Repository: ansible/ansible

Issue:
Ansible facts override special variables
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##### SUMMARY
Certain scenarios can result in internal ansible facts being overridden, this was originally fixed in v2.4.x however this bug (previously reported: https://github.com/ansible/ansible/issues/16935) has been reintroduced on version 2.5.0+ and still exists on the devel branch.

##### ISSUE TYPE
 - Bug Report

##### COMPONENT NAME
<!--- Insert, BELOW THIS COMMENT, the name of the module, plugin, task or feature.
Do not include extra details here, e.g. "vyos_command" not "the network module vyos_command" or the full path-->
gather_facts


##### ANSIBLE VERSION
<!--- Paste, BELOW THIS COMMENT, verbatim output from "ansible --version" between quotes below -->
```
ansible 2.7.0.dev0 (devel 1737b7be3e) last updated 2018/06/18 15:00:52 (GMT +100)
  config file = None
  configured module search path = [u'/home/sam/.ansible/plugins/modules', u'/usr/share/ansible/plugins/modules']
  ansible python module location = /home/sam/Work/src/github.com/ansible/ansible/lib/ansible
  executable location = /home/sam/pythonEnv/bin/ansible
  python version = 2.7.12+ (default, Sep  1 2016, 20:27:38) [GCC 6.2.0 20160927]
```

##### CONFIGURATION
<!--- If using Ansible 2.4 or above, paste, BELOW THIS COMMENT, the results of "ansible-config dump --only-changed"
Otherwise, mention any settings you have changed/added/removed in ansible.cfg
(or using the ANSIBLE_* environment variables).-->

##### OS / ENVIRONMENT
<!--- Mention, BELOW THIS COMMENT, the OS you are running Ansible from, and the OS you are
managing, or say "N/A" for anything that is not platform-specific.
Also mention the specific version of what you are trying to control,
e.g. if this is a network bug the version of firmware on the network device.-->
Observed on RHEL, Centos 7, Debian Jessie and Ubuntu 16.04 

##### STEPS TO REPRODUCE
<!--- For bugs, show exactly how to reproduce the problem, using a minimal test-case.
For new features, show how the feature would be used. -->

Create a network interface with a name that conflicts with an ansible internal variable, in this case I'm using a veth pair (with one end called "user" and other end "password") but it could be a tap interface or a vlan interface.
```
ip link add user type veth peer name password
```

Run a playbook with two plays:

<!--- Paste example playbooks or commands between quotes below -->
```yaml
---
- name: Do the actual task
  hosts: all
  tasks:
    - debug:
        msg: "{{ansible_user}}"
    - name: install vim
      package:
        name: vim
        state: present
      become: true
```

<!--- You can also paste gist.github.com links for larger files -->

##### EXPECTED RESULTS
<!--- What did you expect to happen when running the steps above? -->

```
PLAY [Do the actual task] ************************************************************************************************************

TASK [Gathering Facts] ***************************************************************************************************************
 [WARNING]: Removed restricted key from module data: ansible_password = {u'macaddress ... ther'}

 [WARNING]: Removed restricted key from module data: ansible_user = {u'macaddress ... ther'}

ok: [localhost]

TASK [debug] *************************************************************************************************************************
ok: [localhost] => {
    "msg": "sam"
}

TASK [install vim] *******************************************************************************************************************
ok: [localhost]

PLAY RECAP ***************************************************************************************************************************
localhost                  : ok=3    changed=0    unreachable=0    failed=0   

```

##### ACTUAL RESULTS
<!--- What actually happened? If possible run with extra verbosity (-vvvv) -->

<!--- Paste verbatim command output between quotes below -->
```

PLAY [Do the actual task] ************************************************************************************************************

TASK [Gathering Facts] ***************************************************************************************************************
 [WARNING]: Removed restricted key from module data: ansible_password = {u'macaddress ... ther'}

 [WARNING]: Removed restricted key from module data: ansible_user = {u'macaddress ... ther'}

ok: [localhost]

TASK [debug] *************************************************************************************************************************
ok: [localhost] => {
    "msg": {
        "active": false, 
        "device": "user", 
        "macaddress": "9a:67:85:d7:9e:e7", 
        "mtu": 1500, 
        "promisc": false, 
        "type": "ether"
    }
}

TASK [install vim] *******************************************************************************************************************
fatal: [localhost]: UNREACHABLE! => {"changed": false, "msg": "Failed to connect to the host via ssh: command-line line 0: garbage at end of line; \"u'9a:67:85:d7:9e:e7',\".\r\n", "unreachable": true}
	to retry, use: --limit @/home/sam/Work/sandbox/playbook.retry

PLAY RECAP ***************************************************************************************************************************
localhost                  : ok=2    changed=0    unreachable=1    failed=0   
```



