Start tracking which store paths are in use

This will enable garbage collection of the Guix store, without
removing things that are still in use.

2 files changed, 8 insertions, 2 deletions

diff --git a/app/jobs/govuk_guix/create_data_snapshot_job.rb b/app/jobs/govuk_guix/create_data_snapshot_job.rb
index 88a5ba4..bcc8aa1 100644
--- a/app/jobs/govuk_guix/create_data_snapshot_job.rb
+++ b/app/jobs/govuk_guix/create_data_snapshot_job.rb
@@ -87,6 +87,8 @@ class GovukGuix::CreateDataSnapshotJob < Que::Job
       from_remote_host: remote_host
     )
 
+    backend.add_in_use_store_path(build_output)
+
     GovukGuix::DataSnapshot.transaction do
       GovukGuix::DataSnapshot.create!(data_snapshot_fields)
 
diff --git a/app/jobs/govuk_guix/fetch_revision_job.rb b/app/jobs/govuk_guix/fetch_revision_job.rb
index fd6e09c..7b1acdf 100644
--- a/app/jobs/govuk_guix/fetch_revision_job.rb
+++ b/app/jobs/govuk_guix/fetch_revision_job.rb
@@ -27,9 +27,11 @@ class GovukGuix::FetchRevisionJob < Que::Job
   def run(commit_hash, options = {})
     backend_type_and_id = options[:backend_type_and_id]
     if backend_type_and_id
-      remote_host = Backends.find_by_type_and_id(
+      backend = Backends.find_by_type_and_id(
         *backend_type_and_id.split('=')
-      ).build_remote_host
+      )
+
+      remote_host = backend.build_remote_host
     end
 
     sha = fetch_and_checkout(commit_hash, remote_host)
@@ -51,6 +53,8 @@ class GovukGuix::FetchRevisionJob < Que::Job
     store_path = output.last.strip
     logger.debug(self.class) { "store_path: #{store_path}" }
 
+    backend.add_in_use_store_path(store_path) if backend
+
     GovukGuix::Revision.transaction do
       GovukGuix::Revision.create(
         commit_hash: sha,