Using CoreOS ISO to install


This morning I posted how CoreOS needed more memory than its name implied. I also had an adventure with the installer.

If you look at the official install docs for CoreOS, you install from ISO with this command:

$ sudo su - root
# coreos-install -d /dev/sda

Except you can't. The ISO doesn't contain the production image. Or if it did, it wasn't made clear and/or I couldn't find it.

So I update my networking, to allow it to download.

# ifconfig eth0 <ethernet-ip/24>
# route add default gw <gateway-ip>

Still no dice, it complained it couldn't resolve the address. Shoot yes, I didn't have an entry in resolv.conf.

echo "" >> /etc/resolv.conf
Still nothing. As John Cleese said of a certain gentleman's walk, this was getting rather silly.

Reading the documentation, you define networking in the following horrible systemd path. So I edited the file:

vim /etc/systemd/network/

And added the following:


Then it was simply a matter of restarting networking:

# service network restart
==> -su: service: command not found

Then it was simply a matter of restarting networking, using systemd's more streamlined syntax:

# systemctl restart systemd-networkd

And finally we were cooking with gas.

==> Downloading, writing and verifying coreos_production_image.bin.bz2...

You'll also want to specify a cloud-config as well.

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Ruben Schade is a technical writer and IaaS engineer in Sydney, Australia who refers to himself in the third person in bios. Wait, not BIOS… my brain should be EFI by now.

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