Onboard istio ztunnel

[IbraAoad]

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• I am following the CONTRIBUTING guidelines

Ping the @canonical/rocks team.

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Description

This PR adds the ztunnel ROCK to the OCI factory.

Related issues

#317

[zhijie-yang]

Thanks for the code.

I have to manually terminate the workflow runs for the black-box testing, as this rock is causing infinite loops there.

The is due to using ztunnel as the entrypoint-service rather than the default pebble, causing the test to fail to run the command pebble help, while having pebble indefinitely trying to run the failing ztunnel [ ] command.

Besides, using the programs other than pebble as the entry point service does not comply with the guidelines to build rocks. You can observe the warnings when running rockcraft pack:

Warning: defining an entrypoint-service will result in a rock with an atypical OCI Entrypoint. While that might be acceptable for testing and personal use, it shall require prior approval before submitting to a Canonical registry namespace.

I believe it is necessary to change the entry point service of this rock. Otherwise, please provide justifications for doing so.

Discussions are welcomed. Cheers!

[simskij]

@zhijie-yang

I believe it is necessary to change the entry point service of this rock. Otherwise, please provide justifications for doing so.

Discussions are welcomed. Cheers!

We cannot get rid of the entrypoint service, as Istio launches the container with arguments that are resolved at deploy-time. As the rock needs to be interchangeable with the upstream OCI, we can't really change this without making the rock unusable outside of the charm context.