-cert-file=CERTFILE --tls-key-file=KEYFILE)] [--tls-ca-file=CAFILE]
  rabtap queue bind QUEUE to EXCHANGE [--uri=URI] [-kv]
              (--bindingkey=KEY | (--header=KV)... (--all|--any))
              [(--tls-cert-file=CERTFILE --tls-key-file=KEYFILE)] [--tls-ca-file=CAFILE]
  rabtap queue unbind QUEUE from EXCHANGE [--uri=URI] [-kv]
              (--bindingkey=KEY | (--header=KV)... (--all|--any))
              [(--tls-cert-file=CERTFILE --tls-key-file=KEYFILE)] [--tls-ca-file=CAFILE]
  rabtap queue rm QUEUE [--uri=URI] [-kv]
              [(--tls-cert-file=CERTFILE --tls-key-file=KEYFILE)] [--tls-ca-file=CAFILE]
  rabtap queue purge QUEUE [--uri=URI] [-kv]
              [(--tls-cert-file=CERTFILE --tls-key-file=KEYFILE)] [--tls-ca-file=CAFILE]
  rabtap conn close CONNECTION [--api=APIURI] [--reason=REASON] [-kv]
              [(--tls-cert-file=CERTFILE --tls-key-file=KEYFILE)] [--tls-ca-file=CAFILE]
  rabtap --version

Arguments and options:
 EXCHANGES            comma-separated list of exchanges and optional binding keys,
                      e.g. amq.topic:# or exchange1:key1,exchange2:key2.
 EXCHANGE             name of an exchange, e.g. amq.direct.
 DESTEXCHANGE         name of a a destination exchange in an exchange-to-exchange binding.
 SOURCE               file or directory to publish in pub mode. If omitted, stdin will be read.
 QUEUE                name of a queue.
 CONNECTION           name of a connection.
 DIR                  directory to read messages from.
 -a, --autodelete     create auto delete exchange/queue.
 --all                set x-match=all option in header based routing.
 --any                set x-match=any option in header based routing.
 --api=APIURI         connect to given API server. If APIURL is omitted,
                      the environment variable RABTAP_APIURI will be used.
 --args=KV            A key value pair in the form of "key=value" passed as
                      additional arguments. e.g. '--args=x-queue-type=quorum'
 -b, --bindingkey=KEY binding key to use in bind queue command.
 --by-connection      output of info command starts with connections.
 -c, --color          force colored output
 --confirms           enable publisher confirms and wait for confirmations.
 --consumers          include consumers and connections in output of info command.
 --delay=DELAY        Time to wait between sending messages during publish.
                      If not set then messages will be delayed as recorded.
					  The value must be suffixed with a time unit, e.g. ms, s etc.
 -d, --durable        create durable exchange/queue.
 --exchange=EXCHANGE  Optional exchange to publish to. If omitted, exchange will
                      be taken from message being published (see JSON message format).
 --filter=EXPR        Predicate for info command to filter queues [default: true]
 --format=FORMAT      * for tap, pub, sub command: format to write/read messages to console
                        and optionally to file (when --saveto DIR is given).
                        Valid options are: "raw", "json", "json-nopp". Default: raw
                      * for info command: controls generated output format. Valid
                        options are: "text", "dot". Default: text
 -h, --help           print this help.
 --header=KV          A key value pair in the form of "key=value" used as a
                      routing- or binding-key. Can occur multiple times.
 --idle-timeout=DURATION end reading messages when no new message was received
                      for the given duration.  The value must be suffixed with 
					  a time unit, e.g. ms, s etc.
 -j, --json           deprecated. Use "--format json" instead.
 -k, --insecure       allow insecure TLS connections (no certificate check).
 --lazy               create a lazy queue.
 --limit=NUM          Stop afer NUM messages were received. When set to 0, will
                      run until terminated [default: 0].
 --mandatory          enable mandatory publishing (messages must be delivered to queue).
 --mode=MODE          mode for info command. One of "byConnection", "byExchange".
                      [default: byExchange].
 -n, --no-color       don't colorize output (see also environment variable NO_COLOR).
 --omit-empty         don't show echanges without bindings in info command.
 --offset=OFFSET      Offset when reading from a stream. Can be 'first', 'last',
                      'next', a duration like '10m', a RFC3339-Timestamp or
					  an integer index value. Basically it is an alias for
					  '--args=x-stream-offset=OFFSET'.
 --queue-type=TYPE    type of queue [default: classic].
 --reason=REASON      reason why the connection was closed [default: closed by rabtap].
 --reject             Reject messages. Default behaviour is to acknowledge messages.
 --requeue            Instruct broker to requeue rejected message
 -r, --routingkey=KEY routing key to use in publish mode. If omitted, routing key
                      will be taken from message being published (see JSON
					  message format).
 --saveto=DIR         also save messages and metadata to DIR.
 --show-default       include default exchange in output info command.
 -s, --silent         suppress message output to stdout.
 --speed=FACTOR       Speed factor to use during publish [default: 1.0].
 --stats              include statistics in output of info command.
 -t, --type=TYPE		  type of exchange [default: fanout].
 --tls-cert-file=CERTFILE A Cert file to use for client authentication.
 --tls-key-file=KEYFILE   A Key file to use for client authentication.
 --tls-ca-file=CAFILE     A CA Cert file to use with TLS.
 --uri=URI            connect to given AQMP broker. If omitted, the
                      environment variable RABTAP_AMQPURI will be used.
 -v, --verbose        enable verbose mode.
 --version            show version information and exit.

