https: sowatcher scan process ended

[nplanel]

What does this PR do?

Scan ended pids every 10 sec and unregister library if process doesn't exist anymore.

Motivation

The main issue is when in host propagation HostToContainer, with uprobe the kernel lock the ELF file and runc seems to wait on a free filesystem to unmount the overlay.

Describe how to test/QA your changes

• on a k8s cluster
• edit the daemonset : kubectl edit ds
  • in system-probe section

        - mountPath: /host/root
          mountPropagation: HostToContainer
          name: hostroot
          readOnly: true

• change the image to the docker build

• kubectl get pods -o wide

• kubectl logs -f datadog-sysprobe-pod-that-run-on-the-same-node-than-haproxy -c system-probe

• kubectl delete pod/haproxy

output logs

2022-10-07 21:03:53 UTC | SYS-PROBE | DEBUG | (pkg/network/http/shared_libraries.go:213 in checkProcessDone) | process /host/proc/2933421 doesn't exist anymore, unregister /host/root/run/containerd/io.containerd.runtime.v2.task/k8s.io/d48eb1059ba90ef6e1ec00b2756120a0239f3da5bbc97deeda4d36992481255f/rootfs/usr/lib/x86_64-linux-gnu/libcrypto.so.1.1
2022-10-07 21:03:53 UTC | SYS-PROBE | DEBUG | (pkg/network/http/shared_libraries.go:292 in unregister) | unregistering library=/host/root/run/containerd/io.containerd.runtime.v2.task/k8s.io/d48eb1059ba90ef6e1ec00b2756120a0239f3da5bbc97deeda4d36992481255f/rootfs/usr/lib/x86_64-linux-gnu/libcrypto.so.1.1

Reviewer's Checklist

• [ ] If known, an appropriate milestone has been selected; otherwise the Triage milestone is set.
• [ ] Use the major_change label if your change either has a major impact on the code base, is impacting multiple teams or is changing important well-established internals of the Agent. This label will be use during QA to make sure each team pay extra attention to the changed behavior. For any customer facing change use a releasenote.
• [ ] A release note has been added or the changelog/no-changelog label has been applied.
• [ ] Changed code has automated tests for its functionality.
• [ ] Adequate QA/testing plan information is provided if the qa/skip-qa label is not applied.
• [ ] At least one team/.. label has been applied, indicating the team(s) that should QA this change.
• [ ] If applicable, docs team has been notified or an issue has been opened on the documentation repo.
• [ ] If applicable, the need-change/operator and need-change/helm labels have been applied.
• [ ] If applicable, the k8s/<min-version> label, indicating the lowest Kubernetes version compatible with this feature.
• [ ] If applicable, the config template has been updated.