Developing and deploying CKAN with Docker

Dockerfiles, Docker-compose service definition & Vagrantfile to develop & deploy CKAN, Postgres, Solr & datapusher using Docker.

Docker containers included:

• CKAN (should work with any version 2.x)
• Postgres (Postgres 9.3 and PostGIS 2.1, CKAN datastore & spatial extension supported)
• Solr (4.10.1, custom schemas & spatial extension supported)
• Docker-compose [optional] (to manage the containers)
• Data [optional] (to store Postgres data & CKAN FileStore separately)

Other contrib containers:

• Nginx (1.7.6 official) as a caching reverse proxy
• Datapusher

├── Dockerfile (CKAN Dockerfile)
├── README.md
├── Vagrantfile (CKAN Vagrantfile)
├── _etc (config copied to /etc)
│   ├── apache2
│   ├── ckan
│   ├── cron.d
│   ├── my_init.d
│   ├── postfix
│   └── supervisor
├── _service-provider (any service provider such as datapusher)
│   └── datapusher
├── _solr
│   └── schema.xml (version specific & custom schema)
├── _src (CKAN source code & extensions)
│   ├── ckan
│   └── ckanext-...
├── docker
│   ├── ckan
│   ├── data
│   ├── compose
│   ├── nginx
│   ├── insecure_key (baseimage insecure SSH key)
│   ├── postgres
│   └── solr
├── docker-compose.yml (CKAN services definition)
└── vagrant
    └── docker-host (Linux Docker host if required)

the content from the directories prefixed with _ need to be edited / configured as required before building the Dockerfiles.

contains configuration files that are copied to /etc in the container. see _etc/README

contains your custom Solr schema (for your version of CKAN, & extensions installed). see _solr/README

contains your packages source code (CKAN & extensions). see _src/README

contains any service providers (e.g. datapusher) with their Dockerfiles. see _service-provider/README.

contains the Dockerfiles and any supporting files

contains the Docker host if the host cannot run Docker containers natively (OS X & Windows)

The Dockerfiles are currently based on phusion/baseimage:0.9.16.

SSH is supported using an insecure key which is enabled by default for development purposes. You should disable it in production use for obvious reasons.

Read this to find out more about phusion baseimage

The app container runs the following services

• Apache
• Postfix
• Supervisor
• Cron

The database container runs Postgres 9.3 and PostGIS 2.1. It supports the datastore & ckanext-spatial

The data container is optional but recommended. It exposes two volumes to store the Postgres data ($PGDATA) & CKAN FileStore. This means you can recreate / app containers without losing your data.

The Solr container runs version 4.10.1. This can easily be changed by customising SOLR_VERSION in the Dockerfile.

By detault the schema.xml of the upstream version (2.3) is copied in the container. This can be overriden at runtime by mounting it as a volume. This default path of the volume is <path to>/_src/ckan/ckan/config/solr/schema.xml so it mounts the schema corresponding to your version of CKAN.

For example for Docker-compose:

solr:
  build: docker/solr
  hostname: solr
  domainname: localdomain
  ports:
    - "8983:8983"
  volumes:
    - <path to>/_src/ckan/ckan/config/solr/schema.xml:/opt/solr/example/solr/ckan/conf/schema.xml

If you need a custom schema, put it in <full path to>/_solr and change the path in the docker-compose or vagrant file.

  volumes:
    - <path to>/_solr/schema.xml:/opt/solr/example/solr/ckan/conf/schema.xml

The container is cross version compatible. You need mount the appropriate schema.xml as a volume, or build a child image, which will copy the schema.xml next to your Dockerfile.

Read the ckanext-spatial documentation to add the required fields to your Solr schema if you use ckanext-spatial

The Docker-compose container runs the latests Docker-compose & Docker within a container.

The Docker socket needs to be mounted as a volume to control Docker on the host. A source folder must be mounted to access the docker-compose definition

see docker/compose/Readme to find out how to use

Defines VMs provided by Docker, a Virtual Box docker-host is used if the host can't run Docker containers natively. This is an alternative to Boot2Docker.

