Running multiple versions of Juju

You may wish to use the 2.x series of Juju for new projects, tests, or development work, but still require to support legacy deployments, which use the 1.x series. It is possible to install both series on the same host but how it's done depends on your OS.

The data directory for 1.x is ~/.juju and for 2.x it is ~/.local/share/juju/. Keep these as-is; do not attempt to co-locate files in a central directory.

The instructions given in this guide must be followed by a user logout, login, and a verification of what series is associated with the called binary. For example, if the called binary is juju-1 then a verification consists of:

juju-1 version

Ubuntu and 2.x

On Ubuntu, install 2.x using these standard instructions.

Ubuntu 16.04 LTS (Xenial) and 1.x

On Xenial, how to install 1.x depends on which series you want to be the default binary.

To make 2.x be the default

To let 2.x be the default install 1.x with the following deb:

sudo apt install juju-1.25

Here, juju will call 2.x and juju-1 will call 1.x.

To make 1.x be the default

To let 1.x be the default install 1.x with this deb:

sudo apt install juju-1-default

Now, juju will call 1.x and /snap/bin/juju will call 2.x.

Ubuntu 14.04 LTS (Trusty) and 1.x

On Trusty, there is only one way to install 1.x:

sudo apt install juju

To make 2.x be the default

There's no fancy way to make 2.x be called by juju by default.

Edit your PATH environment variable so that /snap/bin appears before /usr/bin. For the Bash shell, one way is to add a line at the bottom of ~/.profile. For example:

PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/snap/bin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games

To fully reflect the corresponding Xenial scenario, you can create a symbolic link for the 1.x series:

sudo ln -s /usr/bin/juju /usr/bin/juju-1

After these changes, juju will call 2.x and juju-1 will call 1.x.

To make 1.x be the default

In this scenario, by default, juju will call 1.x and /snap/bin/juju will call 2.x.

Other Linux

The CentOS download, available here, includes the binaries for Juju which should also work on other flavours of Linux. As these tarballs simply contain an executable binary, you can place them wherever you wish, renaming them if required.

It is recommended to install them in /usr/lib/juju-1.25/bin and /usr/lib/juju-2.0/bin. After which you can use ùpdate-alternatives to configure which one to use:

update-alternatives --install /usr/bin/juju juju /usr/lib/juju-2.0/bin/juju 1
update-alternatives --install /usr/bin/juju juju /usr/lib/juju-1.25/bin/juju 0
update-alternatives --config juju

The same data directories as noted above for Ubuntu are created on first use of the Juju binary.

Windows

The latest Windows version of Juju can be downloaded from here.

Unlike Linux and OS X binary releases, the Microsoft Windows version of Juju is bundled within an executable installer. Running this will walk you through a GPL licence agreement, a request for an install location and the opportunity to add this install location to your environment path.

By default, a new installation will upgrade any previous installation. If you wish to install two versions alongside one another, such as versions 1.25 and 2.0, you will need to install the first package without specifying an environment path. This will stop the second installation automatically overwriting the first. You can then specify a different install location for the second installation and either manually rename and add the binaries to your Windows environment path, or run each executable directly from their respective directories.

Juju can be uninstalled from the Windows 'Add or remove programs' system pane, just like any other Windows application.

macOS

The Apple OS X download, available here, includes the binaries for Juju. These will work work with any recent version of Mac OS X, including 10.9 (Mavericks), 10.10 (Yosemite), 10.11 (El Capitan) and 10.12 (Sierra).

As the download tarball contains executable binaries, you can place them wherever you wish within your user's shell path (such as /usr/bin), renaming them or their parent folders if required. Renaming is particularly useful if you want to install two versions of Juju alongside one another, such as versions 1.25 and 2.5, as the binary files within each archive have identical names.

Unfortunately, OS X doesn't currently support a system similar to update-alternatives (see above), which means you'll need to manually update and name the files differently when installing and using multiple versions.