Prevent Template Units id from being rendered when using Jinja2

By default, templates using Jinja2 engine gets their id rendered as soon
as they get accessed, but since they don't have the appropriate
environment, the parameters are replaced with an empty string.

This is why when you run the command `checkbox-cli list template`, you
may see things like this:

    template 'com.canonical.certification::camera/still_'

instead of

    template 'com.canonical.certification::camera/still_{{ name }}'

Note that this does not happen with standard Python formatted strings:

    template 'com.canonical.certification::camera/led_{name}'

In order to make the behavior consistent regardless of the template
engine used, this commit:

- introduces a unit property that always returns "template" (similar to
how the Job unit always returns "job").
- modifies Unit.get_record_value() to prevent rendering using Jinja2
templating if the unit is a Checkbox Template

It also contains unit tests for both the TemplateUnit and its Validator.

checkbox-ng/plainbox/impl/unit/template.py

@@ -166,9 +166,13 @@ def __str__(self):
  return "{} <~ {}".format(self.id, self.resource_id)
 
  @property
+ def unit(self):
  """
+ The value of the unit field (overridden)
 
+ The return value is always "template"
  """
+ return "template"
 
  @property
  def resource_partial_id(self):

checkbox-ng/plainbox/impl/unit/test_template.py

@@ -42,6 +42,14 @@
 
 class TemplateUnitTests(TestCase):
 
+ def test_id(self):
+ template = TemplateUnit({
+ "template-resource": "resource",
+ "template-id": "check-devices",
+ "id": "check-device-{dev_name}",
+ })
+ self.assertEqual(template.id, "check-device-{dev_name}")
+
  def test_resource_partial_id__empty(self):
  """
  Ensure that ``resource_partial_id`` defaults to None
@@ -351,6 +359,14 @@ def test_instantiate_all(self):
 
 class TemplateUnitJinja2Tests(TestCase):
 
+ def test_id_jinja2(self):
+ template = TemplateUnit({
+ 'template-resource': 'resource',
+ 'template-engine': 'jinja2',
+ 'id': 'check-device-{{ dev_name }}',
+ })
+ self.assertEqual(template.id, "check-device-{{ dev_name }}")
+
  def test_instantiate_one_jinja2(self):
  template = TemplateUnit({
  'template-resource': 'resource',
@@ -374,6 +390,17 @@ class TemplateUnitFieldValidationTests(UnitFieldValidationTests):
 
  unit_cls = TemplateUnit
 
+ def test_unit__present(self):
+ """
+ TemplateUnit.unit always returns "template", the default error for the
+ base Unit class should never happen.
+ """
+ issue_list = self.unit_cls({
+ }, provider=self.provider).check()
+ message = "field 'unit', unit should explicitly define its type"
+ self.assertIssueNotFound(issue_list, self.unit_cls.Meta.fields.unit,
+ Problem.missing, Severity.advice, message)
+
  def test_template_unit__untranslatable(self):
  issue_list = self.unit_cls({
  # NOTE: the value must be a valid unit!

checkbox-ng/plainbox/impl/unit/test_unit.py

@@ -79,6 +79,49 @@ def assertIssueFound(self, issue_list, field=None, kind=None,
  '\n'.join(" - {!r}".format(issue) for issue in issue_list))
  return self.fail(msg)
 
+ def assertIssueNotFound(self, issue_list, field=None, kind=None,
+ severity=None, message=None):
+ """
+ Raise an assertion if no issue matching the provided criteria is found
+
+ :param issue_list:
+ A list of issues to look through
+ :param field:
+ (optional) value that must match the same attribute on the Issue
+ :param kind:
+ (optional) value that must match the same attribute on the Issue
+ :param severity:
+ (optional) value that must match the same attribute on the Issue
+ :param message:
+ (optional) value that must match the same attribute on the Issue
+ :returns:
+ The issue matching those constraints, if found
+ """
+ for issue in issue_list:
+ if field is not None and issue.field is not field:
+ continue
+ if severity is not None and issue.severity is not severity:
+ continue
+ if kind is not None and issue.kind is not kind:
+ continue
+ if message is not None and issue.message != message:
+ continue
+ # return issue
+ return self.fail("Issue matching the given criteria found!")
+ msg = "Issue matching:\n{}\nwas found in:\n{}".format(
+ '\n'.join(
+ ' * {} is {!r}'.format(issue_attr, value)
+ for issue_attr, value in
+ [('field', field),
+ ('severity', severity),
+ ('kind', kind),
+ ('message', message)]
+ if value is not None),
+ '\n'.join(" - {!r}".format(issue) for issue in issue_list))
+ return self.fail(msg)
+ else:
+ return issue
+
 
 class TestUnitDefinition(TestCase):
 

checkbox-ng/plainbox/impl/unit/unit.py

@@ -713,6 +713,7 @@ def get_record_value(self, name, default=None):
  value is not None
  and self.template_engine == "jinja2"
  and not self.is_parametric
+ and not self.unit == "template"
  ):
  tmp_params = {
  "__checkbox_env__": self._checkbox_env(),
@@ -755,6 +756,7 @@ def get_raw_record_value(self, name, default=None):
  value is not None
  and self.template_engine == "jinja2"
  and not self.is_parametric
+ and not self.unit == "template"
  ):
  tmp_params = {
  "__checkbox_env__": self._checkbox_env(),