Examples:
  rabtap tap --uri amqp://guest:guest@localhost/ amq.fanout:
  rabtap tap --uri amqp://guest:guest@localhost/ amq.topic:#,amq.fanout:
  rabtap pub --uri amqp://guest:guest@localhost/ --exchange amq.topic message.json --format=json
  rabtap info --api http://guest:guest@localhost:15672/api

  # use RABTAP_AMQPURI environment variable to specify broker instead of --uri
  export RABTAP_AMQPURI=amqp://guest:guest@localhost:5672/
  rabtap queue create JDQ
  rabtap queue bind JDQ to amq.topic --bindingkey=key
  echo "Hello" | rabtap pub --exchange amq.topic --routingkey "key"
  rabtap sub JDQ
  rabtap queue rm JDQ

  # use RABTAP_APIURI environment variable to specify mgmt api uri instead of --api
  export RABTAP_APIURI=http://guest:guest@localhost:15672/api
  rabtap info
  rabtap info --filter "binding.Source == 'amq.topic'" --omit-empty
  rabtap conn close "172.17.0.1:40874 -> 172.17.0.2:5672"

  # use RABTAP_TLS_CERTFILE | RABTAP_TLS_KEYFILE | RABTAP_TLS_CAFILE environments variables
  # instead of specifying --tls-cert-file=CERTFILE --tls-key-file=KEYFILE --tls-ca-file=CAFILE

Basic commands

Rabtap understands the following commands:

tap - taps to an exchange and receives messages sent to the exchange, without affecting actual message delivery (using an exchange-to-exchange binding).
sub - subscribes to a queue and consumes messages sent to the queue (acts like a RabbitMQ consumer)
pub - publish messages to an exchange, optionally with the timing as recorded.
info - show broker related info (exchanges, queues, bindings, stats).
queue - create/bind/unbind/remove/purge queue
exchange - create/remove exchange
conn - close connections

See the examples section for further information.

Broker URI specification

The specification of the RabbitMQ broker URI follows the AMQP URI specification as implemented by the go RabbitMQ client library.

Examples:

amqp://guest:guest@localhost:5672/
amqps://guest:guest@my-broker.dev:5671/
amqps://guest:guest@my-broker.dev:5671/vhost

Note that according to RFC3986 it might be necessary to escape certain characters like e.g. ? (%3F) or # (%23) as otherwise parsing of the URI may fail with an error.

Authentication

Authentication is either by the username and password provided in the broker URI as desribed above (RabbitMQ PLAIN method), or by mTLS providing a client certificate and key using the --tls-key, --tls-cert options (RabbitMQ EXTERNAL method). If both mTLS and a username and password is provided, then rabtap will use mTLS and PLAIN authentication with the given username and password.

