List of model configuration keys

Configuration > Model configuration > List of model configuration keys

See also: Model, How to configure a model

Source

This document gives a list of all the configuration keys that can be applied to a Juju model.

Some are only defined for a given cloud; see <cloud specific key>. Others are defined generally but may still only be available for some clouds; e.g., container-inherit-properties.

Contents:

<cloud-specific key>

See List of supported clouds > <cloud name> > Cloud > definition or run juju show-cloud <cloud> --include-config.

agent-metadata-url

agent-metadata-url is the URL of the private stream.

Type: string

Default value: “”

agent-stream

agent-stream is the version of Juju to use for deploy/upgrades.

Type: string

Default value: “”

Valid values: released, devel, proposed

agent-version

agent-version is the desired Juju agent version to use.

See more: Agent

Type: string

Details:

The agent-stream key specifies the “stream” to use when a Juju agent is to be installed or upgraded. This setting reflects the general stability of the software and defaults to ‘released’, indicating that only the latest stable version is to be used.

To run the upcoming stable release (before it has passed the normal QA process) you can set:

agent-stream: proposed

For testing purposes, you can use the latest unstable version by setting:

agent-stream: devel

The agent-version option specifies a “patch version” for the agent that is to be installed on a new controller relative to the Juju client’s current major.minor version (Juju uses a major.minor.patch numbering scheme).

For example, Juju 2.3.2 means major version 2, minor version 3, and patch version 2. On a client system with this release of Juju installed, the machine agent’s version for a newly-created controller would be the same. To specify a patch version of 1 (instead of 2), the following would be run:

juju bootstrap aws --agent-version='2.3.1'

If a patch version is available that is greater than that of the client then it can be targeted in this way:

juju bootstrap aws --auto-upgrade

apt-ftp-proxy*

apt-ftp-proxy* is the APT FTP proxy for the model.

Type: string

Default value: “”

apt-http-proxy*

apt-http-proxy* is the APT HTTP proxy for the model.

Type: string

Default value: “”

apt-https-proxy*

apt-https-proxy* is the APT HTTPS proxy for the model.

Type: string

Default value: “”

apt-mirror

apt-mirror is the APT mirror for the model.

Type: string

Default value: “”

Details:

The APT packaging system is used to install and upgrade software on machines provisioned in the model, and many charms also use APT to install software for the applications they deploy. It is possible to set a specific mirror for the APT packages to use, by setting ‘apt-mirror’:

juju model-config apt-mirror=http://archive.ubuntu.com/ubuntu/

To restore the default behaviour you would run:

juju model-config --reset apt-mirror

The apt-mirror option is often used to point to a local mirror.

apt-no-proxy

apt-no-proxy is the list of domain addresses not to be proxied for APT (comma-separated).

Type: string

Default value: “”

automatically-retry-hooks

automatically-retry-hooks determines whether the uniter should automatically retry failed hooks.

Type: boolean

Default value: true

Details:

Juju retries failed hooks automatically using an exponential backoff algorithm. They will be retried after 5, 10, 20, 40 seconds up to a period of 5 minutes, and then every 5 minutes. The logic behind this is that some hook errors are caused by timing issues or the temporary unavailability of other applications - automatic retry enables the Juju model to heal itself without troubling the user.

However, in some circumstances, such as debugging charms, this behaviour can be distracting and unwelcome. For this reason, it is possible to set the automatically-retry-hooks option to ‘false’ to disable this behaviour. In this case, users will have to manually retry any hook which fails, using the command above, as with earlier versions of Juju.

Even with the automatic retry enabled, it is still possible to use the juju resolved unit-name/# command to retry manually.

backup-dir

backup-dir is the directory used to store the backup working directory.

Type: string

Default value: “”

charmhub-url

charmhub-url is the url for Charmhub API calls.

Type:

Default value: https://api.charmhub.io

cloudinit-userdata

This is a sharp knife feature - be careful with it.

cloudinit-userdata is the cloud-init user-data (in yaml format) to be added to userdata for new machines created in this model.

