good ideas, tom. We should chat about this stuff during this or next cloudhackers. In the mean time, the implementation plan tom laid out is already a part of jclouds and is working pretty well. There's a tool called pallet [1] that uses these hooks to run chef and resize node sets.
FWIW, here's the user docs on how this works. Happy to discuss implementation, as well. http://code.google.com/p/jclouds/wiki/ComputeGuide#Advanced_Usage Cheers, -Adrian [1] http://github.com/hugoduncan/pallet On Fri, Feb 19, 2010 at 11:22 AM, Tom White <[email protected]> wrote: > On Thu, Feb 18, 2010 at 3:36 AM, Upayavira <[email protected]> wrote: > > This is all the exact use-case I had for libcloud. > > Me too. I like Solomon's idea of providing a runurl service on boot. > This is easy to do with EC2 as a user data script > (http://alestic.com/2009/06/ec2-user-data-scripts). Rackspace too, > with its file injection facility at create time. > > As Paul notes, there are a few obstacles to doing this on all > providers. For example, on Terremark you would have to scp a script > (using a known password), then run it (using ssh, again using the > known password). The script would probably disable the default account > as the first thing it did. > > I imagine this would be an optional feature. If it couldn't be > implemented for a provider, it would be a no op. > > Another feature I would like to see is the ability to assign roles > (groups) to instances. You can then perform operations for all > instances in a particular role in one go - e.g. terminate all > instances in a given role. This wouldn't necessarily be a core feature > - it could be an extension module or something. I do this today using > security groups in EC2, metadata in Rackspace, and instance-name > encoding in Terremark. I find it useful for an instance to know which > roles it is in too (so it can configure itself appropriately) so this > would probably tie into the boot time information. > > Cheers, > Tom > > > > > > > Ideally I could use it to fire up a VM, and tell the host how to > > configure itself. I have had such code working against ec2, and now > > working against Voxel. I've considered Puppet, but one issue is that it > > doesn't handle instance creation. Combine Puppet with something like > > libcloud and you end up with a powerful combination. > > > > Note, for the Voxel API you can provide a script as a parameter at > > creation time. That script will be executed on the VM once it has been > > instantiated. > > > > Upayavira > > > > On Thu, 2010-02-11 at 08:51 -0800, Paul Querna wrote: > >> On Thu, Feb 11, 2010 at 2:38 AM, Solomon Hykes <[email protected]> > wrote: > >> > On Thu, Feb 11, 2010 at 3:18 AM, Paul Querna <[email protected]> wrote: > >> > > >> >> I think an interesting API to provide is the minimum needed to > >> >> kickstart any of the above deployment systems. > >> > > >> > I agree entirely. The less abstraction we can get away with, the > better. > >> > > >> >> For example, if we provided a deploy_node() api, which takes a > similar > >> >> kwargs to create_node [...] > >> > > >> > Why not simply add kwargs to create_node? See below. > >> > > >> >> after the node is booted, SSHes in, > >> >> installs a few specific things, copies a small number of files into > >> >> the machine, and starts a service. The actual actions could be a > >> >> class for each of the above configuration management systems, with > the > >> >> ability to add your own. > >> > > >> > I like the process. It seems to me the only abstraction we need here > >> > is the ability to run commands on the node, with a "runurl" ability to > >> > pull commands from a remote url. > >> > > >> > The result would look like this: > >> > create_node(runurl="http://somewhere.tld/webserver-bootstrap.sh";) > >> > >> Well, not quite, there are a few barriers: > >> - You need to authenticate into the host. Depending on the provider, > >> this is either done by providing a password, an ssh key, or receiving > >> a password after booting, or as Ian mentioned, via an existing ssh > >> key. > >> - You would need to install runurl, this most likely means either > >> just SCPing it up, but you'll still want to use apt or yum or X to > >> install curl or wget etc. > > > > > > >
