GoCD Server Docker image

An Alpine Linux based docker image for GoCD server.

Docker Image

You could either download the latest built image from docker hub or build one locally with the zip file from GoCD Download webpage.

1.1 Download the latest Image

docker pull gocd/gocd-server:v18.6.0

1.2 Build One Locally

Build one with version 18.6.0; zip file is from GoCD download webpage.

GOCD_VERSION=18.6.0 \
GOCD_FULL_VERSION=18.6.0-6883
GOCD_SERVER_DOWNLOAD_URL=https://download.gocd.org/binaries/18.6.0-6883/generic/go-server-18.6.0-6883.zip \
rake build_image

Build an image locally with different UID and GID for go user

By default, the UID and GID of the go user in the docker container is 1000. This can be overidden at the time of building the image with

GOCD_VERSION=18.6.0 \
GOCD_FULL_VERSION=18.6.0-6883
GOCD_SERVER_DOWNLOAD_URL=https://download.gocd.org/binaries/18.6.0-6883/generic/go-server-18.6.0-6883.zip \
rake create_dockerfile
docker build --build-arg UID=2000 --build-arg GID=2000 -t gocd-server-image:tag .

Usage

Start the container with this:

docker run -d -p8153:8153 -p8154:8154 gocd/gocd-server:v18.6.0

This will expose container ports 8153(http) and 8154(https) onto your server. You can now open http://localhost:8153 and https://localhost:8154

Available configuration options

Mounting volumes

The GoCD server will store all configuration, pipeline history database, artifacts, plugins, and logs into /godata. If you'd like to provide secure credentials like SSH private keys among other things, you can mount /home/go

docker run -v /path/to/godata:/godata -v /path/to/home-dir:/home/go gocd/gocd-server:v18.6.0

Note: Ensure that /path/to/home-dir and /path/to/godata is accessible by the go user in container (go user - uid 1000).

Installing plugins

All plugins can be installed under /godata.

Installing plugins using an environment configuration

To install plugins, just add an ENV variable with the prefix GOCD_PLUGIN_INSTALL_ and your name as suffix and the value being the download URL. The plugin will only be downloaded if not yet present.

An example example would be GOCD_PLUGIN_INSTALL_docker-elastic-agents=https://github.com/gocd-contrib/docker-elastic-agents/releases/download/v0.8.0/docker-elastic-agents-0.8.0.jar:

docker run \
  -e GOCD_PLUGIN_INSTALL_docker-elastic-agents=https://github.com/gocd-contrib/docker-elastic-agents/releases/download/v0.8.0/docker-elastic-agents-0.8.0.jar \
  gocd/gocd-server:v18.6.0

To install multiple plugins, add several -e arguments as such:

docker run \
  -e GOCD_PLUGIN_INSTALL_a-plugin=https://example.com/a-plugin.jar \
  -e GOCD_PLUGIN_INSTALL_b-plugin=https://example.com/b-plugin.jar \
  gocd/gocd-server:v18.6.0

Installing plugins using a custom entry-point script (see below)

mkdir -p /godata/plugins/external
curl --location --fail https://example.com/plugin.jar > /path/to/godata/plugins/external/plugin.jar
chown -R 1000 /godata/plugins/external

Loading configuration from existing git repo

To load existing configuration from git repo, just add an ENV variable CONFIG_GIT_REPO. Auth token may be used to access private repo. Branch master would be cloned by default. To load another branch, define an ENV variable CONFIG_GIT_BRANCH. If /godata/config already is git repo then CONFIG_GIT_REPO will be ignored. Cloned repo must contain all files from /godata/config dir.

docker run \
  -e CONFIG_GIT_REPO=https://gocd_user:<password_or_auth_token>/config.git \
  -e CONFIG_GIT_BRANCH=branch_with_config \
  gocd/gocd-server:v17.12.0

Checkouted content would overwrite files in /godata/config/.

Running custom entrypoint scripts

To execute custom script(s) during the container boostrap, but before the GoCD server starts just add -v /path/to/your/script.sh:/docker-entrypoint.d/your-script.sh like so:

docker run -v /path/to/your/script.sh:/docker-entrypoint.d/your-script.sh ... gocd/gocd-server:v18.6.0

If you have several scripts in a directory that you'd like to execute:

docker run -v /path/to/script-dir:/docker-entrypoint.d ... gocd/gocd-server:v18.6.0

Note: Ensure that your scripts are executable chmod a+x — you can add as many scripts as you like, bash is available on the container. If your script uses other scripting language (perl, python), please ensure that the scripting language is installed in the container.

Installing addons

All addons can be installed under /godata.

mkdir -p /path/to/godata/addons
curl --location --fail https://example.com/addon.jar > /path/to/godata/addons/plugin.jar
chown -R 1000 /path/to/godata/addons

Tweaking JVM options (memory, heap etc)

JVM options can be tweaked using the environment variable GO_SERVER_SYSTEM_PROPERTIES.

docker run -e GO_SERVER_SYSTEM_PROPERTIES="-Xmx4096mb -Dfoo=bar" gocd/gocd-server:v18.6.0

Under the hood

The GoCD server runs as the go user, the location of the various directories is:

Directory	Description
`/godata/addons`	the directory where GoCD addons are stored
`/godata/artifacts`	the directory where GoCD artifacts are stored
`/godata/config`	the directory where the GoCD configuration is store
`/godata/db`	the directory where the GoCD database and configuration change history is stored
`/godata/logs`	the directory where GoCD logs will be written out to
`/godata/plugins`	the directory containing GoCD plugins
`/home/go`	the home directory for the GoCD server

Determine Server IP and Ports on Host

Once the GoCD server is up, we should be able to determine its ip address and the ports mapped onto the host by doing the following: The IP address and ports of the GoCD server in a docker container are important to know as they will be used by the GoCD agents to connect to it. If you have started the container with

docker run --name server -it -p8153:8153 -p8154:8154 gocd/gocd-server:v18.6.0

Then, the below commands will determine to GoCD server IP, server port and ssl port

docker inspect --format='{{(index (index .NetworkSettings.IPAddress))}}' server
docker inspect --format='{{(index (index .NetworkSettings.Ports "8153/tcp") 0).HostPort}}' server
docker inspect --format='{{(index (index .NetworkSettings.Ports "8154/tcp") 0).HostPort}}' server

Troubleshooting

The GoCD server does not come up

Check if the docker container is running docker ps -a
Check the STDOUT to see if there is any output that indicates failures docker logs CONTAINER_ID
Check the server logs docker exec -it CONTAINER_ID tail -f /godata/logs/go-server.log (or check the log file in the volume mount, if you're using one)

Bugs with Docker Server Image 17.3.0

Anyone using our docker image as the base image for your customized image, and writing to /home/go as part of your Dockerfile, these changes in /home/go don't persist while you start the container with your custom image. A fix has been applied here and will be available for subsequent releases of the docker images.

License

Copyright 2017 ThoughtWorks, Inc.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

aerostitch/docker-gocd-server