build: Restructure how BuildCommand.build() is called

Rather than take a list of triplets to build, the BuildCommand.build()
function now takes a single repo/ref/morph triplet. Iterating through
multiple sets of triplets is now done in the build plugin.

There are a couple of cosmetic changes to the status output at the start
and end of a build as a result.

1 files changed, 14 insertions, 12 deletions

diff --git a/morphlib/buildcommand.py b/morphlib/buildcommand.py
index 7eb6c0ab..650ee13a 100644
--- a/morphlib/buildcommand.py
+++ b/morphlib/buildcommand.py
@@ -50,21 +50,23 @@ class BuildCommand(object):
         self.lac, self.rac = self.new_artifact_caches()
         self.lrc, self.rrc = self.new_repo_caches()
 
-    def build(self, args):
-        '''Build triplets specified on command line.'''
+    def build(self, repo_name, ref, filename):
+        '''Build a given system morphology.'''
 
-        self.app.status(msg='Build starts', chatty=True)
+        self.app.status(
+            msg='Building %(repo_name)s %(ref)s %(filename)s',
+            repo_name=repo_name, ref=ref, filename=filename)
 
-        for repo_name, ref, filename in self.app.itertriplets(args):
-            self.app.status(msg='Building %(repo_name)s %(ref)s %(filename)s',
-                            repo_name=repo_name, ref=ref, filename=filename)
-            self.app.status(msg='Deciding on task order')
-            srcpool = self.create_source_pool(repo_name, ref, filename)
-            self.validate_sources(srcpool)
-            root_artifact = self.resolve_artifacts(srcpool)
-            self.build_in_order(root_artifact)
+        self.app.status(msg='Deciding on task order')
+        srcpool = self.create_source_pool(repo_name, ref, filename)
+        self.validate_sources(srcpool)
+        root_artifact = self.resolve_artifacts(srcpool)
+        self.build_in_order(root_artifact)
 
-        self.app.status(msg='Build ends successfully')
+        self.app.status(
+            msg='Build of %(repo_name)s %(ref)s %(filename)s ended '
+                'successfully',
+            repo_name=repo_name, ref=ref, filename=filename)
 
     def new_artifact_caches(self):
         '''Create interfaces for the build artifact caches.