don't use /tmp anymore, but /var/run/albatross for fifos + sockets + vm images,
and /var/db/albatross for ukvm-bin and crls, and /var/log/albatross for logging
vmm_console/vmm_log/vmm_stats_lwt: delete socket on startup if it exists
vmm_influxdb_stats: connects to vmm_stats socket and pushes every interval in
influxdb line format via tcp to specified host and port
allows to cleanup various hacks, such as checking for pid in vmm_resources
or removing temporarily the allocated resources from the resource map in vmm_engine
semantics is now slightly different, but for sure enhanced.
- each VM has a Lwt.wait () task attached in Vmm_engine.t (tasks : 'c String.Map.t)
- normal create shouldn't be much different, apart from memoizing the sleeper
- after waitpid is done in vmmd, and vmm_engine.shutdown succeeded, Lwt.wakeup is called for the sleeper
- force create now:
- checks static policies
- looks for existing VM (and task), if present: kill and wait for task in vmmd
- continue with presence checking of vm name, dynamic policies, allocate resources (tap, img, fifo)
this means the whole randomness in filenames can be removed, and the
communication between vmm_console and vmm_client is working again (attach/detach
could not work since vmm_console knew only about "albatross.AAA.BBB.RANDOM",
whereas vmm_client insisted on "AAA.BBB"
resource overcommitment (and races in e.g. block device closing + opening) are
gone now, only if the old vm is cleanup up, resources for the new one are
allocated and it is executed
- vm_open only once per vm (vmmapi_open), returning vmctx
- get stats descriptions only once in lifetime (vmmapi_statnames)
- close file descriptor on `remove_pid` (vmmapi_close)
vmm_stats_once: command line utility (for debugging) for stats gathering
a client certificate may either contain `Create or `Force_create permission. If
the latter is used (vmm_req_vm --force), and a VM with the same name already
exists, this is destroyed (if the dynamic resources without the existing would
allow the new one to be deployed) and the new one is started.
I had this concrete deployment scenario, where kill ; create takes some minutes
since it is 10MB data which needs to be transferred from my laptop to a remote
server (me behind dialup).
- renamed `Image to `Create
- renamed `Destroy_image to `Destroy_vm
