Optimize pipelines for GitHub status reporting

GitHub status checks usually only report in the status check
area -- let's try to optimize for that. We don't have much control
with the current GitHub driver on what shows up there, except
pipeline names and a link.

Separate Gerrit from GitHub pipelines, and rename GitHub pipelines
so that they match the test being run. Avoid comments (at least for
now). Link to the Zuul build results, filtered by the appropriate
pipeline name.

Change-Id: Id9f8848941320b41be86ac62efcf768b33c526db

zuul.d/pipelines.yaml

@@ -2,9 +2,9 @@
 # Contains definitions of pipelines
 
 - pipeline:
-    name: check
+    name: gerrit-check
     description: |
-      Newly uploaded patchsets enter this pipeline to receive an
+      Newly uploaded Gerrit patchsets enter this pipeline to receive an
       initial +/-1 Verified vote.
     success-message: Build succeeded (check pipeline).
     failure-message: |
@@ -22,40 +22,21 @@
         - event: change-restored
         - event: comment-added
           comment: (?i)^(Patch Set [0-9]+:)?( [\w\\+-]*)*(\n\n)?\s*recheck
-      github:
-        - event: pull_request
-          action:
-            - opened
-            - changed
-            - reopened
-        - event: pull_request
-          action: comment
-          comment: (?i)^\s*recheck\s*$
-    start:
-      github:
-        status: pending
-        comment: false
     success:
       gerrit:
         # Note that gerrit keywords are case-sensitive.
         Verified: 1
-      github:
-        status: 'success'
       mysql:
     failure:
       gerrit:
         Verified: -1
-      github:
-        status: 'failure'
       mysql:
 
 - pipeline:
-    name: gate
+    name: gerrit-gate
     description: |
-      Changes that have been approved by core reviewers are enqueued
-      in order in this pipeline, and if they pass tests, will be
-      merged. For documentation on how gating with Zuul works, please see
-      https://zuul-ci.org/docs/zuul/user/gating.html
+      Gerrit changes that have been approved by core reviewers are enqueued
+      in order in this pipeline, and if they pass tests, will be merged.
     success-message: Build succeeded (gate pipeline).
     failure-message: |
       Build failed (gate pipeline).  For information on how to proceed, see
@@ -90,9 +71,9 @@
     window-increase-factor: 2
 
 - pipeline:
-    name: pr-check
+    name: SoB-check
     description: |
-      New PRs and modified PRs enter this pipeline to be tested.
+      New and modified GitHub PRs enter this pipeline to be tested.
     success-message: DCO (Signed-Off-By) is present.
     failure-message: Missing DCO (Signed-Off-By) in commit message.
     manager: independent
@@ -114,19 +95,25 @@
     success:
       github:
         status: 'success'
+        comment: false
+        status-url: |
+          https://zuul.opendev.org/t/kata-containers/builds?pipeline=SoB-check
       mysql:
     failure:
       github:
         status: 'failure'
+        comment: false
+        status-url: |
+          https://zuul.opendev.org/t/kata-containers/builds?pipeline=SoB-check
       mysql:
     # Don't report merge-failures to github
     merge-failure:
       mysql:
 
 - pipeline:
-    name: pr-status
+    name: WIP-check
     description: |
-      New PRs, modified PRs and re-labelled PRs enter this pipeline to
+      New, modified and re-labelled GitHub PRs enter this pipeline to
       have their merge-readiness status reevaluated.
     success-message: PR is ready to merge.
     failure-message: PR merging is blocked by a WIP label or title keyword.
@@ -148,10 +135,16 @@
     success:
       github:
         status: 'success'
+        comment: false
+        status-url: |
+          https://zuul.opendev.org/t/kata-containers/builds?pipeline=WIP-check
       mysql:
     failure:
       github:
         status: 'failure'
+        comment: false
+        status-url: |
+          https://zuul.opendev.org/t/kata-containers/builds?pipeline=WIP-check
       mysql:
     # Don't report merge-failures to github
     merge-failure: