What is going on during 'juju bootstrap' command?

Question

I am new to Juju. I want to know what is going on during executing juju bootstrap command.

Let's say if I am using Juju version 1.23 locally and executed bootstrap command then:

1. What version of juju is installed on the remote machine? and where is it getting this juju from to install.

2. Is it possible to install different version of juju on remote machine than local during bootstrap? If yes, how can I use juju version 1.23 locally but version 1.22 remotely?

3. If I am using Windows Juju client 1.23 and performed bootstrap, what version of Juju gets installed on the remote or on the bootstrapped node?

Answer 1

The first thing that bootstrap does is to provision a machine through the cloud provider that matches the constraints you specified.

When the machine has booted, the client connects to the machine through SSH to run the provisioning script. This installs some packages, downloads and unpacks the 'tools', executes the jujud command with the bootstrap arg which initializes the mongo database. It installs the machine agent, and waits for it to start up.

By default, the same version as the client is attempted. The 'tools' are downloaded from streams.canonical.com, which has signed tools files for Juju.

I believe it is possible to specify a different version to be installed.

juju help bootstrap

Shows the following:

options:
--agent-version (= "")
    the version of tools to initially use for Juju agents

So you should be able to do the following:

juju bootstrap --agent-version=1.22.6

The tools are downloaded by default from streams.canonical.com the same way whether you are using Ubuntu or Windows.