Ruby on Rails

 1services:
 2  # What to call the service hosting the site.
 3  rails:
 4    # Use a Tugboat Debian image as a starting point because it contains tools
 5    # and configurations to help them work well with Tugboat
 6    image: tugboatqa/debian
 7
 8    # Set this as the default service. This does a few things
 9    #   1. Clones the git repository into the service container
10    #   2. Exposes port 80 to the Tugboat HTTP proxy
11    #   3. Routes requests to the Preview URL to this service
12    default: true
13
14    # Don't build the Ruby service until the database service is started
15    depends: database
16
17    # A set of commands to run while building this service
18    commands:
19      # Commands that set up the basic preview infrastructure
20      init:
21        # Check for updates to apt-get, and then use it to install Ruby
22        - apt-get update
23        - apt-get install ruby ruby-dev
24
25        # Install a minimal set of PostgreSQL binaries and headers to interact with the database
26        - apt-get install libpq-dev
27
28        # Install the gems required for the project
29        - gem update --system
30        - gem install bundler
31        - bundle install
32
33        # Clean up apt artifacts to keep the Preview small
34        - apt-get clean
35        - rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
36
37      # Commands that import files, databases,  or other assets. When an
38      # existing preview is refreshed, the build workflow starts here,
39      # skipping the init step, because the results of that step will
40      # already be present.
41      update:
42        # A common practice in many Rails projects is to run this command to
43        # set up a database. This step is why the 'database' service has an 'init'
44        # command to give the default Tugboat user permission to create the database.
45        # If you're not creating a database here, you don't need the 'init' and
46        # 'online' commands in the `database` service. If you're connecting to a remote
47        # database, you won't need this.
48        - bin/rails db:setup
49
50      # Commands that should happen every time the Preview starts.
51      start:
52        # Start the Rails server. The '&' trailing this statement puts the process
53        # in the background.
54        - bin/rails s -b 0.0.0.0 -p 80 &
55
56  # What to call the service hosting the database. This name also acts as the
57  # hostname to access the service by from the 'rails' service.
58  database:
59    # Use the latest available version of postgres by not specifying a
60    # version
61    image: tugboatqa/postgres
62
63    # A set of commands to run while building this service
64    commands:
65      # Commands that import files, databases, or other assets. When an
66      # existing preview is refreshed, the build workflow starts here,
67      # skipping the init step, because the results of that step will
68      # already be present.
69      init:
70        # Give the default Tugboat user the permission to create a database.
71        # This is only required if using 'rails db:setup'
72        - psql -U postgres -d tugboat -c "ALTER USER tugboat WITH CREATEDB;"