checks.py: support 'append' option

If 'append' is defined for a property, append the values from append
options to the property. Note: The property must support to be a list
of values.

For example:

with schema:

    schema = {
        "$schema": "http://json-schema.org/draft-04/schema#",
        "title": "Pungi Configuration",
        "type": "object",
        "definitions": {
            "list_of_strings": {
                "type": "array",
                "items": {"type": "string"},
            },
            "strings": {
                "anyOf": [
                    {"type": "string"},
                    {"$ref": "#/definitions/list_of_strings"},
                ]
            },
        },
        "properties": {
            "release_name": {"type": "string"},
            "repo": {"$ref": "#/definitions/strings", "append": "repo_from"}
        },
        "additionalProperties": False,
    }

and config:

    repo = "http://url/to/repo"
    repo_from = "Server"

config will be updated to:

    repo = ["http://url/to/repo", "Server"]

It supports multiple append options too, like:

    "repo": {
        "$ref": "#/definitions/strings",
        "append": ["repo_from", "source_repo_from"],
    }

Signed-off-by: Qixiang Wan <qwan@redhat.com>

pungi/checks.py

@@ -40,6 +40,7 @@ import os.path
 import platform
 import jsonschema
 import re
+from kobo.shortcuts import force_list
 
 from . import util
 
@@ -263,12 +264,34 @@ def _extend_with_default_and_alias(validator_class):
                           "In:\n%s" % (subschema['alias'], property, property, instance)
                     errors.append(ConfigOptionWarning(msg))
                     if property in instance:
-                        msg = "ERROR: Config option '%s' is an alias of '%s', only one can be used. In:\n%s" \
+                        msg = "ERROR: Config option '%s' is an alias of '%s', only one can be used." \
-                              % (subschema['alias'], property, instance)
+                              % (subschema['alias'], property)
                         errors.append(ConfigOptionError(msg))
                         instance.pop(subschema['alias'])
                     else:
                         instance.setdefault(property, instance.pop(subschema['alias']))
+            # update instance for append option
+            # If append is defined in schema, append values from append options to property. If property
+            # is not present in instance, set it to empty list, and append the values from append options.
+            # Note: property's schema must support a list of values.
+            if "append" in subschema:
+                appends = force_list(subschema['append'])
+                for append in appends:
+                    if append in instance:
+                        msg = "WARNING: Config option '%s' is deprecated, its value will be appended to option '%s'. " \
+                              "In:\n%s" % (append, property, instance)
+                        errors.append(ConfigOptionWarning(msg))
+                        if property in instance:
+                            msg = "WARNING: Value from config option '%s' is now appended to option '%s'." \
+                                  % (append, property)
+                            errors.append(ConfigOptionWarning(msg))
+                            instance[property] = force_list(instance[property])
+                            instance[property].extend(force_list(instance.pop(append)))
+                        else:
+                            msg = "WARNING: Config option '%s' is not found, but '%s' is specified, value from '%s' " \
+                                  "is now added as '%s'." % (property, append, append, property)
+                            errors.append(ConfigOptionWarning(msg))
+                            instance[property] = instance.pop(append)
         yield errors
 
     def _set_defaults(validator, properties, instance, schema):

tests/test_checks.py

@@ -357,6 +357,130 @@ class TestSchemaValidator(unittest.TestCase):
         self.assertEqual(config.get("release_name", None), "dummy product")
         self.assertEqual(config.get("foophase", {}).get("repo", None), "http://www.exampe.com/os")
 
