add observability bind mount to retrieve logs from guest

[egernst]

We'd like to be able to reliably pull 'custom userspace application' logs from the Kata sandbox to facilitate getting event details out of the guest (imagine running something like auditd, or any other app...).

By creating a /var/log/kata/ directory on the host and bind mounting it to the host shared directory, we can provide a path that custom guest-userspace applications can leverage to provide logs onto the host, which could then be processed accordingly.

This path and mount is tied to the lifecycle of the sandbox, and is not exposed to the underlying container(s). Filesystem sharing is required for this.

Alternative considered:

• We looked at mimicking what is done with the agent traces, by sending application output over vsock onto the host. This requires a separate service running in the guest to forward this output, as well as at least one agent on the host to demux all of this. Similarly, it is painful since the vsock implementation varies per VMM configuration utilized.
• Looked at sidecar. This was avoided because we didn't want to expose this debug infra to the end user.

[fidencio]

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This issue is being automatically closed as Kata Containers 1.x has now reached EOL (End of Life). This means it is no longer being maintained.

Important:

All users should switch to the latest Kata Containers 2.x release to ensure they are using a maintained release that contains the latest security fixes, performance improvements and new features.

This decision was discussed by the @kata-containers/architecture-committee and has been announced via the Kata Containers mailing list:

• http://lists.katacontainers.io/pipermail/kata-dev/2020-November/001601.html
• http://lists.katacontainers.io/pipermail/kata-dev/2021-April/001843.html
• http://lists.katacontainers.io/pipermail/kata-dev/2021-May/001896.html

If you believe this issue still applies to Kata Containers 2.x, please open an issue against the Kata Containers 2.x repository, pointing to this one, providing details to allow us to migrate it.

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