Support for gdb errors in Docker containers

Overview

When I tried to debug a C program using the gdb command in a Docker container, the following warning: Error disabling address space randomization: Operation not permitted I was angry.

(gdb) b 5
Breakpoint 1 at 0x117c: file test.c, line 5.
(gdb) r
Starting program: /home/user/dev/test 
warning: Error disabling address space randomization: Operation not permitted

As you might expect, gdb uses system calls, but it seems that you cannot access the device of the host machine because you do not have the authority from inside the container.

solution

Option to allow system call will be added.

• When docker run is executed

$ docker run -it --cap-add=SYS_PTRACE --security-opt="seccomp=unconfined" [CONTAINER_NAME] /bin/bash

• For docker-compose

Write the following under service.

docker-compose.yaml

    cap_add: 
      - "SYS_PTRACE"
    security_opt: 
      - "seccomp=unconfined"

Reference article

https://sott0n.github.io/posts/docker_gdb/