Merge ~sylvain-pineau/checkbox-ng:fix-1748371 into checkbox-ng:master

[Sylvain Pineau]

New parameter for jinja2 templated jobs (Nota: not only template units), the content of the checkbox config environment section.

Fixes the linked bug, to avoid job description with for example hardcoded <ap_name> where in config we set $AP_NAME.

[Maciej Kisielewski (kissiel)]

I'm going to call for a better solution for the problem.
I really don't like passing the config through provider units.
Runtime configuration should not be a provider's property (logically it isn't). I understand the need for environment info to be present when instantiating templates, but I think we don't need to get providers involved in this dynamic process (providers are fairly static monsters).
What I would advocate doing instead is:
 - pass config to the code that does the instantiation (IDK how many steps in the callstack the config would have to be passed). or,
 - exposing the current config (or current SA instance) through a module interface, I'm doing something similar for the remote functionality, see remote.py: 75-87

review: Needs Fixing

[Sylvain Pineau (sylvain-pineau)]

New version using a class attribute to store the config rather than passing through provider objects. should be better in term of memory consumption IMHO.

review: Needs Resubmitting

[Maciej Kisielewski (kissiel)]

Great stuff, thanks! +1

review: Approve

diff --git a/docs/units/template.rst b/docs/units/template.rst
index f16e314..5b31010 100644
--- a/docs/units/template.rst
+++ b/docs/units/template.rst
@@ -176,7 +176,13 @@ Plainbox populates the template parameter dictionary with some extra keys to aid
 ``__index__``:
     If a template unit can result in N content jobs then this variable is equal to how many jobs have been created so far.
 
+Following parameters are only available for ``template-engine``: ``jinja2``:
+
 ``__system_env__``:
-    When the plainbox encounters a template to render it will populate this variable with the executing shell's enviroment variables as ``os.environ``
+    When checkbox encounters a template to render it will populate this variable with the executing shell's enviroment variables as ``os.environ``
+
+``__on_ubuntucore__``:
+    Helper function (boolean) checking if checkbox runs from on ubuntu core
 
-    Available for ``template-engine``: ``jinja2``
+``__checkbox_env__``:
+    Dictionary containing the checkbox config environment section
diff --git a/plainbox/impl/session/assistant.py b/plainbox/impl/session/assistant.py
index db60157..4836c8c 100644
--- a/plainbox/impl/session/assistant.py
+++ b/plainbox/impl/session/assistant.py
@@ -61,6 +61,7 @@ from plainbox.impl.session.restart import detect_restart_strategy
 from plainbox.impl.session.storage import SessionStorageRepository
 from plainbox.impl.transport import OAuthTransport
 from plainbox.impl.transport import TransportError
+from plainbox.impl.unit.unit import Unit
 from plainbox.vendor import morris
 
 _logger = logging.getLogger("plainbox.session.assistant")
@@ -168,6 +169,7 @@ class SessionAssistant:
         self._api_flags = api_flags
         self._repo = SessionStorageRepository()
         self._config = PlainBoxConfig().get()
+        Unit.config = self._config
         self._execution_ctrl_list = None  # None is "default"
         self._ctrl_setup_list = []
         # List of providers that were selected. This is buffered until a
@@ -335,6 +337,7 @@ class SessionAssistant:
         """
         UsageExpectation.of(self).enforce()
         self._config = config
+        Unit.config = config
         # NOTE: We expect applications to call this at most once.
         del UsageExpectation.of(self).allowed_calls[
             self.use_alternate_configuration]
diff --git a/plainbox/impl/unit/unit.py b/plainbox/impl/unit/unit.py
index ec1cd55..cd7b365 100644
--- a/plainbox/impl/unit/unit.py
+++ b/plainbox/impl/unit/unit.py
@@ -36,6 +36,7 @@ from jinja2 import Template
 from plainbox.i18n import gettext as _
 from plainbox.impl.decorators import cached_property
 from plainbox.impl.decorators import instance_method_lru_cache
+from plainbox.impl.secure.config import Unset
 from plainbox.impl.secure.origin import Origin
 from plainbox.impl.secure.rfc822 import normalize_rfc822_value
 from plainbox.impl.symbol import Symbol
@@ -380,6 +381,8 @@ class Unit(metaclass=UnitType):
         class.
     """
 
