Support per repository configuration for fetching substitutes

This is so that data.qa.guix.gnu.org can be configured only to query the
branches from the main repository.

guix-data-service/model/git-repository.scm

@@ -22,6 +22,7 @@
   #:use-module (guix-data-service model utils)
   #:export (all-git-repositories
             select-git-repository
+            git-repository-query-substitutes?
             git-repository-id->url
             select-includes-and-excluded-branches-for-git-repository
             count-git-repositories-with-x-git-repo-header-values
@@ -57,6 +58,14 @@
            cgit_url_base
            (string=? fetch_with_authentication "t")))))
 
+(define (git-repository-query-substitutes? conn id)
+  (match (exec-query
+          conn
+          "SELECT query_substitutes FROM git_repositories WHERE id = $1"
+          (list (simple-format #f "~A" id)))
+    (((query_substitutes))
+     (string=? query_substitutes "t"))))
+
 (define (git-repository-id->url conn id)
   (match
       (exec-query

guix-data-service/substitutes.scm

@@ -130,6 +130,7 @@
               (for-each
                (match-lambda
                  ((git-repository-id rest ...)
+                  (when (git-repository-query-substitutes? conn git-repository-id)
                     (for-each
                      (match-lambda
                        ((branch-name rest ...)
@@ -145,7 +146,7 @@
                                   #f)))))
                      (all-branches-with-most-recent-commit
                       conn
-                    git-repository-id))))
+                      git-repository-id)))))
                (all-git-repositories conn))))
 
            (simple-format #t "finished checking substitutes, now sleeping\n")

sqitch/deploy/git_repositories_query_substitutes.sql

@@ -0,0 +1,8 @@
+-- Deploy guix-data-service:git_repositories_query_substitutes to pg
+
+BEGIN;
+
+ALTER TABLE git_repositories
+  ADD COLUMN query_substitutes boolean NOT NULL DEFAULT TRUE;
+
+COMMIT;

sqitch/revert/git_repositories_query_substitutes.sql

@@ -0,0 +1,7 @@
+-- Revert guix-data-service:git_repositories_query_substitutes from pg
+
+BEGIN;
+
+-- XXX Add DDLs here.
+
+COMMIT;

sqitch/sqitch.plan

@@ -87,3 +87,4 @@ git_branch_id 2022-05-23T18:11:14Z Chris <chris@felis> # Add git_branch.id
 partition_package_derivations_by_guix_revision_range 2022-05-23T18:20:37Z Chris <chris@felis> # Partition package_derivations_by_guix_revision_range
 package_range_index 2022-06-17T10:39:31Z Chris <chris@felis> # Add index on package_derivations_by_guix_revision_range.package_name
 fix_git_commits_duplicates 2022-06-17T10:39:50Z Chris <chris@felis> # Fix git_commits duplicates
+git_repositories_query_substitutes 2022-09-09T11:35:16Z Chris <chris@felis> # Add git_repositories.query_substitutes

sqitch/verify/git_repositories_query_substitutes.sql

@@ -0,0 +1,7 @@
+-- Verify guix-data-service:git_repositories_query_substitutes on pg
+
+BEGIN;
+
+-- XXX Add verifications here.
+
+ROLLBACK;