CLI commands#

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

$ cloud-init --help

Example output:

usage: cloud-init [-h] [--version] [--file FILES] [--debug] [--force]
                                                            {init,modules,single,query,features,analyze,devel,collect-logs,clean,status,schema} ...

 options:
   -h, --help            show this help message and exit
   --version, -v         Show program's version number and exit.
   --file FILES, -f FILES
                         Use additional yaml configuration files.
   --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,features,analyze,devel,collect-logs,clean,status,schema}
     init                Initialize cloud-init and perform initial modules.
     modules             Activate modules using a given configuration key.
     single              Run a single module.
     query               Query standardized instance metadata from the command line.
     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.
     schema              Validate cloud-config files using jsonschema.

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 Performance.

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 initialisation, kernel finish initialisation, and cloud-init start.

clean#

Remove cloud-init artifacts from /var/lib/cloud and config files (best effort) 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.

  • --machine-id: Set /etc/machine-id to uninitialized\n on this image for systemd environments. On distributions without systemd, remove the file. Best practice when cloning a golden image, to ensure the next boot of that image auto-generates a unique machine ID. More details on machine-id.

  • --configs [all | ssh_config | network ]: Optionally remove all cloud-init generated config files. Argument ssh_config cleans config files for ssh daemon. Argument network removes all generated config files for network. all removes config files of all types.

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 using 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:

net-convert#

Manually use cloud-init’s network format conversion. Useful for testing configuration or testing changes to the network conversion logic itself.

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.

hotplug-hook#

Respond to newly added system devices by retrieving updated system metadata and bringing up/down the corresponding device. This command is intended to be called via a systemd service and is not considered user-accessible except for debugging purposes.

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

Example output:

NETWORK_CONFIG_V1
NETWORK_CONFIG_V2

init#

Generally run by OS init systems to execute cloud-init’s stages: init and init-local. See 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 Module reference 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_final_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 Boot stages for more info.

query#

Query standardised 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 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 standardised aliases:

$ cloud-init query --list-keys

Example output:

_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

Here are a few examples of how to query standardised metadata from clouds:

$ cloud-init query v1.cloud_name

Example output:

aws  # or openstack, azure, gce etc.

Any standardised instance-data under a <v#> key is aliased as a top-level key for convenience:

$ cloud-init query cloud_name

Example output:

aws  # or openstack, azure, gce etc.

One can also query datasource-specific metadata on EC2, e.g.:

$ cloud-init query ds.meta_data.public_ipv4

Note

The standardised instance data keys under v# are guaranteed not to change behaviour or format. If using top-level convenience aliases for any standardised 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. For example, we can 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

schema#

Validate cloud-config files using jsonschema.

  • -h, --help: Show this help message and exit.

  • -c CONFIG_FILE, --config-file CONFIG_FILE: Path of the cloud-config YAML file to validate.

  • -t SCHEMA_TYPE, --schema-type SCHEMA_TYPE: The schema type to validate –config-file against. One of: cloud-config, network-config. Default: cloud-config.

  • --system: Validate the system cloud-config user data.

  • -d DOCS [cc_module ...], --docs DOCS [cc_module ...]: Print schema module docs. Choices are: “all” or “space-delimited” cc_names.

  • --annotate: Annotate existing cloud-config file with errors.

The following example checks a config file and annotates the config file with errors on stdout.

$ cloud-init schema -c ./config.yml --annotate

single#

Attempt to run a single, named, cloud config module.

  • --name: The cloud-config module name to run.

  • --frequency: Module frequency for this run. One of (always``|``once-per-instance``|``once).

  • --report: Enable reporting.

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.

  • --format [yaml|json|tabular]: Machine-readable JSON or YAML detailed output.

The status command can be used simply as follows:

$ cloud-init status

Which shows whether cloud-init is currently running, done, disabled, or in error, as in this example output:

status: running

The --long option, shown below, provides a more verbose output.

$ cloud-init status --long

Example output when cloud-init is running:

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

Example output when cloud-init is done:

status: done
boot_status_code: enabled-by-generator
last_update: Tue, 16 Aug 2022 19:12:58 +0000
detail:
DataSourceNoCloud [seed=/var/lib/cloud/seed/nocloud-net][dsmode=net]

The detailed output can be shown in machine-readable JSON or YAML with the format option, for example:

$ cloud-init status --format=json

Which would produce the following example output:

{
 "boot_status_code": "enabled-by-generator",
 "datasource": "nocloud",
 "detail": "DataSourceNoCloud [seed=/var/lib/cloud/seed/nocloud-net][dsmode=net]",
 "errors": [],
 "last_update": "Tue, 16 Aug 2022 19:12:58 +0000",
 "status": "done"
}