Format specification for tap and sub command

The --format=FORMAT option controls the format of the tap and sub commands when writing messages to the console and optionally to the filesystem (i.e. when --saveto is set).

The FORMAT parameter has the following effect on the output:

`FORMAT`	Format on console	Format of saved messages (`--saveto DIR`)
`raw` (default)	Pretty-printed metadata + raw Message body	Metadata as JSON-File + Body as-is
`json`	Pretty-printed JSON wiht base64 encoded body	Pretty-printed JSON with base64 encoded body
`json-nopp`	Single line JSON wiht base64 encoded body	Pretty-printed JSON with base64 encoded body

Notes:

the --json option is now deprecated. Use --format=json instead
nopp stands for no pretty-print

Environment variables

Use environment variables to specify standard values for broker and api endpoint.

Default RabbitMQ broker

In cases where the URI argument is optional, e.g. rabtap tap [-uri URI] exchange ..., the URI of the RabbitMQ broker can be set with the environment variable RABTAP_AMQPURI. Example:

$ export RABTAP_AMQPURI=amqp://guest:guest@localhost:5672/
$ rabtap tap amq.fanout:
...

Default RabbitMQ management API endpoint

The default RabbitMQ management API URI can be set using the RABTAP_APIURI environment variable. Example:

$ export RABTAP_APIURI=http://guest:guest@localhost:15672/api
$ rabtap info
...

Default RabbitMQ TLS config

The default TLS certificates path can be set using the RABTAP_TLS_CERTFILE and RABTAP_TLS_KEYFILE and RABTAP_TLS_CAFILE environments variables. All certificate and key files are expected in PEM format. Example:

$ export RABTAP_TLS_CERTFILE=/path/to/certs/user.crt
$ export RABTAP_TLS_KEYFILE=/path/to/certs/user.key
$ export RABTAP_TLS_CAFILE =/path/to/certs/ca.crt
$ echo "Hello" | rabtap pub --exchange amq.topic --routingkey "key"
...

Colored output

Output is colored, when writing to a terminal. This behaviour can be changed:

set environment variable NO_COLOR to disable color output (or set --no-color option)
set --color option to force colored output

Examples

The following examples assume a RabbitMQ broker running on localhost:5672 and the management API available on port 15672. Easiest way to start such an instance is by running docker run -ti --rm -p 5672:5672 -p 15672:15672 rabbitmq:3-management or similar command to start a RabbitMQ container.

Broker info

The info command uses the REST API of RabbitMQ to gather and display topolgy related information from the broker.

The --mode MODE option controls how the output is structured. Valid options for MODE are byExchange (default) or byConnection.

The --format=FORMAT option controls the format of generated output. Valid options are text for console text format (default) or dot to output the tree structure in dot format for visualization with graphviz.

The features of an exchange are displayed in square brackets with D (durable), AD (auto delete) and I (internal). The features of a queue are displayed in square brackets with D (durable), AD (auto delete) and EX (exclusive).

If the --statistics option is enabled, basic statistics are included in the output.

The --filter option allows to filter output. See filtering section for details. Use the --by-connection to sort output by connection (implies --consumers)

Examples (assume that RABTAP_APIURI environment variable is set):

rabtap info --consumers - shows virtual hosts exchanges, queues and consumers of given broker in a tree view (see screenshot).
rabtap info --mode=byConnection - shows virtual hosts, connections, consumers and queues of given broker in an tree view.
rabtap info --format=dot | dot -T svg > broker.svg - renders broker info into dot format and uses graphviz to render a SVG file for final visualization.

Wire-tapping messages

The tap command allows to tap exchanges and transparently receives messages sent to the exchanges. Rabtap automatically reconnects on connections failures. The syntax of the tap command is rabtap tap [--uri URI] EXCHANGES where the EXCHANGES argument specifies the exchanges and binding keys to use. The EXCHANGES argument is of the form EXCHANGE:[KEY][,EXCHANGE:[KEY]]*. If the exchange name contains a colon, use \\: to escape it, e.g. myexchange\\:with\\:colons:KEY.

