Iss #161 - Add merge_group webhook support to the webhook callback

A commit status is required for merge queues as separate branches w/
different SHAs are created, which no longer contain the ECA check
status. As all commits in the queue will have been validated, we can
just send a request to create the missing commit status without checks.

src/main/java/org/eclipsefoundation/git/eca/api/models/GithubCommitStatusRequest.java

@@ -15,14 +15,17 @@ import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
 import com.fasterxml.jackson.databind.annotation.JsonPOJOBuilder;
 import com.google.auto.value.AutoValue;
 
+import jakarta.annotation.Nullable;
+
 /**
- * @author martin
+ * @author Martin Lowe
  *
  */
 @AutoValue
 @JsonDeserialize(builder = AutoValue_GithubCommitStatusRequest.Builder.class)
 public abstract class GithubCommitStatusRequest {
     public abstract String getState();
+    @Nullable
     public abstract String getTargetUrl();
     public abstract String getDescription();
     public abstract String getContext();
@@ -35,7 +38,7 @@ public abstract class GithubCommitStatusRequest {
     @JsonPOJOBuilder(withPrefix = "set")
     public abstract static class Builder {
         public abstract Builder setState(String state);
-        public abstract Builder setTargetUrl(String targetUrl);
+        public abstract Builder setTargetUrl(@Nullable String targetUrl);
         public abstract Builder setDescription(String description);
         public abstract Builder setContext(String context);
 

src/main/java/org/eclipsefoundation/git/eca/api/models/GithubWebhookRequest.java

@@ -36,6 +36,9 @@ public abstract class GithubWebhookRequest {
     @Nullable
     public abstract PullRequest getPullRequest();
 
+    @Nullable
+    public abstract MergeGroup getMergeGroup();
+
     /**
      * Generate basic builder with default properties for constructing a webhook request.
      * 
@@ -78,6 +81,8 @@ public abstract class GithubWebhookRequest {
 
         public abstract Builder setPullRequest(@Nullable PullRequest pullRequest);
 
+        public abstract Builder setMergeGroup(@Nullable MergeGroup mergeGroup);
+
         public abstract GithubWebhookRequest build();
     }
 
@@ -150,6 +155,25 @@ public abstract class GithubWebhookRequest {
         }
     }
 
+    @AutoValue
+    @JsonDeserialize(builder = AutoValue_GithubWebhookRequest_MergeGroup.Builder.class)
+    public abstract static class MergeGroup {
+
+        public abstract String getHeadSha();
+
+        public static Builder builder() {
+            return new AutoValue_GithubWebhookRequest_MergeGroup.Builder();
+        }
+
+        @AutoValue.Builder
+        @JsonPOJOBuilder(withPrefix = "set")
+        public abstract static class Builder {
+            public abstract Builder setHeadSha(String headSha);
+
+            public abstract MergeGroup build();
+        }
+    }
+
     @AutoValue
     @JsonDeserialize(builder = AutoValue_GithubWebhookRequest_Installation.Builder.class)
     public abstract static class Installation {

src/main/java/org/eclipsefoundation/git/eca/helper/GithubValidationHelper.java

@@ -60,8 +60,8 @@ import jakarta.ws.rs.ServerErrorException;
 import jakarta.ws.rs.core.MultivaluedMap;
 
 /**
- * This class is used to adapt Github requests to the standard validation workflow in a way that could be reused by both
- * resource calls and scheduled tasks for revalidation.
+ * This class is used to adapt Github requests to the standard validation workflow in a way that could be reused by both resource calls and
+ * scheduled tasks for revalidation.
  */
 @ApplicationScoped
 public class GithubValidationHelper {
@@ -95,16 +95,15 @@ public class GithubValidationHelper {
     GithubAPI ghApi;
 
