Add support for override-checkout, deprecate override-branch

We want to support jobs specifying that they check out a tag
rather than merely a branch.  This accidentally worked in Zuul v2
with zuul-cloner, and some jobs have come to rely on the behavior.
There's no reason not to support it, so let's do so.

However, for clarity, change the name of the option to
"override-checkout".  This is intended to be intuitive (anything
you can tell git to 'checkout' you can put here), while avoiding
the suggestion that only branches or tags may be checked out.

The old form, "override-branch" is deprecated and will be removed.

Change-Id: Icc2907e72596626e96d2dc9f6ab1c3026f4085ab

12 files changed, 121 insertions, 30 deletions

diff --git a/doc/source/user/config.rst b/doc/source/user/config.rst
index 001993288..fa874a9df 100644
--- a/doc/source/user/config.rst
+++ b/doc/source/user/config.rst
@@ -744,7 +744,7 @@ Here is an example of two job definitions:
       If a job has an empty or no nodeset definition, it will still
       run and may be able to perform actions on the Zuul executor.
 
-   .. attr:: override-branch
+   .. attr:: override-checkout
 
       When Zuul runs jobs for a proposed change, it normally checks
       out the branch associated with that change on every project
@@ -752,13 +752,13 @@ Here is an example of two job definitions:
       branch tip or tag), then that ref is normally checked out.  This
       attribute is used to override that behavior and indicate that
       this job should, regardless of the branch for the queue item,
-      use the indicated branch instead.  This can be used, for
-      example, to run a previous version of the software (from a
-      stable maintenance branch) under test even if the change being
-      tested applies to a different branch (this is only likely to be
-      useful if there is some cross-branch interaction with some
+      use the indicated ref (i.e., branch or tag) instead.  This can
+      be used, for example, to run a previous version of the software
+      (from a stable maintenance branch) under test even if the change
+      being tested applies to a different branch (this is only likely
+      to be useful if there is some cross-branch interaction with some
       component of the system being tested).  See also the
-      project-specific :attr:`job.required-projects.override-branch`
+      project-specific :attr:`job.required-projects.override-checkout`
       attribute to apply this behavior to a subset of a job's
       projects.
 
@@ -915,7 +915,7 @@ Here is an example of two job definitions:
 
          The name of the required project.
 
-      .. attr:: override-branch
+      .. attr:: override-checkout
 
          When Zuul runs jobs for a proposed change, it normally checks
          out the branch associated with that change on every project
@@ -923,9 +923,10 @@ Here is an example of two job definitions:
          branch tip or tag), then that ref is normally checked out.
          This attribute is used to override that behavior and indicate
          that this job should, regardless of the branch for the queue
-         item, use the indicated branch instead, for only this
-         project.  See also the :attr:`job.override-branch` attribute
-         to apply the same behavior to all projects in a job.
+         item, use the indicated ref (i.e., branch or tag) instead,
+         for only this project.  See also the
+         :attr:`job.override-checkout` attribute to apply the same
+         behavior to all projects in a job.
 
    .. attr:: vars
 
diff --git a/tests/fixtures/layouts/repo-checkout-no-timer-override.yaml b/tests/fixtures/layouts/repo-checkout-no-timer-override.yaml
index ca4929205..89d2b93e2 100644
--- a/tests/fixtures/layouts/repo-checkout-no-timer-override.yaml
+++ b/tests/fixtures/layouts/repo-checkout-no-timer-override.yaml
@@ -15,7 +15,7 @@
 - job:
     name: integration
     branches: master
-    override-branch: stable/havana
+    override-checkout: stable/havana
     required-projects:
       - org/project1
     run: playbooks/integration.yaml
diff --git a/tests/fixtures/layouts/repo-checkout-no-timer.yaml b/tests/fixtures/layouts/repo-checkout-no-timer.yaml
index 6b8880116..037489739 100644
--- a/tests/fixtures/layouts/repo-checkout-no-timer.yaml
+++ b/tests/fixtures/layouts/repo-checkout-no-timer.yaml
@@ -14,7 +14,7 @@
 
