Add a cloud_platform 'profile' addon

* When installed, it pulls the addons required for Odoo to run on the
  Cloud Platform.
* It provides a method to configure Odoo at the installation.
* It checks if the environment variables are correct according the the
  'server environment'
* And add documentation

cloud_platform/models/cloud_platform.py

@@ -0,0 +1,127 @@
+# -*- coding: utf-8 -*-
+# Copyright 2016 Camptocamp SA
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html)
+
+import logging
+import os
+import re
+
+from collections import namedtuple
+
+from distutils.util import strtobool
+
+from openerp import api, models, SUPERUSER_ID
+from openerp.tools.config import config
+
+
+_logger = logging.getLogger(__name__)
+
+
+def is_true(strval):
+    return bool(strtobool(strval or '0'.lower()))
+
+
+PlatformConfig = namedtuple(
+    'PlatformConfig',
+    'filestore filestore_readonly'
+)
+
+
+class FilestoreKind(object):
+    db = 'db'
+    s3 = 's3://'  # or compatible s3 object storage
+    file = 'file'
+
+
+
+class CloudPlatform(models.AbstractModel):
+    _name = 'cloud.platform'
+
+    @api.model
+    def _config_by_server_env(self, environment):
+        configs = {
+            'prod': PlatformConfig(filestore=FilestoreKind.s3,
+                                   filestore_readonly=False),
+            'integration': PlatformConfig(filestore=FilestoreKind.s3,
+                                          filestore_readonly=True),
+            'test': PlatformConfig(filestore=FilestoreKind.db,
+                                   filestore_readonly=True),
+            'dev': PlatformConfig(filestore=FilestoreKind.db,
+                                  filestore_readonly=True),
+        }
+        return configs.get(environment) or configs['dev']
+
+    @api.model
+    def install_exoscale(self):
+        params = self.env['ir.config_parameter'].sudo()
+        params.set_param('cloud.platform.kind', 'exoscale')
+        environment = config['running_env']
+        configs = self._config_by_server_env(environment)
+        params.set_param('ir_attachment.location', configs.filestore)
+        self.check(self.env)
+        if configs.filestore == FilestoreKind.s3:
+            self.env['ir.attachment'].sudo().force_storage()
+        _logger.info('cloud platform configured for exoscale')
+
+    @api.model
+    def _check_s3(self, environment_name):
+        params = self.env['ir.config_parameter'].sudo()
+        attachment_readonly = is_true(
+            os.environ.get('AWS_ATTACHMENT_READONLY')
+        )
+        if environment_name in ('prod', 'integration'):
+            assert os.environ.get('AWS_ACCESS_KEY_ID')
+            assert os.environ.get('AWS_SECRET_ACCESS_KEY')
+            assert os.environ.get('AWS_BUCKETNAME')
+            bucket_name = os.environ['AWS_BUCKETNAME']
+            assert re.match(r'[a-z]+-odoo-prod', bucket_name), (
+                "AWS_BUCKETNAME should match '<client>-odoo-prod', "
+                "we got: '%s'" % (bucket_name,)
+            )
+            assert params.get_param('ir_attachment.location') == 's3://'
+            # on the integration, we read the filestore from the production
+            # s3, but we must be readonly!
+            if environment_name == 'integration':
+                assert attachment_readonly
+            else:
+                assert not attachment_readonly
+        elif environment_name == 'test':
+            assert params.get_param('ir_attachment.location') == 'db'
+        else:
+            assert params.get_param('ir_attachment.location') in ('db', 'file')
+
+    @api.model
+    def _check_redis(self, environment_name):
+        assert is_true(os.environ.get('ODOO_SESSION_REDIS'))
+        assert os.environ.get('ODOO_SESSION_REDIS_HOST')
+        assert os.environ.get('ODOO_SESSION_REDIS_PREFIX')
+        prefix = os.environ['ODOO_SESSION_REDIS_PREFIX']
+        if environment_name in ('prod', 'integration', 'test'):
+            assert re.match(r'[a-z]+-odoo-%s' % (environment_name,), prefix), (
+                "ODOO_SESSION_REDIS_PREFIX should match '<client>-odoo-%s', "
+                "we got: '%s'" % (environment_name, prefix)
+            )
+
+    @api.model
+    def check(self):
+        if is_true(os.environ.get('ODOO_CLOUD_PLATFORM_UNSAFE')):
+            _logger.warning(
+                "cloud platform checks disabled, this is not safe"
+            )
+            return
+        params = self.env['ir.config_parameter'].sudo()
+        kind = params.get_param('cloud.platform.kind')
+        if not kind:
+            _logger.warning(
+                "cloud platform not configured, you should "
+                "probably run 'env['cloud.platform'].install_exoscale()'"
+            )
+            return
+        environment_name = config['running_env']
+        self._check_s3(environment_name)
+        self._check_redis(environment_name)
+
+    @api.cr
+    def _register_hook(self, cr):
+        env = api.Environment(cr, SUPERUSER_ID, {})
+        env['cloud.platform'].check()