Re: Dynamic config for apps - download file(s) on boot, or mounting a network filesystem ?
- From: Antti Kantee <pooka@xxxxxx>
- To: rumpkernel-users@xxxxxxxxxxxxx
- Date: Sat, 14 Apr 2018 23:09:53 +0000
On 14/04/18 17:37, lemonnierk@xxxxxxxxx wrote:> Generating a .conf is
easy enough, but I don't really know how to feed
it to haproxy. By hand I'd generate an iso file and start the unikernel
with that mounted as /etc/haproxy, but that'd required developping
something ton run on the hypervisors to generate the iso, not ideal.
Have a look at cookfs. You can use it to generate components, which
when baked into an image, have their files mapped into memory. You need
to have separate images, and a toolchain, so it might not be what you
what, though.
Is there some way to run something before the "main binary" that got
baked is started somehow ? I'd be great to be able to run something like
wget <url>/config?id=<XXX> for example. I suppose that requires
including two binaries
Yes, you can do that. You have to write the config file by hand. Be
warned, that while "kernel" process state is separate, libc process
state and userspace symbol is the same. So, you can't run two
arbitrarily complex programs, and essentially the only way to know if
two programs are compatible is to test them. The book describes
multiple programs at least to some extent.
I suppose what I've been wanting to do for years would work too :
mounting any kind of network filesystems, but as far as I know it's
still not possible ?
Rump kernels support at least nfs and smb, and you could probably figure
out how to use those in Rumprun with reasonable effort. With rumpctrl
it would be even less effort, but that may or may not provide the amount
of moving parts that you'd like.
As usual, there probably isn't precise documentation telling how to do
exactly what you want to do. So, you'll have to figure out a bunch of
details by yourself. If you're really feeling energetic, write the
documentation too. Good luck! ;)
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