Remove format function

The format function allowed too arbitrary access to the values being
formatted, and this behavior caused information leakage in some cases.

Closes-Bug: #2048114
Change-Id: Id7ec5f267314bb7166ca64802ab47d768bb5eb89

releasenotes/notes/bug-2048114-0968eea052838381.yaml

@@ -0,0 +1,12 @@
+---
+upgrade:
+  - |
+    The format YAQL function has been removed, because of its vulnability. See
+    the security section to find more details.
+
+security:
+  - |
+    `<https://bugs.launchpad.net/murano/+bug/2048114>`_: The format YAQL
+    function has been removed, because it allowed too arbitrary data access
+    which results in data leak. Users can replace the format function by
+    ``+`` operator and ``str`` YAQL function.

yaql/standard_library/strings.py

@@ -564,38 +564,6 @@ def replace_with_dict(string, str_func, replacements, count=-1):
     return string
 
 
-@specs.parameter('__format_string', yaqltypes.String())
-@specs.extension_method
-def format_(__format_string, *args, **kwargs):
-    """:yaql:format
-
-    Returns a string formatted with positional and keyword arguments.
-
-    :signature: string.format([args], {kwargs})
-    :receiverArg string: input string for formatting. Can be passed only as
-        first positional argument if used as a function. Can contain literal
-        text or replacement fields marked by braces {}. Every replacement field
-        should contain either the numeric index of a positional argument or the
-        name of a keyword argument
-    :argType string: string
-    :arg [args]: values for replacements for numeric markers
-    :argType [args]: chain of strings
-    :arg {kwargs}: values for keyword replacements
-    :argType {kwargs}: chain of key-value arguments, where values are strings
-    :returnValue: string
-
-    .. code::
-
-        yaql> "abc{0}ab{1}abc".format(" ", ",")
-        "abc ab,abc"
-        yaql> "abc{foo}ab{bar}abc".format(foo => " ", bar => ",")
-        "abc ab,abc"
-        yaql> format("abc{0}ab{foo}abc", ' ', foo => ",")
-        "abc ab,abc"
-    """
-    return __format_string.format(*args, **kwargs)
-
-
 @specs.parameter('left', yaqltypes.String())
 @specs.parameter('right', int)
 @specs.name('#operator_*')
@@ -1045,7 +1013,6 @@ def register(context):
     context.register_function(trim_right)
     context.register_function(replace)
     context.register_function(replace_with_dict)
-    context.register_function(format_)
     context.register_function(is_empty)
     context.register_function(string_by_int)
     context.register_function(int_by_string)

yaql/tests/test_regex.py

@@ -50,9 +50,10 @@ class TestRegex(yaql.tests.TestCase):
             '24.16 = 24(2-4) + 16(5-7)',
             self.eval(
                 r"regex(`(\d+)\.?(\d+)?`).search("r"'aa24.16bb', "
-                r"format('{0} = {1}({2}-{3}) + {4}({5}-{6})', "
-                r"$.value, $2.value, $2.start, $2.end, "
-                r"$3.value, $3.start, $3.end))"))
+                r"$.value + ' = ' + "
+                r"$2.value + '(' + str($2.start) + '-' + str($2.end) + ') + ' "
+                r"+ $3.value + '(' + str($3.start) + '-' + str($3.end) + ')')"
+            ))
 
     def test_search_all(self):
         self.assertEqual(

yaql/tests/test_strings.py

@@ -118,10 +118,6 @@ class TestStrings(yaql.tests.TestCase):
     def test_concat_func(self):
         self.assertEqual('abc', self.eval("concat(a, b, c)"))
 
-    def test_format(self):
-        self.assertEqual('a->b', self.eval("'{0}->{x}'.format(a, x => b)"))
-        self.assertEqual('a->b', self.eval("format('{0}->{x}', a, x => b)"))
-
     def test_trim(self):
         self.assertEqual('x', self.eval("'  x  '.trim()"))
         self.assertEqual('x', self.eval("'abxba'.trim(ab)"))