gdb does not hit any breakpoints when I run it from inside Docker container
update 2020.01.04: Use the answer given by Kevin W Matthews --- it's better because it grants the necessary individual capabilities without elevating the entire container.
tldr; use
docker run --privilegedLonger: I was having some problems with gdb in docker---it was attempting (and failing) to disable address space layout randomization---but only on docker-machine, not on my native linux host.
When gdb failed to disable ASLR, all of my breakpoints would be ignored. Using the --privileged flag fixed my issue. Your mileage may vary.
Rather than elevating the entire container, I was able to use the option
--security-opt seccomp=unconfinedto fix address space randomization problems.
Some also recommend enabling the ptrace capability with
--cap-add=SYS_PTRACEbut this didn't seem to have any effect for me.
Here are the same settings for Docker compose:
security_opt: - seccomp:unconfinedcap_add: - SYS_PTRACEDetails are taken from this Stack Overflow post.
thanks the answer from @rubicks.
and if you can't use --privileged option(e.g. you are using a container from cloud), you can print stacktrace from your program:
How to automatically generate a stacktrace when my gcc C++ program crashes