Execute commands inside a running container

To run a command in a running container and investigate that container, you can use the podman exec command. The reason for using the podman exec command instead of the podman run command is that you can investigate the running container without interrupting the container activity.

Before you begin

  • The container-tools meta-package is installed.
  • The container is running.

Procedure

  1. Enter the rpm -qa command inside the my-support-tools container to list all installed packages: 
    $ podman exec -it my-support-tools rpm -qa
     
    gpg-pubkey-fd431d51-4ae0493b
gpg-pubkey-5a6340b3-6229229e
libgcc-11.5.0-2.el9.x86_64
setup-2.13.7-10.el9.noarch
...
  2. Enter a /bin/bash command in the my-support-tools container: 
    $ podman exec -it my-support-tools /bin/bash
  3. Install the procps-ng package containing a set of system utilities (for example ps, top, uptime, and so on): 
    # dnf install procps-ng
  4. Inspect the container:
    • To list every process on the system: 
      # ps -ef
       
      UID          PID    PPID  C STIME TTY          TIME CMD
root           8       0  0 11:07 pts/0    00:00:00 /bin/bash
root          47       8  0 11:13 pts/0    00:00:00 ps -ef
    • To display file system disk space usage: 
      # df -h
       
      Filesystem      Size  Used Avail Use% Mounted on
tmpfs           6.3G  448K  6.3G   1% /etc/hosts
shm              63M     0   63M   0% /dev/shm
overlay         953G   76G  877G   8% /
tmpfs            64M     0   64M   0% /dev
devtmpfs        4.0M     0  4.0M   0% /dev/tty
...
    • To display system information: 
      # uname -r
       
      6.12.0-124.15.1.el10_1.x86_64
    • To display amount of free and used memory in megabytes: 
      # free --mega
       
      total        used        free      shared  buff/cache   available
Mem:       2818         615        1183          12         1020        1957
Swap:      3124           0        3124