show_containers.bash

#!/bin/bash
set -eu
set -o pipefail

show_containers() {
  local RED='\033[0;31m'
  local GREEN='\033[0;32m'
  local YELLOW='\033[1;33m'
  local NOCOLOR='\033[0m'

  local container_count
  container_count=$(docker ps -a -q | wc -l)

  if [ "$container_count" -eq 0 ]; then
    return
  fi

  echo
  if [ "$container_count" -eq 1 ]; then
    echo -e "${YELLOW}There is a running container:${NOCOLOR}"
  else
    echo -e "${YELLOW}There are running containers:${NOCOLOR}"
  fi

  local line
  docker ps -a | while IFS= read -r line; do
    if echo "$line" | grep -q -E '\<Up\>'; then
      echo -e "${GREEN}${line}${NOCOLOR}"
    elif echo "$line" | grep -q -E '\<Created|Paused\>'; then
      echo -e "${YELLOW}${line}${NOCOLOR}"
    elif echo "$line" | grep -q -E '\<Exited\>'; then
      echo -e "${RED}${line}${NOCOLOR}"
    else
      echo "${line}"
    fi
  done
  echo
}

if shopt -q login_shell; then
  show_containers
fi