arbabnazar · January 14, 2023 18:33 · Jul 8, 2015 · Jul 8, 2015 · Jul 8, 2015
diff --git a/test-lookup.yml b/test-lookup.yml
@@ -0,0 +1,14 @@
+# this is just to test the custom lookup plugin
+- hosts: all
+  gather_facts: false
+  connection: local
+
+  vars_files:
+  - vars/app_defaults.yml
+
+  tasks:
+  - name: shut down services (app)
+    debug: msg="shutting down {{item.app_name}} on port {{item.instance}}"
+    with_app_defaults:
+    - apps_packages
+    - app_defaults
diff --git a/gistfile1.txt → app_defaults.py b/gistfile1.txt → app_defaults.py
diff --git a/gistfile1.txt b/gistfile1.txt
@@ -0,0 +1,57 @@
+import ansible.utils as utils
+#
+# Put this file in lookup_plugins/ alongside your playbooks.
+#
+# Lookup plugins can be called two ways: via with_ as a task loop
+# construct, or via lookup('name').
+# 
+# You can find the code for the basic lookup plugins here:
+# v1: https://github.com/ansible/ansible/tree/devel/v1/ansible/runner/lookup_plugins
+# v2: https://github.com/ansible/ansible/tree/devel/lib/ansible/plugins/lookup
+#
+
+class LookupModule(object):
+    def __init__(self, basedir=None, **kwargs):
+        self.basedir = basedir
+
+    def run(self, terms, inject=None, **kwargs):
+        # "listify" basically dereferences a variable name passed into the plugin
+        # ie: with_app_defaults:
+        #      - foo
+        #      - bar
+        # 
+        # ...where foo and bar are data structures.
+        # 
+        terms = utils.listify_lookup_plugin_terms(terms, self.basedir, inject)
+        apps = utils.listify_lookup_plugin_terms(terms[0], self.basedir, inject)
+        app_defaults = utils.listify_lookup_plugin_terms(terms[1], self.basedir, inject)
+
+        # everything below is very specific to the application --you'll need to change
+        # it to suit your needs. perhaps you could use it to merge the global security
+        # groups data structure with the region-specific list and return a flattened list.
+        results = []
+
+        # .......
+        # each item in the *_packages list -- can be either a string, to take the default
+        # instance from app_defaults, or a dict, in which case we might specify a list of
+        # instances (ports)
+        for x in apps:
+            # if hostvars specifies an instance list, use it. if not, take the first one
+            # from the defaults.
+            name = x['name']
+            if 'instances' in x:
+                instances = x['instances']
+            else:
+                instances = [app_defaults[name]['ports'][0]]
+
+            if name not in app_defaults:
+                print "WARNING: invalid application name:", x
+                continue
+
+            for instance in instances:
+                y = dict(app_defaults[name])
+                del y['ports']
+                y['instance'] = instance
+                y['app_name'] = name
+                results.append(y)
+        return results