Download and compile external assets during deployment

Dockerfile

@@ -1,4 +1,8 @@
 FROM ruby:2.3.0
+ARG CUSTOM_ASSETS_URL
+ARG CUSTOM_ASSETS_BRANCH
+ARG CUSTOM_ASSETS_CREDENTIALS
+
 # Install system dependencies
 RUN apt-get update -qq; apt-get install -y nodejs npm imagemagick netcat && \
     update-alternatives --install /usr/bin/node nodejs /usr/bin/nodejs 100
@@ -13,6 +17,12 @@ RUN bundle install --jobs 4 && npm install && npm install -g phantomjs-prebuilt
 
 EXPOSE 3000
 ADD . /myapp
-RUN RAILS_ENV=production bundle exec rake assets:precompile
+RUN if [ -z "$CUSTOM_ASSETS_URL" ]; then\
+      echo "Skipping external assets download";\
+    else\
+      echo "Downloading external assets";\
+      CUSTOM_ASSETS_PATHS=$(_URL=$CUSTOM_ASSETS_URL _CREDENTIALS=$CUSTOM_ASSETS_CREDENTIALS _BRANCH=$CUSTOM_ASSETS_BRANCH bundle exec rake custom_assets:download);\
+    fi;\
+    RAILS_ENV=production bundle exec rake assets:precompile
 
 CMD bundle exec puma -b tcp://0.0.0.0 -p 3000 -t 5:16

Gemfile

@@ -23,6 +23,7 @@ gem 'font-awesome-sass'
 gem 'money'
 gem 'google_currency'
 gem 'rack-cors', require: 'rack/cors'
+gem 'httparty'
 
 # Sprockets 3 breaks Teaspoon.
 # see https://github.com/modeset/teaspoon/issues/443

Gemfile.lock

@@ -528,6 +528,7 @@ DEPENDENCIES
   google_currency
   guard-rspec
   hiredis
+  httparty
   i18n-js (>= 3.0.0.rc12)
   jbuilder (~> 2.0)
   jquery-rails

circle.yml

@@ -1,4 +1,7 @@
 machine:
+  pre:
+    # Update docker version
+    - curl -sSL https://s3.amazonaws.com/circle-downloads/install-circleci-docker.sh | bash -s -- 1.10.0
   services:
     - docker
 
@@ -10,7 +13,7 @@ dependencies:
     # install AWS CLI
     - sudo pip install awscli
     # build the image
-    - docker build -t soutech/champaign_web:$CIRCLE_SHA1 .
+    - docker build -t soutech/champaign_web:$CIRCLE_SHA1 --build-arg CUSTOM_ASSETS_URL=$CUSTOM_ASSETS_URL --build-arg CUSTOM_ASSETS_CREDENTIALS=$CUSTOM_ASSETS_CREDENTIALS --build-arg CUSTOM_ASSETS_BRANCH=$CIRCLE_BRANCH .
 
 test:
   override:
@@ -32,7 +35,7 @@ deployment:
       - docker push soutech/champaign_web
       - ./deploy.sh $CIRCLE_SHA1 'champaign' 'env-production' 'champaign-assets-production' 'logs3.papertrailapp.com:44107' 'actions.sumofus.org'
   staging:
-    branch: development
+    branch: external-assets
     commands:
       - docker login -e $DOCKER_EMAIL -u $DOCKER_USER -p $DOCKER_PASS
       - docker push soutech/champaign_web

config/application.rb

@@ -38,7 +38,7 @@ class Application < Rails::Application
     config.i18n.enforce_available_locales = true
 
     config.active_record.observers = :liquid_partial_observer
-    config.assets.paths += (Settings.custom_assets_paths || "").split(":") if Settings.custom_assets_paths.present?
+    config.assets.paths += Settings.custom_assets_paths.split(":") if Settings.custom_assets_paths.present?
 
     # We're using Redis as our cache. Configure that here.
     # we use 'redis' as the host name because that's configured by docker

lib/tasks/deploy.rake

@@ -0,0 +1,57 @@
+namespace :custom_assets do
+  # Downloads a tar from a URL, extracts its contents into ./tmp,
+  # and returns a colon separated list of paths belonging to the first level directories
+  # inside the original tar file.
+  #
+  # Params:
+  # * url: any http[s] url. Optionally it can include a tag <branch> that will be replaced with
+  #    the contents of the branch param
+  # * credentials: http basic auth credentials. The format should be user:password
+  # * branch: Mainly for Github URLs usage. The content of this param will replace the <branch> tag
+  #     in the url param
+  desc "Download external assets"
+  task :download, [:url, :credentials, :branch] do |t, args|
+    Bundler.require :default, :development
+
+    url = args[:url]
+    credentials = args[:credentials]
+    branch = args[:branch]
+    tar_file_path = "./tmp/assets.tar"
+
+    raise ArgumentError.new("usage: rake custom_assets:download[<url>,<credentials>,<branch>]") if url.blank?
+
+    if branch.present?
+      url = url.gsub("<branch>", branch)
+    end
+
+    # Download tar file --------------------------
+    http_options = {}
+    if credentials.present?
+      u, p = credentials.split(":")
+      http_options[:basic_auth] = { username: u, password: p }
+    end
+    response = HTTParty.get url, http_options
+
+    if !response.success?
+      raise "HTTP while trying to download assets #{response.inspect}"
+    end
+
+
+    # Extract tar file --------------------------
+    File.open(tar_file_path, "w+b") do |file|
+      file.write response.body
+    end
+
+    untar_cmd = "tar -xf #{tar_file_path} -C ./tmp"
+    result = system(untar_cmd)
+    raise "Error running `#{untar_cmd}`" unless result
+
+    # Print dir where assets were extracted -----
+    base_assets_dir = `tar -tf #{tar_file_path} | head -n 1`
+    base_assets_dir.strip!
+    base_assets_path = Pathname.new("./tmp").join(base_assets_dir)
+
+    assets_dirs = Dir.glob(base_assets_path.join("*")).select { |f| File.directory? f }
+    puts assets_dirs.join(":")
+  end
+end