While debugging a bootstrap of xenial on vsphere (see 1588041). I saw Juju could not connect to the host's ipv4 address. I added all my keys to gthe authorized-keys option and rebooted. While Juju could not get into the host, I could. I catted .ssh/authorised_keys and saw the new lines were lost. All keys were on one line. The keys for a vsphere trusty deployment, and every other provider + series combination I test has 1 key per line.
bootstrap-timeout: 1200
default-series: xenial
enable-os-upgrade: false
test-mode: true
authorized-keys: |
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCrXoztXs5X89N7SwxGjXYjL4M8Coclk+/blvzyiqZDaWsH234DETiv3Rwc2wJlEk3K1HSLnpBQHL6HQME7j/PpMaFGiJqD0tfF0JU2Kj6FEsgV43IR0YvXm0/2EvzO4NMplukmJVUPIAa++Tpl/72F+t8t2mSK73PwzeycpC+X9z/NC5EwsOMH87NYrM1HdwwZlz2GJswcG0IHDB/5oKV4nPMkm6EFweKt4N5HrRjA9l7y3tUbNhGMuEJVIbskfn6LTdir6CghRHY+OT70RrN+gqRVw3y/GvrfVE3m8ZqgbqAFE9UDBXDSI8AX2dYAlmvTI/B9X2QiMrNC0DXvnY/X oil-ci-bot
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC9aoIHpnF4Y4w3PvUP0rhruNRaCFf0kPpYqM8V8uHvm/z//S2EE4wjIN3mxBv97kwGRmJWTYm8wu2ZepKxqsiH1LMpPiLHM2vOZyRkrz7wprHwxwH0ler6lZvM6hrWG7Pae6UcQuDASkV89hNdLPE20whyhIl07uPt+hjpMXJM82aSAhT57/rdOSRMgV518j1Aq/xNpbIKIaXA9P/TTHtLOxJvItKialx+MS0BSiE7O9dE8MeR4SyaAQr+yH81I5TlB1D2Qot80CB7eCiV0gSGt/azLhWTX/sDItQ2VVBxaYcEj9eoOUiVCDKx6eQ7tMJdWE/63wKYCs07sbu5G4Z3 juju-client-key
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDyEdd8eDyy2WA6Q+W4GV2NqKX+yfkkW5ogSu3/7DjlqjED7dCNkevq2qpdR1AMkbKTouihWdyc8QKl9lzuwn0zoocXJUVgIOPV+KFxSAhj1djGvryHDjYUwdrLYUMu3CUFeIsRao2cn7EgZs0w1Y1quqr9c8cEg7XsAs0ZMN9YksEjG000VupOIZJNtk+5EYJm/6vNFI83IOn7ctWfjXymBuh7XM8d8vszyYDRdeDXY5Q9VLqHOP7/CFteIvcdHnSC1ObQuKzXRWz+m9thgQnRQjvirdwvDUXhjjQk9MNJZj84EukB8HyAVSN863MfuVGoCsNn7iEdtT6W2nKTWyL3 abentley@speedy
I cannot reproduce this issue. I've just added a vsphere model with multiple ssh keys, and added a xenial machine. It comes up with the keys as expected, one per line, and I can "juju ssh" to it.