Add optional, decomposed jobs for pg12 specs

- pg12
- pg12 as-if-foss
- pg12 ee

But not:
- pg12 ee geo

These jobs only run if a label is present,
and the allow failures for now as all of these jobs have some failures.

.gitlab/ci/rails.gitlab-ci.yml

@@ -23,6 +23,10 @@
   variables:
     RSPEC_TESTS_MAPPING_ENABLED: "true"
 
+.decomposed-database-rspec:
+  variables:
+    DECOMPOSED_DB: "true"
+
 .rspec-base:
   extends: .rails-job-base
   stage: test
@@ -296,6 +300,12 @@ rspec migration pg12 minimal:
     - .minimal-rspec-tests
     - .rails:rules:ee-and-foss-migration:minimal
 
+rspec migration pg12 decomposed:
+  extends:
+    - rspec migration pg12
+    - .decomposed-database-rspec
+    - .rails:rules:decomposed-databases
+
 rspec unit pg12:
   extends:
     - .rspec-base-pg12
@@ -308,6 +318,12 @@ rspec unit pg12 minimal:
     - .minimal-rspec-tests
     - .rails:rules:ee-and-foss-unit:minimal
 
+rspec unit pg12 decomposed:
+  extends:
+    - rspec unit pg12
+    - .decomposed-database-rspec
+    - .rails:rules:decomposed-databases
+
 rspec integration pg12:
   extends:
     - .rspec-base-pg12
@@ -320,6 +336,12 @@ rspec integration pg12 minimal:
     - .minimal-rspec-tests
     - .rails:rules:ee-and-foss-integration:minimal
 
+rspec integration pg12 decomposed:
+  extends:
+    - rspec integration pg12
+    - .decomposed-database-rspec
+    - .rails:rules:decomposed-databases
+
 rspec system pg12:
   extends:
     - .rspec-base-pg12
@@ -332,6 +354,12 @@ rspec system pg12 minimal:
     - .minimal-rspec-tests
     - .rails:rules:ee-and-foss-system:minimal
 
+rspec system pg12 decomposed:
+  extends:
+    - rspec system pg12
+    - .decomposed-database-rspec
+    - .rails:rules:decomposed-databases
+
 # Dedicated job to test DB library code against PG11.
 # Note that these are already tested against PG12 in the `rspec unit pg12` / `rspec-ee unit pg12` jobs.
 rspec db-library-code pg11:
@@ -554,6 +582,12 @@ rspec migration pg12-as-if-foss minimal:
     - .minimal-rspec-tests
     - .rails:rules:as-if-foss-migration:minimal
 
+rspec migration pg12-as-if-foss decomposed:
+  extends:
+    - rspec migration pg12-as-if-foss
+    - .decomposed-database-rspec
+    - .rails:rules:decomposed-databases
+
 rspec unit pg12-as-if-foss:
   extends:
     - .rspec-base-pg12-as-if-foss
@@ -566,6 +600,12 @@ rspec unit pg12-as-if-foss minimal:
     - .minimal-rspec-tests
     - .rails:rules:as-if-foss-unit:minimal
 
+rspec unit pg12-as-if-foss decomposed:
+  extends:
+    - rspec unit pg12-as-if-foss
+    - .decomposed-database-rspec
+    - .rails:rules:decomposed-databases
+
 rspec integration pg12-as-if-foss:
   extends:
     - .rspec-base-pg12-as-if-foss
@@ -578,6 +618,12 @@ rspec integration pg12-as-if-foss minimal:
     - .minimal-rspec-tests
     - .rails:rules:as-if-foss-integration:minimal
 
+rspec integration pg12-as-if-foss decomposed:
+  extends:
+    - rspec integration pg12-as-if-foss
+    - .decomposed-database-rspec
+    - .rails:rules:decomposed-databases
+
 rspec system pg12-as-if-foss:
   extends:
     - .rspec-base-pg12-as-if-foss
@@ -590,6 +636,12 @@ rspec system pg12-as-if-foss minimal:
     - .minimal-rspec-tests
     - .rails:rules:as-if-foss-system:minimal
 
+rspec system pg12-as-if-foss decomposed:
+  extends:
+    - rspec system pg12-as-if-foss
+    - .decomposed-database-rspec
+    - .rails:rules:decomposed-databases
+
 rspec-ee migration pg12:
   extends:
     - .rspec-ee-base-pg12
@@ -603,6 +655,12 @@ rspec-ee migration pg12 minimal:
     - .minimal-rspec-tests
     - .rails:rules:ee-only-migration:minimal
 
+rspec-ee migration pg12 decomposed:
+  extends:
+    - rspec-ee migration pg12
+    - .decomposed-database-rspec
+    - .rails:rules:decomposed-databases
+
 rspec-ee unit pg12:
   extends:
     - .rspec-ee-base-pg12
@@ -615,6 +673,12 @@ rspec-ee unit pg12 minimal:
     - .minimal-rspec-tests
     - .rails:rules:ee-only-unit:minimal
 
+rspec-ee unit pg12 decomposed:
+  extends:
+    - rspec-ee unit pg12
+    - .decomposed-database-rspec
+    - .rails:rules:decomposed-databases
+
 rspec-ee integration pg12:
   extends:
     - .rspec-ee-base-pg12
@@ -627,6 +691,12 @@ rspec-ee integration pg12 minimal:
     - .minimal-rspec-tests
     - .rails:rules:ee-only-integration:minimal
 
+rspec-ee integration pg12 decomposed:
+  extends:
+    - rspec-ee integration pg12
+    - .decomposed-database-rspec
+    - .rails:rules:decomposed-databases
+
 rspec-ee system pg12:
   extends:
     - .rspec-ee-base-pg12
@@ -639,6 +709,12 @@ rspec-ee system pg12 minimal:
     - .minimal-rspec-tests
     - .rails:rules:ee-only-system:minimal
 
+rspec-ee system pg12 decomposed:
+  extends:
+    - rspec-ee system pg12
+    - .decomposed-database-rspec
+    - .rails:rules:decomposed-databases
+
 rspec-ee unit pg12 geo:
   extends:
     - .rspec-ee-base-geo-pg12

.gitlab/ci/rules.gitlab-ci.yml

@@ -46,6 +46,9 @@
 .if-merge-request-title-run-all-rspec: &if-merge-request-title-run-all-rspec
   if: '$CI_MERGE_REQUEST_LABELS =~ /pipeline:run-all-rspec/'
 
+.if-merge-request-run-decomposed: &if-merge-request-run-decomposed
+  if: '$CI_MERGE_REQUEST_LABELS =~ /pipeline:run-decomposed/'
+
 .if-security-merge-request: &if-security-merge-request
   if: '$CI_PROJECT_NAMESPACE == "gitlab-org/security" && $CI_MERGE_REQUEST_IID'
 
@@ -607,6 +610,11 @@
 ###############
 # Rails rules #
 ###############
+.rails:rules:decomposed-databases:
+  rules:
+    - <<: *if-merge-request-run-decomposed
+      allow_failure: true
+
 .rails:rules:ee-and-foss-migration:
   rules:
     - <<: *if-merge-request-title-run-all-rspec