diff --git a/dev/zuul/layout.yaml b/dev/zuul/layout.yaml
index a913d9ea8d..909a82ddef 100644
--- a/dev/zuul/layout.yaml
+++ b/dev/zuul/layout.yaml
@@ -4,15 +4,26 @@ includes:
 pipelines:
   - name: check
     description: Newly uploaded patchsets enter this pipeline to receive an initial +/-1 Verified vote from Jenkins.
+    success-message: Build succeeded (check pipeline).
+    failure-message: Build failed (check pipeline).  For information on how to proceed, see http://docs.openstack.org/infra/manual/developers.html#automated-testing
     manager: IndependentPipelineManager
-    failure-message: Build failed.  For information on how to proceed, see http://docs.openstack.org/infra/manual/developers.html#automated-testing
+    source: gerrit
     precedence: low
+    require:
+      open: True
+      current-patchset: True
     trigger:
       gerrit:
         - event: patchset-created
         - event: change-restored
         - event: comment-added
-          comment_filter: (?i)^(Patch Set [0-9]+:\n\n)?\s*(recheck|reverify)
+          comment: (?i)^(Patch Set [0-9]+:)?( [\w\\+-]*)*(\n\n)?\s*(recheck|reverify)
+        - event: comment-added
+           require-approval:
+            - verified: [-1, -2]
+              username: jenkins
+          approval:
+            - workflow: 1
     success:
       gerrit:
         verified: 1
@@ -22,16 +33,27 @@ pipelines:
 
   - name: gate
     description: Changes that have been approved by core developers are enqueued in order in this pipeline, and if they pass tests in Jenkins, will be merged.
-    failure-message: Build failed.  For information on how to proceed, see http://docs.openstack.org/infra/manual/developers.html#automated-testing
+    success-message: Build succeeded (gate pipeline).
+    failure-message: Build failed (gate pipeline).  For information on how to proceed, see http://docs.openstack.org/infra/manual/developers.html#automated-testing
     manager: DependentPipelineManager
+    source: gerrit
     precedence: low
+    require:
+      open: True
+      current-patchset: True
+      approval:
+        - verified: [1, 2]
+          username: jenkins
+        - workflow: 1
     trigger:
       gerrit:
         - event: comment-added
           approval:
             - workflow: 1
         - event: comment-added
-          comment_filter: (?i)^(Patch Set [0-9]+:\n\n)?\s*(recheck|reverify)
+          approval:
+            - verified: 1
+          username: jenkins
     start:
       gerrit:
         verified: 0
@@ -48,6 +70,7 @@ pipelines:
   - name: post
     description: This pipeline runs jobs that operate after each change is merged.
     manager: IndependentPipelineManager
+    source: gerrit
     precedence: low
     trigger:
       gerrit:
@@ -57,6 +80,7 @@ pipelines:
   - name: tag
     description: This pipeline runs jobs in response to any tag event.
     manager: IndependentPipelineManager
+    source: gerrit
     precedence: high
     trigger:
       gerrit:
@@ -66,54 +90,78 @@ pipelines:
   - name: pre-release
     description: This pipeline runs jobs on projects in response to pre-release tags.
     manager: IndependentPipelineManager
+    source: gerrit
     precedence: high
     trigger:
       gerrit:
         - event: ref-updated
-          ref: ^refs/tags/([0-9]+\.)+[0-9]*(alpha|beta|candidate|rc|a|b|c|r|g)[0-9]*$
+          ref: ^refs/tags/[0-9]+(\.[0-9]+)*(a|b|rc)[0-9]+$
 
   - name: release
     description: When a commit is tagged as a release, this pipeline runs jobs that publish archives and documentation.
     manager: IndependentPipelineManager
+    source: gerrit
     precedence: high
     trigger:
       gerrit:
         - event: ref-updated
-          ref: ^refs/tags/([0-9]+\.)+[0-9]+$
+          ref: ^refs/tags/[0-9]+(\.[0-9]+)*$
 
   - name: silent
     description: This pipeline is used for silently testing new jobs.
     manager: IndependentPipelineManager
+    source: gerrit
     precedence: low
     trigger:
       gerrit:
         - event: patchset-created
         - event: comment-added
-          comment_filter: (?i)^(Patch Set [0-9]+:\n\n)?\s*(recheck|reverify)
+          comment: (?i)^(Patch Set [0-9]+:)?( [\w\\+-]*)*(\n\n)?\s*(recheck|reverify)
 
   - name: experimental
     description: On-demand pipeline for requesting a run against a set of jobs that are not yet gating. Leave review comment of "check experimental" to run jobs in this pipeline.
+    success-message: Build succeeded (experimental pipeline).
+    failure-message: Build failed (experimental pipeline).
     manager: IndependentPipelineManager
+    source: gerrit
     precedence: low
     trigger:
       gerrit:
         - event: comment-added
-          comment_filter: (?i)^(Patch Set [0-9]+:\n\n)?\s*check experimental\s*$
+          comment: (?i)^(Patch Set [0-9]+:)?( [\w\\+-]*)*(\n\n)?\s*check experimental\s*$
     success:
-      gerrit:
-        force-message: true
+      gerrit: {}
     failure:
-      gerrit:
-        force-message: true
+      gerrit: {}
 
   - name: periodic
     description: Jobs in this queue are triggered on a timer.
     manager: IndependentPipelineManager
+    source: gerrit
     precedence: low
     trigger:
       timer:
         - time: '0 6 * * *'
 
+  - name: merge-check
+    description: >
+      Each time a change merges, this pipeline verifies that all open changes
+      on the same project are still mergeable.
+    failure-message: Build failed (merge-check pipeline).
+    manager: IndependentPipelineManager
+    source: gerrit
+    precedence: low
+    require:
+      approval:
+        - verified: [1, 2]
+          username: jenkins
+    trigger:
+      zuul:
+        - event: project-change-merged
+    merge-failure:
+      gerrit:
+        verified: -1
+
 jobs:
   - name: ^.*$
     parameter-function: set_log_url
@@ -140,6 +188,8 @@ projects:
       - noop
     experimental:
       - noop
+    merge-check:
+      - noop
 
   - name: gtest-org/gtest2
     periodic: