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Hi List! |
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Let me tell you about a little scenario. |
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dhcpcd starts, calls resolvconf |
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resolvconf then updates it's files and runs it's plugins - libc (nscd), |
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dnsmasq and bind which restart via their init script if required. |
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Each service (nscd, dnsmasq and bind) can be stopped and started easily. |
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Now, when dhcpcd receives a stop signal it runs resolvconf again, which it |
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should by design. Quite happily it runs he plugins and restarts dnsmasq, bind |
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and/or nscd so that the interface that dhcpcd handled doesn't publish its dns |
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information anymore. |
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However - if dhcpcd was stopped by a SIGTERM then the restarted services do |
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get restarted and it seems to work, but the services (nscd, dnsmasq, bind) |
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are unresponsive and can only be killed by a SIGKILL. Not good. |
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Every other signal that causes a "stop" (SIGINT, SIGQUIT, etc) that can be |
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trapped works just fine and services continue as they are. |
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So why am I writing this email? Well, start-stop-daemon, by default, uses |
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SIGTERM. Another example of this was my new openvpn scripts calling |
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resolvconf when openvpn stopped causing the same behaviour as dhcpcd as |
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described above. |
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As more and more init scripts "stopping" can trigger other services to |
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restart, it becomes very desirable for this not to happen. So I propose for |
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the next baselayout release (1.12.0_pre17) to default start-stop-daemon calls |
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to SIGINT for stop commands instead of the current SIGTERM. My testing on my |
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boxes has no adverse effects so far. |
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So ...... thoughts? Good or bad idea? Reasons and explanations welcome :) |
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-- |
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Roy Marples <uberlord@g.o> |
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Gentoo Linux Developer |
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-- |
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gentoo-dev@g.o mailing list |
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