Running multiple versions of Juju

You may wish to use the new 2.x series of Juju releases for new projects, tests and development work, but still require to support legacy deployments which were built on and use the 1.x version of Juju.

Juju 2.x has been designed to be able to co-exist with earlier versions, so you can install both. The details vary depending on your OS, as detailed below:

Ubuntu 16.04LTS (Xenial) and later releases

Running

apt install juju

...will install the latest Juju 2.x. If you also want to run the legacy 1.x series, you may install that separately:

apt install juju-1.25

OR, if you wish to run Juju 1.x as the 'primary' Juju (i.e. the version the juju command points to by default), you can install this package:

apt install juju-1-default

(Juju 2.x will be available by running the juju-2.0 command).

Data directories

The 1.x series keeps data in ~/.juju The 2.x series keeps data in ~/.local/share/juju/

You can alter these by setting the environment variables JUJU_HOME and JUJU_DATA respectively. DO NOT co-locate the files in these directories or unfortunate things will happen.

Ubuntu 14.04LTS (Trusty)

Both series 1.x and 2.x can co-exist in Trusty. If you have already installed and used 1.x and subsequently install 2.0, the binary for 2.0 will be installed at /usr/lib/juju-2.0/bin/juju

You can replicate the experience for Ubuntu 16.04 by using the ùpdate-alternatives command to add 2.x as an alternative for the binary to call when issuing the juju command, and to add a juju-1 command for the 1.x series:

update-alternatives --install /usr/bin/juju juju /usr/lib/juju-2.0/bin/juju 1
update-alternatives --install /usr/bin/juju-1 juju-1 /usr/lib/juju-1.25.6/bin/juju 0
update-alternatives --config juju

This last command will present a choice for which version to use for the juju command.

Data directories

The 1.x series keeps data in ~/.juju The 2.x series keeps data in ~/.local/share/juju/

You can alter these by setting the environment variables JUJU_HOME and JUJU_DATA respectively. DO NOT co-locate the files in these directories or unfortunate things will happen.

Other Linux

The CentOS download 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 also 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 2.0, 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.