Enable signal proxying with --tty option #6955
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docs/man/docker-run.1.md
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Should be "proxy" not "Proxify" |
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I agree that this is something we probably want to change. However, @mheon, could you tell us how this changes behavior for various use cases and what this would break, please? |
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Fixed the Docs issues (capitalization of TTY, proxify changed to proxy) @unclejack, this should not significant change or break existing use cases. Signals the client would currently ignore (or crash upon receiving) will be proxied to the container. The biggest difference I can see will be that signal 15 will be send to the container, not the client, so it is no longer a reliable way to cause a graceful exit of the client. Signal 2 is handled separately by the TTY handler, so SIGINT and Control-C can be substituted for that case. |
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Fixes #5547
At present, signal proxying doesn't work when --tty is specified during container creation. This patch removes the checks that would otherwise prevent this from happening.
There are a few quirks associated with this. Most notable, SIGTTIN, SIGTTOU, and SIGTSTP are ignored if a TTY is attached. This doesn't seem to be worth fixing - those signals are mostly related to TTYs already, so the pseudo-TTY attached to the container can handle them. Instead, I documented the behavior to prevent confusion.
Also notably, the terminal hijack handler will register a separate signal handler for SIGINT, so sending SIGINT will close the client instead of proxying the signal. This could be fixed, but this would prevent control-C from stopping terminal hijack, which could be undesirable?