cloud-init/doc/sources/smartos

SmartOS Datasource

This datasource finds metadata and user-data from the SmartOS virtualization platform (i.e. Joyent).

Please see http://smartos.org/ for information about SmartOS.

SmartOS Platform

The SmartOS virtualization platform uses meta-data to the instance via the second serial console. On Linux, this is /dev/ttyS1. The data is a provided via a simple protocol: something queries for the data, the console responds responds with the status and if "SUCCESS" returns until a single ".n".

New versions of the SmartOS tooling will include support for base64 encoded data.

Meta-data channels

Cloud-init supports three modes of delivering user/meta-data via the flexible channels of SmartOS.

• user-data is written to /var/db/user-data
  • per the spec, user-data is for consumption by the end-user, not provisioning tools
  • cloud-init entirely ignores this channel other than writting it to disk
  • removal of the meta-data key means that /var/db/user-data gets removed
  • a backup of previous meta-data is maintained as /var/db/user-data.<timestamp>
    • <timestamp> is the epoch time when cloud-init ran
• user-script is written to /var/lib/cloud/scripts/per-boot/99_user_data
  • this is executed each boot
  • a link is created to /var/db/user-script
  • previous versions of the user-script is written to /var/lib/cloud/scripts/per-boot.backup/99_user_script.<timestamp>.
    • <timestamp> is the epoch time when cloud-init ran.
  • when the 'user-script' meta-data key goes missing, the user-script is removed from the file system, although a backup is maintained.
  • if the script is not shebanged (i.e. starts with #!<executable>), then or is not an executable, cloud-init will add a shebang of "#!/bin/bash"
• cloud-init:user-data is treated like on other Clouds.
  • this channel is used for delivering _all cloud-init instructions
  • scripts delivered over this channel must be well formed (i.e. must have a shebang)

Cloud-init supports reading the traditional meta-data fields supported by the SmartOS tools. These are: * root_authorized_keys * hostname * enable_motd_sys_info * iptables_disable

Note: At this time iptables_disable and enable_motd_sys_info are read but

are not actioned.

disabling user-script

Cloud-init uses the per-boot script functionality to handle the execution of the user-script. If you want to prevent this use a cloud-config of:

#cloud-config cloud_final_modules: - scripts-per-once - scripts-per-instance - scripts-user - ssh-authkey-fingerprints - keys-to-console - phone-home - final-message - power-state-change

Alternatively you can use the json patch method #cloud-config-jsonp [ { "op": "replace", "path": "/cloud_final_modules", "value": ["scripts-per-once", "scripts-per-instance", "scripts-user", "ssh-authkey-fingerprints", "keys-to-console", "phone-home", "final-message", "power-state-change"] } ]

The default cloud-config includes "script-per-boot". Cloud-init will still ingest and write the user-data but will not execute it, when you disable the per-boot script handling.

Note: Unless you have an explicit use-case, it is recommended that you not

disable the per-boot script execution, especially if you are using any of the life-cycle management features of SmartOS.

The cloud-config needs to be delivered over the cloud-init:user-data channel in order for cloud-init to ingest it.

base64

The following are exempt from base64 encoding, owing to the fact that they are provided by SmartOS: * root_authorized_keys * enable_motd_sys_info * iptables_disable * user-data * user-script

This list can be changed through system config of variable 'no_base64_decode'.

This means that user-script and user-data as well as other values can be base64 encoded. Since Cloud-init can only guess as to whether or not something is truly base64 encoded, the following meta-data keys are hints as to whether or not to base64 decode something: * base64_all: Except for excluded keys, attempt to base64 decode the values. If the value fails to decode properly, it will be returned in its text * base64_keys: A comma deliminated list of which keys are base64 encoded. * b64-<key>: for any key, if there exists an entry in the metadata for 'b64-<key>' Then 'b64-<key>' is expected to be a plaintext boolean indicating whether or not its value is encoded. * no_base64_decode: This is a configuration setting (i.e. /etc/cloud/cloud.cfg.d) that sets which values should not be base64 decoded.

disk_aliases and ephemeral disk: ---------------By default, SmartOS only supports a single ephemeral disk. That disk is completely empty (un-partitioned with no filesystem).

The SmartOS datasource has built-in cloud-config which instructs the 'disk_setup' module to partition and format the ephemeral disk.

You can control the disk_setup then in 2 ways:

1. through the datasource config, you can change the 'alias' of ephermeral0 to reference another device. The default is: 'disk_aliases': {'ephemeral0': '/dev/vdb'}, Which means anywhere disk_setup sees a device named 'ephemeral0' then /dev/vdb will be substituted.
2. you can provide disk_setup or fs_setup data in user-data to overwrite the datasource's built-in values.

See doc/examples/cloud-config-disk-setup.txt for information on disk_setup.