[libvirt] [PATCH sandbox 21/24] docker: refactor download method exception handling

Split off code which rolls back and deletes files when download fails. Signed-off-by: Daniel P. Berrange <berrange(a)redhat.com&gt; --- libvirt-sandbox/image/sources/docker.py | 91 +++++++++++++++++---------------- 1 file changed, 46 insertions(+), 45 deletions(-) diff --git a/libvirt-sandbox/image/sources/docker.py b/libvirt-sandbox/image/sources/docker.py index b2706b1..3cc321b 100644 --- a/libvirt-sandbox/image/sources/docker.py +++ b/libvirt-sandbox/image/sources/docker.py @@ -304,8 +304,26 @@ class DockerSource(base.Source): except Exception: return False - def download_template(self, image, template, templatedir): + try: + createdFiles = [] + createdDirs = [] + + self._download_template_impl(image, template, templatedir, createdFiles, createdDirs) + except Exception as e: + for f in createdFiles: + try: + os.remove(f) + except: + pass + for d in createdDirs: + try: + shutil.rmtree(d) + except: + pass + raise + + def _download_template_impl(self, image, template, templatedir, createdFiles, createdDirs): self._check_cert_validate() registry = DockerRegistry.from_template(template) @@ -340,50 +358,33 @@ class DockerSource(base.Source): raise ValueError(["Expected first layer id '%s' to match image id '%s'", data[0], imagetagid]) - try: - createdFiles = [] - createdDirs = [] - - for layerid in data: - layerdir = templatedir + "/" + layerid - if not os.path.exists(layerdir): - os.makedirs(layerdir) - createdDirs.append(layerdir) - - jsonfile = layerdir + "/template.json" - datafile = layerdir + "/template.tar.gz" - - if not os.path.exists(jsonfile) or not os.path.exists(datafile): - res = registry.save_data("/v1/images/" + layerid + "/json", - jsonfile) - createdFiles.append(jsonfile) - - registry.save_data("/v1/images/" + layerid + "/layer", - datafile) - createdFiles.append(datafile) - - index = { - "repo": image.repo, - "name": image.name, - "tag": image.tag, - } - - indexfile = templatedir + "/" + imagetagid + "/index.json" - print("Index file " + indexfile) - with open(indexfile, "w") as f: - f.write(json.dumps(index)) - except Exception as e: - traceback.print_exc() - for f in createdFiles: - try: - os.remove(f) - except: - pass - for d in createdDirs: - try: - shutil.rmtree(d) - except: - pass + for layerid in data: + layerdir = templatedir + "/" + layerid + if not os.path.exists(layerdir): + os.makedirs(layerdir) + createdDirs.append(layerdir) + + jsonfile = layerdir + "/template.json" + datafile = layerdir + "/template.tar.gz" + + if not os.path.exists(jsonfile) or not os.path.exists(datafile): + res = registry.save_data("/v1/images/" + layerid + "/json", + jsonfile) + createdFiles.append(jsonfile) + + registry.save_data("/v1/images/" + layerid + "/layer", + datafile) + createdFiles.append(datafile) + + index = { + "repo": image.repo, + "name": image.name, + "tag": image.tag, + } + + indexfile = templatedir + "/" + imagetagid + "/index.json" + with open(indexfile, "w") as f: + f.write(json.dumps(index)) def create_template(self, template, templatedir, connect=None): image = DockerImage.from_template(template) -- 2.7.4