Defines the set of services required to run CKAN. Read the docker-compose.yml reference to understand and edit.

1. Clone your code in the _src directory (see _src/README)
2. Clone the datapusher in _service-provider (see _service-provider/README)
3. Set the full path of the volumes in docker-compose.yml
4. Run up with Docker-compose or Vagrant

Note that this configuration uses Skydock to facilitate bidirectional networking between the CKAN and DataPusher containers. You must configure your Docker daemon to use the bridge IP 172.17.42.1./16. For example:

docker-machine create ckan --driver virtualbox --engine-opt bip=172.17.42.1/16 --engine-opt dns=172.17.42.1

Additionally, the skydock container must be running before other containers are kicked off since those containers use skydock for DNS resolution. To start CKAN:

1. docker-compose -p ckan start skydock.
2. docker-compose -p ckan up.

If you have it installed, just type

docker-compose up

Otherwise, you can use the container provided

Build the Docker-compose container

docker build --tag="dockercompose_container" docker/compose

Run it

docker run -it -d --name="dockercompose-ckan" -p 2375 -v /var/run/docker.sock:/tmp/docker.sock -v $(pwd):/src dockercompose_container

In the Docker-compose container docker-compose won't work with relative path, because the mount namespace is different, you need to change the relative path to absolute path

for example, change the ./:

volumes:
    - ./_src:/usr/lib/ckan/default/src

to an absolute path to you ckan-docker directory: /Users/username/git/ckan/ckan-docker/

volumes:
    - /Users/username/git/ckan/ckan-docker/_src:/usr/lib/ckan/default/src

Build & Run the services defined in docker-compose.yml

docker exec -it dockercompose-ckan docker-compose up

If you are using boot2docker, add entries in your hosts file e.g. 192.168.59.103 ckan.localdomain

You can now access CKAN at http://ckan.localdomain:8080/ (Apache) & http://ckan.localdomain/ (Ngnix)

Build & run

vagrant up --provider=docker --no-parallel

You can now access CKAN at http://localhost:8080/ (Apache)

You can also SSH inside the container if you have left the --enable-insecure-key option in the run command.

vagrant ssh ckan

SSH insecure key can be disabled by removing the --enable-insecure-key option from the run command.

The simplest thing to do is to use the docker exec command, for example:

docker exec -it src_ckan_1 /bin/bash

You can also SSH inside the container if you have left the --enable-insecure-key option in the run command.

ssh -i docker/insecure_key -p 2222 root@ckan.localdomain

SSH insecure key can be disabled by removing the --enable-insecure-key option from the run command.

You should use docker-compose to manage your containers & images, this will ensure they are started/stopped in order

If you want to quickly remove all untagged images:

docker images -q --filter "dangling=true" | xargs docker rmi

If you want to quickly remove all stopped containers

docker rm $(docker ps -a -q)

CKAN container starts Apache2 by default and the ckan.site_url port is set to 8080 in 50_configure. You can override that permanently in the custom_options.ini, or manually in the container, for instance if you want to use paster in a development context.

Example (paster serve --reload in debug mode):

docker exec -it src_ckan_1 /bin/bash
supervisorctl stop apache2
sed -i -r 's/debug = false/debug = true/' $CKAN_CONFIG/$CONFIG_FILE
sed -i -r 's/ckan.localdomain:8080/ckan.localdomain:5000/' $CKAN_CONFIG/$CONFIG_FILE
$CKAN_HOME/bin/paster serve --reload $CKAN_CONFIG/$CONFIG_FILE

Front end development is also possible (see Frontend development guidelines)

Install frontend dependencies:

docker exec -it src_ckan_1 /bin/bash
apt-get update
apt-get install -y nodejs npm
ln -s /usr/bin/nodejs /usr/bin/node
source $CKAN_HOME/bin/activate
cd $CKAN_HOME/
npm install nodewatch less@1.3.3

Both examples show that development dependencies should only be installed in the containers when required. Since they are not part of the Dockerfile they do not persist and only serve the purpose of development. When they are no longuer needed the container can be rebuilt allowing to test the application in a production-like state.

• Docker
• Docker-compose
• Vagrant Docker provider