Implement override and reset analog to docker-compose (https://docs.d…

…ocker.com/compose/compose-file/13-merge/)

Signed-off-by: Sebastian Sellmeier <mail@sebastian-sellmeier.de>

podman_compose.py

@@ -1149,6 +1149,47 @@ def flat_deps(services, with_extends=False):
  for name, srv in services.items():
  rec_deps(services, name)
 
+###################
+# Override and reset tags
+###################
+
+class OverrideTag(yaml.YAMLObject):
+ yaml_dumper = yaml.Dumper
+ yaml_loader = yaml.SafeLoader
+ yaml_tag = u'!override'
+
+ def __init__(self, value):
+ values = list()
+
+ for item in value:
+ values.append(item.value)
+
+ self.value = values
+
+ @classmethod
+ def from_yaml(cls, loader, node):
+ return OverrideTag(node.value)
+
+ @classmethod
+ def to_yaml(cls, dumper, data):
+ return dumper.represent_scalar(cls.yaml_tag, data.value)
+
+class ResetTag(yaml.YAMLObject):
+ yaml_dumper = yaml.Dumper
+ yaml_loader = yaml.SafeLoader
+ yaml_tag = u'!reset'
+
+ @classmethod
+ def toJSON(self):
+ return self.yaml_tag
+
+ @classmethod
+ def from_yaml(cls, loader, node):
+ return ResetTag()
+
+ @classmethod
+ def to_yaml(cls, dumper, data):
+ return dumper.represent_scalar(cls.yaml_tag, '')
 
 ###################
 # podman and compose classes
@@ -1245,6 +1286,14 @@ def volume_ls(self, proj=None):
 
 
 def normalize_service(service, sub_dir=""):
+ if isinstance(service, ResetTag):
+ return service
+
+ if isinstance(service, OverrideTag):
+ tagObj = service
+ service = tagObj.value
+ print(subdir)
+
  if "build" in service:
  build = service["build"]
  if is_str(build):
@@ -1284,7 +1333,12 @@ def normalize_service(service, sub_dir=""):
  if is_str(extends):
  extends = {"service": extends}
  service["extends"] = extends
- return service
+
+ try:
+ tagObj.value = serivce
+ return tagObj
+ except NameError:
+ return service
 
 
 def normalize(compose):
@@ -1330,6 +1384,8 @@ def rec_merge_one(target, source):
  update target from source recursively
  """
  done = set()
+ remove = set()
+
  for key, value in source.items():
  if key in target:
  continue
@@ -1339,17 +1395,37 @@ def rec_merge_one(target, source):
  if key in done:
  continue
  if key not in source:
+ if isinstance(value, ResetTag):
+ log("INFO: Unneeded !reset found for [{key}]")
+ remove.add(key)
+
+ if isinstance(value, OverrideTag):
+ log("INFO: Unneeded !override found for [{key}] with value '{value}'")
+ target[key] = clone(value.value)
+
  continue
+
  value2 = source[key]
+
+ if isinstance(value, ResetTag) or isinstance(value2, ResetTag):
+ remove.add(key)
+ continue
+
+ if isinstance(value, OverrideTag) or isinstance(value2, OverrideTag):
+ target[key] = clone(value.value) if isinstance(value, OverrideTag) else clone(value2.value)
+ continue
+
  if key in ("command", "entrypoint"):
  target[key] = clone(value2)
  continue
+
  if not isinstance(value2, type(value)):
  value_type = type(value)
  value2_type = type(value2)
  raise ValueError(
  f"can't merge value of [{key}] of type {value_type} and {value2_type}"
  )
+
  if is_list(value2):
  if key == "volumes":
  # clean duplicate mount targets
@@ -1368,6 +1444,10 @@ def rec_merge_one(target, source):
  rec_merge_one(value, value2)
  else:
  target[key] = value2
+
+ for key in remove:
+ del target[key]
+
  return target
 
 
@@ -1629,7 +1709,7 @@ def _parse_compose_file(self):
  compose["services"] = resolved_services
  if not getattr(args, "no_normalize", None):
  compose = normalize_final(compose, self.dirname)
- self.merged_yaml = yaml.safe_dump(compose)
+ self.merged_yaml = yaml.dump(compose)
  merged_json_b = json.dumps(compose, separators=(",", ":")).encode("utf-8")
  self.yaml_hash = hashlib.sha256(merged_json_b).hexdigest()
  compose["_dirname"] = dirname