+    config = None
+
     def __init__(self, data, raw_data=None, origin=None, provider=None,
                  parameters=None, field_offset_map=None, virtual=False):
         """
@@ -605,6 +608,13 @@ class Unit(metaclass=UnitType):
                    field_offset_map=record.field_offset_map)
 
     @instance_method_lru_cache(maxsize=None)
+    def _checkbox_env(self):
+        if self.config is not None and self.config.environment is not Unset:
+            return self.config.environment
+        else:
+            return {}
+
+    @instance_method_lru_cache(maxsize=None)
     def get_record_value(self, name, default=None):
         """
         Obtain the normalized value of the specified record attribute
@@ -628,6 +638,7 @@ class Unit(metaclass=UnitType):
                 # template instantiation we avoid problems with creation of
                 # checkpoints
                 tmp_params = self.parameters.copy()
+                tmp_params.update({'__checkbox_env__': self._checkbox_env()})
                 tmp_params.update({'__system_env__': os.environ})
                 tmp_params.update({'__on_ubuntucore__': on_ubuntucore()})
                 value = Template(value).render(tmp_params)
@@ -640,6 +651,7 @@ class Unit(metaclass=UnitType):
         elif (value is not None and self.template_engine == 'jinja2'
                                 and not self.is_parametric):
             tmp_params = {
+                '__checkbox_env__': self._checkbox_env(),
                 '__system_env__': os.environ,
                 '__on_ubuntucore__': on_ubuntucore()
                 }
@@ -669,6 +681,7 @@ class Unit(metaclass=UnitType):
         if value is not None and self.is_parametric:
             if self.template_engine == 'jinja2':
                 tmp_params = self.parameters.copy()
+                tmp_params.update({'__checkbox_env__': self._checkbox_env()})
                 tmp_params.update({'__system_env__': os.environ})
                 tmp_params.update({'__on_ubuntucore__': on_ubuntucore()})
                 value = Template(value).render(tmp_params)
@@ -677,6 +690,7 @@ class Unit(metaclass=UnitType):
         elif (value is not None and self.template_engine == 'jinja2'
                                 and not self.is_parametric):
             tmp_params = {
+                '__checkbox_env__': self._checkbox_env(),
                 '__system_env__': os.environ,
                 '__on_ubuntucore__': on_ubuntucore()
                 }
@@ -722,6 +736,7 @@ class Unit(metaclass=UnitType):
                 # of the problem?
                 if self.template_engine == 'jinja2':
                     tmp_params = self.parameters.copy()
+                    tmp_params.update({'__checkbox_env__': self._checkbox_env()})
                     tmp_params.update({'__system_env__': os.environ})
                     tmp_params.update({'__on_ubuntucore__': on_ubuntucore()})
                     msgstr = Template(msgstr).render(tmp_params)
@@ -730,6 +745,7 @@ class Unit(metaclass=UnitType):
                         msgstr, (), self.parameters)
             elif self.template_engine == 'jinja2':
                 tmp_params = {
+                    '__checkbox_env__': self._checkbox_env(),
                     '__system_env__': os.environ,
                     '__on_ubuntucore__': on_ubuntucore()
                     }
@@ -744,6 +760,7 @@ class Unit(metaclass=UnitType):
             if self.is_parametric:
                 if self.template_engine == 'jinja2':
                     tmp_params = self.parameters.copy()
+                    tmp_params.update({'__checkbox_env__': self._checkbox_env()})
                     tmp_params.update({'__system_env__': os.environ})
                     tmp_params.update({'__on_ubuntucore__': on_ubuntucore()})
                     msgstr = Template(msgstr).render(tmp_params)
@@ -752,6 +769,7 @@ class Unit(metaclass=UnitType):
                         msgstr, (), self.parameters)
             elif self.template_engine == 'jinja2':
                 tmp_params = {
+                    '__checkbox_env__': self._checkbox_env(),
                     '__system_env__': os.environ,
                     '__on_ubuntucore__': on_ubuntucore()
                     }