Type: string

Default value: “”

Details:

The cloudinit-userdata allows the user to provide additional cloudinit data to be included in the cloudinit data created by Juju.

Specifying a key will overwrite what juju puts in the cloudinit file with the following caveats:

  1. users and bootcmd keys will cause an error
  2. The packages key will be appended to the packages listed by juju
  3. The runcmds key will cause an error. You can specify preruncmd and postruncmd keys to prepend and append the runcmd created by Juju.

Use cases

  • setting a default locale for deployments that wish to use their own locale settings
  • adding custom CA certificates for models that are sitting behind an HTTPS proxy
  • adding a private apt mirror to enable private packages to be installed
  • add SSH fingerprints to a deny list to prevent them from being printed to the console for security-focused deployments

Background

Juju uses cloud-init to customise instances once they have been provisioned by the cloud. The cloudinit-userdata model configuration setting (model config) allows you to tweak what happens to machines when they are created up via the “user data” feature.

From the website:

cinit-logo

Cloud images are operating system templates and every instance starts out as an identical clone of every other instance. It is the user data that gives every cloud instance its personality and cloud-init is the tool that applies user data to your instances automatically.

How-to

Provide custom user data to cloudinit

Create a file, cloudinit-userdata.yaml, which starts with the cloudinit-userdata key and data you wish to include in the cloudinit file. Note: juju reads the value as a string, though formatted as YAML.

Template cloudinit-userdata.yaml:

cloudinit-userdata: |
    <key>: <value>
    <key>: <value>

Provide the path your file to the model-config command:

juju model-config --file cloudinit-userdata.yaml

Read the current setting

To read the current value, provide the cloudinit-userdata key to the model-config command as a command-line parameter. Adding the --format yaml option ensures that it is properly formatted.

juju model-config cloudinit-userdata --format yaml

Sample output:

cloudinit-userdata: |
  packages:
    - 'python-keystoneclient'
    - 'python-glanceclient'

Clear the current custom user data

Use the --reset option to the model-config command to clear anything that has been previously set.

juju model-config --reset cloudinit-userdata

Known issues

  • custom cloudinit-userdata must be passed via file, not as options on the command line (like the config command)

container-image-metadata-url

container-image-metadata-url is the URL at which the metadata used to locate container OS image ids is located.

Type: string

Default value: "

Valid values: url

container-image-stream

container-image-stream is the simplestreams stream used to identify which image ids to search when starting a container.

Type: string

Default value: released

Valid values: url

container-inherit-properties

container-inherit-properties is the list of properties to be copied from the host machine to new containers created in this model (comma-separated).

Type: string

Default value: “”

Details:

The container-inherit-properties key allows for a limited set of parameters enabled on a Juju machine to be inherited by any hosted containers (KVM guests or LXD containers). The machine and container must be running the same series.

This key is only supported by the MAAS provider.

The parameters are:

  • apt-primary
  • apt-security
  • apt-sources
  • ca-certs

For MAAS v.2.5 or greater the parameters are:

  • apt-sources
  • ca-certs

For example:

juju model-config container-inherit-properties="ca-certs, apt-sources"

container-networking-method

container-networking-method is the method of container networking setup - one of fan, provider, local.

Type: string

Valid values: local, provider, fan

default-base

default-base is the default base image to use for deploying charms, will act like --base when deploying charms.

Type: string

Default value: “”

default-space

default-space is the default network space used for application endpoints in this model.

Type: string

Default value: “”

development

development determines whether the model is in development mode.

Type: boolean

Default value: false

disable-network-management

disable-network-management determines whether the provider should control networks (on MAAS models, set to true for MAAS to control networks).