The acutal format of the binding key depends on the exchange type (e.g. direct, topic, headers) and is described in the RabbitMQ documentation.

Examples for binding keys used in tap command:

# on an exchange of type topic will make the tap receive all messages on the exchange.
a valid queue name for an exchange of type direct binds exactly to messages destined for this queue
an empty binding key for exchanges of type fanout or type headers will receive all messages published to these exchanges

Note: on exchanges of type headers the binding key is currently ignored and all messages are received by the tap.

The following examples assume that the RABTAP_AMQPURI environment variable is set, otherwise you have to pass the additional --uri URI parameter to the commands below.

$ rabtap tap my-topic-exchange:#
$ rabtap tap my-fanout-exchange:
$ rabtap tap my-headers-exchange:
$ rabtap tap my-direct-exchange:binding-key

The following example connects to multiple exchanges:

$ rabtap tap my-fanout-exchange:,my-topic-exchange:#,my-other-exchange:binding-key

Tap all messages published or delivered (RabbitMQ FireHose)

The RabbitMQ Firehose Tracer allows to "see" every message that is published or delivered. To use it, the FireHose tracer has to be enabled first:

$ rabbitmqctl trace_on

Afterwards, every message published or delivered will be CC'd to the topic exhange amq.rabbitmq.trace. The messages can now be tapped with rabtap:

$ rabtap --uri amqp://guest:guest@localhost:5672/ tap amq.rabbitmq.trace:published.#

RabbitMQ sends all messages published or delivered to the FireHose exchange. Published messages are sent with the routing key publish.{exchangename}, while delivered messages are sent with the routing key deliver.{queuename}. Depending on what you want to record, specify your binding accordingly.

Replaying messages from the FireHose exchange

When messages are tapped or subscribed from the FireHose tracer exchange, these messages have the original meta data stored in the headers section of the message. When published later, rabtap detects that these message was recorded from the FireHose (by examining the exchange attribute, which will be set to amq.rabbitmq.trace by RabbitMQ in that case) and automatically transform the message so that the originally published messages are replayed again.

Connect to multiple brokers

Rabtap allows you also to connect simultaneously to multiple brokers and exchanges:

$ rabtap tap --uri amqp://broker1 amq.topic:# tap --uri amqp://broker2 amq.fanout:

The example connects to broker1 and taps to the amq.topic exchange and to the amq.fanout exchange on broker2.

Message recorder

All tapped messages can be also be saved for later analysis or replay. Rabtap supports saving of messages in two formats: raw body and metadata in separate files or JSON message format with embedded metadata and message the body base64 encode. Examples:

$ rabtap tap amq.topic:# --saveto /tmp - saves messages as pair of files consisting of raw message body and JSON meta data file to /tmp directory.
$ rabtap tap amq.topic:# --saveto /tmp --format json - saves messages as JSON files to /tmp directory.

Files are created with file name rabtap-+<Unix-Nano-Timestamp>+ . + <extension>.

Consume Messages (subscribe)

The sub command reads messages from a queue or a stream. The general form of the sub command is:

  rabtap sub QUEUE [--uri URI] [--saveto=DIR] [--format=FORMAT] [--limit=NUM]
              [--offset=OFFSET] [--args=KV]... [(--reject [--requeue])] [-jksvn]
			  [--idle-timeout=DURATION]

Use the --limit=NUM option to limit the number of received messages. If specified, rabtap will terminate, after NUM messages were successfully read.

Use the --reject option to 'nack' messages, which in turn will be discarded by the broker or routed to a configured dead letter exchange (DLX). if --requeue is also set, the message will be returned to the queue.

The --offset=OFFSET option is used when subscribing to streams. Streams are append-only data structures with non-destructive semantics and were introduced with RabbitMQ 3.9. The OFFSET parameter specifies where to start reading from the stream and must be any of: first, last, next, a numerical offset, a RFC3339-Timestamp or a duration specification like 10m. Consult the RabbitMQ documentation for more information on streams.

When --idle-timeout=DURATION is set, the subscribe command will terminate when no new messages were received in the given time period. Look for the description of the --delay option for the format of the DURATION parameter.

