t7tran/gcloud-pubsub-emulator repository overview

⁠Google Cloud Pub/Sub Emulator Image⁠

Cloud Pub/Sub⁠ is a global service for real-time and reliable messaging and streaming data

This image provides a dockerized version of the Google Cloud Pub/Sub Emulator. It is intended to be used as a service on development environments (it SHOULD NOT be used in production environments). You can check Cloud Pub/Sub documentation on Google Cloud Platform documentation website⁠.

⁠Usage

The following shell statement show the most simple execution of the provided image. It will execute the Pub/Sub Emulator that will listen on port 8538.

docker run --rm --tty --interactive --publish 8538:8538 --name pubsub t7tran/gcloud-pubsub-emulator:380.0.0

The image is much more useful when it is used in a CD/CI automated environment. The following example shows how to configure the Pub/Sub Emulator to be used in a Wercker⁠ development pipeline.

box: python:3.5

dev:
  services:
    - name: pubsub
      id: t7tran/gcloud-pubsub-emulator:380.0.0
      cmd: start --host-port 0.0.0.0:8538

  steps:
    - script:
      name: Define Pub/Sub environment variables
      code: |
        ADDR=$PUBSUB_PORT_8538_TCP_ADDR
        PORT=$PUBSUB_PORT_8538_TCP_PORT
        export PUBSUB_EMULATOR_HOST=$ADDR:$PORT

    - internal/shell:
      cmd: bash

⁠Configuration

The most important configuration parameters of the Pub/Sub emulator image are the host/port value the server will listen on and the directory where data files will be placed. By default, the image is configured to listen on 127.0.0.1:8538 and store its files in the /data directory. This behavior can be changed by providing the correct command-line options.

The following example shows how to start the Pub/Sub emulator to listen on 192.168.1.3:12345 and to store its files in the /pubsub-data directory.

docker run --rm --tty --interactive --name pubsub t7tran/gcloud-pubsub-emulator:380.0.0 start --host-port=192.168.1.3:12345 --data-dir=/pubsub-data

NOTE: Wercker's documentation can be checked online on Wercker Documentation Website⁠

⁠Helpers

Assuming the above commands were used to launch the container, the following commands can be used. Just run the command to reveal its syntax.

docker exec -it pubsub publish # publish some data to a topic
docker exec -it pubsub pull # pull (await) message(s) from a subscription
docker exec -it pubsub pull-data # pull (await) data from a subscription
docker exec -it pubsub ack # acknowledge a message from a subscription
docker exec -it pubsub pull-ack # pull (await) data from a subscription then acknowledge upon receipt