webdiss/docs/webdis-redis-docker-compose.md

Running Webdis and Redis in Docker Compose

This page describes how to start Redis and Webdis in Docker Compose. A different page describes a variant of this model, where connections from Webdis to Redis are encrypted: see "Running Webdis & Redis in Docker Compose with SSL connections".

Setup

We'll keep all our files together in a playground directory:

mkdir playground
cd playground

The files we'll need are:

1. A config file for webdis, named webdis.json
2. A Compose file for Docker Compose, named docker-compose.yml

Webdis configuration

First, download webdis.json from GitHub by following this link or running this curl command:

curl -sL -o ./webdis.json https://github.com/nicolasff/webdis/raw/0.1.19/webdis.json

Edit ./webdis.json in the playground directory and set:

• "redis_host" to "redis"
• "logfile" to "/dev/stderr"

Docker Compose configuration

Create a new file named docker-compose.yml in your playground directory, with the following contents:

services:
  webdis:
    image: nicolas/webdis:latest
    command: /usr/local/bin/webdis /config/webdis.json
    volumes:  # mount volume containing the config file
      - ./:/config
    networks:
      - shared
    depends_on:  # make sure Redis starts first, so that Webdis can connect to it without retries
      - redis
    ports:  # allow connections from the Docker host on localhost, port 7379
      - "127.0.0.1:7379:7379"

  redis:
    image: redis:6.2.6
    networks:
      - shared
    ports:   # make the Redis port visible to Webdis
      - "6379:6379"

networks:
  shared: 

This configures two services named webdis and redis, sharing a common network named shared. With the expose property, Redis allows connections from Webdis on port 6379. The webdis container mounts the local playground directory under /config and starts its binary using the configuration file we've just downloaded and edited. Finally, Webdis also allows binds its (container) port 7379 to the hosts's loopback interface also on port 7379. This will let us run curl locally to connect to Webdis from the host.

Note: While the Webdis Docker image does bundle a Redis binary, it makes more sense to use multiple containers to demonstrate the use of SSL connections. This bundled Redis service does not run in this example, since we replace the Webdis command with one that only starts Webdis instead of starting Redis and Webdis together in the same container.

Start the Docker Compose stack

From the playground directory, run:

docker-compose up

You should see both services logging to the console in different colors, with an output like:

Creating playground_redis_1 ... done
Creating playground_webdis_1 ... done
Attaching to playground_redis_1, playground_webdis_1
redis_1   | 1:C 30 Oct 2021 06:14:55.150 # oO0OoO0OoO0Oo Redis is starting oO0OoO0OoO0Oo
redis_1   | 1:C 30 Oct 2021 06:14:55.150 # Redis version=6.2.6, bits=64, commit=00000000, modified=0, pid=1, just started
redis_1   | 1:C 30 Oct 2021 06:14:55.150 # Warning: no config file specified, using the default config. In order to specify a config file use redis-server /path/to/redis.conf
redis_1   | 1:M 30 Oct 2021 06:14:55.152 * monotonic clock: POSIX clock_gettime
redis_1   | 1:M 30 Oct 2021 06:14:55.153 * Running mode=standalone, port=6379.
redis_1   | 1:M 30 Oct 2021 06:14:55.154 # Server initialized
redis_1   | 1:M 30 Oct 2021 06:14:55.155 * Ready to accept connections
webdis_1  | [1] 30 Oct 06:14:56 I Webdis listening on port 7379
webdis_1  | [1] 30 Oct 06:14:56 I Webdis 0.1.19 up and running

You can now run commands against Webdis by connecting to port 7379 on localhost, e.g.

$ curl -s 'http://localhost:7379/ping'
{"ping":[true,"PONG"]}

$ curl -s 'http://localhost:7379/info' | jq -r .info.uptime_in_seconds
27

Clean-up

Stop the services with ctrl-c and remove the entire Docker Compose stack by running docker-compose rm from the playground directory.