Examples:

$ rabtap sub somequeue --format=json - will consume messages from queue somequeue and print out messages in JSON format. The Example assumes that RABTAP_AMQPURI environment variable is set, as the --uri=AMQPURI parameter is omitted.
rabtap sub somequeue --limit=1 --reject --requeue - consume one message from the queue somequeue and let the broker requeue the message.
rabtap sub mystream --offset=first - read all messages from stream mystream.
rabtap sub mystream --offset=50 - read messages from stream mystream starting with the 50th message.
rabtap sub mystream --offset=10m - read messages from stream mystream which are aged 10 minutes or less.
rabtap sub somequeue --idle-timeout=5s - read messages from queue somequeue and exit when there is no new message received for 5 seconds.

Publish messages

The pub command is used to publish messages to an exchange. The messages to be published are either read from a file, or from a directory which contains previously recorded messages (e.g. using the --saveto option of the tap command). The general form of the pub command is:

rabtap pub  [--uri=URI] [SOURCE] [--exchange=EXCHANGE] [--format=FORMAT] 
            [--routingkey=KEY | (--header=HEADERKV)...]
            [--confirms] [--mandatory] [--delay=DELAY | --speed=FACTOR] [-jkv]

Message routing is either specified with a routing key and the --routingkey option or, when header based routing should be used, by specifying the headers with the --header option. Each header is specified in the form KEY=VALUE. Multiple headers can be specified by specifying multiple --header options.

Messages can be published either in raw format, in which they are sent as-is, or in JSON-format, as described here, which includes message metadata and the body in a single JSON document. When multiple messages are published with metadata, rabtap will calculate the time elapsed of consecutive recorded messages using the metadata, and delay publishing accordingly. To set the publishing delay to a fix value, use the --delay option. To publish without delays, use --delay=0s. To modify publishing speed use the --speed option, which allows to set a factor to apply to the delays. A delay is a sequence of decimal numbers, each with optional fraction and a unit suffix, such as "300ms", "-1.5h" 0or "2h45m". Valid time units are "ns", "us" (or "µs"), "ms", "s", "m", "h".

When the --confirms option is set, rabtap waits for publisher confirmations from the server and logs an error if a confirmation is negative or not received (slows down throughput),

When the --mandatory option is set, rabtap publishes message in mandatory mode. If set and a message can not be delivered to a queue, the server returns the message and rabtap will log an error.

Examples:

$ echo hello | rabtap pub --exchange amq.fanout - publish "hello" to exchange amqp.fanout
echo "hello" | rabtap pub --exchange amq.header --header KEY=VAL --header X=Y - publish hello to exchange amq.header use set message headers.
$ rabtap pub messages.json --format=json - messages are read from file messages.json in rabtap JSON format. Target exchange and routing keys are read from the messages meta data. The messages.json file can contain multiple JSON documents as it is treated as a JSON stream. Rabtap will honor the XRabtapReceived timestamps of the messages and by default will delay the messages as they were recorded. This behaviour can be overridden by the --delay and --speed options.
$ rabtap pub --exchange amq.direct -r myKey --format=json messages.json --delay=0s - as before, but publish messages always to exchange amq.direct with routing key myKey and without any delays.
$ rabtap pub --exchange amq.direct -r myKey --format=raw somedir --delay=0s - as before, but assuming that somedir is a directory, the messages are read from message files previously recorded to this directory and replayed in the order they were recorded.

Poor mans shovel

Rabtap instances can be connected through a pipe and messages will be read on one side and published to the other. Note that for publish to work in streaming mode, the JSON mode (--format json) must be used on both sides, so that messages are encapsulated in JSON messages.

