Files
netbird/client/mdm/ticker.go
T

119 lines
3.3 KiB
Go

package mdm
import (
"context"
"reflect"
"sort"
"time"
log "github.com/sirupsen/logrus"
)
// DefaultReloadInterval is the cadence at which the desktop daemon re-reads
// the OS-native MDM policy. Picked to balance responsiveness against
// registry/plist I/O overhead. Mobile builds use OS-side notifications
// instead and bypass this ticker entirely.
const DefaultReloadInterval = 1 * time.Minute
// Ticker periodically re-reads the OS-native MDM policy via LoadPolicy and
// invokes onChange whenever the observed Policy diverges from the last
// observation (added / removed / changed keys). Launch with Run from a
// goroutine; cancel the supplied context to stop.
type Ticker struct {
interval time.Duration
onChange func(prev, curr *Policy)
prev *Policy
}
// NewTicker constructs a Ticker that calls LoadPolicy every `interval` and
// invokes `onChange` on any diff. Pass a zero interval to fall back to
// DefaultReloadInterval. onChange may be nil for a log-only ticker.
func NewTicker(interval time.Duration, onChange func(prev, curr *Policy)) *Ticker {
if interval <= 0 {
interval = DefaultReloadInterval
}
return &Ticker{
interval: interval,
onChange: onChange,
prev: LoadPolicy(),
}
}
// Run blocks until ctx is cancelled, polling the OS-native policy store at
// the configured cadence and emitting log lines + onChange callback on
// every observed diff.
func (t *Ticker) Run(ctx context.Context) {
tk := time.NewTicker(t.interval)
defer tk.Stop()
log.Infof("MDM policy reload ticker started (interval=%s)", t.interval)
for {
select {
case <-ctx.Done():
log.Info("MDM policy reload ticker stopped")
return
case <-tk.C:
curr := LoadPolicy()
if PoliciesEqual(t.prev, curr) {
continue
}
added, removed, changed := diffPolicies(t.prev, curr)
log.Infof("MDM policy changed: added=%v removed=%v changed=%v",
added, removed, changed)
prev := t.prev
t.prev = curr
if t.onChange != nil {
t.onChange(prev, curr)
}
}
}
}
// PoliciesEqual reports whether two Policy instances carry the same managed
// key set with identical values. Nil and empty policies compare equal.
func PoliciesEqual(a, b *Policy) bool {
if a.IsEmpty() && b.IsEmpty() {
return true
}
if a == nil || b == nil {
return false
}
return reflect.DeepEqual(a.values, b.values)
}
// diffPolicies returns the keys added in curr, removed from prev, and whose
// value changed. Returned slices are sorted for stable log output.
func diffPolicies(prev, curr *Policy) (added, removed, changed []string) {
prevKeys := mapOf(prev)
currKeys := mapOf(curr)
for k := range currKeys {
if _, ok := prevKeys[k]; !ok {
added = append(added, k)
} else if !reflect.DeepEqual(prevKeys[k], currKeys[k]) {
changed = append(changed, k)
}
}
for k := range prevKeys {
if _, ok := currKeys[k]; !ok {
removed = append(removed, k)
}
}
sort.Strings(added)
sort.Strings(removed)
sort.Strings(changed)
return added, removed, changed
}
// mapOf returns a (possibly empty, never nil) copy of the underlying values
// map of a Policy so callers outside this package can compare across the
// public Policy boundary without touching unexported state.
func mapOf(p *Policy) map[string]any {
if p == nil {
return map[string]any{}
}
out := make(map[string]any, len(p.values))
for k, v := range p.values {
out[k] = v
}
return out
}