Add check for Postgres revision

.github/workflows/build_and_test.yml

@@ -174,6 +174,26 @@ jobs:
           submodules: true
           fetch-depth: 1
 
+      - name: Check Postgres submodules revision
+        run: |
+          # This is a temporary solution to ensure that the Postgres submodules revision is correct (i.e. the updated intentionally).
+          # Eventually it will be replaced by a regression test https://github.com/neondatabase/neon/pull/4603
+
+          FAILED=false
+          for postgres in postgres-v14 postgres-v15; do
+            expected=$(cat vendor/revisions.json | jq --raw-output '."'"${postgres}"'"')
+            actual=$(git rev-parse "HEAD:vendor/${postgres}")
+            if [ "${expected}" != "${actual}" ]; then
+              echo >&2 "Expected ${postgres} rev to be at '${expected}', but it is at '${actual}'"
+              FAILED=true
+            fi
+          done
+
+          if [ "${FAILED}" = "true" ]; then
+            echo >&2 "Please update vendors/revisions.json if these changes are intentional"
+            exit 1
+          fi
+
       - name: Set pg 14 revision for caching
         id: pg_v14_rev
         run: echo pg_rev=$(git rev-parse HEAD:vendor/postgres-v14) >> $GITHUB_OUTPUT

vendor/revisions.json

@@ -0,0 +1,4 @@
+{
+    "postgres-v15": "1984832c740a7fa0e468bb720f40c525b652835d",
+    "postgres-v14": "1144aee1661c79eec65e784a8dad8bd450d9df79"
+}