 - job:
     name: integration
-    override-branch: stable/havana
+    override-checkout: stable/havana
     required-projects:
       - org/project1
     run: playbooks/integration.yaml
diff --git a/tests/fixtures/layouts/repo-checkout-six-project.yaml b/tests/fixtures/layouts/repo-checkout-six-project.yaml
index 607961269..48786654b 100644
--- a/tests/fixtures/layouts/repo-checkout-six-project.yaml
+++ b/tests/fixtures/layouts/repo-checkout-six-project.yaml
@@ -44,7 +44,7 @@
       - org/project2
       - org/project3
       - name: org/project4
-        override-branch: master
+        override-checkout: master
       - org/project5
       - org/project6
     run: playbooks/integration.yaml
diff --git a/tests/fixtures/layouts/repo-checkout-tag.yaml b/tests/fixtures/layouts/repo-checkout-tag.yaml
new file mode 100644
index 000000000..3f1af1ceb
--- /dev/null
+++ b/tests/fixtures/layouts/repo-checkout-tag.yaml
@@ -0,0 +1,36 @@
+- pipeline:
+    name: check
+    manager: independent
+    trigger:
+      gerrit:
+        - event: patchset-created
+    success:
+      gerrit:
+        Verified: 1
+    failure:
+      gerrit:
+        Verified: -1
+
+- job:
+    name: base
+    parent: null
+
+- job:
+    name: integration
+    required-projects:
+      - org/project1
+      - name: org/project2
+        override-checkout: test-tag
+    run: playbooks/integration.yaml
+
+- project:
+    name: org/project1
+    check:
+      jobs:
+        - integration
+
+- project:
+    name: org/project2
+    check:
+      jobs:
+        - integration
diff --git a/tests/fixtures/layouts/repo-checkout-timer-override.yaml b/tests/fixtures/layouts/repo-checkout-timer-override.yaml
index af5bd3c45..4aacfee53 100644
--- a/tests/fixtures/layouts/repo-checkout-timer-override.yaml
+++ b/tests/fixtures/layouts/repo-checkout-timer-override.yaml
@@ -13,7 +13,7 @@
 - job:
     name: integration
     branches: master
-    override-branch: stable/havana
+    override-checkout: stable/havana
     required-projects:
       - org/project1
     run: playbooks/integration.yaml
diff --git a/tests/unit/test_executor.py b/tests/unit/test_executor.py
index f051ec446..5d276636d 100755
--- a/tests/unit/test_executor.py
+++ b/tests/unit/test_executor.py
@@ -378,6 +378,32 @@ class TestExecutorRepos(ZuulTestCase):
 
         self.assertBuildStates(states, projects)
 
+    @simple_layout('layouts/repo-checkout-tag.yaml')
+    def test_tag_checkout(self):
+        self.executor_server.hold_jobs_in_build = True
+        p1 = "review.example.com/org/project1"
+        p2 = "review.example.com/org/project2"
+        projects = [p1, p2]
+        upstream = self.getUpstreamRepos(projects)
+
+        self.create_branch('org/project2', 'stable/havana')
+        files = {'README': 'tagged readme'}
+        self.addCommitToRepo('org/project2', 'tagged commit',
+                             files, branch='stable/havana', tag='test-tag')
+
+        A = self.fake_gerrit.addFakeChange('org/project1', 'master', 'A')
+        self.fake_gerrit.addEvent(A.getPatchsetCreatedEvent(1))
+        self.waitUntilSettled()
+
+        states = [
+            {p1: dict(present=[A], branch='master'),
+             p2: dict(commit=str(upstream[p2].commit('test-tag')),
+                      absent=[A]),
+             },
+        ]
+
+        self.assertBuildStates(states, projects)
+
 
