distbuild: Add distbuild start and cancel functionality

Add command for distbuild-start to build_plugin in morphlib,
and create a boolean parameter to inform the initiator whether
to disconnect the controller and leave the build running remotely.

Add distbuild-cancel command to parse currently-running distbuild
build-request IDs and cancel the one matching the given argument

Change-Id: I458a5767bb768ceb2b4d8876adf1c86075d452bd

3 files changed, 80 insertions, 3 deletions

diff --git a/morphlib/buildcommand.py b/morphlib/buildcommand.py
index 37dccf82..efd10f26 100644
--- a/morphlib/buildcommand.py
+++ b/morphlib/buildcommand.py
@@ -525,10 +525,11 @@ class InitiatorBuildCommand(BuildCommand):
     RECONNECT_INTERVAL = 30 # seconds
     MAX_RETRIES = 1
 
-    def __init__(self, app, addr, port):
+    def __init__(self, app, addr, port, allow_detach):
         self.app = app
         self.addr = addr
         self.port = port
+        self.allow_detach = allow_detach
         self.app.settings['push-build-branches'] = True
         super(InitiatorBuildCommand, self).__init__(app)
 
@@ -546,10 +547,15 @@ class InitiatorBuildCommand(BuildCommand):
         loop = distbuild.MainLoop()
         args = [repo_name, ref, filename, original_ref or ref,
                 component_names]
+        if self.allow_detach:
+            initiator_type = distbuild.InitiatorStart
+        else:
+            initiator_type = distbuild.Initiator
+
         cm = distbuild.InitiatorConnectionMachine(self.app,
                                                   self.addr,
                                                   self.port,
-                                                  distbuild.Initiator,
+                                                  initiator_type,
                                                   [self.app] + args,
                                                   self.RECONNECT_INTERVAL,
                                                   self.MAX_RETRIES)
diff --git a/morphlib/plugins/build_plugin.py b/morphlib/plugins/build_plugin.py
index 12d69545..8da66358 100644
--- a/morphlib/plugins/build_plugin.py
+++ b/morphlib/plugins/build_plugin.py
@@ -46,10 +46,14 @@ class BuildPlugin(cliapp.Plugin):
                                              '[COMPONENT...]')
         self.app.add_subcommand('distbuild', self.distbuild,
                                 arg_synopsis='SYSTEM [COMPONENT...]')
+        self.app.add_subcommand('distbuild-start', self.distbuild_start,
+                                arg_synopsis='SYSTEM [COMPONENT...]')
         self.use_distbuild = False
+        self.allow_detach = False
 
     def disable(self):
         self.use_distbuild = False
+        self.allow_detach = False
 
     def distbuild_morphology(self, args):
         '''Distbuild a system, outside of a system branch.
@@ -97,6 +101,12 @@ class BuildPlugin(cliapp.Plugin):
         your system, the system artifact will be copied from your trove
         and cached locally.
 
+        Log information can be found in the current working directory, in
+        directories called build-xx.
+
+        If you do not have a persistent connection to the server on which
+        the distbuild runs, consider using `morph distbuild-start` instead.
+
         Example:
 
             morph distbuild devel-system-x86_64-generic.morph
@@ -106,6 +116,25 @@ class BuildPlugin(cliapp.Plugin):
         self.use_distbuild = True
         self.build(args)
 
+    def distbuild_start(self, args):
+        '''Distbuild a system image without a lasting client-server connection.
+
+        This command launches a distributed build, and disconnects from the
+        distbuild cluster once the build starts, leaving the build running
+        remotely.
+
+        The command will return a build-ID which can be used to cancel the
+        distbuild via `morph distbuild-cancel`. Builds started in this manner
+        can be found via `morph distbuild-list-jobs`
+
+        See `morph help distbuild` for more information and example usage.
+
+        '''
+
+        self.use_distbuild = True
+        self.allow_detach = True
+        self.build(args)
+
     def build_morphology(self, args):
         '''Build a system, outside of a system branch.
 
@@ -211,7 +240,7 @@ class BuildPlugin(cliapp.Plugin):
             port = self.app.settings['controller-initiator-port']
 
             build_command = morphlib.buildcommand.InitiatorBuildCommand(
-                self.app, addr, port)
+                self.app, addr, port, self.allow_detach)
         else:
             build_command = morphlib.buildcommand.BuildCommand(self.app)
 
diff --git a/morphlib/plugins/distbuild_plugin.py b/morphlib/plugins/distbuild_plugin.py
index 09669988..68a80784 100644
--- a/morphlib/plugins/distbuild_plugin.py
+++ b/morphlib/plugins/distbuild_plugin.py
@@ -40,6 +40,48 @@ class DistbuildOptionsPlugin(cliapp.Plugin):
         pass
 
 
+class DistbuildCancel(cliapp.Plugin):
+
+    RECONNECT_INTERVAL = 30 # seconds
+    MAX_RETRIES = 1
+
+    def enable(self):
+        self.app.add_subcommand('distbuild-cancel', self.distbuild_cancel,
+                                arg_synopsis='ID')
+
+    def disable(self):
+        pass
+
+    def distbuild_cancel(self, args):
+        '''Cancels a currently-running distbuild
+
+        Command line arguments:
+
+        `ID` of the running process that you wish to cancel
+        (this can be found via distbuild-list-jobs)
+
+        Example:
+
+            * morph distbuild-cancel InitiatorConnection-1
+
+        '''
+
+        if len(args) != 1:
+            raise cliapp.AppException(
+                'usage: morph distbuild-cancel <build-request id>')
+
+        addr = self.app.settings['controller-initiator-address']
+        port = self.app.settings['controller-initiator-port']
+        icm = distbuild.InitiatorConnectionMachine(self.app, addr, port,
+                                                   distbuild.InitiatorCancel,
+                                                   [self.app] + args,
+                                                   self.RECONNECT_INTERVAL,
+                                                   self.MAX_RETRIES)
+        loop = distbuild.MainLoop()
+        loop.add_state_machine(icm)
+        loop.run()
+
+
 class DistbuildListJobsPlugin(cliapp.Plugin):
 
     RECONNECT_INTERVAL = 30 # seconds