Add json parameter to get JSON output from ansible.command*

CHANGES.md

@@ -1,5 +1,33 @@
 # Changelog
 
+## v0.6.0
+
+* Add a json parameter to `ansible.command` and `ansible.command_local` actions. When False (the default), stdout is not changed. When True, this replaces ansible's stdout with a valid JSON object. We do this by using ansible's `--tree` argument to save the output to a temporary directory, and then sending a json object where the node name is the key, and the ansible output is the value.
+
+```
+$ st2 run ansible.command_local become=true module_name=setup json=True
+.
+id: 594d6657c4da5f08e9ec7c51
+status: succeeded
+parameters:
+  become: true
+  json: true
+  module_name: setup
+result:
+  failed: false
+  return_code: 0
+  stderr: ''
+  stdout:
+    127.0.0.1:
+      ansible_facts:
+        ansible_all_ipv4_addresses:
+      ...
+      changed: false
+  succeeded: true
+
+```
+
+
 ## v0.5.0
 
 * Added ability to use yaml structures to pass arbitrarily complex values through extra_vars. key=value and @file syntax is still supported. Example usage:

README.md

@@ -34,6 +34,52 @@ ansible all -c local -i '127.0.0.1,' -a 'echo $TERM'
 ansible all --connection=local --inventory-file='127.0.0.1,' --args='echo $TERM'
 ```
 
+##### structured output from `ansible.command` and `ansible.command_local`:
+
+To get a JSON object back from `ansible.command*`, set the json parameter to True. This uses ansible's `--tree` output to generate a JSON object with one element per node: `{"node-name": node-ouput}`
+
+
+```
+$ st2 run ansible.command_local become=true module_name=setup json=True
+.
+id: 594d6657c4da5f08e9ec7c51
+status: succeeded
+parameters:
+  become: true
+  json: true
+  module_name: setup
+result:
+  failed: false
+  return_code: 0
+  stderr: ''
+  stdout:
+    127.0.0.1:
+      ansible_facts:
+        ansible_all_ipv4_addresses:
+      ...
+      changed: false
+  succeeded: true
+```
+
+With this structured output, you could use the setup module as the first step of a workflow, and then base additional workflow steps on variables from ansible's setup. It should work similarly for other modules.
+
+For instance, if you needed the default ipv4 address of a node, you could publish the appropriate ansible_fact like this (in an action-chain workflow):
+
+```yaml
+chain:
+  -
+    name: ansible_setup
+    ref:  ansible.command_local
+    parameters:
+      become: True
+      json: True
+      module_name: setup
+    publish:
+      default_ip: "{{ ansible_setup.stdout['127.0.0.1'].ansible_facts.ansible_default_ipv4.address }}"
+```
+
+
+
 #### `ansible.playbook` examples
 ```sh
 # run some simple playbook

actions/ansible.py

@@ -1,7 +1,13 @@
 #!/usr/bin/env python
 
+from __future__ import print_function
+
+import json
+import os
+import shutil
 import sys
-from lib.ansible_base import AnsibleBaseRunner
+import tempfile
+from lib.ansible_base import AnsibleBaseRunner, ParamaterConflict
 
 __all__ = [
     'AnsibleRunner'
@@ -32,8 +38,53 @@ class AnsibleRunner(AnsibleBaseRunner):
     }
 
     def __init__(self, *args, **kwargs):
+        self.tree_dir = None
+        self.one_line = False
+        if '--one_line' in args:
+            self.one_line = True
         super(AnsibleRunner, self).__init__(*args, **kwargs)
 
+    def handle_json_arg(self):
+        if next((True for arg in self.args if arg.startswith('--tree')), False):
+            msg = "--json uses --tree internally. Setting both --tree and --json is not supported."
+            raise ParamaterConflict(msg)
+        execution_id = os.environ.get('ST2_ACTION_EXECUTION_ID', 'EXECUTION_ID_NA')
+        self.tree_dir = tempfile.mkdtemp(prefix='{}.'.format(execution_id))
+
+        tree_arg = '--tree={}'.format(self.tree_dir)
+        self.args.append(tree_arg)
+
+        # This sends all ansible stdout to /dev/null - if there's anything in there that's not in
+        # the --tree output, then it will be lost. Hopefully ansible doesn't print anything truly
+        # important... If something breaks, I guess we'll just have to run it without --json
+        # to see what is going on.
+        self.stdout = open(os.devnull, 'w')
+
+    def output_json(self):
+        output = {}
+        for host in os.listdir(self.tree_dir):
+            # one file per host in tree dir; name of host is name of file
+            with open(os.path.join(self.tree_dir, host), 'r') as host_output:
+                try:
+                    output[host] = json.load(host_output)
+                except ValueError:
+                    # something is messed up in the json, so include it as a string.
+                    host_output.seek(0)
+                    output[host] = host_output.read()
+        if self.one_line:
+            print(json.dumps(output))
+        else:
+            print(json.dumps(output, indent=2))
+
+    def cleanup(self):
+        shutil.rmtree(self.tree_dir)
+        self.stdout.close()
+
+    def post_execute(self):
+        if self.json_output:
+            self.output_json()
+            self.cleanup()
+
 
