Multi-user basic setup - tutorial

This is a tutorial in connection with the multi-user framework of Juju. See Working with multiple users for background information.

This tutorial will give an overview of how Juju can be used with one person assuming the role of a traditional administrator and a second person acting as the Juju operator. The administrator creates the controller, creates users, and grants user permissions whereby the operator is responsible for creating models and installing software.

The following topics will be covered:

  • Controller creation and the initial controller administrator
  • User creation and controller registration
  • User login, logout, and password changing
  • User model creation
  • User charm deployment

Controller creation and the initial controller administrator

Besides resulting in a new controller the bootstrap command sets up a Juju user called 'admin' with controller permissions of 'superuser'. This is the initial controller administrator.

Here we'll add credentials and then create a GCE-based controller:

juju add-credential google -f credentials-administrator.yaml
juju bootstrap google gce

In the above the credentials file contains a single credential for the 'google' cloud, allowing it to become the default credential in the subsequent bootstrap command.

Inspecting the controller's users with the users command allows us to confirm the above information:

juju users

Example output:

Controller: gce

Name    Display name  Access     Date created   Last connection
admin*  admin         superuser  2 minutes ago  just now

Note that the new administrator does not have a password per se. Create one now:

juju change-user-password

User creation and controller registration

Let the administrator now create a regular user called 'tom':

juju add-user tom

The output includes a string (token) to give to the intended operator of the new user. This will enable the operator to add the controller to their own Juju client running on a separate host.

Sample output:

User "tom" added
Please send this command to tom:
    juju register MGcTA3RvbTA5ExQzNS4yMzcuMTY1LjI[...]

"tom" has not been granted access to any models. You can use "juju grant" to grant access.

Important: The client host must be able to contact the controller host on TCP port 17070 in order for controller registration to succeed. This is the case for any client-controller communication.

Registration is done with the register command. On a separate host, then:

juju register MGcTA3RvbTA5ExQzNS4yMzcuMTY1LjI[...]

Example output:

Enter a new password: ******
Confirm password: ******
Enter a name for this controller [gce]: 
Initial password successfully set for tom.

Welcome, tom. You are now logged into "gce".

There are no models available. You can add models with
"juju add-model", or you can ask an administrator or owner
of a model to grant access to that model with "juju grant".

User login, logout, and password changing

A newly-created user is granted controller access of 'login' out of the box (implicitly: juju grant -c gce tom login). So besides logging in, the user cannot do much else.

Registration implies a controller login (as can be seen by the previous command's messaging). To log out, use the logout command:

juju logout

A login session also expires after a fixed amount of time (24 hours).

To log back in, use the login command with the username as argument. Provide the password that was set up during registration:

juju login -u tom

Supply a controller name (-c gce) if there is more than one controller registered with the client.

Change the user's password with the change-user-password command:

juju change-user-password

User model creation

In order for the user to be able to add models the administrator must grant 'add-model' controller access:

juju grant tom add-model

Yet before the remote operator is able to create a model he will first need to add a credential to Juju. In a single-user setup this is done prior to controller creation, but in this context the operator is devoid of a credential.

On the (user) operator's host, add a credential and then add a model:

juju add-credential google -f credentials-operator.yaml
juju add-model gce-model-1

In the above the credentials file contains a single credential for the 'google' cloud, allowing it to become the default credential in the subsequent add-model command.

User model SSH access

The operator user can now connect, using Juju's ssh command, to any machine that may get created within their new model. This is standard Juju behaviour that the model creator always enjoys. Note, however, that the SSH keys necessary for this to work are found within the client system's filesystem at ~/.local/share/juju/ssh/ (and ~/.ssh/ if it existed at the time of model creation).

Verify SSH access now on the operator host:

juju add-machine
juju ssh 0

Above we assume the machine that was added got assigned an ID of '0' (the default for the first machine in a model).

User charm deployment

The operator user can now deploy charms as normal. See Deploying applications for help.

That's the end of this tutorial!