Handle SIGINT

[aaronmondal]

This allows Ctrl+c killing the cas executable in environments that don't invoke the it via a shell wrapper. This is the case in, for instance, minimal container images.

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This change is 

[allada]

Reviewable status: 0 of 3 files reviewed, 1 unresolved discussion (waiting on @aaronmondal)

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src/bin/cas.rs line 655 at r1 (raw file):

    let runtime = tokio::runtime::Builder::new_multi_thread()
        .enable_all()
        .on_thread_start(move || set_metrics_enabled_for_this_thread(metrics_enabled))

Can't change this. This function gets ran on every thread that tokio spawns. We need to use this form of tokio runtime creation.

[aaronmondal]

Reviewable status: 0 of 3 files reviewed, 1 unresolved discussion (waiting on @allada)

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src/bin/cas.rs line 655 at r1 (raw file):

Previously, allada (Nathan (Blaise) Bruer) wrote…

Can't change this. This function gets ran on every thread that tokio spawns. We need to use this form of tokio runtime creation.

Done.

[allada]

Sorry, in my head I thought I approved it so I was ignoring it.

Reviewed 2 of 3 files at r1, 1 of 1 files at r2, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @aaronmondal)