Discussion:
I have resolve this locally by making this change:

```
diff --git a/lib/ansible/executor/task_executor.py b/lib/ansible/executor/task_executor.py
index e2adba0d73..c8e6c7bedb 100644
--- a/lib/ansible/executor/task_executor.py
+++ b/lib/ansible/executor/task_executor.py
@@ -624,7 +624,8 @@ class TaskExecutor:
                 else:
                     vars_copy.update(namespace_facts(result['ansible_facts']))
                     if C.INJECT_FACTS_AS_VARS:
-                        vars_copy.update(clean_facts(result['ansible_facts']))
+                        result['ansible_facts'] = clean_facts(result['ansible_facts'])
+                        vars_copy.update(result['ansible_facts'])
 
             # set the failed property if it was missing.
             if 'failed' not in result:
@@ -685,7 +686,8 @@ class TaskExecutor:
             else:
                 variables.update(namespace_facts(result['ansible_facts']))
                 if C.INJECT_FACTS_AS_VARS:
-                    variables.update(clean_facts(result['ansible_facts']))
+                    result['ansible_facts'] = clean_facts(result['ansible_facts'])
+                    variables.update(result['ansible_facts'])
 
         # save the notification target in the result, if it was specified, as
         # this task may be running in a loop in which case the notification
```

However I'm ensure if this logic should move to a more common location for example:
https://github.com/ansible/ansible/blob/devel/lib/ansible/plugins/strategy/__init__.py#L606
@Tehsmash the code change you provided seems like a sane fix, if you'd like to open a pull request I'll review ... or I can open the PR and credit you in the commit message. Either way, thank you! :)

Resolving patch:
diff --git a/lib/ansible/constants.py b/lib/ansible/constants.py
--- a/lib/ansible/constants.py
+++ b/lib/ansible/constants.py
@@ -22,7 +22,7 @@ def _deprecated(msg, version='2.8'):
     try:
         from __main__ import display
         display.deprecated(msg, version=version)
-    except:
+    except Exception:
         import sys
         sys.stderr.write('[DEPRECATED] %s, to be removed in %s' % (msg, version))
 
@@ -43,7 +43,7 @@ def get_config(parser, section, key, env_var, default_value, value_type=None, ex
     if value is None:
         try:
             value = get_ini_config_value(parser, {'key': key, 'section': section})
-        except:
+        except Exception:
             pass
     if value is None:
         value = default_value
@@ -113,6 +113,10 @@ def set_constant(name, value, export=vars()):
 # object. The dictionary values are tuples, to account for aliases
 # in variable names.
 
+COMMON_CONNECTION_VARS = frozenset(set(('ansible_connection', 'ansbile_host', 'ansible_user', 'ansible_shell_executable',
+                                        'ansible_port', 'ansible_pipelining', 'ansible_password', 'ansible_timeout',
+                                        'ansible_shell_type', 'ansible_module_compression', 'ansible_private_key_file')))
+
 MAGIC_VARIABLE_MAPPING = dict(
 
     # base
@@ -183,7 +187,7 @@ def set_constant(name, value, export=vars()):
                 value = literal_eval(value)
             except ValueError:
                 pass  # not a python data structure
-        except:
+        except Exception:
             pass  # not templatable
 
         value = ensure_type(value, setting.type)
diff --git a/lib/ansible/vars/clean.py b/lib/ansible/vars/clean.py
--- a/lib/ansible/vars/clean.py
+++ b/lib/ansible/vars/clean.py
@@ -63,8 +63,13 @@ def clean_facts(facts):
     fact_keys = set(data.keys())
     # first we add all of our magic variable names to the set of
     # keys we want to remove from facts
+    # NOTE: these will eventually disappear in favor of others below
     for magic_var in C.MAGIC_VARIABLE_MAPPING:
         remove_keys.update(fact_keys.intersection(C.MAGIC_VARIABLE_MAPPING[magic_var]))
+
+    # remove common connection vars
+    remove_keys.update(fact_keys.intersection(C.COMMON_CONNECTION_VARS))
+
     # next we remove any connection plugin specific vars
     for conn_path in connection_loader.all(path_only=True):
         try:
@@ -72,7 +77,7 @@ def clean_facts(facts):
             re_key = re.compile('^ansible_%s_' % conn_name)
             for fact_key in fact_keys:
                 # most lightweight VM or container tech creates devices with this pattern, this avoids filtering them out
-                if re_key.match(fact_key) and not fact_key.endswith(('_bridge', '_gwbridge')):
+                if (re_key.match(fact_key) and not fact_key.endswith(('_bridge', '_gwbridge'))) or re_key.startswith('ansible_become_'):
                     remove_keys.add(fact_key)
         except AttributeError:
             pass
diff --git a/lib/ansible/vars/manager.py b/lib/ansible/vars/manager.py
--- a/lib/ansible/vars/manager.py
+++ b/lib/ansible/vars/manager.py
@@ -43,7 +43,7 @@
 from ansible.utils.listify import listify_lookup_plugin_terms
 from ansible.utils.vars import combine_vars
 from ansible.utils.unsafe_proxy import wrap_var
-from ansible.vars.clean import namespace_facts
+from ansible.vars.clean import namespace_facts, clean_facts
 
 try:
     from __main__ import display
@@ -308,7 +308,7 @@ def plugins_by_groups():
 
                 # push facts to main namespace
                 if C.INJECT_FACTS_AS_VARS:
-                    all_vars = combine_vars(all_vars, wrap_var(facts))
+                    all_vars = combine_vars(all_vars, wrap_var(clean_facts(facts)))
                 else:
                     # always 'promote' ansible_local
                     all_vars = combine_vars(all_vars, wrap_var({'ansible_local': facts.get('ansible_local', {})}))


Test patch: