Improve volumes format check of yaml-validate.py

Currently, yaml-validate.py cannot detect trailing slashes under
"list_concat" and "if".

  volumes:
    - /example:/example/ # <======= detected

  volumes:
    list_concat:
    - - /example1:/example1/ # <===== not detected
      - /example2:/example2
    - if:
      - {get_param: TestValue}
      - - /example3:/example3/ # <==== not detected
        - /example4:/example4

This fix makes yaml-validate.py detect the these trailing slashes.

Because the current implementation digs "list" twice in one call to
check_volumes(), trailing slashes under "list_concat" are not detected.
Because the current implementation ignores "if", trailing slashes under
"if" are not deleted. check_volumes() doesn't have to ignore "if"
because non-volume-style value is ignored because of IndexError.

Change-Id: I4288738c2c95ab990024845fa43653854e790bd8

deployment/database/mysql-container-puppet.yaml

@@ -254,7 +254,7 @@ outputs:
           config_image: *mysql_config_image
           volumes:
             list_concat:
-            - - /var/lib/mysql:/var/lib/mysql/:rw
+            - - /var/lib/mysql:/var/lib/mysql:rw
               - /var/log/containers/mysql:/var/log/mariadb
               - /var/lib/config-data/puppet-generated/mysql/root:/root:rw #provides .my.cnf for puppet, changed on password update
             - if:

tools/yaml-validate.py

@@ -785,30 +785,21 @@ def validate_ct_volumes(data):
     def check_volumes(volumes):
         if not volumes:
             return 0
-        result = 0
-        if isinstance(volumes, list):
-            for vol in volumes:
-                if isinstance(vol, dict):
-                    # Avoid 'if', 'get_*' etc
-                    continue
-                elif isinstance(vol, list):
-                    for item in vol:
-                        result += check_volumes(item)
-                elif isinstance(vol, str):
-                    vol_def = vol.split(':')
-                    try:
-                        if vol_def[0][-1] == '/' or vol_def[1][-1] == '/':
-                            print('ERROR: trailing "/" detected'
-                                  ' for {}'.format(vol))
-                            return 1
-                    except IndexError:
-                        # Not a volume definition, ignore it
-                        continue
+        elif isinstance(volumes, list):
+            return sum([check_volumes(item) for item in volumes])
         elif isinstance(volumes, dict):
-            # Step into 'list_concat', 'map_*' etc.
-            for item in volumes.values():
-                result += check_volumes(item)
-        return result
+            return sum([check_volumes(item) for item in volumes.values()])
+        elif isinstance(volumes, str):
+            vol_def = volumes.split(':')
+            try:
+                if vol_def[0][-1] == '/' or vol_def[1][-1] == '/':
+                    print('ERROR: trailing "/" detected'
+                          ' for {}'.format(volumes))
+                    return 1
+            except IndexError:
+                # Not a volume definition, ignore it
+                pass
+        return 0
 
     if not data:
         return 0