Credentials

In order to access your cloud, Juju needs to know how to authenticate itself. We use the term credentials to describe the material necessary to do this (e.g. username & password, or just a secret key). Such a set of credentials is represented by a credential name that is used to refer to those credentials in subsequent commands.

Juju selects a credential according to how many credentials are defined. If you have only one credential, or if a credential is labelled 'default', then this is the credential that will be used by Juju. When multiple credentials are defined, with no default, a credential name must be specified at the model level.

Adding credentials

Juju supports three methods for adding credentials:

  • Accepting credentials provided interactively by the user on the command line
  • Scanning for existing credentials via environment variables and/or "rc" files (only supported by certain providers)
  • Reading a user-provided YAML-formatted file

Note: LXD deployments are a special case. Accessed from a Juju admin user, they do not require credentials. Accessed from a non-admin user, a certificate credential is needed. See Additional LXD resources for details.

Adding credentials interactively

You can add credentials interactively in this way:

juju add-credential <cloud>

You will be asked for credential information based on the chosen cloud. Here we're adding credentials for cloud 'aws':

Enter credential name: carol
Using auth-type "access-key".
Enter access-key: *******
Enter secret-key: *******
Credentials added for cloud aws.

If you eventually set multiple credential names for the same cloud you will need to set one as the default:

juju set-default-credential <cloud> <credential-name>

The default credential will be used when creating a controller with the bootstrap command. Otherwise, a credential can be specified with the --credential option with both the bootstrap and add-model commands.

Adding credentials from environment variables

Certain cloud providers offer command line tools that rely on environment variables to store credentials. Juju supports the scanning of such variables as a way to add them to itself. Scanning is done with the autoload-credentials command:

juju autoload-credentials

Any variables detected will cause a prompt to appear. You will be asked to confirm the addition of their respective values as well as to provide a name to call the credential set.

Note: You will need to rescan the variables if their values ever change. A scan only picks up current values.

There are three providers that use tools that support this variables method:

Amazon AWS | Google GCE | OpenStack

Each page provides details on using this method with its respective provider.

Note: The autoload-credentials command is also used to generate a certificate credential for localhost clouds. This is needed for providing access to non-admin Juju users. See Additional LXD resources.

Adding credentials from a file

You can use a YAML-formatted file to store credentials for any cloud. Below we provide a sample file, which we will call mycreds.yaml. It includes many of the clouds supported by Juju and uses the most common options. Note the MAAS cloud and the two OpenStack clouds, called 'homemaas', 'myopenstack' and 'homestack' respectively.

credentials:
  aws:
    default-credential: peter
    default-region: us-west-2
    peter:
      auth-type: access-key
      access-key: AKIAIH7SUFMBP455BSQ
      secret-key: HEg5Y1DuGabiLt72LyCLkKnOw+NZkgszh3qIZbWv
    paul:
      auth-type: access-key
      access-key: KAZHUKJHE33P455BSQB
      secret-key: WXg6S5Y1DvwuGt72LwzLKnItt+GRwlkn668sXHqq
  homemaas:
    peter:
      auth-type: oauth1
      maas-oauth: 5weWAsjhe9lnaLKHERNSlke320ah9naldIHnrelks
  myopenstack:
    default-region: region-a
    john:
      auth-type: access-key
      access-key: bae7651caeab41ed876cfdb342bae23e
      secret-key: 7172bc91a21c3df1787423ac12093bcc
      tenant-name: admin
      username: admin   
  homestack:
    default-region: region-b
    peter:
      auth-type: userpass
      password: UberPassK3yz
      tenant-name: appserver
      username: peter
  google:
    peter:
      auth-type: jsonfile
      file: ~/.config/gcloud/application_default_credentials.json
    juju-gce-1-sa:
      auth-type: oauth2
      project-id: juju-gce-1
      private-key: |
        -----BEGIN PRIVATE KEY-----
        MIIEvAIBADANBgkqhkiG9w0BAQEFAASCBKYwggSiAgEAAoIBAQCzTFMj0/GvhrcZ
        3B2584ZdDdsnVuHb7OYo8eqXVLYzXEkby0TMu2gM81LdGp6AeeB3nu5zwAf71YyP
        erF4s0falNPIyRjDGYV1wWR+mRTbVjYUd/Vuy+KyP0u8UwkktwkP4OFR270/HFOl
        Kc0rzflag8zdKzRhi7U1dlgkchbkrio148vdaoZZo67nxFVF2IY52I2qGW8VFdid
        z+B9pTu2ZQKVeEpTVe5XEs3y2Y4zt2DCNu3rJi95AY4VDgVJ5f1rnWf7BwZPeuvp
        0mXLKzcvD31wEcdE6oAaGu0x0UzKvEB1mR1pPwP6qMHdiJXzkiM9DYylrMzuGL/h
        VAYjhFQnAgMBAAECggEADTkKkJ10bEt1FjuJ5BYCyYelRLUMALO4RzpZrXUArHz/
        CN7oYTWykL68VIE+dNJU+Yo6ot99anC8GWclAdyTs5nYnJNbRItafYd+3JwRhU0W
        vYYZqMtXs2mNMYOC+YNkibIKxYZJ4joGksTboRvJne4TN7Et/1uirr+GtLPn+W/e
        umXfkpbOTDDAED8ceKKApAn6kLIW98DwHyK0rUzorOgp4DFDX9CjuWC+RG3CFGsk
        oVOcDuTevJlb9Rowj1S2qYhGjuQVpVD7bcRg5zaSJKS88YbK63DCHZFpXn9JR0Fg
        Vou9dnc99FdMo5vtHg7Adxh91gdqEvoaF1lHx8Var0q32QDse+spvv7K6/+7G35k
        3+1gDgF74/uMr/AVrjpoUjmGAuWweXY/vn1MVN2Uld4KPYafkOF8oTuDK5f1fu0d
        cMEoKRSXQh1NCD3PZWfQt4ypYPzn9R+VBGwnBcPorytlhM9qdLxKKlaHjBlprS6Y
        Be1z6FO+MqWhFlwPrKH/2uwd4QKBgQDCGESJur9OdEeroBQyYyJF7DnJ/+wHSiOr
        qzvb9YW1Ddtg1iiKHHZO5FS59/D62kPaGsysCMKxI9FW53TzSxUiTaEG636C5v8J
        eRdzxX04BNYNzqXbm1agBEjAa7tK8xJAjk0to4zqadUaYZog0uQs2X7Aexj2c9T/
        HQVLILHjBwKBgD/yuoLNbST+cGbuZl1s2EnTP796xPkkUm3qcUzofzmn6uivz7Qp
        FMThZhHZ/Der98tra91a4e8fHaUTL5d4eCMeCL1mWXoNMnm02D/ugpEC8yDefi3T
        xlM/Ed0IEVogcd49tvTvQfrhfbW/6Que/rkLKCoUlAldfIOYkS4YyyTBAoGACCpH
        L9gYVi+UGEc6skfzWCew4quOfVwEFiO09/LjNhOoJ/G6cNzzqSv32H7yt0rZUeKQ
        u6f+sL8F/nbsN5PwBqpnXMgpYU5gakCa2Pb05pdlfd00owFs6nxjpxyhG20QVoDm
        BEZ+FhpvqZVzi2/zw2M+7s/+49dJnZXV9Cwi758CgYAquNdD4RXU96Y2OjTlOSvM
        THR/zY6IPeO+kCwmBLiQC3cv59gaeOp1a93Mnapet7a2/WZPL2Al7zwnvZYsHc4z
        nu1acd6D7H/9bb1YPHMNWITfCSNXerJ2idI689ShYjR2sTcDgiOQCzx+dwL9agaC
        WKjypRHpiAMFbFqPT6W2uA==
        -----END PRIVATE KEY-----
      client-id: "206517233375074786882"
      client-email: juju-gce-sa@juju-gce-123.iam.gserviceaccount.com
  azure:
    peter:
      auth-type: service-principal-secret
      application-id: niftyapp
      subscription-id: 31fb132e-e774-49dd-adbb-d6a4e966c583
      application-password: UberPassK3yz
  joyent:
    peter:
      auth-type: userpass
      sdc-user: admingal
      sdc-key-id: 2048 00:11:22:33:44:55:66:77:88:99:aa:bb:cc:dd:ee:ff
      private-key: key (or private-key-path, like `~/.ssh/id_rsa.pub`)
      algorithm: "rsa-sha256"
  vsphere:
    ashley:
      auth-type: userpass
      password: passw0rd
      user: administrator@xyz.com
  lxd-node2:
    interactive:
      auth-type: interactive
      trust-password: ubuntu

Credentials are added to Juju on a per-cloud basis. To add credentials for the defined 'azure' cloud, for instance, we would do this:

juju add-credential azure -f mycreds.yaml

Note: All available authentication types are outlined in section Adding clouds manually on the Clouds page.

Managing credentials

There are several management tasks that can be done related to credentials.

Listing credentials

When credentials are added to Juju they become available to use on a controller and its models. There are therefore two categories of credentials: those that are available and those that are currently in use.

Available

You can display what credentials are available by running the command:

juju list-credentials

Sample output:

Cloud   Credentials
aws     bob*, carol
google  wayne

The asterisk '*' denotes the default credential, which will be used for the named cloud unless another is specified.

To reveal actual authentication material (e.g. passwords, keys):

juju list-credentials --format yaml --show-secrets

Sample output:

local-credentials:
  aws:
    bob:
      auth-type: access-key
      access-key: AKIAXZUYGB6UED2GNC5A
      secret-key: StB2bmL1+tX+VX7neVgy/3JosJAwOcBIO53nyCVp

Notice how the output says 'local-credentials', meaning they are stored on the local Juju client.

In use

To see what credentials are in use by a model (here the 'default' model):

juju show-model default

Partial output:

default:
  name: admin/default
  ...
  ...
  credential:
    name: bob
    owner: admin
    cloud: aws

The models --format yaml command also shows this information, albeit for all models.

The above commands do not display authentication material. To view the active credentials, including the cloud name, credential names, and the names of models:

juju show-credentials --show-secrets

Sample output:

controller-credentials:
  aws:
    bob:
      content:
        auth-type: access-key
        access-key: AKIAXZUYGB6UED2GNC5A
        secret-key: StB2bmL1+tX+VX7neVgy/3JosJAwOcBIO53nyCVp
      models:
        controller: admin
        default: admin

Notice how the output says 'controller-credentials', meaning they are stored on the controller.

The show-credentials command queries the controller to get its information.

Setting default credentials

You can set the default credential for a cloud:

juju set-default-credential aws carol

Notes:

  • This affects operations that require a newly-input credential (e.g. juju add-model). In particular, it does not change what is currently in use (on a controller).
  • If only one credential name exists, it will become the effective default credential.

Updating local credentials

To update an existing credential locally use the add-credential command with the --replace option.

Here we decided to use the file 'mycreds.yaml' from a previous example:

juju add-credential aws -f mycreds.yaml --replace

This will overwrite existing credential information, so make sure all current credentials are contained in the file, not just the new or changed one.

Updating credentials in this way does not update credentials currently in use (on an existing controller/cloud). See the next section for that. The add-credential command is always "pre-bootstrap" in nature.

Updating remote credentials

To update credentials currently in use (i.e. cached on the controller) the update-credential command is used. The requirements for using this command, as compared to the initial juju bootstrap (or juju add-model) command, are:

  • same cloud name
  • same Juju username (logged in)
  • same credential name

The update is a two-step process. First change the credentials locally with the add-credential command (in conjunction with the --replace option) and then upload those credentials to the controller.

Below, we explicitly log in with the correct Juju username ('admin'), change the contents of the credential called 'joe', and then update them on a Google cloud controller:

juju login -u admin
juju add-credential --replace joe
juju update-credential google joe

Updating remote credentials using a different Juju user

If you are unable to ascertain the original Juju username then you will need to use a different one. This implies adding a new credential name, copying over any authentication material into the old credential name, and finally updating the credentials. Below we demonstrate this for the Azure cloud:

Add a new temporary credential name (like 'new-credential-name') and gather all credential sets (new and old):

juju add-credential azure
juju credentials azure --format yaml --show-secrets > azure-creds.yaml

Copy the values of application-id and application-password from the new set to the old set.

Then replace the local credentials and upload them to the controller:

juju add-credential azure -f azure-creds.yaml --replace
juju update-credential azure old-credential-name

To be clear, the file azure-creds.yaml (used with add-credential) should look similar to:

Credentials:
  azure:
    new-credential-name:
      auth-type: service-principal-secret
      application-id: foo1
      application-password: foo2
      subscription-id: bar
    old-credential-name:
      auth-type: service-principal-secret
      application-id: foo1
      application-password: foo2
      subscription-id: bar

Removing local credentials

If a local credential (i.e. not cached on a controller) is no longer required, it can be removed:

juju remove-credential aws bob

© 2018 Canonical Ltd. Ubuntu and Canonical are registered trademarks of Canonical Ltd.