Merge pull request #4 from zdc/T2117

Cloud-init: T2117: Updated to 20.1 version

1 files changed, 68 insertions, 0 deletions

diff --git a/doc/rtd/topics/datasources/exoscale.rst b/doc/rtd/topics/datasources/exoscale.rst
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+.. _datasource_exoscale:
+
+Exoscale
+========
+
+This datasource supports reading from the metadata server used on the
+`Exoscale platform <https://exoscale.com>`_.
+
+Use of the Exoscale datasource is recommended to benefit from new features of
+the Exoscale platform.
+
+The datasource relies on the availability of a compatible metadata server
+(``http://169.254.169.254`` is used by default) and its companion password
+server, reachable at the same address (by default on port 8080).
+
+Crawling of metadata
+--------------------
+
+The metadata service and password server are crawled slightly differently:
+
+ * The "metadata service" is crawled every boot.
+ * The password server is also crawled every boot (the Exoscale datasource
+   forces the password module to run with "frequency always").
+
+In the password server case, the following rules apply in order to enable the
+"restore instance password" functionality:
+
+ * If a password is returned by the password server, it is then marked "saved"
+   by the cloud-init datasource. Subsequent boots will skip setting the
+   password (the password server will return "saved_password").
+ * When the instance password is reset (via the Exoscale UI), the password
+   server will return the non-empty password at next boot, therefore causing
+   cloud-init to reset the instance's password.
+
+Configuration
+-------------
+
+Users of this datasource are discouraged from changing the default settings
+unless instructed to by Exoscale support.
+
+The following settings are available and can be set for the datasource in
+system configuration (in `/etc/cloud/cloud.cfg.d/`).
+
+The settings available are:
+
+ * **metadata_url**: The URL for the metadata service (defaults to
+   ``http://169.254.169.254``)
+ * **api_version**: The API version path on which to query the instance
+   metadata (defaults to ``1.0``)
+ * **password_server_port**: The port (on the metadata server) on which the
+   password server listens (defaults to ``8080``).
+ * **timeout**: the timeout value provided to urlopen for each individual http
+   request. (defaults to ``10``)
+ * **retries**: The number of retries that should be done for an http request
+   (defaults to ``6``)
+
+
+An example configuration with the default values is provided below:
+
+.. sourcecode:: yaml
+
+   datasource:
+     Exoscale:
+       metadata_url: "http://169.254.169.254"
+       api_version: "1.0"
+       password_server_port: 8080
+       timeout: 10
+       retries: 6