Initial cut of interface

.gitignore

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+.tox
+.testrepository

.gitreview

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+[gerrit]
+host=review.openstack.org
+port=29418
+project=openstack/charm-interface-keystone-domain-backend

README.md

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+# Overview
+
+This interface layer handles the communication with Keystone via the
+'keystone-domain-backend' interface protocol.
+
+# Usage
+
+## Provides
+
+The interface layer will set the following state:
+
+  * `{relation_name}.connected`  The relation is established.
+
+For example:
+
+```python
+from charms.reactive import when
+
+
+@when('domain-backend.connected')
+@when('configuration.complete')
+def configure_domain(domain):
+    domain.domain_name('mynewkeystonedomain')
+    domain.trigger_restart()
+```
+
+Typically a domain backend charm should validate that that it
+has sufficient and good configuration for the domain backend,
+write its configuration to
+`/etc/keystone/domains/keystone.<domain-name>.conf` and then
+trigger a restart of keystone using the `trigger_restart`
+method of the inteface, supplying the domain name at this
+point in time as well.
+
+The keystone charm will create the domain in the keystone
+database, mapping to the underlying domain configuration
+on disk.

interface.yaml

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+name: keystone-domain-backend
+summary: Interface for configuring Keystone Domain specific identity backends
+maintainer: OpenStack Charmers <openstack-charmers@lists.ubuntu.com>

provides.py

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+# Copyright 2017 Canonical Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#  http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import uuid
+
+from charms.reactive import RelationBase
+from charms.reactive import hook
+from charms.reactive import scopes
+
+
+class KeystoneDomainBackendProvides(RelationBase):
+    scope = scopes.GLOBAL
+
+    @hook('{provides:keystone-domain-backend}-relation-joined')
+    def joined(self):
+        self.set_state('{relation_name}.connected')
+
+    @hook('{provides:keystone-domain-backend}-relation-{broken,departed}')
+    def departed(self):
+        self.remove_state('{relation_name}.connected')
+
+    def domain_name(self, name):
+        """
+        Set the domain name for the identity backend
+        """
+        relation_info = {
+            'domain-name': name,
+        }
+        self.set_remote(**relation_info)
+
+    def trigger_restart(self):
+        """
+        Trigger a restart of keystone
+        """
+        relation_info = {
+            'restart-nonce': str(uuid.uuid4())
+        }
+        self.set_remote(**relation_info)

test-requirements.txt

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+flake8>=2.2.4,<=2.4.1
+os-testr>=0.4.1

tox.ini

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+[tox]
+envlist = pep8,py27,py34,py35
+skipsdist = True
+skip_missing_interpreters = True
+
+[testenv]
+setenv = VIRTUAL_ENV={envdir}
+         PYTHONHASHSEED=0
+install_command =
+  pip install --allow-unverified python-apt {opts} {packages}
+commands = ostestr {posargs}
+
+[testenv:py27]
+basepython = python2.7
+deps = -r{toxinidir}/test-requirements.txt
+# TODO: Need to write unit tests then remove the following command.
+commands = /bin/true
+
+[testenv:py34]
+basepython = python3.4
+deps = -r{toxinidir}/test-requirements.txt
+# TODO: Need to write unit tests then remove the following command.
+commands = /bin/true
+
+[testenv:py35]
+basepython = python3.5
+deps = -r{toxinidir}/test-requirements.txt
+# TODO: Need to write unit tests then remove the following command.
+commands = /bin/true
+
+[testenv:pep8]
+basepython = python2.7
+deps = -r{toxinidir}/test-requirements.txt
+commands = flake8 {posargs}
+
+[testenv:venv]
+commands = {posargs}
+
+[flake8]
+ignore = E402,E226