Add debug log for check-in miss (#5348)

* Add debug log for check-in miss

Logging the time details to debug flaky tests
like #4203.

* fix errcheck linter

* Log with `logp.Logger`'s `Debugf` function

pkg/component/runtime/command.go

@@ -67,6 +67,7 @@ type procState struct {
 
 // commandRuntime provides the command runtime for running a component as a subprocess.
 type commandRuntime struct {
+	log    *logger.Logger
 	logStd *logWriter
 	logErr *logWriter
 
@@ -108,6 +109,7 @@ type commandRuntime struct {
 // newCommandRuntime creates a new command runtime for the provided component.
 func newCommandRuntime(comp component.Component, log *logger.Logger, monitor MonitoringManager) (*commandRuntime, error) {
 	c := &commandRuntime{
+		log:         log,
 		current:     comp,
 		monitor:     monitor,
 		ch:          make(chan ComponentState),
@@ -238,6 +240,7 @@ func (c *commandRuntime) Run(ctx context.Context, comm Communicator) error {
 						c.missedCheckins = 0
 					} else {
 						c.missedCheckins++
+						c.log.Debugf("Last check-in was: %s, now is: %s. The diff %s is higher than allowed %s.", c.lastCheckin.Format(time.RFC3339Nano), now.Format(time.RFC3339Nano), now.Sub(c.lastCheckin), checkinPeriod)
 					}
 					if c.missedCheckins == 0 {
 						c.compState(client.UnitStateHealthy)