     /**
-     * Using the wrapper and the passed unique information about a Github validation instance, lookup or create the tracking
-     * request and validate the data.
+     * Using the wrapper and the passed unique information about a Github validation instance, lookup or create the tracking request and
+     * validate the data.
      * 
      * @param wrapper the wrapper for the current request
      * @param org the name of the GH organization
      * @param repoName the slug of the repo that has the PR to be validated
      * @param prNo the PR number for the current request.
      * @param forceRevalidation true if revalidation should be forced when there is no changes, false otherwise.
-     * @return the validated response if it is a valid request, or throws a web exception if there is a problem validating
-     * the request.
+     * @return the validated response if it is a valid request, or throws a web exception if there is a problem validating the request.
      */
     public ValidationResponse validateIncomingRequest(RequestWrapper wrapper, String org, String repoName, Integer prNo,
             boolean forceRevalidation) {
@@ -158,8 +157,8 @@ public class GithubValidationHelper {
     }
 
     /**
-     * Generate a ValidationRequest object based on data pulled from Github, grabbing commits from the noted pull request
-     * using the installation ID for access/authorization.
+     * Generate a ValidationRequest object based on data pulled from Github, grabbing commits from the noted pull request using the
+     * installation ID for access/authorization.
      * 
      * @param installationId the ECA app installation ID for the organization
      * @param repositoryFullName the full name of the repository where the PR resides
@@ -212,13 +211,35 @@ public class GithubValidationHelper {
     }
 
     /**
-     * Process the current request and update the checks state to pending then success or failure. Contains verbose TRACE
-     * logging for more info on the states of the validation for more information
+     * Process the current 'merge_group' request and create a commit status for the HEAD SHA. As commits need to pass branch rules including
+     * the existing ECA check, we don't need to check the commits here.
      * 
-     * @param request information about the request from the GH webhook on what resource requested revalidation. Used to
-     * target the commit status of the resources
-     * @param vr the pseudo request generated from the contextual webhook data. Used to make use of existing validation
-     * logic.
+     * @param request information about the request from the GH webhook on what resource requested revalidation. Used to target the commit
+     * status of the resources
+     */
+    public void sendMergeQueueStatus(GithubWebhookRequest request) {
+        if (request.getMergeGroup() == null) {
+            throw new BadRequestException("Merge group object required in webhook request to send status for merge queue");
+        }
+        // send the success status for the head SHA
+        ghApi
+                .updateStatus(jwtHelper.getGhBearerString(request.getInstallation().getId()), apiVersion,
+                        request.getRepository().getFullName(), request.getMergeGroup().getHeadSha(),
+                        GithubCommitStatusRequest
+                                .builder()
+                                .setDescription("Commits in merge group should be previously validated, auto-passing HEAD commit")
+                                .setState(GithubCommitStatuses.SUCCESS.toString())
+                                .setContext(webhooksConfig.github().context())
+                                .build());
+    }
+
+    /**
+     * Process the current request and update the checks state to pending then success or failure. Contains verbose TRACE logging for more
+     * info on the states of the validation for more information
+     * 
+     * @param request information about the request from the GH webhook on what resource requested revalidation. Used to target the commit
+     * status of the resources
+     * @param vr the pseudo request generated from the contextual webhook data. Used to make use of existing validation logic.
      * @return true if the validation passed, false otherwise.
      */
     public ValidationResponse handleGithubWebhookValidation(GithubWebhookRequest request, ValidationRequest vr, RequestWrapper wrapper) {
@@ -246,8 +267,8 @@ public class GithubValidationHelper {
     }
 
     /**
-     * Shortcut method that will retrieve existing GH tracking info, create new entries if missing, and will update the
-     * state of existing requests as well.
+     * Shortcut method that will retrieve existing GH tracking info, create new entries if missing, and will update the state of existing
+     * requests as well.
      * 
      * @param installationId the installation ID for the ECA app in the given repository
      * @param repositoryFullName the full repository name for the target repo, e.g. eclipse/jetty
@@ -262,8 +283,7 @@ public class GithubValidationHelper {
     }
 
