open-nomad/client/pluginmanager/csimanager/usage_tracker.go
Tim Gross f6b3d38eb8
CSI: move node unmount to server-driven RPCs (#7596)
If a volume-claiming alloc stops and the CSI Node plugin that serves
that alloc's volumes is missing, there's no way for the allocrunner
hook to send the `NodeUnpublish` and `NodeUnstage` RPCs.

This changeset addresses this issue with a redesign of the client-side
for CSI. Rather than unmounting in the alloc runner hook, the alloc
runner hook will simply exit. When the server gets the
`Node.UpdateAlloc` for the terminal allocation that had a volume claim,
it creates a volume claim GC job. This job will made client RPCs to a
new node plugin RPC endpoint, and only once that succeeds, move on to
making the client RPCs to the controller plugin. If the node plugin is
unavailable, the GC job will fail and be requeued.
2020-04-02 16:04:56 -04:00

70 lines
1.7 KiB
Go

package csimanager
import (
"sync"
)
// volumeUsageTracker tracks the allocations that depend on a given volume
type volumeUsageTracker struct {
// state is a map of volumeUsageKey to a slice of allocation ids
state map[volumeUsageKey][]string
stateMu sync.Mutex
}
func newVolumeUsageTracker() *volumeUsageTracker {
return &volumeUsageTracker{
state: make(map[volumeUsageKey][]string),
}
}
type volumeUsageKey struct {
id string
usageOpts UsageOptions
}
func (v *volumeUsageTracker) allocsForKey(key volumeUsageKey) []string {
return v.state[key]
}
func (v *volumeUsageTracker) appendAlloc(key volumeUsageKey, allocID string) {
allocs := v.allocsForKey(key)
allocs = append(allocs, allocID)
v.state[key] = allocs
}
func (v *volumeUsageTracker) removeAlloc(key volumeUsageKey, needle string) {
allocs := v.allocsForKey(key)
var newAllocs []string
for _, allocID := range allocs {
if allocID != needle {
newAllocs = append(newAllocs, allocID)
}
}
if len(newAllocs) == 0 {
delete(v.state, key)
} else {
v.state[key] = newAllocs
}
}
func (v *volumeUsageTracker) Claim(allocID, volID string, usage *UsageOptions) {
v.stateMu.Lock()
defer v.stateMu.Unlock()
key := volumeUsageKey{id: volID, usageOpts: *usage}
v.appendAlloc(key, allocID)
}
// Free removes the allocation from the state list for the given alloc. If the
// alloc is the last allocation for the volume then it returns true.
func (v *volumeUsageTracker) Free(allocID, volID string, usage *UsageOptions) bool {
v.stateMu.Lock()
defer v.stateMu.Unlock()
key := volumeUsageKey{id: volID, usageOpts: *usage}
v.removeAlloc(key, allocID)
allocs := v.allocsForKey(key)
return len(allocs) == 0
}