linux: Alpine sysadmin commands

Alpine has some different systems to the more common GNU/Linux distros:

• OpenRC instead of systemd as init process
  • rc-service, rc-update instead of systemctl
• apk instead of apt for package management
• doas instead of sudo for priviledge escalation
• ash instead of bash for shell
• ens3 instead of eth0 for (predictable) network interface naming