Noticed issue when rebuilding dockerfile and running image:-

panic: standard_init_linux.go:178: exec user process caused "exec format error" [recovered]
	panic: standard_init_linux.go:178: exec user process caused "exec format error"

goroutine 1 [running, locked to thread]:
panic(0x6f3080, 0xc4201393b0)

Did much digging, identified that when specifying a script as a CMD in the Dockerfile, this script now requires a proper hashbang (aka shebang) or the above panic results.

#!/bin/bash
rm -rf /run/httpd/* /tmp/httpd*
exec /usr/sbin/apachectl -DFOREGROUND

Rebuilding the docker image with –no-cache option ensures the updated file is included.