juju uses wget to fetch tools from streams.canonical.com which uses SNI but wget on precise doesn't support SNI, causing bootstrap to fail. Running the equivalent command using cURL instead of wget works on precise and later.
Bootstrap failure:
Installing add-apt-repository
Adding apt repository: deb http://ubuntu-cloud.archive.canonical.com/ubuntu precise-updates/cloud-tools main
Running apt-get update
Running apt-get upgrade
Installing package: git
Installing package: cpu-checker
Installing package: mongodb-server
Fetching tools: wget --no-verbose -O $bin/tools.tar.gz 'https://streams.canonical.com/juju/tools/releases/juju-1.17.2-precise-amd64.tgz'
2014-02-20 11:43:48 ERROR juju.provider.common bootstrap.go:140 bootstrap failed: exit status 1
Stopping instance...
2014-02-20 11:43:49 ERROR juju.cmd supercommand.go:294 exit status 1
Wget failure on precise:
$ wget --no-verbose -O tools.tar.gz 'https://streams.canonical.com/juju/tools/releases/juju-1.17.2-precise-amd64.tgz'
ERROR: no certificate subject alternative name matches
requested host name `streams.canonical.com'.
To connect to streams.canonical.com insecurely, use `--no-check-certificate'.
Precise's version of wget does not support SNI, but curl does. So I'll replace the wget call with a curl call and add curl to the list of installed packages.