/
modelfirewallruleswatcher.go
90 lines (74 loc) · 1.91 KB
/
modelfirewallruleswatcher.go
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// Copyright 2023 Canonical Ltd.
// Licensed under the AGPLv3, see LICENCE file for details.
package firewaller
import (
"github.com/juju/collections/set"
"github.com/juju/errors"
"github.com/juju/worker/v3/catacomb"
)
type modelFirewallRulesWatcher struct {
catacomb catacomb.Catacomb
backend State
out chan struct{}
sshAllowCache set.Strings
}
// NewModelFirewallRulesWatcher returns a worker that notifies when a change to something
// determining the model firewall rules takes place
//
// NOTE: At this time, ssh-allow model config item is the only thing that needs to be watched
func NewModelFirewallRulesWatcher(st State) (*modelFirewallRulesWatcher, error) {
w := &modelFirewallRulesWatcher{
backend: st,
out: make(chan struct{}),
}
err := catacomb.Invoke(catacomb.Plan{
Site: &w.catacomb,
Work: w.loop,
})
return w, err
}
func (w *modelFirewallRulesWatcher) loop() error {
defer close(w.out)
configWatcher := w.backend.WatchForModelConfigChanges()
if err := w.catacomb.Add(configWatcher); err != nil {
return errors.Trace(err)
}
var out chan struct{}
for {
select {
case <-w.catacomb.Dying():
return w.catacomb.ErrDying()
case out <- struct{}{}:
out = nil
case _, ok := <-configWatcher.Changes():
if !ok {
return w.catacomb.ErrDying()
}
cfg, err := w.backend.ModelConfig()
if err != nil {
return errors.Trace(err)
}
sshAllow := set.NewStrings(cfg.SSHAllow()...)
if !setEquals(sshAllow, w.sshAllowCache) {
out = w.out
w.sshAllowCache = sshAllow
}
}
}
}
func (w *modelFirewallRulesWatcher) Changes() <-chan struct{} {
return w.out
}
func (w *modelFirewallRulesWatcher) Kill() {
w.catacomb.Kill(nil)
}
func (w *modelFirewallRulesWatcher) Wait() error {
return w.catacomb.Wait()
}
func (w *modelFirewallRulesWatcher) Stop() error {
w.Kill()
return w.Wait()
}
func (w *modelFirewallRulesWatcher) Err() error {
return w.catacomb.Err()
}