gdb in docker container returns “ptrace: Operation not permitted.”

Question

I\'ve checked /proc/sys/kernel/yama/ptrace_scope in the container and on the host - both report the value as zero but when attached to pid one gdb reports

Answer 1

I discovered the answer - the container needs to be started with strace capabilities

Adding this to my docker-compose.yml file allows GDB to work

cap_add:
    - SYS_PTRACE

Or it can also be passed on the docker command line with --cap-add=SYS_PTRACE