From 3f7e38a7f2721a404ebbfb130b51fa639a9e7360 Mon Sep 17 00:00:00 2001 From: Adam Coldrick Date: Wed, 28 Jan 2015 15:53:27 +0000 Subject: Use overlayfs when deploying When deploying, configuration extensions are run against the unpacked tarball of a system created by a build. If we are to use OSTree to store systems (rather than tarballs) this will not be possible as the result of `ostree checkout` would be read-only. To solve this, we use overlayfs to mount the unpacked tarball underneath a temporary directory somewhere, and run the configuration extensions on that mount point. This means that the changes are made in the temporary directory rather than directly on the tarball. --- morphlib/plugins/deploy_plugin.py | 38 ++++++++++++++++++++++++++++++++++---- 1 file changed, 34 insertions(+), 4 deletions(-) (limited to 'morphlib/plugins/deploy_plugin.py') diff --git a/morphlib/plugins/deploy_plugin.py b/morphlib/plugins/deploy_plugin.py index 87fd259f..4f78d126 100644 --- a/morphlib/plugins/deploy_plugin.py +++ b/morphlib/plugins/deploy_plugin.py @@ -438,6 +438,8 @@ class DeployPlugin(cliapp.Plugin): system_status_prefix = '%s[%s]' % (old_status_prefix, system['morph']) self.app.status_prefix = system_status_prefix try: + system_tree = None + # Find the artifact to build morph = morphlib.util.sanitise_morphology_path(system['morph']) srcpool = build_command.create_source_pool(build_repo, ref, morph) @@ -501,6 +503,9 @@ class DeployPlugin(cliapp.Plugin): system_tree, deploy_location) finally: self.app.status_prefix = system_status_prefix + if system_tree and os.path.exists(system_tree): + morphlib.fsutils.unmount(self.app.runcmd, system_tree) + shutil.rmtree(system_tree) finally: self.app.status_prefix = old_status_prefix @@ -538,9 +543,22 @@ class DeployPlugin(cliapp.Plugin): artifact, deployment_type, location, env): # deployment_type, location and env are only used for saving metadata - # Create a tempdir to extract the rootfs in - system_tree = tempfile.mkdtemp(dir=deploy_tempdir) + deployment_dir = tempfile.mkdtemp(dir=deploy_tempdir) + # Create a tempdir to extract the rootfs in + system_tree = tempfile.mkdtemp(dir=deployment_dir) + + # Create temporary directory for overlayfs + overlay_dir = os.path.join(deployment_dir, + '%s-upperdir' % artifact.name) + if not os.path.exists(overlay_dir): + os.makedirs(overlay_dir) + work_dir = os.path.join(deployment_dir, '%s-workdir' % artifact.name) + if not os.path.exists(work_dir): + os.makedirs(work_dir) + + deploy_tree = os.path.join(deployment_dir, + 'overlay-deploy-%s' % artifact.name) try: # Unpack the artifact (tarball) to a temporary directory. self.app.status(msg='Unpacking system for configuration') @@ -562,18 +580,30 @@ class DeployPlugin(cliapp.Plugin): msg='System unpacked at %(system_tree)s', system_tree=system_tree) + options = '-olowerdir=%s,upperdir=%s,workdir=%s' % \ + (system_tree, overlay_dir, work_dir) + morphlib.fsutils.mount(self.app.runcmd, + 'overlay-deploy-%s' % artifact.name, + deploy_tree, fstype='overlay', + options=options) + self.app.status( msg='Writing deployment metadata file') metadata = self.create_metadata( artifact, root_repo_dir, deployment_type, location, env) metadata_path = os.path.join( - system_tree, 'baserock', 'deployment.meta') + deploy_tree, 'baserock', 'deployment.meta') with morphlib.savefile.SaveFile(metadata_path, 'w') as f: json.dump(metadata, f, indent=4, sort_keys=True, encoding='unicode-escape') - return system_tree + return deploy_tree except Exception: shutil.rmtree(system_tree) + shutil.rmtree(overlay_dir) + shutil.rmtree(work_dir) + if deploy_tree and os.path.exists(deploy_tree): + morphlib.fsutils.unmount(self.app.runcmd, deploy_tree) + shutil.rmtree(deploy_tree) raise def run_deploy_commands(self, deploy_tempdir, env, artifact, root_repo_dir, -- cgit v1.2.1