Fix healthcheck for newer manila versions

Manila introduced in the main branch a manila-manage patch that makes
the healthcheck script no longer 100% compatible with newer version (E+)
[1].
While in the long term the idea is to change this script to use a json
representation of the output, we need to keep it compatible with
previous releases, because the operator is supposed to manage (at the
time of writing) Manila versions that go from Antelope to Flamingo.
This patch updates the service parsing table based on the layout
established in manila-manage command [2].

[1] https://review.opendev.org/c/openstack/manila/+/899295
[2] https://github.com/openstack/manila/blob/master/manila/cmd/manage.py

Signed-off-by: Francesco Pantano <fpantano@redhat.com>

Author: fmount

templates/manila/bin/healthcheck.py

@@ -52,6 +52,26 @@
 STATE_UP = ":-)"
 STATUS_ENABLED = "enabled"
 
+'''
+manila-manage returns services using the following layout:
+
+# SERVICE LAYOUT
+
+| binary    | -> 0
+| host      | -> 1
+| zone      | -> 2
+| status    | -> 3
+| state     | -> 4
+| udated_at | -> 5
+
+The layout is defined in the upstream manila-manage code [1].
+Every time a manila-manage command is performed, we can resolve the position
+of each field, and we can easily decode into a dict.
+
+[1] https://github.com/openstack/manila/blob/master/manila/cmd/manage.py#L376
+'''
+
+
 class HTTPServerV6(server.HTTPServer):
     address_family = socket.AF_INET6
 
@@ -96,6 +116,47 @@ def initialize_class(cls, binary, config_dir):
         # Store the filters used to find out services.
         cls.services_filters = services_filters
 
+    @staticmethod
+    def get_status(service):
+        """
+        Because status is either enabled or disabled, this function looks for
+        it by iterating the array; by doing this it does not ave to rely on a
+        particular position
+        """
+        return STATUS_ENABLED if STATUS_ENABLED in service else "disabled"
+
+    @staticmethod
+    def validate_line(service):
+        """
+        Process the line if there's at least one element
+        """
+        return False if ((len(service) - 1) <= 0) else True
+
+    @staticmethod
+    def get_state(service):
+        """
+        Because STATE_UP has a special symbol, the function does not need to
+        search for it at a given position, but it can match it by iterating
+        the array and return a negative result if the symbol is not found
+        """
+        return STATE_UP if STATE_UP in service else "XXX"
+
+    @staticmethod
+    def get_hostgroup(service):
+        """
+        As per the layout defined in the manila-manage command, hostgroup is
+        always the second entry of the table
+        """
+        return service[1] if len(service) > 1 else None
+
+    @staticmethod
+    def get_service_name(service):
+        """
+        Service name is always the first entry of the table defined by the
+        manila-manage command
+        """
+        return service[0] if service else None
+
     @staticmethod
     def check_service(services, **filters):
         # Check if services were already created and are registered in the db
@@ -114,49 +175,36 @@ def check_service(services, **filters):
             raise ServiceNotUp()
 
     def _parse_service_list_output(self, services_list):
+        # reuse the existing BINARIES tuple to resolve the allowed services
+        # and prefix each item
+        allowed_services = tuple('manila-{}'.format(item) for item in BINARIES)
         # Decode the characters, remove the line splits and the
         # blank spaces
         services_list = services_list.decode('utf-8').split('\n')
-        parsed_service_list = []
+        services = []
         for service in services_list:
-            if "DEBUG" in service:
+            # clean up tokens of the current line
+            tokens = [token for token in service.split() if token]
+            # invalid line: stop early and move to the next item, no need to
+            # try to process each element
+            if not self.validate_line(tokens):
                 continue
-            parsed_service_list.append(service)
-
-        if not parsed_service_list:
-            raise ServiceNotFoundException(filters={})
-
-        parsed_service_list = [
-            service.split() for service in parsed_service_list]
-
-        # First line is related to the headers. We don't care about the
-        # updated at, so we drop it and sanitize the strings.
-        services_list_headers = parsed_service_list[0]
-        columns_to_ignore_starts_at = (
-            services_list_headers.index("Updated")
-            if "Updated" in services_list_headers else None)
-
-        if not columns_to_ignore_starts_at:
+            # First line is related to the headers. We don't care about the
+            # updated at, so we ignore it
+            if "Binary" in tokens:
+                continue
+            # Process a valid line for a given service and fill the dict
+            service_name = self.get_service_name(tokens)
+            if service_name and service_name in allowed_services:
+                services.append({
+                    'binary': service_name,
+                    'host': self.get_hostgroup(tokens),
+                    'status': self.get_status(tokens),
+                    'state': self.get_state(tokens),
+                })
+        if not services:
             raise ServiceNotFoundException(filters={})
-
-        services_list_headers = (
-            services_list_headers[0:columns_to_ignore_starts_at])
-        services_list_headers = (
-            [header.lower() for header in services_list_headers])
-
-        # Remove the headers from the list, so we can iterate on the items
-        parsed_service_list.pop(0)
-
-        # Finally, we can get a dictionary out of the manila-manage command.
-        parsed_services_dict_list = []
-
-        for service in parsed_service_list:
-            if service:
-                service_dict = {}
-                for i, header in enumerate(services_list_headers):
-                    service_dict[header] = service[i]
-                parsed_services_dict_list.append(service_dict)
-        return parsed_services_dict_list
+        return services
 
     def do_GET(self):
         try: