CoreOS cluster installation alternatives (offline)

Question

I'm trying to install a CoreOS cluster on several bare metal servers. I have successfully installed and configured a PXE server which allows me to start CoreOS on RAM on those servers. After some time I realized that I really need to install CoreOS physically so I'm trying options; my main problem is that I don't have internet so I can't use coreos-install as it is because it wgets the images from CoreOS servers, I downloaded all needed images elsewhere but I'm still stuck on how to install them offline. I would like to be recommended on: (in order to install CoreOS physically offline with docker support)

1- Which is the best way to do it?

2- Does the ISO image work for this?

3- Is there any tool which help me to do the job?

4- What options do I have if I can't use a PXE server?

Answer 1

1- Which is the best way to do it?

coreos-install doesn't work with offline images. But if you absolutely want it to work offline on some machine, you can run coreos-install on the machine, that has branch.release.core-os.net domain redirected to 127.0.0.1 using /etc/hosts, has nginx running with a config like this to redirect requests to coreos servers to a local file. Nginx must impersonate core-os.net server. Never tried ;) But it may even work ;)

4- What options do I have if I can't use a PXE server?

I think you can use CloneZilla to install CoreOS offline. Again, I never tried it, so it's just a suggestion.

Answer 2

While not a new question, I am posting this answer because, at least right now, the accepted answer is incorrect (might have been correct at the time).

You can do an install of CoreOS without access to the Internet. There is a switch you can pass to the coreos-install script that gives a local mirror of the image repository.

The valid switches for coreos-install are:

-d DEVICE   Install CoreOS to the given device.
-V VERSION  Version to install (e.g. current)
-C CHANNEL  Release channel to use (e.g. beta)
-o OEM      OEM type to install (e.g. openstack)
-c CLOUD    Insert a cloud-init config to be executed on boot.
-t TMPDIR   Temporary location with enough space to download images.
-v          Super verbose, for debugging.
-b BASEURL  URL to the image mirror

So if you give -b http://mylocalserver/ and that is a valid web server with the files there then it will work.

You also don't need a PXE server, you simply need to booth with a CD/ISO that enables you to run the install script. CoreOS provides such an ISO.

Ref: CoreOS documentation, Installing to disk