The example taps messages on broker1 and publishes the messages to the amq.direct exchange on broker2

$ rabtap tap --uri amqp://broker1 my-topic-exchange:# --format json | \
  rabtap pub --uri amqp://broker2 --exchange amq.direct -r routingKey --format json

Close connection

The conn command allows to close a connection. The name of the connection to be closed is expected as parameter. Use the info command with the --consumers option to find the connection associated with a queue. Example:

$ rabtap info --consumers
http://localhost:15672/api (broker ver='3.6.9', mgmt ver='3.6.9', cluster='rabbit@ae1ad1477419')
└── Vhost /
    ├── amq.direct (exchange, type 'direct', [D])
    :
    └── test-topic (exchange, type 'topic', [AD])
        ├── test-q-test-topic-0 (queue, key='test-q-test-topic-0', running, [])
        │   └── __rabtap-consumer-4823a3c0 (consumer user='guest', chan='172.17.0.1:59228 -> 172.17.0.2:5672 (1)')
        │       └── '172.17.0.1:59228 -> 172.17.0.2:5672' (connection client='https://github.com/streadway/amqp', host='172.17.0.2:5672', peer='172.17.0.1:59228')
        ├── test-q-test-topic-1 (queue, key='test-q-test-topic-1', running, [])
        :
$ rabtap conn close '172.17.0.1:59228 -> 172.17.0.2:5672'

Exchange commands

The exchange command is used to create, remove and bind exchanges:

$ rabtap exchange create myexchange --type topic
$ rabtap exchange rm myexchange

The create commands allows to specify additional arguments to be passed to RabbitMQ using the --args=key=value syntax:

$ rabtap exchange create myexchange --type topic --args=alternate-exchange=myae

The bind command creates an exchange-to-exchange binding (similar to a queue-to-exchange binding):

$ rabtap exchange bind myechange to destexchange --bindingkey=KEY

Queue commands

The queue command is used to create, remove, bind or unbind queues:

$ rabtap queue create myqueue
$ rabtap info --show-default
http://localhost:15672/api (broker ver='3.7.8', mgmt ver='3.7.8', cluster='rabbit@b2fe3b3b6826')
└── Vhost /
    ├── (default) (exchange, type 'direct', [D])
    │   └── myqueue (queue, key='myqueue', idle since 2018-12-07 20:46:15, [])
    :
    └── amq.topic (exchange, type 'topic', [D])
$ rabtap queue bind myqueue to amq.topic --bindingkey hello
$ rabtap info --show-default
http://localhost:15672/api (broker ver='3.7.8', mgmt ver='3.7.8', cluster='rabbit@b2fe3b3b6826')
└── Vhost /
    ├── (default) (exchange, type 'direct', [D])
    │   └── myqueue (queue, key='myqueue', idle since 2018-12-07 20:46:15, [])
    :
    └── amq.topic (exchange, type 'topic', [D])
        └── myqueue (queue, key='hello', idle since 2018-12-07 20:46:15, [])
$ rabtap queue unbind myqueue from amq.topic --bindingkey hello
$ rabtap info --show-default
http://localhost:15672/api (broker ver='3.7.8', mgmt ver='3.7.8', cluster='rabbit@b2fe3b3b6826')
└── Vhost /
    ├── (default) (exchange, type 'direct', [D])
    │   └── myqueue (queue, key='myqueue', idle since 2018-12-07 20:46:15, [])
    :
    └── amq.topic (exchange, type 'topic', [D])
$ rabtap queue purge myqueue
$ rabtap queue rm myqueue
$ rabtap info
http://localhost:15672/api (broker ver='3.7.8', mgmt ver='3.7.8', cluster='rabbit@b2fe3b3b6826')
└── Vhost /
    :
    └── amq.topic (exchange, type 'topic', [D])

The create commands allows to specify additional arguments to be passed to RabbitMQ using the --args=key=value syntax. This allows for example to specify the queue type or mode:

rabtap queue create quorum_queue --args=x-queue-type=quorum --durable - create a quorum queue named quorum_queue. The same can be achieved by using the --queue-type option, which is an alias for setting the arg x-queue-type: rabtap queue create quorum --queue-type=quorum --durable
rabtap queue create mystream --queue-type=stream --durable - create a stream
rabtap queue create lazy_queue --lazy - create a classic queue in lazy mode that is named lazy_queue. --lazy is an alias for setting the arg x-queue-mode.

