Refactor the FetchRevisionJob

Move the repository directory in to a constant, and make the
repository remote location configurable.

Also, fix an issue with parsing the JSON output from the
available-services command, as there were some messages appearing
prior to the JSON output.

1 files changed, 14 insertions, 10 deletions

diff --git a/app/jobs/govuk_guix/fetch_revision_job.rb b/app/jobs/govuk_guix/fetch_revision_job.rb
index c2c3c17..c747c13 100644
--- a/app/jobs/govuk_guix/fetch_revision_job.rb
+++ b/app/jobs/govuk_guix/fetch_revision_job.rb
@@ -23,6 +23,8 @@ require 'git'
 class GovukGuix::FetchRevisionJob < GovukGuix::Job
   extend EnqueuedJobs
 
+  REPOSITORY_DIRECTORY = 'tmp/cache/govuk-guix'.freeze
+
   @retry_interval = 30
 
   def run(commit_hash)
@@ -33,7 +35,7 @@ class GovukGuix::FetchRevisionJob < GovukGuix::Job
     repository.checkout(sha)
 
     command = [
-      "#{repository_directory}/guix-pre-inst-env",
+      "#{REPOSITORY_DIRECTORY}/guix-pre-inst-env",
       'guix',
       'build',
       '-e',
@@ -54,10 +56,10 @@ class GovukGuix::FetchRevisionJob < GovukGuix::Job
 
   def repository
     @_repository ||= begin
-      if File.exist? repository_directory
-        Git.open(repository_directory, log: Rails.logger)
+      if File.exist? REPOSITORY_DIRECTORY
+        Git.open(REPOSITORY_DIRECTORY, log: Rails.logger)
       else
-        Git.clone(repository_remote_location, repository_directory)
+        Git.clone(self.class.repository_remote_location, REPOSITORY_DIRECTORY)
       end
     end
   end
@@ -70,14 +72,16 @@ class GovukGuix::FetchRevisionJob < GovukGuix::Job
       "--json"
     )
 
-    JSON.parse(command_output.join)
-  end
+    json_start = command_output.find_index { |line| line.starts_with?('[') }
+    json_output = command_output[json_start..command_output.length].join
 
-  def repository_directory
-    'tmp/cache/govuk-guix'
+    JSON.parse(json_output)
   end
 
-  def repository_remote_location
-    'git@git.cbaines.net:gds/govuk-guix'
+  def self.repository_remote_location
+    ENV.fetch(
+      'GOVUK_GUIX_REPOSITORY_REMOTE',
+      'https://github.com/alphagov/govuk-guix.git'
+    )
   end
 end