zuul-stream: Add variable to disable writing streaming files

Upon further discussion we recently found another case of leaking
console streaming files; if the zuul_console is not running on port
19885, or can not be reached, the streaming spool files will still be
leaked.

The prior work in I823156dc2bcae91bd6d9770bd1520aa55ad875b4 has the
receiving side indicate to the zuul_console daemon that it should
remove the spool file.

If this doesn't happen, either because the daemon was never there, or
it is firewalled off, the streaming spool files are left behind.

This modifies the command action plugin to look for a variable
"zuul_console_disable" which will indicate to the library running the
shell/command task not to write out the spool file at all, as it will
not be consumed.

It is expected this would be set at a host level in inventory for
nodes that you know can not or will not have access to zuul_console
daemon.

We already have a mechanism to disable this for commands running in a
loop; we expand this with a new string type.  The advantage of this is
it leaves the library/command.py side basically untouched.

Documentation is updated, and we cover this with a new test.

Change-Id: I0273993c3ece4363098e4bf30bfc4308bb69a8b4

2 files changed, 18 insertions, 6 deletions

diff --git a/zuul/ansible/base/action/command.py b/zuul/ansible/base/action/command.py
index 3bb88d8e5..a969a8b2b 100644
--- a/zuul/ansible/base/action/command.py
+++ b/zuul/ansible/base/action/command.py
@@ -13,8 +13,10 @@
 # You should have received a copy of the GNU General Public License
 # along with this software.  If not, see <http://www.gnu.org/licenses/>.
 
-
 from zuul.ansible import paths
+
+from ansible.module_utils.parsing.convert_bool import boolean
+
 command = paths._import_ansible_action_plugin("command")
 
 
@@ -25,10 +27,17 @@ class ActionModule(command.ActionModule):
         if self._task.action in (
                 'command', 'shell',
                 'ansible.builtin.command', 'ansible.builtin.shell'):
-            # This is a bit lame, but we do not log loops in the
-            # zuul_stream.py callback.  This allows us to not write
-            # out command.py output to files that will never be read.
-            if 'ansible_loop_var' in task_vars:
+            # Overloading the UUID is a bit lame, but it stops us
+            # having to modify the library command.py too much.  Both
+            # of these below stop the creation of the files on disk
+            # for situations where they won't be read and cleaned-up.
+            skip = boolean(
+                self._templar.template(
+                    "{{zuul_console_disabled|default(false)}}"))
+            if skip:
+                self._task.args['zuul_log_id'] = 'skip'
+            elif 'ansible_loop_var' in task_vars:
+                # we do not log loops in the zuul_stream.py callback.
                 self._task.args['zuul_log_id'] = 'in-loop-ignore'
             else:
                 # Get a unique key for ZUUL_LOG_ID_MAP.  ZUUL_LOG_ID_MAP
diff --git a/zuul/ansible/base/library/command.py b/zuul/ansible/base/library/command.py
index 3c22849ae..c52412edf 100755
--- a/zuul/ansible/base/library/command.py
+++ b/zuul/ansible/base/library/command.py
@@ -270,6 +270,8 @@ class Console(object):
         # special-casing for any of this path.
         if log_uuid == 'in-loop-ignore':
             self.logfile_name = os.devnull
+        elif log_uuid == 'skip':
+            self.logfile_name = os.devnull
         else:
             self.logfile_name = LOG_STREAM_FILE.format(log_uuid=log_uuid)
 
@@ -494,7 +496,8 @@ def zuul_run_command(self, args, zuul_log_id, check_rc=False, close_fds=True, ex
 
     try:
         if self._debug:
-            self.log('Executing: ' + self._clean_args(args))
+            self.log('Executing <%s>: %s',
+                     zuul_log_id, self._clean_args(args))
 
         # ZUUL: Replaced the execution loop with the zuul_runner run function