JSON message format

When using the --format json option, messages are print/read as a stream of JSON messages in the following format:

...
{
  "ContentType": "text/plain",
  "ContentEncoding": "",
  "DeliveryMode": 0,
  "Priority": 0,
  "CorrelationID": "",
  "ReplyTo": "",
  "Expiration": "",
  "MessageID": "",
  "Timestamp": "2017-11-10T00:13:38+01:00",
  "Type": "",
  "UserID": "",
  "AppID": "rabtap.testgen",
  "DeliveryTag": 27,
  "Redelivered": false,
  "Exchange": "amq.topic",
  "RoutingKey": "test-q-amq.topic-0",
  "XRabtapReceivedTimestamp": "2019-06-13T19:33:51.920711583+02:00",
  "Body": "dGhpcyB0ZXN0IG1lc3NhZ2U .... IGFuZCBoZWFkZXJzIGFtcXAuVGFibGV7fQ=="
}
...

Note that in JSON mode, the Body is base64 encoded.

Filtering output of info command

When your brokers topology is complex, the output of the info command can become very bloated. The --filter helps you to narrow output to the desired information.

Filtering expressions

A filtering expression is a function that evaluates to true or false (i.e. a predicate). Rabtap allows the specification of predicates to be applied when printing queues using the info command. The output will only proceed if the predicate evaluates to true.

Rabtap uses the govalute to evaluate the predicate. This allows or complex expressions.

See official govaluate documentation for further information.

Note: currently the filter is ignored when used in conjunction with --by-connection.

Evaluation context

During evaluation the context (i.e. the current exchange, queue and binding) is available in the expression as variables:

the current exchange is bound to the variable exchange
the current queue is bound to the variable queue
the curren binding is bound to the variable binding

Examples

The examples assume that RABTAP_APIURI environment variable points to the broker to be used, e.g. http://guest:guest@localhost:15672/api).

rabtap info --filter "exchange.Name == 'amq.direct'" --omit-empty - print only queues bound to exchange amq.direct and skip all empty exchanges.
rabtap info --filter "queue.Name =~ '.*test.*'" --omit-empty - print all queues with test in their name.
rabtap info --filter "queue.Name =~ '.*test.*' && exchange.Type == 'topic'" --omit-empty - like before, but consider only exchanges of type topic.
rabtap info --filter "queue.Consumers > 0" --omit --stats --consumers - print all queues with at least one consumer

Type reference

The types reflect more or less the JSON API objects of the REST API of RabbitMQ transformed to golang types.

Exchange type

<details> <summary>Definition of the Exchange type</summary>

type Exchange struct {
    Name       string
    Vhost      string
    Type       string
    Durable    bool
    AutoDelete bool
    Internal   bool
    MessageStats struct {
        PublishOut
        PublishOutDetails struct {
            Rate float64
        }
        PublishIn        int
        PublishInDetails struct {
            Rate float64
        }
    }
}

</details>

Queue type

<details> <summary>Definition of the Queue type</summary>

type Queue struct {
    MessagesDetails struct {
        Rate float64
    }
    Messages
    MessagesUnacknowledgedDetails struct {
        Rate float64
    }
    MessagesUnacknowledged int
    MessagesReadyDetails   struct {
        Rate float64
    }
    MessagesReady     int
    ReductionsDetails struct {
        Rate float64
    }
    Reductions int
    Node       string
    Exclusive            bool
    AutoDelete           bool
    Durable              bool
    Vhost                string
    Name                 string
    MessageBytesPagedOut int
    MessagesPagedOut     int
    BackingQueueStatus   struct {
        Mode string
        Q1   int
        Q2   int
        Q3  int
        Q4  int
        Len int
        NextSeqID         int
        AvgIngressRate    float64
        AvgEgressRate     float64
        AvgAckIngressRate float64
        AvgAckEgressRate  float64
    }
    MessageBytesPersistent     int
    MessageBytesRAM            int
    MessageBytesUnacknowledged int
    MessageBytesReady          int
    MessageBytes               int
    MessagesPersistent         int
    MessagesUnacknowledgedRAM  int
    MessagesReadyRAM           int
    MessagesRAM                int
    GarbageCollection          struct {
        MinorGcs        int
        FullsweepAfter  int
        MinHeapSize     int
        MinBinVheapSize int
        MaxHeapSize     int
    }
    State string
    Consumers int
    IdleSince string
    Memory    int
}

</details>

Binding type

<details> <summary>Definition of the Binding type</summary>

type Binding struct {
    Source          string
    Vhost           string
    Destination     string
    DestinationType string
    RoutingKey      string
    PropertiesKey string
}

</details>

Build from source

Download and build using go install

$ go install github.com/jandelgado/rabtap/cmd/rabtap@latest

Build using Makefile and tests

To build rabtap from source, you need go (version >= 1.18) and golangci-lint installed.

