Support storing whether to authenticate commits by git repository

To allow using the Guix Data Service when commits aren't authenticated.

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

@@ -47,12 +47,15 @@
 (define (select-git-repository conn id)
   (match (exec-query
           conn
-          "SELECT label, url, cgit_url_base FROM git_repositories WHERE id = $1"
+          "SELECT label, url, cgit_url_base, fetch_with_authentication FROM git_repositories WHERE id = $1"
           (list id))
     (()
      #f)
-    ((result)
-     result)))
+    (((label url cgit_url_base fetch_with_authentication))
+     (list label
+           url
+           cgit_url_base
+           (string=? fetch_with_authentication "t")))))
 
 (define (git-repository-id->url conn id)
   (match

guix-data-service/web/repository/controller.scm

@@ -69,7 +69,7 @@
              (with-thread-postgresql-connection
               (lambda (conn)
                 (select-git-repository conn id))))
-       ((label url cgit-url-base)
+       ((label url cgit-url-base fetch-with-authentication?)
         (letpar& ((branches
                    (with-thread-postgresql-connection
                     (lambda (conn)

sqitch/deploy/git_repositories_add_fetch_with_authentication_field.sql

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

sqitch/revert/git_repositories_add_fetch_with_authentication_field.sql

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

sqitch/sqitch.plan

@@ -72,3 +72,4 @@ change_locale_values 2020-09-26T10:20:22Z Christopher Baines <mail@cbaines.net>
 change_autovacuum_config 2020-10-01T21:24:46Z Christopher Baines <mail@cbaines.net> # Change autovacuum config
 change_derivation_source_file_nars_constraint 2020-10-02T17:12:58Z Christopher Baines <mail@cbaines.net> # Change derivation source file nars constraint
 add_derivation_sources_derivation_source_file_id_index 2020-10-02T19:11:59Z Christopher Baines <mail@cbaines.net> # Add derivation_sources.derivation_source_file_id index
+git_repositories_add_fetch_with_authentication_field 2020-10-07T17:31:20Z Christopher Baines <mail@cbaines.net> # Add git_repositories.fetch_with_authentication

sqitch/verify/git_repositories_add_fetch_with_authentication_field.sql

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