Add pre-stop hook to print maps before exit

Author: dalehamel

pkg/tracejob/job.go

@@ -296,6 +296,21 @@ func (t *TraceJobClient) CreateJob(nj TraceJob) (*batchv1.Job, error) {
 							SecurityContext: &apiv1.SecurityContext{
 								Privileged: boolPtr(true),
 							},
+							// We want to send SIGINT prior to the pod being killed, so we can print the map
+							// we will also wait for an arbitrary amount of time (10s) to give bpftrace time to
+							// process and summarize the data
+							// FIXME should this sleep be configurable? 10s is probably ample for most cases.
+							Lifecycle: &apiv1.Lifecycle{
+								PreStop: &apiv1.Handler{
+									Exec: &apiv1.ExecAction{
+										Command: []string{
+											"/bin/bash",
+											"-c",
+											"kill -SIGINT $(pidof bpftrace) && sleep 10",
+										},
+									},
+								},
+							},
 						},
 					},
 					RestartPolicy: "Never",