Buildbot: build automatically when git commits are made

But don't package and upload them, that only happens nightly still.
There will be one build per set of commits that arrives within 120s
of each other.

The idea behind this is that it will help us more easily find which
commits break the build or tests.

Differential Revision: https://developer.blender.org/D8438

master.cfg

@@ -34,6 +34,8 @@ from buildbot.process.factory import BuildFactory
 from buildbot.plugins import steps, util
 from buildbot.config import BuilderConfig
 from buildbot.schedulers import timed, forcesched
+from buildbot.schedulers.basic import SingleBranchScheduler
+from buildbot.schedulers.filter import ChangeFilter
 from buildbot.changes.gitpoller import GitPoller
 from buildbot.changes.svnpoller import SVNPoller
 from buildbot.worker import Worker
@@ -81,8 +83,9 @@ c['protocols'] = {
 ################################################################################
 # CHANGE SOURCES
 
-c['change_source'] = GitPoller('git://git.blender.org/blender.git',
-                               pollinterval=1200)
+c['change_source'] = GitPoller(repourl='git://git.blender.org/blender.git',
+                               pollinterval=120,
+                               project='blender')
 
 ################################################################################
 # CODEBASES
@@ -150,8 +153,7 @@ def schedule_force_build(name, branch):
                 name='project',
                 default='',
                 hide=True)),
-        ],
-        properties=[]))
+        ]))
 
 
 def schedule_nightly_build(name, branch, hour, minute=0):
@@ -170,6 +172,23 @@ def schedule_nightly_build(name, branch, hour, minute=0):
         minute=minute))
 
 
+def schedule_change_build(name, branch):
+    """
+    Creates scheduler for building on changes.
+    This will not package and upload the build.
+    """
+    scheduler_name = f'change_{name} {branch}'
+    c['schedulers'].append(SingleBranchScheduler(
+        name=scheduler_name,
+        codebases={
+            'blender': {'repository': '',
+                        'branch': branch}},
+        builderNames=[name],
+        treeStableTimer=120,
+        change_filter=ChangeFilter(project=['blender'], branch=branch),
+        properties={'skip_upload': True, 'skip_codesign': True}))
+
+
 ################################################################################
 # BUILDERS
 #
@@ -201,6 +220,7 @@ def add_builder(c, name, platforms, factory, branch='', hour=3, minute=0):
 
             if branch != '':
                 schedule_nightly_build(builder_name, branch, hour, minute)
+                schedule_change_build(builder_name, branch)
             schedule_force_build(builder_name, branch)
 
 
@@ -226,6 +246,9 @@ def git_step(branch=''):
 
 # Generic builder.
 
+def do_upload(step):
+    return not step.hasProperty('skip_upload')
+
 @util.renderer
 def script_command(props, script, id, branch):
     # NOTE: On Windows never includes major version in the executable name,
@@ -236,7 +259,10 @@ def script_command(props, script, id, branch):
         python_command = 'python3'
 
     git_branch = branch or Interpolate('%(src:blender:branch)s')
-    args = [python_command, script, id, git_branch, '--codesign']
+    args = [python_command, script, id, git_branch]
+
+    if not props.hasProperty('skip_codesign'):
+        args += ['--codesign']
 
     return args
 
@@ -269,19 +295,22 @@ def generic_builder(id, branch=''):
         command=script_command.withArgs(pack_script, id, branch),
         description='packaging',
         descriptionDone='packaged',
-        haltOnFailure=True))
+        haltOnFailure=True,
+        doStepIf=do_upload))
 
     f.addStep(FileUpload(name='upload',
                          workersrc='buildbot_upload.zip',
                          masterdest=filename,
                          maxsize=500 * 1024 * 1024,
-                         workdir='install'))
+                         workdir='install',
+                         doStepIf=do_upload))
     f.addStep(MasterShellCommand(name='unpack',
                                  command=['python3.7',
                                           unpack_script,
                                           filename],
                                  description='unpacking',
-                                 descriptionDone='unpacked'))
+                                 descriptionDone='unpacked',
+                                 doStepIf=do_upload))
     return f