feat(ci): add is_forked_pull_request parameter to CircleCI configuration (#755)

* feat(ci): add is_forked_pull_request parameter to CircleCI configuration

* fix(ci): remove unnecessary blank line in CircleCI configuration

* feat(ci): add support for forked pull requests in configuration diff workflows

* docs: clarify CircleCI checks requirements for pull requests

* nit

* docs: update CONTRIBUTING.md to remove redundant information about CircleCI checks

Author: raffaele-oplabs

.circleci/artifact_upload_config.yml

@@ -10,6 +10,9 @@ parameters:
   chain:
     type: string
     default: "__required__"
+  is_forked_pull_request:
+    type: boolean
+    default: false
 
 commands:
   gcp-oidc-authenticate:

.circleci/config.yml

@@ -35,8 +35,12 @@ jobs:
       - run:
           name: Generate Configuration
           command: |
-
-            echo "{}" > .circleci/parameters.json
+            if [[ $CIRCLE_BRANCH == pull/* ]]; then
+                is_forked_pull_request=true
+            else
+                is_forked_pull_request=false
+            fi
+            echo "{\"is_forked_pull_request\":$is_forked_pull_request}" > .circleci/parameters.json
 
             if [ "<< pipeline.parameters.chain >>" = "__required__" ]; then
               # This will always be selected unless the user chooses to interact with the configuration by setting a non default value in the chain parameter. This would happens if the user launch the pipeline with a specific chain value via either curl or the CircleCI GUI.

.circleci/main_config.yml

@@ -10,6 +10,9 @@ parameters:
   chain:
     type: string
     default: "__required__"
+  is_forked_pull_request:
+    type: boolean
+    default: false
 
 commands:
   notify-failures-on-main:
@@ -407,6 +410,8 @@ workflows:
       - check-codegen
 
   compute-config-diff-and-report:
+    when:
+      not: << pipeline.parameters.is_forked_pull_request >>
     jobs:
       - compute-config-diff:
           name: compute-genesis-diff
@@ -430,3 +435,17 @@ workflows:
           message: "Detected nonzero diff in rollup config. This PR modifies the configuration of at least one chain in the registry, which may or may not have been intended"
           context: circleci-superchain-registry
           requires: [compute-rollup-config-diff]
+
+  compute-config-diff-only:
+    when: << pipeline.parameters.is_forked_pull_request >>
+    jobs:
+      - compute-config-diff:
+          name: compute-genesis-diff
+          command: "generate-genesis"
+          save_to: "GENESIS"
+          directory: "generate-genesis"
+      - compute-config-diff:
+          name: compute-rollup-config-diff
+          command: "generate-rollup-config"
+          save_to: "ROLLUP"
+          directory: "generate-rollup-config"

CONTRIBUTING.md

@@ -180,10 +180,13 @@ See [Superchain Upgrades] OP Stack specifications.
 [Superchain Upgrades]: https://specs.optimism.io/protocol/superchain-upgrades.html
 
 ## CircleCI Checks
-
-The following CircleCI checks are required and must pass before submitting a pull request:
+The following CircleCI checks are not mandatory for submitting a pull request, but they should be reviewed:
 
 - `ci/circleci: compute-genesis-diff`
 - `ci/circleci: compute-rollup-config-diff`
 
-If these checks did not run, they can be triggered manually from CircleCI without any parameters or by submitting and empty commit after the PR has being created.
+These jobs will run at every commit in every branch.
+
+For pull requests from forks, these checks will not appear directly in the PR comments, but **the jobs will still run** and their results can be viewed in the diffs.
+
+Please note that while these jobs are **not blocking**, they must pass to ensure the accuracy of the changes.