+    @mock.patch('pungi.checks._make_schema')
+    def test_append_option(self, make_schema):
+        schema = {
+            "$schema": "http://json-schema.org/draft-04/schema#",
+            "title": "Pungi Configuration",
+            "type": "object",
+            "definitions": {
+                "list_of_strings": {
+                    "type": "array",
+                    "items": {"type": "string"},
+                },
+                "strings": {
+                    "anyOf": [
+                        {"type": "string"},
+                        {"$ref": "#/definitions/list_of_strings"},
+                    ]
+                },
+            },
+            "properties": {
+                "release_name": {"type": "string"},
+                "repo": {"$ref": "#/definitions/strings", "append": "repo_from"}
+            },
+            "additionalProperties": False,
+        }
+        make_schema.return_value = schema
+
+        string = """
+        release_name = "dummy product"
+        repo = "http://url/to/repo"
+        repo_from = 'Server'
+        """
+        config = self._load_conf_from_string(string)
+        errors, warnings = checks.validate(config)
+        self.assertEqual(len(errors), 0)
+        self.assertEqual(len(warnings), 2)
+        self.assertRegexpMatches(warnings[0], r"^WARNING: Config option 'repo_from' is deprecated, its value will be appended to option 'repo'.*")
+        self.assertRegexpMatches(warnings[1], r"^WARNING: Value from config option 'repo_from' is now appended to option 'repo'")
+        self.assertEqual(config.get("release_name", None), "dummy product")
+        self.assertEqual(config.get("repo", None), ["http://url/to/repo", "Server"])
+
+    @mock.patch('pungi.checks._make_schema')
+    def test_append_to_nonexist_option(self, make_schema):
+        schema = {
+            "$schema": "http://json-schema.org/draft-04/schema#",
+            "title": "Pungi Configuration",
+            "type": "object",
+            "definitions": {
+                "list_of_strings": {
+                    "type": "array",
+                    "items": {"type": "string"},
+                },
+                "strings": {
+                    "anyOf": [
+                        {"type": "string"},
+                        {"$ref": "#/definitions/list_of_strings"},
+                    ]
+                },
+            },
+            "properties": {
+                "release_name": {"type": "string"},
+                "repo": {"$ref": "#/definitions/strings", "append": "repo_from"}
+            },
+            "additionalProperties": False,
+        }
+        make_schema.return_value = schema
+
+        string = """
+        release_name = "dummy product"
+        repo_from = ['http://url/to/repo', 'Server']
+        """
+        config = self._load_conf_from_string(string)
+        errors, warnings = checks.validate(config)
+        self.assertEqual(len(errors), 0)
+        self.assertEqual(len(warnings), 2)
+        self.assertRegexpMatches(warnings[0], r"^WARNING: Config option 'repo_from' is deprecated, its value will be appended to option 'repo'.*")
+        self.assertRegexpMatches(warnings[1], r"^WARNING: Config option 'repo' is not found, but 'repo_from' is specified,")
+        self.assertEqual(config.get("release_name", None), "dummy product")
+        self.assertEqual(config.get("repo", None), ["http://url/to/repo", "Server"])
+
+    @mock.patch('pungi.checks._make_schema')
+    def test_multiple_appends(self, make_schema):
+        schema = {
+            "$schema": "http://json-schema.org/draft-04/schema#",
+            "title": "Pungi Configuration",
+            "type": "object",
+            "definitions": {
+                "list_of_strings": {
+                    "type": "array",
+                    "items": {"type": "string"},
+                },
+                "strings": {
+                    "anyOf": [
+                        {"type": "string"},
+                        {"$ref": "#/definitions/list_of_strings"},
+                    ]
+                },
+            },
+            "properties": {
+                "release_name": {"type": "string"},
+                "repo": {
+                    "$ref": "#/definitions/strings",
+                    "append": ["repo_from", "source_repo_from"]
+                }
+            },
+            "additionalProperties": False,
+        }
+        make_schema.return_value = schema
+
+        string = """
+        release_name = "dummy product"
+        repo_from = ['http://url/to/repo', 'Server']
+        source_repo_from = 'Client'
+        """
+        config = self._load_conf_from_string(string)
+        errors, warnings = checks.validate(config)
+        self.assertEqual(len(errors), 0)
+        self.assertEqual(len(warnings), 4)
+        self.assertRegexpMatches(warnings[0], r"^WARNING: Config option 'repo_from' is deprecated, its value will be appended to option 'repo'.*")
+        self.assertRegexpMatches(warnings[1], r"^WARNING: Config option 'repo' is not found, but 'repo_from' is specified,")
+        self.assertRegexpMatches(warnings[2], r"^WARNING: Config option 'source_repo_from' is deprecated, its value will be appended to option 'repo'")
+        self.assertRegexpMatches(warnings[3], r"^WARNING: Value from config option 'source_repo_from' is now appended to option 'repo'.")
+        self.assertEqual(config.get("release_name", None), "dummy product")
+        self.assertEqual(config.get("repo", None), ["http://url/to/repo", "Server", "Client"])
+
 
 class TestUmask(unittest.TestCase):
     def setUp(self):