Type: boolean

Default value: false

Details:

This key can only be used with MAAS models and should otherwise be set to ‘false’ (default) unless you want to take over network control from Juju because you have unique and well-defined needs. Setting this to ‘true’ with MAAS gives you the same behaviour with containers as you already have with other providers: one machine-local address on a single network interface, bridged to the default bridge.

disable-telemetry

disable-telemetry disables telemetry reporting of model information.

Type: boolean

Default value: false

egress-subnets

egress-subnets is the source address(es) for traffic originating from this model.

Type: string

Default value: “”

enable-os-refresh-update

enable-os-refresh-update determines whether newly provisioned instances should run their respective OS’s update capability.

Type: boolean

Default value: true

Details:

When Juju provisions a machine, its default behaviour is to upgrade existing packages to their latest version. If your OS images are fresh and/or your deployed applications do not require the latest package versions, you can disable upgrades in order to provision machines faster.

Two boolean configuration options are available to disable APT updates and upgrades: enable-os-refresh-update (apt update) and enable-os-upgrade (apt upgrade), respectively.

enable-os-refresh-update: false
enable-os-upgrade: false

You may also want to just update the package list to ensure a charm has the latest software available to it by disabling upgrades but enabling updates.

enable-os-upgrade

enable-os-upgrade determines whether newly provisioned instances should run their respective OS’s upgrade capability.

Type: boolean

Default value: true

Details:

When Juju provisions a machine, its default behaviour is to upgrade existing packages to their latest version. If your OS images are fresh and/or your deployed applications do not require the latest package versions, you can disable upgrades in order to provision machines faster.

Two Boolean configuration options are available to disable APT updates and upgrades: enable-os-refresh-update (apt update) and enable-os-upgrade (apt upgrade), respectively.

enable-os-refresh-update: false
enable-os-upgrade: false

You may also want to just update the package list to ensure a charm has the latest software available to it by disabling upgrades but enabling updates.

fan-config

fan-config is the configuration for fan networking for this model.

Type: string

Default value: “”

Valid values: overlay_CIDR<par>=<par>underlay_CIDR

firewall-mode

firewall-mode is the mode to use for network firewalling. It’s useful for clouds without support for either global or per instance security groups.

Type: string

Default value: instance

Valid values: instance, global, none. instance requests the use of an individual firewall per instance; global uses a single firewall for all instances (access for a network port is enabled to one instance if any instance requires that port); none requests that no firewalling should be performed inside the model.

ftp-proxy*

ftp-proxy* is the FTP proxy value to configure on instances, in the FTP_PROXY environment variable.

Type: string

Default value: “”

Valid values: url

http-proxy*

http-proxy* is the HTTP proxy value to configure on instances, in the HTTP_PROXY environment variable.

Type: string

Default value: “”

Valid values: url

https-proxy*

https-proxy* is the HTTPS proxy value to configure on instances, in the HTTPS_PROXY environment variable.

Type: string

Default value: “”

Valid values: url

ignore-machine-addresses

ignore-machine-addresses determines whether the machine worker should discover machine addresses on startup.

Type: boolean

Default value: false

Valid values:

image-metadata-url

image-metadata-url is the URL at which the metadata used to locate OS image ids is located.

Type: string

Default value: “”

Valid values: url

image-stream

image-stream is the simplestreams stream used to identify which image ids to search when starting an instance.

Type: string

Default value: `released

Details:

Juju, by default, uses the slow-changing ‘released’ images when provisioning machines. However, the image-stream option can be set to ‘daily’ to use more up-to-date images, thus shortening the time it takes to perform APT package upgrades.

juju-ftp-proxy*

juju-ftp-proxy* is the FTP proxy value to pass to charms in the JUJU_CHARM_FTP_PROXY environment variable.

Type: string

Default value: “”

juju-http-proxy*

juju-http-proxy* is the HTTP proxy value to pass to charms in the JUJU_CHARM_HTTP_PROXY environment variable.

Type: string

Default value: “”

juju-https-proxy*

juju-https-proxy* is the HTTPS proxy value to pass to charms in the JUJU_CHARM_HTTPS_PROXY environment variable.

