Redirect stdout and stderr to /dev/null if possible #143
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src/common/os/posix/divorce.cpp
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| { | ||
| dup2(dev_null, fileno(stdout)); | ||
| dup2(dev_null, fileno(stderr)); | ||
| } |
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What if dev_null is 1 or 2? What will do dup2(1, 1)?
If dev_null is not 1 or 2 - should it be closed after dup2 calls?
May be let users put stdout/stderr to some not-null file - for example as a tool to debug UDR?
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What if dev_null is 1 or 2? What will do dup2(1, 1)?
If dev_null is not 1 or 2 - should it be closed after dup2 calls?
Will fix it.
May be let users put stdout/stderr to some not-null file - for example as a tool to debug UDR?
Originally this commit intended to fix *nix only problem caused by guardian. If we want to use output redirecting as some debugging tool it should be more unified and work on all platforms and without guardian. May be then server binary should have ability to redirect its output to /dev/null or any other file from config?
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@AlexPeshkoff I have updated branch. Please review. I have added config option to allow user define path. Also both classic and super now will behave same way when handling stdout/stderr. Changes are only for posix build for now.
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For posix everything appears good.
Before these changes guardian and server binary closed stdin/stdout/stderr/... and server can reuse those descriptors when opening files or using shmem for example. So some stray stdout can introduce unwanted data or even crash server. Server do not emit any stdout/stderr in release build but UDRs or external libraries can print to stdout. After these changes stdout/stderr will be kept opened and user have options to redirect it to /dev/null (by default) or other file by choise or just allow server to print. New config option OutputRedirectionFile was introduced to allow user control server behavior.
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Guardian closes stdin/stdout/stderr/... before
launching server binary so server can reuse those
descriptors when opening files or using shmem for
example. So some stray stdout can introduce
unwanted data or even crash server. Server do not
emit any stdout/stderr in release build but
UDRs or external libraries can print to stdout.