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CLI Interface

For the latest list of subcommands and arguments use cloud-init's --help option. This can be used against cloud-init itself or any of its subcommands.

$ cloud-init --help
  usage: /usr/bin/cloud-init [-h] [--version] [--file FILES] [--debug] [--force]
                          {init,modules,single,query,dhclient-hook,features,analyze,devel,collect-logs,clean,status}
                          ...

  optional arguments:
  -h, --help            show this help message and exit
  --version, -v         show program's version number and exit
  --file FILES, -f FILES
                          additional yaml configuration files to use
  --debug, -d           show additional pre-action logging (default: False)
  --force               force running even if no datasource is found (use at
                          your own risk)

  Subcommands:
  {init,modules,single,query,dhclient-hook,features,analyze,devel,collect-logs,clean,status}
      init                initializes cloud-init and performs initial modules
      modules             activates modules using a given configuration key
      single              run a single module
      query               Query standardized instance metadata from the command
                          line.
      dhclient-hook       Run the dhclient hook to record network info.
      features            list defined features
      analyze             Devel tool: Analyze cloud-init logs and data
      devel               Run development tools
      collect-logs        Collect and tar all cloud-init debug info
      clean               Remove logs and artifacts so cloud-init can re-run.
      status              Report cloud-init status or wait on completion.

The rest of this document will give an overview of each of the subcommands.

analyze

Get detailed reports of where cloud-init spends its time during the boot process. For more complete reference see :ref:`analyze`.

Possible subcommands include:

  • blame: report ordered by most costly operations
  • dump: machine-readable JSON dump of all cloud-init tracked events
  • show: show time-ordered report of the cost of operations during each boot stage
  • boot: show timestamps from kernel initialization, kernel finish initialization, and cloud-init start

clean

Remove cloud-init artifacts from /var/lib/cloud to simulate a clean instance. On reboot, cloud-init will re-run all stages as it did on first boot.

  • \-\-logs: optionally remove all cloud-init log files in /var/log/
  • \-\-reboot: reboot the system after removing artifacts

collect-logs

Collect and tar cloud-init generated logs, data files, and system information for triage. This subcommand is integrated with apport.

Logs collected include:

  • /var/log/cloud-init.log
  • /var/log/cloud-init-output.log
  • /run/cloud-init
  • /var/lib/cloud/instance/user-data.txt
  • cloud-init package version
  • dmesg output
  • journalctl output

Note

Ubuntu users can file bugs with ubuntu-bug cloud-init to automatically attach these logs to a bug report

devel

Collection of development tools under active development. These tools will likely be promoted to top-level subcommands when stable.

Do NOT rely on the output of these commands as they can and will change.

Current subcommands:

  • schema: a #cloud-config format and schema validator. It accepts a cloud-config yaml file and annotates potential schema errors locally without the need for deployment. Schema validation is work in progress and supports a subset of cloud-config modules.
  • render: use cloud-init's jinja template render to process #cloud-config or custom-scripts, injecting any variables from /run/cloud-init/instance-data.json. It accepts a user-data file containing the jinja template header ## template: jinja and renders that content with any instance-data.json variables present.

features

Print out each feature supported. If cloud-init does not have the features subcommand, it also does not support any features described in this document.

$ cloud-init features
NETWORK_CONFIG_V1
NETWORK_CONFIG_V2

init

Generally run by OS init systems to execute cloud-init's stages init and init-local. See :ref:`boot_stages` for more info. Can be run on the commandline, but is generally gated to run only once due to semaphores in /var/lib/cloud/instance/sem/ and /var/lib/cloud/sem.

  • \-\-local: run init-local stage instead of init

modules

Generally run by OS init systems to execute modules:config and modules:final boot stages. This executes cloud config :ref:`modules` configured to run in the init, config and final stages. The modules are declared to run in various boot stages in the file /etc/cloud/cloud.cfg under keys:

  • cloud_init_modules
  • cloud_config_modules
  • cloud_init_modules

Can be run on the command line, but each module is gated to run only once due to semaphores in /var/lib/cloud/.

  • \-\-mode [init|config|final]: run modules:init, modules:config or modules:final cloud-init stages. See :ref:`boot_stages` for more info.

query

Query standardized cloud instance metadata crawled by cloud-init and stored in /run/cloud-init/instance-data.json. This is a convenience command-line interface to reference any cached configuration metadata that cloud-init crawls when booting the instance. See :ref:`instance_metadata` for more info.

  • \-\-all: dump all available instance data as json which can be queried
  • \-\-instance-data: optional path to a different instance-data.json file to source for queries
  • \-\-list-keys: list available query keys from cached instance data
  • \-\-format: a string that will use jinja-template syntax to render a string replacing
  • <varname>: a dot-delimited variable path into the instance-data.json object

Below demonstrates how to list all top-level query keys that are standardized aliases:

$ cloud-init query --list-keys
_beta_keys
availability_zone
base64_encoded_keys
cloud_name
ds
instance_id
local_hostname
platform
public_ssh_keys
region
sensitive_keys
subplatform
userdata
v1
vendordata

Below demonstrates how to query standardized metadata from clouds:

% cloud-init query v1.cloud_name
aws  # or openstack, azure, gce etc.

# Any standardized instance-data under a <v#> key is aliased as a top-level key for convenience.
% cloud-init query cloud_name
aws  # or openstack, azure, gce etc.

# Query datasource-specific metadata on EC2
% cloud-init query ds.meta_data.public_ipv4

Note

The standardized instance data keys under v# are guaranteed not to change behavior or format. If using top-level convenience aliases for any standardized instance data keys, the most value (highest v#) of that key name is what is reported as the top-level value. So these aliases act as a 'latest'.

This data can then be formatted to generate custom strings or data:

# Generate a custom hostname fqdn based on instance-id, cloud and region
% cloud-init query --format 'custom-{{instance_id}}.{{region}}.{{v1.cloud_name}}.com'
custom-i-0e91f69987f37ec74.us-east-2.aws.com

single

Attempt to run a single named cloud config module.

  • \-\-name: the cloud-config module name to run
  • \-\-frequency: optionally override the declared module frequency with one of (always|once-per-instance|once)

The following example re-runs the cc_set_hostname module ignoring the module default frequency of once-per-instance:

$ cloud-init single --name set_hostname --frequency always

Note

Mileage may vary trying to re-run each cloud-config module, as some are not idempotent.

status

Report whether cloud-init is running, done, disabled or errored. Exits non-zero if an error is detected in cloud-init.

  • \-\-long: detailed status information
  • \-\-wait: block until cloud-init completes

Below are examples of output when cloud-init is running, showing status and the currently running modules, as well as when it is done.

$ cloud-init status
status: running

$ cloud-init status --long
status: running
time: Fri, 26 Jan 2018 21:39:43 +0000
detail:
Running in stage: init-local

$ cloud-init status
status: done

$ cloud-init status --long
status: done
time: Wed, 17 Jan 2018 20:41:59 +0000
detail:
DataSourceNoCloud [seed=/var/lib/cloud/seed/nocloud-net][dsmode=net]
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