Type: string

Default value: “”

juju-no-proxy*

juju-no-proxy* is the list of domain addresses not to be proxied (comma-separated), may contain CIDRs. Passed to charms in the JUJU_CHARM_NO_PROXY environment variable.

Type: string

Default value: 127.0.0.1,localhost,::1

Valid values:

logforward-enabled

logforward-enabled determines whether syslog forwarding is enabled.

Type: boolean

Default value: false

logging-config

logging-config is the configuration string to use when configuring Juju agent logging (see this link for details).

Type: string

Value: A (list of semicolon-separated) <filter>=<verbosity level> pairs,

where <filter> can be any of the following:

  • <root> - matches all machine agent logs

  • unit - matches all unit agent logs

  • a module name, e.g. juju.worker.apiserver

    A module represents a single component of Juju, e.g. a worker. Generally, modules correspond one-to-one with Go packages in the Juju source tree. The module name is the value passed to loggo.GetLogger or loggo.GetLoggerWithLabels.

    Modules have a nested tree structure - for example, the juju.api module includes submodules juju.api.application, juju.api.cloud, etc. <root> is the root of this module tree.

  • a label, e.g. #charmhub

    Labels cut across the module tree, grouping various modules which deal with a certain feature or information flow. For example, the #charmhub label includes all modules involved in making a request to Charmhub.

    The currently supported labels are:

Label Description
#http HTTP requests
#metrics Metric outputs - use as a fallback when Prometheus isn’t available
#charmhub Charmhub client and callers.
#cmr Cross model relations
#cmr-auth Authentication for cross model relations
#secrets Juju secrets

See more: https://github.com/juju/juju/blob/main/core/logger/labels.go

and where <verbosity level> can be, in decreasing order of severity:

Level Description
CRITICAL Indicates a severe failure which could bring down the system.
ERROR Indicates failure to complete a routine operation.
WARNING Indicates something is not as expected, but this is not necessarily going to cause an error.
INFO A regular log message intended for the user.
DEBUG Information intended to assist developers in debugging.
TRACE The lowest level - includes the full details of input args, return values, HTTP requests sent/received, etc.

When you set logging-config to module=level, then Juju saves that module’s logs for the given severity level and above. For example, setting logging-config to juju.worker.uniter=WARNING will capture all CRITICAL, ERROR and WARNING logs for the uniter, but discard logs for lower severity levels (INFO, DEBUG, TRACE).

See more: https://github.com/juju/loggo/blob/master/level.go#L13

Examples:

To collect debug logs for the dbaccessor worker:

juju model-config -m controller logging-config="juju.worker.dbaccessor=DEBUG"

To collect debug logs for the mysql/0 unit:

juju model-config -m foo logging-config="unit.mysql/0=DEBUG"

To collect trace logs for Charmhub requests:

juju model-config -m controller logging-config="#charmhub=TRACE"

To see what API requests are being made:

juju model-config -m controller logging-config="juju.apiserver=DEBUG"

To view details about each API request:

juju model-config -m controller logging-config="juju.apiserver=TRACE"

logging-output

logging-output is the logging output destination: database and/or syslog.

Type: string

Default value: “”

Valid values:

lxd-snap-channel

lxd-snap-channel is the channel to use when installing LXD from a snap (cosmic and later).

Type: string

Valid values: latest, stable

max-action-results-age

max-action-results-age is the maximum age for action entries before they are pruned, in human-readable time format.

Default value: 336h

max-action-results-size

max-action-results-size is the maximum size for the action collection, in human-readable memory format.

Default value: 5G

max-status-history-age

max-status-history-age the maximum age for status history entries before they are pruned, in human-readable time format.

Type: string

Default value: 336h

Valid values: 72h, etc.

max-status-history-size

max-status-history-size is the maximum size for the status history collection, in human-readable memory format.