 if __name__ == '__main__':
     AnsibleRunner(sys.argv).execute()

actions/command.yaml

@@ -105,3 +105,6 @@ parameters:
   version:
     description: "Show ansible version number and exit"
     type: boolean
+  json:
+    description: "Clean up Ansible's output to ensure it is valid jSON"
+    type: boolean

actions/command_local.yaml

@@ -105,3 +105,6 @@ parameters:
   version:
     description: "Show ansible version number and exit"
     type: boolean
+  json:
+    description: "Clean up Ansible's output to ensure it is valid jSON"
+    type: boolean

actions/lib/ansible_base.py

@@ -23,7 +23,11 @@ def __init__(self, args):
         :param args: Input command line arguments
         :type args: ``list``
         """
+        self.json_output = False
+        self.stdout = None
+
         self.args = args[1:]
+        self._json_output_arg()
         self._parse_extra_vars()  # handle multiple entries in --extra_vars arg
         self._prepend_venv_path()
 
@@ -64,7 +68,7 @@ def _parse_extra_vars(self):
 
                     # Add --extra-vars for each json object
                     elif t == 'json':
-                        self.args.append("--extra-vars='{0}'".format(json.dumps(v)))
+                        self.args.append("--extra-vars={0}".format(json.dumps(v)))
 
                     # Combine contiguous kwarg vars into a single space-separated --extra-vars kwarg
                     elif t == 'kwarg' and last != t:
@@ -96,17 +100,37 @@ def _prepend_venv_path():
 
         os.environ['PATH'] = ':'.join(new_path)
 
+    def _json_output_arg(self):
+        for i, arg in enumerate(self.args):
+            if '--json' in arg:
+                self.json_output = True
+                self.handle_json_arg()
+                # if ansible-playbook, add env arg
+                del self.args[i]  # The json arg is a ST2 specific addition & should not pass on.
+                break
+            elif '--one_line' in arg:
+                self.one_line = True
+
+    def handle_json_arg(self):
+        pass
+
     def execute(self):
         """
         Execute the command and stream stdout and stderr output
         from child process as it appears without delay.
         Terminate with child's exit code.
         """
-        exit_code = subprocess.call(self.cmd, env=os.environ.copy())
+        exit_code = subprocess.call(self.cmd, env=os.environ.copy(), stdout=self.stdout)
         if exit_code is not 0:
             sys.stderr.write('Executed command "%s"\n' % ' '.join(self.cmd))
+
+        self.post_execute()
+
         sys.exit(exit_code)
 
+    def post_execute(self):
+        pass
+
     @property
     @shell.replace_args('REPLACEMENT_RULES')
     def cmd(self):
@@ -139,3 +163,7 @@ def binary(self):
             sys.exit(1)
 
         return binary_path
+
+
+class ParamaterConflict(Exception):
+    pass

pack.yaml

@@ -6,6 +6,6 @@ keywords:
   - ansible
   - cfg management
   - configuration management
-version : 0.5.1
+version : 0.6.0
 author : StackStorm, Inc.
 email : info@stackstorm.com

tests/test_actions_lib_ansiblebaserunner.py

@@ -86,7 +86,7 @@ def extra_vars_json_yaml_fixture(self, test_name):
         test_yaml = self.load_yaml('extra_vars_json.yaml')
         test = next(t for t in test_yaml if t['name'] == test_name)
         case = test['test']
-        expected = ['--extra-vars=\'{}\''.format(json.dumps(e)) for e in case]
+        expected = ['--extra-vars={}'.format(json.dumps(e)) for e in case]
         self.check_arg_parse(arg, case, expected)
 
     def test_parse_extra_vars_json_yaml_dict(self):
@@ -115,7 +115,7 @@ def extra_vars_complex_yaml_fixture(self, test_name):
         # this does not preserve the order exactly, but it shows that elements are correctly parsed
         expected = ['--extra-vars={}'.format(e)
                     for e in test['expected'] if isinstance(e, six.string_types)]
-        expected.extend(['--extra-vars=\'{}\''.format(json.dumps(e))
+        expected.extend(['--extra-vars={}'.format(json.dumps(e))
                          for e in test['expected'] if isinstance(e, dict)])
         self.check_arg_parse(arg, case, expected)