fix: the ebpf program in the tcpretrans plugin failed to load

[wenhuwang]

Description

Fix the issues of abnormal status of retina-agent caused by opening tcpretrans plugin. The retina-agent nil pointer is because the Tracer.socketEnricherMap field of the tcpretrans plugin is nil.

Related Issue

#311

Checklist

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• [x] I have tested the changes locally.
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• [ ] I have added tests, if applicable.

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[rbtr]

@wenhuwang this doesn't seem to fully resolve the problem. Instead of a nil pointer, now there is an error instantiating the socketEnricher:

failed to reconcile plugin tcpretrans: failed to new socketEnricher: read BPF iterator: checking if current pid namespace is host pid namespace: host.Init() must be called before calling isHostNamespace()

[wenhuwang]

@wenhuwang this doesn't seem to fully resolve the problem. Instead of a nil pointer, now there is an error instantiating the socketEnricher:

failed to reconcile plugin tcpretrans: failed to new socketEnricher: read BPF iterator: checking if current pid namespace is host pid namespace: host.Init() must be called before calling isHostNamespace()

@rbtr Sorry for the late reply, I'm on vacation recently. I have tested it locally before. I will verify this problem in a few days.

[wenhuwang]

I have not reproduced this problem and retina-agent status is normal in local environment .

failed to reconcile plugin tcpretrans: failed to new socketEnricher: read BPF iterator: checking if current pid namespace is host pid namespace: host.Init() must be called before calling isHostNamespace()

platform: OS: Ubuntu 18.04.5 LTS Kubernetes Version: 1.22.2 Host: self-host Kernel Version: 5.10.87-051087-generic Retina Version: v0.0.8

Do you have any specific steps to reproduce the problem? @rbtr

[wenhuwang]

Thanks for the change. Can you add details as to how you verified this change?

1. Before adding this change, the retina-agent would panic because of the nil pointer.
2. After adding this change, retina-agent runs normally and can get tcpretrans plugin metrics.
3. When troubleshooting the following problem through the logs, I can only see the "Initialized tcpretrans plugin" log but not the "failed to new socketEnricher" related logs.

failed to reconcile plugin tcpretrans: failed to new socketEnricher: read BPF iterator: checking if current pid namespace is host pid namespace: host.Init() must be called before calling isHostNamespace()