Stackose - A capistrano addon to use with docker stack [WIP]

This gem is a refactoring to use the capose gem, but with docker stack implementation. The Documentation is owned from capose, and not so far complete for the docker stack, must be rewritten and cleared

This gem is a lighter version of docker-compose strategy found in capistrano-docker gem. The idea is to be much simplier and more custom to use.

Installation

Ensure you already have capistrano gem in your project, with version at least 3.7
Add the following line to your Gemfile: gem 'stackose', require: false
Add the following file to Capfile: require 'stackose'

This gem will automatically hook up to the capistrano after deploy:updated hook to perform the deployment via stackose:deploy hook

Changelog

Defaults

This gem uses couple variables which can be modified inside your deploy scripts, these are:

set :stackose_role - capistrano role for stackose, defaults to :web
set :stackose_copy - list of files/dirs to be copied from shared_path before first command (replaces :link_dirs/files), defaults to []
set :stackose_project - docker-compose project name, defaults to fetch(:application)
set :stackose_file - list of files for the docker-compose -f parameter (defauls to ["docker-compose.yml", "docker-compose-#{fetch(:stage)}.yml"]) and finaly the generated docker-compose-override
set :stackose_commands - list of commands to be run with docker-compose, defaults to []
set :stackose_docker_mount_point - mount point inside the application container, defaults to "/usr/share/www/"
set :stackose_linked_folders     - list of folders to link inside de image 
set :stackose_service_to_build   - name of the services with the application to run (default: ['app']) and should use the deploy user and group id
set :stackose_skip_image_build   - true|[false] to skip the generation of the image, the compose file should have already the image defined(register) the only think is the building of compose_file with user and group id  
set :stackose_compose_version    - string with compose version(default: '3')

Folders to be linked

If you need to link shared folders to the root of your application path, like capistrano standard linked_folders do, you can setup this like:

   set :capose_linked_folders, [ 'public/system',
                                 'public/pictures',
                                 'public/attachments',
                                 'public/pages',
                                 'public/assets',
                                 'uploads']

For custom linking you can provide inside the array a hash with key->value of source->destination

    set :capose_linked_folders, [
       'tmp/pids',
       'tmp/cache',
        ....,
       'uploads',
        "/custom_path/#{fetch(:application)}/":"#{fetch(:capose_docker_mount_point)}/log",
       ]

if you need the shared_path url in the key you can set __shared_path__ as placeholder
or all the other fetch variables can be used inside with __variable_name__

Additional files before first command

If you need to throw in to the "release" folder couple files (say secret files) before image is build, you can use capose_copy for that, ex:

set :capose_copy, %w(config/secrets.yml certs/google.crt certs/google.key)

This command will copy the files from shared/ path before first command is executed, such as:

cp -aR [shared_path]/config/secrets.yml [release_path]/config/secrets.yml
cp -aR [shared_path]/config/google.crt [release_path]/config/google.crt
cp -aR [shared_path]/config/google.key [release_path]/config/google.key
docker-compose -p [application] -f ... build
docker-compose ...

Additional commands to run

If your use-case contains more commands than build and up -d, then you can modify capose_commands to achieve that, ex:

set :capose_commands, ["build", "run --rm web rake db:migrate", "run --rm web rake assets:precompile", "up -d"]

This will tell capistrano to run following commands:

docker-compose -p [application] -f docker-compose-[stage].yml -f docker-compose-image-override.yml build
docker-compose -p [application] -f docker-compose-[stage].yml -f docker-compose-image-override.yml run --rm web rake db:migrate
docker-compose -p [application] -f docker-compose-[stage].yml -f docker-compose-image-override.yml run --rm web rake assets:precompile
docker-compose -p [application] -f docker-compose-[stage].yml -f docker-compose-image-override.yml up -d

Custom docker-compose file paths

If you want to add more compose files or change the name, then modify capose_file variable, ex:

set :stackose_file, ["docker-compose.yml", "docker-compose-override.yml"]

This will tell capistrano to run commands as:

docker-compose -p [application] -f docker-compose.yml -f docker-compose-override.yml -f docker-compose-image-override.yml [command]

Docker-compose image override

This file is generated on deploy, it will create on the "app" service configurations to make it work more correctly: It append the image builded for the release (docker stack don't build images) and the user configuration, so the files generated from inside of the container will have the user oth the host system.

oniram88/stackose