I have a fully-configured instance and an image from that for an autoscaling group. When autoscaling new instances from this image, it calls cloud-init. cloud-init changes the hostname and breaks fstab.
I want to prevent cloud-init from starting on instance launch.
In systems that use systemd and have a current (17.0+) version of cloud-init, upstream documentation describes the process for disabling cloud-init with either of the following:
touch /etc/cloud/cloud-init.disabledcloud-init=disabled to the kernel command line.For older versions of cloud-init (0.7.X) the following information might be useful.
You can disable cloud-init's modification of /etc/fstab in one of 2 ways.
a.) by providing cloud-config that overrides the default 'mounts' entries and disables them.
mounts:
- [ephemeral0, null]
- [swap, null]
b.) by disabling the mounts module from running. This is done by removing it from the 'cloud_config_modules' list that you'll see in /etc/cloud/cloud.cfg.
With regard to hostname, you can also control that also. If you just want to stop cloud-init from modifying /etc/hostname, then:
preserve_hostname: true
Also interesting to you might be manage_etc_hosts.
Both of these are documented in doc/examples/cloud-config.txt (and installed in /usr/share/doc/cloud-init/examples)
I'm interested in knowing how cloud-init is breaking /etc/fstab, though. Please file a bug using ubuntu-bug cloud-init from inside your instance, and describe what it is doing that you think is wrong.
