Re-enable postgres migration tests (#28270)

* Utilize separate image for migration tests
* Re-enable migration tests
* Apply Ibrahim's suggestion
* Apply Saturn's suggestion

.github/workflows/migration.yml

@@ -33,17 +33,16 @@ jobs:
           docker restart ${COMPOSE_PROJECT_NAME}-mysql-1 && sleep 10
       - name: Build test image
         env:
-          BUILD_IMAGE: mattermostdevelopment/mattermost-build-server:${{ steps.go.outputs.GO_VERSION }}
+          BUILD_IMAGE: golang:${{ steps.go.outputs.GO_VERSION }}-bookworm
+          PGLOADER_IMAGE: mattermost/mattermost-pgloader:v3.6.9
         run: |
-          echo -e "FROM $BUILD_IMAGE\n\nRUN apt update && \
-            apt remove -y pgloader && \
-            apt install -y sbcl unzip libsqlite3-dev make curl gawk freetds-dev libzip-dev && \
-            git clone https://github.com/dimitri/pgloader.git && \
-            cd pgloader && \
-            git checkout \$(git tag --list --sort=-v:refname "v*" | head -n1) && \
-            make && \
-            mv build/bin/pgloader /bin" >> dockerfile_tmp
-          docker build -t $TEST_IMAGE - < dockerfile_tmp
+          docker build -t $TEST_IMAGE - <<EOF
+          FROM $PGLOADER_IMAGE AS pgloader
+          FROM $BUILD_IMAGE
+          COPY --from=pgloader /usr/bin/pgloader /usr/bin/pgloader
+          EOF
+          # Print out installed pgloader version
+          docker run --rm $TEST_IMAGE pgloader --version
       - name: Generate test-data
         run: |
           docker run --net ${COMPOSE_PROJECT_NAME}_mm-test \

.github/workflows/server-ci-template.yml

@@ -346,8 +346,7 @@ jobs:
           name: server-build-artifact
           path: server/build/
           retention-days: 2
-  ### Disabled until fixed
-  #test-migration:
-  #  name: MySQL to PostgreSQL Migration
-  #  uses: ./.github/workflows/migration.yml
-  #  secrets: inherit
+  test-migration:
+    name: MySQL to PostgreSQL Migration
+    uses: ./.github/workflows/migration.yml
+    secrets: inherit