Refactor build process

Reorganise the build_artifact() and build_artifacts() functions to
allow more complex work when setting up chunk builds in
build_artifact().

The staging area now holds the BuildEnvironment object (the
environment variables that should be set during build). This makes sense
because all build commands should be run inside the staging area and
therefore through the StagingArea object.

The BuildEnvironment object is now considered immutable after it is
created.  The environment is used in cache key computation when
computing what artifacts are required; if it changes after that point
we risk either computing different artifact keys for the same artifact
or missing data in the cache key that should be included in the hash.
Better to force changes into a separate 'extra_env' variable.

1 files changed, 36 insertions, 16 deletions

diff --git a/morphlib/stagingarea.py b/morphlib/stagingarea.py
index 24d4ebf9..ee3e444f 100644
--- a/morphlib/stagingarea.py
+++ b/morphlib/stagingarea.py
@@ -35,7 +35,9 @@ class StagingArea(object):
 
     '''
 
-    def __init__(self, app, dirname):
+    _base_path = ['/sbin', '/usr/sbin', '/bin', '/usr/bin']
+
+    def __init__(self, app, dirname, build_env, use_chroot=True, extra_env={}):
         self._app = app
         self.dirname = dirname
         self.builddirname = None
@@ -43,6 +45,17 @@ class StagingArea(object):
         self.mounted = None
         self._bind_readonly_mount = None
 
+        self.use_chroot = use_chroot
+        self.env = build_env.env
+        self.env.update(extra_env)
+
+        if use_chroot:
+            path = build_env.extra_path + self._base_path
+        else:
+            full_path = [self.relative(p) for p in build_env.extra_path]
+            path = full_path + os.environ['PATH'].split(':')
+        self.env['PATH'] = ':'.join(path)
+
     # Wrapper to be overridden by unit tests.
     def _mkdir(self, dirname):  # pragma: no cover
         os.mkdir(dirname)
@@ -75,6 +88,9 @@ class StagingArea(object):
     def relative(self, filename):
         '''Return a filename relative to the staging area.'''
 
+        if not self.use_chroot:
+            return filename
+
         dirname = self.dirname
         if not dirname.endswith('/'):
             dirname += '/'
@@ -190,8 +206,7 @@ class StagingArea(object):
         if not os.path.isdir(ccache_repodir):
             os.mkdir(ccache_repodir)
         # Get the destination path
-        ccache_destdir= os.path.join(self.tempdir,
-                                     'tmp', 'ccache')
+        ccache_destdir= os.path.join(self.dirname, 'tmp', 'ccache')
         # Make sure that the destination exists. We'll create /tmp if necessary
         # to avoid breaking when faced with an empty staging area.
         if not os.path.isdir(ccache_destdir):
@@ -247,14 +262,20 @@ class StagingArea(object):
 
     def runcmd(self, argv, **kwargs):  # pragma: no cover
         '''Run a command in a chroot in the staging area.'''
+        assert 'env' not in kwargs
+        kwargs['env'] = self.env
+        if 'extra_env' in kwargs:
+            kwargs['env'].update(kwargs['extra_env'])
+            del kwargs['extra_env']
+
+        if self.use_chroot:
+            cwd = kwargs.get('cwd') or '/'
+            if 'cwd' in kwargs:
+                cwd = kwargs['cwd']
+                del kwargs['cwd']
+            else:
+                cwd = '/'
 
-        cwd = kwargs.get('cwd') or '/'
-        if 'cwd' in kwargs:
-            cwd = kwargs['cwd']
-            del kwargs['cwd']
-        else:
-            cwd = '/'
-        if self._app.settings['staging-chroot']:
             not_readonly_dirs = [self.builddirname, self.destdirname,
                                  'dev', 'proc', 'tmp']
             dirs = os.listdir(self.dirname)
@@ -265,12 +286,11 @@ class StagingArea(object):
 
             for entry in dirs:
                 real_argv += ['--mount-readonly', '/'+entry]
-
             real_argv += [self.dirname]
-        else:
-            real_argv = ['chroot', '/']
 
-        real_argv += ['sh', '-c', 'cd "$1" && shift && exec "$@"', '--', cwd]
-        real_argv += argv
+            real_argv += ['sh', '-c', 'cd "$1" && shift && exec "$@"', '--', cwd]
+            real_argv += argv
 
-        return self._app.runcmd(real_argv, **kwargs)
+            return self._app.runcmd(real_argv, **kwargs)
+        else:
+            return self._app.runcmd(argv, **kwargs)