 class TestAnsibleJob(ZuulTestCase):
     tenant_config_file = 'config/ansible/main.yaml'
diff --git a/zuul/configloader.py b/zuul/configloader.py
index 6737c7b2d..99f10f6b3 100644
--- a/zuul/configloader.py
+++ b/zuul/configloader.py
@@ -417,7 +417,8 @@ class JobParser(object):
     role = vs.Any(zuul_role, galaxy_role)
 
     job_project = {vs.Required('name'): str,
-                   'override-branch': str}
+                   'override-branch': str,
+                   'override-checkout': str}
 
     secret = {vs.Required('name'): str,
               vs.Required('secret'): str}
@@ -452,6 +453,7 @@ class JobParser(object):
                       'dependencies': to_list(str),
                       'allowed-projects': to_list(str),
                       'override-branch': str,
+                      'override-checkout': str,
                       'description': str,
                       'post-review': bool}
 
@@ -474,6 +476,7 @@ class JobParser(object):
         'failure-url',
         'success-url',
         'override-branch',
+        'override-checkout',
     ]
 
     @staticmethod
@@ -633,14 +636,18 @@ class JobParser(object):
                 if isinstance(project, dict):
                     project_name = project['name']
                     project_override_branch = project.get('override-branch')
+                    project_override_checkout = project.get(
+                        'override-checkout')
                 else:
                     project_name = project
                     project_override_branch = None
+                    project_override_checkout = None
                 (trusted, project) = tenant.getProject(project_name)
                 if project is None:
                     raise Exception("Unknown project %s" % (project_name,))
                 job_project = model.JobProject(project_name,
-                                               project_override_branch)
+                                               project_override_branch,
+                                               project_override_checkout)
                 new_projects[project_name] = job_project
             job.required_projects = new_projects
 
diff --git a/zuul/executor/client.py b/zuul/executor/client.py
index cfd652a38..fba472f56 100644
--- a/zuul/executor/client.py
+++ b/zuul/executor/client.py
@@ -196,6 +196,7 @@ class ExecutorClient(object):
         else:
             params['branch'] = None
         params['override_branch'] = job.override_branch
+        params['override_checkout'] = job.override_checkout
         params['repo_state'] = item.current_build_set.repo_state
 
         if job.name != 'noop':
@@ -216,7 +217,8 @@ class ExecutorClient(object):
         projects = set()
         required_projects = set()
 
-        def make_project_dict(project, override_branch=None):
+        def make_project_dict(project, override_branch=None,
+                              override_checkout=None):
             project_config = item.layout.project_configs.get(
                 project.canonical_name, None)
             if project_config:
@@ -228,6 +230,7 @@ class ExecutorClient(object):
                         name=project.name,
                         canonical_name=project.canonical_name,
                         override_branch=override_branch,
+                        override_checkout=override_checkout,
                         default_branch=project_default_branch)
 
         if job.required_projects:
@@ -239,7 +242,8 @@ class ExecutorClient(object):
                                     (job_project.project_name,))
                 params['projects'].append(
                     make_project_dict(project,
-                                      job_project.override_branch))
+                                      job_project.override_branch,
+                                      job_project.override_checkout))
                 projects.add(project)
                 required_projects.add(project)
         for change in dependent_changes:
diff --git a/zuul/executor/server.py b/zuul/executor/server.py
index d72d1eec3..7bcd71c67 100644
--- a/zuul/executor/server.py
+++ b/zuul/executor/server.py
@@ -681,7 +681,9 @@ class AnsibleJob(object):
                                 ref,
                                 args['branch'],
                                 args['override_branch'],
+                                args['override_checkout'],
                                 project['override_branch'],
+                                project['override_checkout'],
                                 project['default_branch'])
 