$ git clone https://github.com/jandelgado/rabtap && cd rabtap
$ make test  -or- make short-test
$ make

In order to run all tests (make test) an instance of RabbitMQ is expected to run on localhost. Easiest way to start one is running make run-broker, which will start a RabbitMQ docker container (i.e. docker run -ti --rm -p 5672:5672 -p 15672:15672 rabbitmq:3-management).

Experimental WASM/wasip1 port

Rabtap can be compiled for Web Assembly (WASM) and the new wasip1 GOOS and run on the console using, e.g. wasirun. Example:

$ go version
go version go1.21.3 linux/amd64
$ make wasm-build
CGO_ENABLED=1 GOOS=wasip1 GOARCH=wasm go build -o ./bin/rabtap-wasm ./cmd/rabtap
$ wasirun --version
wasirun v0.6.5
$ wasirun  bin/rabtap-wasm -- --api "http://guest:password@localhost:15672/api" info --no-color
http://localhost:15672/api (broker ver='3.12.6', mgmt ver='3.12.6', cluster='rabbit@3ea5bf2bac2f')
└─ Vhost /
   ├─ amq.direct (exchange(direct), [D])
   ├─ amq.fanout (exchange(fanout), [D])
   ├─ amq.headers (exchange(headers), [D])
   ├─ amq.match (exchange(headers), [D])
   ├─ amq.rabbitmq.trace (exchange(topic), [D|I])
   └─ amq.topic (exchange(topic), [D])

Another example using wasirun and wasmedge to publish and subscribe to a queue:

$ URI="amqp://guest:password@localhost/"
$ rabtap queue create test
$ rabtap queue bind test to amq.topic --bindingkey=key
$ echo "hello" | wasmedge  bin/rabtap-wasm  --uri "$URI" pub --exchange amq.topic --routingkey=key
$ wasirun  bin/rabtap-wasm -- --uri "$URI" sub test --limit=1
------ message received on 2023-10-29T11:48:56Z ------
exchange.......: amq.topic
routingkey.....: key
hello

See my blog for details.

Limitations:

environment variables like RABTAP_AMQPURI not supported, must specify all options on the command line
depending on the runtime, colors must explicitly set or disabled using --color and --no-color, since terminal detection not working.

Test data generator

A simple test data generator tool for manual tests is included in the cmd/testgen directory.

Contributing

fork this repository
create your feature branch
add code
add tests and make sure test coverage does not fall (make test)
add documentation
commit changes
submit a PR

Author

Jan Delgado (jdelgado at gmx dot net)

Awesome

rabtap - RabbitMQ wire tap

Contents

Features

Screenshots

Show broker topology

Visualize broker topology with graphviz

Tap messages

Installation

Docker image

Pre-compiled binaries

Arch Linux

Installation from source

Usage

Basic commands

Broker URI specification

Authentication

Format specification for tap and sub command

Environment variables

Default RabbitMQ broker

Default RabbitMQ management API endpoint

Default RabbitMQ TLS config

Colored output

Examples

Broker info

Wire-tapping messages

Tap all messages published or delivered (RabbitMQ FireHose)

Replaying messages from the FireHose exchange

Connect to multiple brokers

Message recorder

Consume Messages (subscribe)

Publish messages

Poor mans shovel

Close connection

Exchange commands

Queue commands

JSON message format

Filtering output of info command

Filtering expressions

Evaluation context

Examples

Type reference

Exchange type

Queue type

Binding type

Build from source

Download and build using go install

Build using Makefile and tests

Experimental WASM/wasip1 port

Test data generator

Contributing

Author

Copyright and license