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authorzsdc <taras@vyos.io>2022-03-25 20:58:01 +0200
committerzsdc <taras@vyos.io>2022-03-25 21:42:00 +0200
commit31448cccedd8f841fb3ac7d0f2e3cdefe08a53ba (patch)
tree349631a02467dae0158f6f663cc8aa8537974a97 /doc/rtd/topics/datasources/azure.rst
parent5c4b3943343a85fbe517e5ec1fc670b3a8566b4b (diff)
parent8537237d80a48c8f0cbf8e66aa4826bbc882b022 (diff)
downloadvyos-cloud-init-31448cccedd8f841fb3ac7d0f2e3cdefe08a53ba.tar.gz
vyos-cloud-init-31448cccedd8f841fb3ac7d0f2e3cdefe08a53ba.zip
T2117: Cloud-init updated to 22.1
Merged with 22.1 tag from the upstream Cloud-init repository. Our modules were slightly modified for compatibility with the new version.
Diffstat (limited to 'doc/rtd/topics/datasources/azure.rst')
-rw-r--r--doc/rtd/topics/datasources/azure.rst84
1 files changed, 11 insertions, 73 deletions
diff --git a/doc/rtd/topics/datasources/azure.rst b/doc/rtd/topics/datasources/azure.rst
index e04c3a33..1bd03970 100644
--- a/doc/rtd/topics/datasources/azure.rst
+++ b/doc/rtd/topics/datasources/azure.rst
@@ -5,28 +5,6 @@ Azure
This datasource finds metadata and user-data from the Azure cloud platform.
-walinuxagent
-------------
-walinuxagent has several functions within images. For cloud-init
-specifically, the relevant functionality it performs is to register the
-instance with the Azure cloud platform at boot so networking will be
-permitted. For more information about the other functionality of
-walinuxagent, see `Azure's documentation
-<https://github.com/Azure/WALinuxAgent#introduction>`_ for more details.
-(Note, however, that only one of walinuxagent's provisioning and cloud-init
-should be used to perform instance customisation.)
-
-If you are configuring walinuxagent yourself, you will want to ensure that you
-have `Provisioning.UseCloudInit
-<https://github.com/Azure/WALinuxAgent#provisioningusecloudinit>`_ set to
-``y``.
-
-
-Builtin Agent
--------------
-An alternative to using walinuxagent to register to the Azure cloud platform
-is to use the ``__builtin__`` agent command. This section contains more
-background on what that code path does, and how to enable it.
The Azure cloud platform provides initial data to an instance via an attached
CD formatted in UDF. That CD contains a 'ovf-env.xml' file that provides some
@@ -41,16 +19,6 @@ by calling a script in /etc/dhcp/dhclient-exit-hooks or a file in
'dhclient_hook' of cloud-init itself. This sub-command will write the client
information in json format to /run/cloud-init/dhclient.hook/<interface>.json.
-In order for cloud-init to leverage this method to find the endpoint, the
-cloud.cfg file must contain:
-
-.. sourcecode:: yaml
-
- datasource:
- Azure:
- set_hostname: False
- agent_command: __builtin__
-
If those files are not available, the fallback is to check the leases file
for the endpoint server (again option 245).
@@ -83,9 +51,6 @@ configuration (in ``/etc/cloud/cloud.cfg`` or ``/etc/cloud/cloud.cfg.d/``).
The settings that may be configured are:
- * **agent_command**: Either __builtin__ (default) or a command to run to getcw
- metadata. If __builtin__, get metadata from walinuxagent. Otherwise run the
- provided command to obtain metadata.
* **apply_network_config**: Boolean set to True to use network configuration
described by Azure's IMDS endpoint instead of fallback network config of
dhcp on eth0. Default is True. For Ubuntu 16.04 or earlier, default is
@@ -95,20 +60,6 @@ The settings that may be configured are:
custom DHCP option 245 from Azure fabric.
* **disk_aliases**: A dictionary defining which device paths should be
interpreted as ephemeral images. See cc_disk_setup module for more info.
- * **hostname_bounce**: A dictionary Azure hostname bounce behavior to react to
- metadata changes. The '``hostname_bounce: command``' entry can be either
- the literal string 'builtin' or a command to execute. The command will be
- invoked after the hostname is set, and will have the 'interface' in its
- environment. If ``set_hostname`` is not true, then ``hostname_bounce``
- will be ignored. An example might be:
-
- ``command: ["sh", "-c", "killall dhclient; dhclient $interface"]``
-
- * **hostname_bounce**: A dictionary Azure hostname bounce behavior to react to
- metadata changes. Azure will throttle ifup/down in some cases after metadata
- has been updated to inform dhcp server about updated hostnames.
- * **set_hostname**: Boolean set to True when we want Azure to set the hostname
- based on metadata.
Configuration for the datasource can also be read from a
``dscfg`` entry in the ``LinuxProvisioningConfigurationSet``. Content in
@@ -121,18 +72,11 @@ An example configuration with the default values is provided below:
datasource:
Azure:
- agent_command: __builtin__
apply_network_config: true
data_dir: /var/lib/waagent
dhclient_lease_file: /var/lib/dhcp/dhclient.eth0.leases
disk_aliases:
ephemeral0: /dev/disk/cloud/azure_resource
- hostname_bounce:
- interface: eth0
- command: builtin
- policy: true
- hostname_command: hostname
- set_hostname: true
Userdata
@@ -144,9 +88,7 @@ child of the ``LinuxProvisioningConfigurationSet`` (a sibling to ``UserName``)
If both ``UserData`` and ``CustomData`` are provided behavior is undefined on
which will be selected.
-In the example below, user-data provided is 'this is my userdata', and the
-datasource config provided is ``{"agent_command": ["start", "walinuxagent"]}``.
-That agent command will take affect as if it were specified in system config.
+In the example below, user-data provided is 'this is my userdata'
Example:
@@ -184,21 +126,17 @@ The hostname is provided to the instance in the ovf-env.xml file as
Whatever value the instance provides in its dhcp request will resolve in the
domain returned in the 'search' request.
-The interesting issue is that a generic image will already have a hostname
-configured. The ubuntu cloud images have 'ubuntu' as the hostname of the
-system, and the initial dhcp request on eth0 is not guaranteed to occur after
-the datasource code has been run. So, on first boot, that initial value will
-be sent in the dhcp request and *that* value will resolve.
-
-In order to make the ``HostName`` provided in the ovf-env.xml resolve, a
-dhcp request must be made with the new value. Walinuxagent (in its current
-version) handles this by polling the state of hostname and bouncing ('``ifdown
-eth0; ifup eth0``' the network interface if it sees that a change has been
-made.
+A generic image will already have a hostname configured. The ubuntu
+cloud images have 'ubuntu' as the hostname of the system, and the
+initial dhcp request on eth0 is not guaranteed to occur after the
+datasource code has been run. So, on first boot, that initial value
+will be sent in the dhcp request and *that* value will resolve.
-cloud-init handles this by setting the hostname in the DataSource's 'get_data'
-method via '``hostname $HostName``', and then bouncing the interface. This
+In order to make the ``HostName`` provided in the ovf-env.xml resolve,
+a dhcp request must be made with the new value. cloud-init handles
+this by setting the hostname in the DataSource's 'get_data' method via
+'``hostname $HostName``', and then bouncing the interface. This
behavior can be configured or disabled in the datasource config. See
'Configuration' above.
-.. vi: textwidth=78
+.. vi: textwidth=79