`relation-get`¶

Summary¶

Get relation settings.

Usage¶

relation-get [options] <key> <unit id>

Options¶

Flag	Default	Usage
`--app`	false	Get the relation data for the overall application, not just a unit
`--format`	smart	Specify output format (json\|smart\|yaml)
`-o`, `--output`		Specify an output file
`-r`, `--relation`		Specify a relation by id

Examples¶

# Getting the settings of the default unit in the default relation is done with:
$ relation-get
username: jim
password: "12345"

# To get a specific setting from the default remote unit in the default relation
$ relation-get username
jim

# To get all settings from a particular remote unit in a particular relation you
$ relation-get -r database:7 - mongodb/5
username: bob
password: 2db673e81ffa264c

Details¶

relation-get prints the value of a unit’s relation setting, specified by key. If no key is given, or if the key is “-”, all keys and values will be printed.

A unit can see its own settings by calling “relation-get - MYUNIT”, this will include any changes that have been made with “relation-set”.

When reading remote relation data, a charm can call relation-get –app - to get the data for the application data bag that is set by the remote applications leader.

Further details: relation-get reads the settings of the local unit, or of any remote unit, in a given relation (set with -r, defaulting to the current relation identifier, as in relation-set). The first argument specifies the settings key, and the second the remote unit, which may be omitted if a default is available (that is, when running a relation hook other than -relation-broken).

If the first argument is omitted, a dictionary of all current keys and values will be printed; all values are always plain strings without any interpretation. If you need to specify a remote unit but want to see all settings, use - for the first argument.

The environment variable JUJU_REMOTE_UNIT stores the default remote unit.

You should never depend upon the presence of any given key in relation-get output. Processing that depends on specific values (other than private-address) should be restricted to -relation-changed hooks for the relevant unit, and the absence of a remote unit’s value should never be treated as an error in the local unit.

In practice, it is common and encouraged for -relation-changed hooks to exit early, without error, after inspecting relation-get output and determining the data is inadequate; and for all other hooks to be resilient in the face of missing keys, such that -relation-changed hooks will be sufficient to complete all configuration that depends on remote unit settings.

Key value pairs for remote units that have departed remain accessible for the lifetime of the relation.

relation-get¶