Using Rails/Postgres with Docker and Fig

This is a demo Rails app with Docker. It creates development environment and scripts for deployment to production.

This repository is based on https://github.com/whitesmith/rails-pg-fig-sample.

Installation

1. Install Docker and Fig.
2. Run ./scripts/init_development.sh to create development environment.
3. Run fig up to start rails web server.
4. Open http://localhost:3000/ in the web browser. On Mac OS, run boot2docker ip command to get the IP address.

fig stop - stops the app. fig rm - removes the app containers.

How it works

Rails app docker image

It creates a docker image for the Rails app called web. It is configured to keep the source code on developer host and not in the image. It allows to make changes to the source code and see results in the browser.

Docker containers

Following docker containers are created:

1. Web for Rails app.
2. DB for Postgres DB server.
3. iipersist-db-data is a Data Volume Container for the database storage.
4. iipersist-gems-2.1 is another Data Volume Container for the gems.

Deploying to production

1. Create a deployment image

./scripts/docker_create_deploy_image.sh myaccount/image

Use your Docker Hub account name and deployment image name. The single purpose of this step is to create a production image that contains app's source code. You may want to make this repository private.

2. Push the image to Docker Hub

docker push myaccount/image

3. Copy fig_production.yml

1. In fig_production.yml replace myaccount/image with the image name you specified in step 1.
2. Copy fig_production.yml to fig.yml to your production host.
3. Use docker_upload_data_volume_container.sh script to upload database files and Gems to your server:

./scripts/docker_upload_data_volume_container.sh iipersist-gems-2.1 /usr/local/bundle myserver.com
./scripts/docker_upload_data_volume_container.sh iipersist-db-data /var/lib/postgresql/data myserver.com

Here replace myserver.com with your production server name.

4. Create production environment

Finally, run fig up on your production host to create production environment and launch the app.

Scripts

Scripts are located in scripts directory.

fig_remove_containers.sh

Cleanup script that removes containers for the app. It does not remove the database and gems containers. This script can be run after fig stop and fig rm.

docker_data_volume_container_backup.sh

Backup data from data volume container into a tar.gz file in the current directory.

Usage:

docker_data_volume_container_backup.sh CONTAINER_NAME VOLUME_PATH

Example:

./docker_data_volume_container_backup.sh iipersist-db-data /var/lib/postgresql/data

docker_data_volume_container_restore.sh

Restore data from CONTAINER_NAME.tar.gz into a data volume container.

Usage:

docker_data_volume_container_backup.sh CONTAINER_NAME VOLUME_PATH

Example:

Restore iipersist-db-data.tar.gz into iipersist-db-data Data Volume Container:

./docker_data_volume_container_restore.sh iipersist-db-data /var/lib/postgresql/data

docker_upload_data_volume_container.sh

This script uploads data volume container to a remote host.

The job includes the following steps:

1. It archives a local data volume container.
2. Copies the archive to remote host.
3. Restores the archive into the data volume container on remote host.

Usage:

docker_upload_data_volume_container.sh CONTAINER_NAME VOLUME_PATH HOST_SSH_ADDRESS

Example:

Uploads iipersist-db-data Data Volume Container to myserver.com host.

./docker_upload_data_volume_container.sh iipersist-db-data /var/lib/postgresql/data myserver.com

Reference

Resources that helped me with this project:

• Dockerizing Applications: A "Hello world"

• How to Create a Persistent Ruby Gems Container with Docker

• Orchestrating Docker containers in production using Fig

• A Rails development environment using Docker through Fig

Feedback welcome

Feel free to create an issue ticket. Or if you are stuck and need help please do not hesitate to ask.