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diff --git a/README.md b/README.md
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+ghetto_json
+===========
+
+Need a quick way to edit a JSON file in Ansible?  Ansible has great built-in support for
+ ini files, but a number of more modern applications are using JSON for config files.
+
+ghetto_json lets you make some types of edits to JSON files, and remains simple enough that
+  it's hopefully easier just to extend than to switch to a different module, and you won't feel
+  too guilty just copy-pasting it into your codebase.
+
+
+Installation
+------------
+
+Drop ``ghetto_json`` into your playbook's ``library`` folder,
+ which can be [configured](https://docs.ansible.com/ansible/intro_configuration.html#library)
+ but defaults to ``./library`` inside a playbook.
+
+Synopsis
+--------
+
+Make in-place changes to simple JSON documents,
+ without having to resort to ``replace``.
+
+
+Requirements
+------------
+
+Python 2.7 may be required for some ``shlex`` functionality
+ (like working Unicode), which you probably don't care about.
+
+
+Options
+-------
+
+#### path:
+
+The file on the target to edit.
+
+#### all other options:
+
+A very simple object notation for the location of the property to edit,
+ and its new value.
+
+Mandatory automatic conversion will be applied. Supported values:
+
+ * integers (``5``, ``-17``)
+ * ``true`` / ``false``
+ * ``null``
+ * ``unset`` will delete the key
+
+
+Examples
+--------
+
+For the example JSON document ``/foo/bar.json`` containing:
+````
+{ "a": 5, "b": {"c": 6, "d": "hello" } }
+````
+
+...you can run an invocation like:
+````
+ - ghetto_json:
+    path=/foo/bar.json
+    a=7
+    b.c=yellow
+    b.d=unset
+````
+
+...and the file will be left looking like:
+
+````
+{
+  "a": 7,
+  "b": {
+    "c": "yellow"
+  }
+}
+````
diff --git a/ghetto_json b/ghetto_json
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+#!/usr/bin/env python
+
+import json
+import sys
+import shlex
+
+
+def main(params_list):
+    params = dict(x.split("=", 2) for x in params_list)
+    path = params.pop('path')
+    changed = False
+
+    with open(path) as f:
+        obj = json.load(f)
+        for (key, target) in params.items():
+            parts = key.split('.')
+            ref = obj
+            for part in parts[:-1]:
+                if part not in ref:
+                    ref[part] = {}
+                ref = ref[part]
+
+            last_part = parts[-1]
+            if target == 'unset':
+                if last_part in ref:
+                    del ref[last_part]
+                    changed = True
+            else:
+                if target.isdigit():
+                    target = int(target)
+                if target == 'null':
+                    target = None
+                if target == 'false':
+                    target = False
+                if target == 'true':
+                    target = True
+                if last_part not in ref or ref[last_part] != target:
+                    ref[last_part] = target
+                    changed = True
+
+    if changed:
+        with open(path, 'w') as f:
+            json.dump(obj, f, indent=2, separators=(',', ': '), sort_keys=True)
+
+    print(json.dumps({'changed': changed}))
+
+
+if __name__ == '__main__':
+    if len(sys.argv) == 2:
+        main(shlex.split(open(sys.argv[1]).read()))
+    else:
+        main(sys.argv[1:])
+
diff --git a/test.sh b/test.sh
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+#!/bin/bash
+set -eu
+T=$(mktemp)
+trap "rm $T" EXIT
+echo '{ "a": 5, "b": {"c": 6, "d": "hello" } }' > $T
+python ghetto_json path=$T a=7 b.c=yellow b.d=unset
+diff -u <(printf '{\n  "a": 7,\n  "b": {\n    "c": "yellow"\n  }\n}') $T
+