         # Delete the origin remote from each repo we set up since
@@ -757,22 +759,32 @@ class AnsibleJob(object):
         return True
 
     def checkoutBranch(self, repo, project_name, ref, zuul_branch,
-                       job_branch, project_override_branch,
+                       job_override_branch, job_override_checkout,
+                       project_override_branch, project_override_checkout,
                        project_default_branch):
         branches = repo.getBranches()
+        refs = [r.name for r in repo.getRefs()]
         if project_override_branch in branches:
             self.log.info("Checking out %s project override branch %s",
                           project_name, project_override_branch)
-            repo.checkoutLocalBranch(project_override_branch)
-        elif job_branch in branches:
-            self.log.info("Checking out %s job branch %s",
-                          project_name, job_branch)
-            repo.checkoutLocalBranch(job_branch)
+            repo.checkout(project_override_branch)
+        if project_override_checkout in refs:
+            self.log.info("Checking out %s project override ref %s",
+                          project_name, project_override_checkout)
+            repo.checkout(project_override_checkout)
+        elif job_override_branch in branches:
+            self.log.info("Checking out %s job override branch %s",
+                          project_name, job_override_branch)
+            repo.checkout(job_override_branch)
+        elif job_override_checkout in refs:
+            self.log.info("Checking out %s job override ref %s",
+                          project_name, job_override_checkout)
+            repo.checkout(job_override_checkout)
         elif ref and ref.startswith('refs/heads/'):
             b = ref[len('refs/heads/'):]
             self.log.info("Checking out %s branch ref %s",
                           project_name, b)
-            repo.checkoutLocalBranch(b)
+            repo.checkout(b)
         elif ref and ref.startswith('refs/tags/'):
             t = ref[len('refs/tags/'):]
             self.log.info("Checking out %s tag ref %s",
@@ -781,11 +793,11 @@ class AnsibleJob(object):
         elif zuul_branch and zuul_branch in branches:
             self.log.info("Checking out %s zuul branch %s",
                           project_name, zuul_branch)
-            repo.checkoutLocalBranch(zuul_branch)
+            repo.checkout(zuul_branch)
         elif project_default_branch in branches:
             self.log.info("Checking out %s project default branch %s",
                           project_name, project_default_branch)
-            repo.checkoutLocalBranch(project_default_branch)
+            repo.checkout(project_default_branch)
         else:
             raise ExecutorError("Project %s does not have the "
                                 "default branch %s" %
diff --git a/zuul/merger/merger.py b/zuul/merger/merger.py
index 035d1d007..06ec4b2b9 100644
--- a/zuul/merger/merger.py
+++ b/zuul/merger/merger.py
@@ -176,6 +176,8 @@ class Repo(object):
         return branch in origin.refs
 
     def getBranches(self):
+        # TODO(jeblair): deprecate with override-branch; replaced by
+        # getRefs().
         repo = self.createRepoObject()
         return [x.name for x in repo.heads]
 
@@ -386,7 +388,7 @@ class Merger(object):
         self.log.info("Checking out %s/%s branch %s",
                       connection_name, project_name, branch)
         repo = self.getRepo(connection_name, project_name)
-        repo.checkoutLocalBranch(branch)
+        repo.checkout(branch)
 
     def _saveRepoState(self, connection_name, project_name, repo,
                        repo_state, recent):
diff --git a/zuul/model.py b/zuul/model.py
index cf63f6400..b027c534f 100644
--- a/zuul/model.py
+++ b/zuul/model.py
@@ -845,6 +845,7 @@ class Job(object):
             required_projects={},
             allowed_projects=None,
             override_branch=None,
+            override_checkout=None,
             post_review=None,
         )
 
@@ -1073,9 +1074,11 @@ class Job(object):
 class JobProject(object):
     """ A reference to a project from a job. """
 
-    def __init__(self, project_name, override_branch=None):
+    def __init__(self, project_name, override_branch=None,
+                 override_checkout=None):
         self.project_name = project_name
         self.override_branch = override_branch
+        self.override_checkout = override_checkout
 
 
 class JobList(object):