janus_cli: kube uses rustls rather than OpenSSL even in debug builds

[branlwyd]

The intended behavior is that debug builds will use OpenSSL, while release builds will use rustls. This is to work around kube-rs/kube#153 -- rustls currently can't connect to a Kubernetes cluster through an IP address. The linked issue does not affect "in-cluster" usage, so using rustls for release builds is acceptable.

This worked at time of commit in #314 (should be double-checked), we can bisect from there to find where the breakage occured. Until this issue is resolved, local users of janus_cli need to modify the janus_server/Cargo.toml to switch the default feature list from "kube-rustls" to "kube-openssl".

[branlwyd]

(argh, the issue title was backwards)

[divergentdave]

I checked out 7beee2a, ran some debug builds for both the single binary target and the whole workspace, and the rustc invocations all include --cfg 'feature="kube-rustls"' when building targets in janus_server. (The same is true at the tip of main)

I don't think that we can get anything from default-features = false in janus_server's dev-dependency on itself, because (a) the set of features that are enabled for a crate is the union of all features required by its dependents, so we would be taking the union of the default feature set, ["kube-rustls"] with ["kube-openssl", "test-util"], and (b) development dependencies are only considered when building tests, examples and benchmarks, not binary targets, and the choice of release or dev profile is orthogonal to development dependencies.

I think it would make sense to drop kube-openssl from the self-dev-dependency, and document that when using Kind, the tool should be run with cargo run --bin janus_cli --no-default-features --features kube-openssl -- <SUBCOMMAND> ....