Initial attempt at #47

This commit adds support for the sources concept in yapconf. It
also adds support for etcd and kubernetes config loading.

.gitignore

@@ -55,6 +55,7 @@ coverage.xml
 
 # Sphinx documentation
 docs/_build/
+docs/yapconf.rst
 
 # PyBuilder
 target/

HISTORY.rst

@@ -2,6 +2,12 @@
 History
 =======
 
+0.3.0 TBD
+---------
+* Fixed an issue where utf-8 migrations would break
+* Added support for etcd
+* Added support for kubernetes
+
 0.2.4 (2018-05-21)
 ------------------
 * Flattened configs before loading (#54)

README.rst

@@ -35,6 +35,8 @@ Features
 Yapconf helps manage your python application's configuration
 
 * JSON/YAML config file support
+* Etcd config support
+* Kubernetes ConfigMap support
 * Argparse integration
 * Environment Loading
 * Bootstrapping
@@ -59,11 +61,15 @@ Then you can use Yapconf yourself!
     # First define a specification
     my_spec = YapconfSpec({"foo": {"type": "str", "default": "bar"}}, env_prefix='MY_APP_')
 
+    # Now add your sources (order does not matter)
+    my_spec.add_source('environment', 'environment')
+    my_spec.add_source('config.yaml', 'yaml', filename='/path/to/config.yaml')
+
     # Then load the configuration in whatever order you want!
     # load_config will automatically look for the 'foo' value in
     # '/path/to/config.yml', then the environment, finally
     # falling back to the default if it was not found elsewhere
-    config = my_spec.load_config('/path/to/config.yml', 'ENVIRONMENT')
+    config = my_spec.load_config('config.yaml', 'environment')
 
     print(config.foo)
     print(config['foo'])
@@ -82,7 +88,7 @@ You can also add these arguments to the command line very easily
     cli_args = vars(parser.parse_args(sys.argv[1:]))
 
     # Now you can load these via load_config:
-    config = my_spec.load_config(cli_args, '/path/to/config.yml', 'ENVIRONMENT')
+    config = my_spec.load_config(cli_args, 'config.yaml', 'environment')
 
 For more detailed information and better walkthroughs, checkout the documentation!
 

docs/index.rst

@@ -9,7 +9,8 @@ Contents:
    readme
    installation
    usage
-   modules
+   sources
+   API Documentation <modules>
    contributing
    authors
    history

docs/sources.rst

@@ -0,0 +1,169 @@
+.. _sources:
+
+=======
+Sources
+=======
+
+Yapconf supports a variety of different sources for configuration. Some of these sources require
+third-party libraries to be installed. Each of the sources should be loaded with the ``add_source``
+method call on a specification. The ``add_source`` may require differing keyword arguments
+depending on which source you wish to add.
+
+dict
+----
+
+The ``dict`` source type is just a dictionary.
+
+
+**Example**:
+
+.. code-block:: python
+
+    my_spec.add_source('label', 'dict', data={'foo': 'bar'})
+
+
+
+
++-------------------+----------+------------------------+
+| Keyword Arguments | Required | Description            |
++===================+==========+========================+
+| ``data``          | ``Y``    | The dictionary to use. |
++-------------------+----------+------------------------+
+
+environment
+-----------
+
+The ``environment`` source type is a dictionary, but we will copy the
+environment for you. There are no required keyword arguments.
+
+**Example**:
+
+.. code-block:: python
+
+    my_spec.add_source('label', 'environment')
+
+
+etcd
+----
+
+The ``etcd`` source type specifies that yapconf should load the configuration
+from an etcd.  In order to use the ``etcd`` capabilities in yapconf, you need
+to install the package yapconf uses for etcd:
+
+.. code-block:: console
+
+    $ pip install yapconf[etcd]
+
+**Example**
+
+.. code-block:: python
+
+    import etcd
+    client = etcd.Client()
+
+    my_spec.add_source('label', 'etcd', client=client, key='/')
+
+
++-------------------+----------+--------------------------------------------------------------------+
+| Keyword Arguments | Required | Description                                                        |
++===================+==========+====================================================================+
+| ``client``        | ``Y``    | Etcd client to use.                                                |
++-------------------+----------+--------------------------------------------------------------------+
+| ``key``           | ``N``    | Key to use, default is '/'. Key in etcd where your config resides. |
++-------------------+----------+--------------------------------------------------------------------+
+
+json
+----
+
+The ``json`` source type can specify either a JSON string or a JSON file to load.
+
+
+**Example**
+
+.. code-block:: python
+
+    # Load from JSON file
+    filename = '/path/to/config.json'
+    my_spec.add_source('label1', 'json', filename=filename)
+
+    # You can also load from a JSON string
+    json_string = json.loads(some_info)
+    my_spec.add_source('label2', 'json', data=json_string)
+
++-------------------+----------+--------------------------------------------------------------------+
+| Keyword Arguments | Required | Description                                                        |
++===================+==========+====================================================================+
+| ``filename``      | ``N``    | Filename of a JSON config file.                                    |
++-------------------+----------+--------------------------------------------------------------------+
+| ``data``          | ``N``    | Json String.                                                       |
++-------------------+----------+--------------------------------------------------------------------+
+| ``kwargs``        | ``N``    | Keyword arguments to pass to ``json.loads``                        |
++-------------------+----------+--------------------------------------------------------------------+
+
+
+kubernetes
+----------
+
+The ``kubernetes`` source type sp77ecifies that yapconf should load the configuration
+from a `kubernetes ConfigMap`_.  In order to use the ``kubernetes`` capabilities in yapconf,
+you need to install the package yapconf uses for kubernetes:
+
+.. code-block:: console
+
+    $ pip install yapconf[k8s]
+
+**Example**
+
+.. code-block:: python
+
+    from kubernetes import client, config
+    config.load_kube_config()
+
+    client = client.CoreV1Api()
+
+    my_spec.add_source(
+        'label',
+        'kubernetes',
+        client=client,
+        name='ConfigMapName'
+    )
+
+
++-------------------+----------+--------------------------------------------------------------+
+| Keyword Arguments | Required | Description                                                  |
++===================+==========+==============================================================+
+| ``client``        | ``Y``    | Kubernetes client to use.                                    |
++-------------------+----------+--------------------------------------------------------------+
+| ``name``          | ``Y``    | The name of the ``ConfigMap``.                               |
++-------------------+----------+--------------------------------------------------------------+
+| ``namespace``     | ``N``    | The namespace for the ``ConfigMap``.                         |
++-------------------+----------+--------------------------------------------------------------+
+| ``key``           | ``N``    | The key in the ``data`` portion of the ``ConfigMap``.        |
++-------------------+----------+--------------------------------------------------------------+
+| ``config_type``   | ``N``    | The format of the data in the ``key`` (support json or yaml) |
++-------------------+----------+--------------------------------------------------------------+
+
+
+yaml
+----
+
+The ``yaml`` source type lets you specify a YAML file to load.
+
+**Example:**
+
+.. code-block:: python
+
+    # Load from YAML file
+    filename = '/path/to/config.yaml'
+    my_spec.add_source('label1', 'yaml', filename=filename)
+
+
++-------------------+----------+---------------------------------+
+| Keyword Arguments | Required | Description                     |
++===================+==========+=================================+
+| ``filename``      | ``Y``    | Filename of a YAML config file. |
++-------------------+----------+---------------------------------+
+| ``encoding``      | ``N``    | Encoding of the YAML file       |
++-------------------+----------+---------------------------------+
+
+.. _kubernetes ConfigMap: https://kubernetes.io/docs/tasks/configure-pod-container/configure-pod-configmap