Type: string

Default value: 5G

Valid values: 400M, 5G, etc.

net-bond-reconfigure-delay

net-bond-reconfigure-delay is the amount of time in seconds to sleep between ifdown and ifup when bridging.

Default value: 17

no-proxy*

no-proxy* is the list of domain addresses not to be proxied (comma-separated).

Type: string

Default value: 127.0.0.1,localhost,::1

num-container-provision-workers

num-container-provision-workers is the number of container provisioning workers to use per machine.

Default value: 4

num-provision-workers

num-provision-workers is the number of provisioning workers to use per model.

Default value: 16

provisioner-harvest-mode

provisioner-harvest-mode sets what to do with unknown machines (default destroyed).

Type: string

Default value: destroyed

Valid values: all, none, unknown, destroyed

Details:

Juju keeps state on the running model and it can harvest (remove) machines which it deems are no longer required. This can help reduce running costs and keep the model tidy. Harvesting is guided by what “harvesting mode” has been set.

A Juju machine can be in one of four states:

  • Alive: The machine is running and being used.
  • Dying: The machine is in the process of being terminated by Juju, but hasn’t yet finished.
  • Dead: The machine has been successfully brought down by Juju, but is still being tracked for removal.
  • Unknown: The machine exists, but Juju knows nothing about it.

Juju can be in one of several harvesting modes, in order of most conservative to most aggressive:

  • none: Machines will never be harvested. This is a good choice if machines are managed via a process outside of Juju.
  • destroyed: Machines will be harvested if i) Juju “knows” about them and

ii) they are ‘Dead’. - unknown: Machines will be harvested if Juju does not “know” about them (‘Unknown’ state). Use with caution in a mixed environment or one which may contain multiple instances of Juju. - all: Machines will be harvested if Juju considers them to be ‘destroyed’ or ‘unknown’.

The default mode is destroyed.

Below, the harvest mode key for the current model is set to ‘none’:

juju model-config provisioner-harvest-mode=none

proxy-ssh

proxy-ssh determines whether SSH commands should be proxied through the API server.

Type: boolean

Default value: false

resource-tags

resource-tags is a space-separated list of key=value pairs used to apply as tags on supported cloud models.

Type: string

Default value: none

secret-backend

secret-backend is the name of the secret store backend.

Type: string

Default value: auto

Valid values: internal, auto, <>backend name

snap-http-proxy*

snap-http-proxy* is the HTTP proxy value to for installing snaps.

Type: string

Default value: “”

snap-https-proxy*

snap-https-proxy* is the snap-centric HTTPS proxy value. See Offline mode strategies.

Type: string

Default value: “”

snap-store-assertions

snap-store-assertions is the HTTPS proxy value to for installing snaps. Type: string

Default value: “”

snap-store-proxy*

snap-store-proxy* is the snap store proxy for installing snaps.

Type: string

Default value: “”

snap-store-proxy-url

snap-store-proxy-url is the URL for the defined snap store proxy.

Type: string

Default value: “”

ssl-hostname-verification

ssl-hostname-verification determines whether SSL hostname verification is enabled.

Type: boolean

Default value: true

storage-default-block-source

storage-default-block-sourceis the default block storage source for the model.

Type: string

Default value: -

Valid values: loop or the cloud-specific value

storage-default-filesystem-source

storage-default-filesystem-source is the default filesystem storage source for the model.

Type: string

Default value: -

Valid values: any storage provider (Juju will adjust)

transmit-vendor-metrics

transmit-vendor-metrics determines whether metrics declared by charms deployed into this model are sent for anonymized aggregate analytics.

Type: boolean

Default value: true

update-status-hook-interval

update-status-hook-interval sets how often to run the charm update-status hook, in human-readable time format (default 5m, range 1-60m).

Type: string

Default value: 5m

Valid values: 30s, 6m, 1hr, etc.


Contributors: @bcarbone, @bran-castillo, @brian-murray, @holmanb

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