Update docs and add pull request template

.circleci/config.yml

@@ -373,9 +373,11 @@ jobs:
         run:
           name: Early return if this build is running on upstream
           command: |
-            if [ "$CIRCLE_PR_NUMBER" ]; then
-              echo "Build on upstream"
+            if [ -n "$CIRCLE_PR_NUMBER" ]; then
+              echo "Build on fork"
+            else
               circleci step halt
+              echo "Build on upstream"
             fi
       - checkout
       - run:
@@ -400,10 +402,7 @@ workflows:
   version: 2
   build:
     jobs: &build_jobs
-      - manual-trigger-required-for-fork:
-          filters:
-            branches:
-              only: /^pull\/.*$/
+      - manual-trigger-required-for-fork
       - build:
           context: data-eng-circleci-tests
       - verify-format-sql

.github/pull_request_template.md

@@ -0,0 +1,6 @@
+Checklist for reviewer:
+
+- [ ] Commits should reference a bug or github issue, if relevant (if a bug is referenced, the pull request should include the bug number in the title)
+- [ ] If the PR comes from a fork, trigger integration CI tests by running the [Push to upstream workflow](https://github.com/mozilla/bigquery-etl/actions/workflows/push-to-upstream.yml) and provide the `<username>:<branch>` of the fork as parameter. The parameter will also show up
+in the logs of the `manual-trigger-required-for-fork` CI task together with more detailed instructions.
+- [ ] If adding a new field to a query, ensure that the schema and dependent downstream schemas have been updated

README.md

@@ -446,6 +446,14 @@ pip-compile --generate-hashes requirements.in
 deactivate
 ```
 
+When opening a pull-request to merge a fork, the `manual-trigger-required-for-fork` CI task will
+fail and some integration test tasks will be skipped. A user with repository write permissions
+will have to run the [Push to upstream workflow](https://github.com/mozilla/bigquery-etl/actions/workflows/push-to-upstream.yml)
+and provide the `<username>:<branch>` of the fork as parameter. The parameter will also show up
+in the logs of the `manual-trigger-required-for-fork` CI task together with more detailed instructions.
+Once the workflow has been executed, the CI tasks, including the integration tests, of the PR will be
+executed.
+
 Tests
 ---