     /**
-     * Checks if the Github tracking is present for the current request, and if missing will generate a new record and save
-     * it.
+     * Checks if the Github tracking is present for the current request, and if missing will generate a new record and save it.
      * 
      * @param tracking the optional tracking entry for the current request
      * @param request the pull request that is being validated

src/main/java/org/eclipsefoundation/git/eca/resource/GithubWebhooksResource.java

@@ -67,9 +67,9 @@ public class GithubWebhooksResource extends CommonResource {
     /**
      * Entry point for processing Github webhook requests. Accepts standard fields as described in the <a href=
      * "https://docs.github.com/developers/webhooks-and-events/webhooks/webhook-events-and-payloads#webhook-payload-object-common-properties">Webhook
-     * properties documentation</a>, as well as the <a href=
-     * "https://docs.github.com/developers/webhooks-and-events/webhooks/webhook-events-and-payloads#pull_request">Pull
-     * Request event type documentation.</a>
+     * properties documentation</a>, as well as the
+     * <a href= "https://docs.github.com/developers/webhooks-and-events/webhooks/webhook-events-and-payloads#pull_request">Pull Request
+     * event type documentation.</a>
      * 
      * @param deliveryId Github provided unique delivery ID
      * @param eventType the type of webhook event that was fired
@@ -79,32 +79,33 @@ public class GithubWebhooksResource extends CommonResource {
     @POST
     public Response processGithubWebhook(@HeaderParam(WebhookHeaders.GITHUB_DELIVERY) String deliveryId,
             @HeaderParam(WebhookHeaders.GITHUB_EVENT) String eventType, GithubWebhookRequest request) {
-        // If event isn't a pr event, drop as we don't process them
-        if (!"pull_request".equalsIgnoreCase(eventType)) {
-            return Response.ok().build();
-        }
-
-        // check that the pull request isn't somehow missing
-        if (request.getPullRequest() == null) {
-            throw new BadRequestException("Pull request event submitted, but pull request information was missing");
-        }
-        PullRequest pr = request.getPullRequest();
-
-        // track the request before we start processing
-        GithubWebhookTracking tracking = validationHelper
-                .retrieveAndUpdateTrackingInformation(wrapper, request.getInstallation().getId(), request.getRepository().getFullName(),
-                        pr);
-
-        // start processing the request
-        LOGGER.trace("Processing PR event for install {} with delivery ID of {}", request.getInstallation().getId(), deliveryId);
-        try {
-            // prepare for validation process by pre-processing into standard format
-            ValidationRequest vr = generateRequest(request, pr);
-            // process the request
-            validationHelper.handleGithubWebhookValidation(request, vr, wrapper);
-        } catch (Exception e) {
-            // set the revalidation flag to reprocess if the initial attempt fails before exiting
-            setRevalidationFlagForTracking(tracking);
+        // If event isn't a pr or merge_group event, drop as we don't process them
+        if ("merge_group".equalsIgnoreCase(eventType)) {
+            // if we're in a merge_group, the HEAD SHA should already be validated, so we don't need to check again
+            validationHelper.sendMergeQueueStatus(request);
+        } else if ("pull_request".equalsIgnoreCase(eventType)) {
+            // check that the pull request isn't somehow missing
+            if (request.getPullRequest() == null) {
+                throw new BadRequestException("Pull request event submitted, but pull request information was missing");
+            }
+            PullRequest pr = request.getPullRequest();
+
+            // track the request before we start processing
+            GithubWebhookTracking tracking = validationHelper
+                    .retrieveAndUpdateTrackingInformation(wrapper, request.getInstallation().getId(), request.getRepository().getFullName(),
+                            pr);
+
+            // start processing the request
+            LOGGER.trace("Processing PR event for install {} with delivery ID of {}", request.getInstallation().getId(), deliveryId);
+            try {
+                // prepare for validation process by pre-processing into standard format
+                ValidationRequest vr = generateRequest(request, pr);
+                // process the request
+                validationHelper.handleGithubWebhookValidation(request, vr, wrapper);
+            } catch (Exception e) {
+                // set the revalidation flag to reprocess if the initial attempt fails before exiting
+                setRevalidationFlagForTracking(tracking);
+            }
         }
 
         return Response.ok().build();
@@ -118,8 +119,8 @@ public class GithubWebhooksResource extends CommonResource {
     }
 
     /**
-     * Endpoint for triggering revalidation of a past request. Uses the fingerprint hash to lookup the unique request and to
-     * rebuild the request and revalidate if it exists.
+     * Endpoint for triggering revalidation of a past request. Uses the fingerprint hash to lookup the unique request and to rebuild the
+     * request and revalidate if it exists.
      * 
      * @param fullRepoName the full repository name for the target repo, e.g. eclipse/jetty
      * @param installationId the installation ID for the ECA app in the given repository