remove docker containers based on time

clean.sh

#!/bin/bash -e

if [[ $# > 0 ]]; then
  export MAX_CONTAINER_UPTIME_MINS=$1
else
  export MAX_CONTAINER_UPTIME_MINS=30
fi

echo "Removing containers older than: $MAX_CONTAINER_UPTIME_MINS minutes"

export container_ids=""
export remove_container_ids=""


get_containers() {
  echo "getting containers"
  container_ids=$(sudo docker ps -aq)
}

filter_containers() {
  for container in $container_ids; do
    started_at_string=$(docker inspect $container | grep StartedAt | awk '{print $2}')
    # remove outermost double quotes
    started_at_string=$(echo "$started_at_string" | tr -d '"')
    # converting string to bash date
    started_at_time=$(date --date=$started_at_string +%s)
    current_time=$(date +"%s")
    time_diff_secs=$(($current_time-$started_at_time))
    time_diff_mins=$(($time_diff_secs/60))
    if [[ $time_diff_mins -gt $MAX_CONTAINER_UPTIME_MINS ]]; then
      remove_container_ids="$remove_container_ids $container"
    fi  
  done
}

remove_containers() {
  if [[ ! -z $remove_container_ids ]]; then
    remove_count=$(echo "$remove_container_ids" | wc -w)
    echo "removing [$remove_count] containers $remove_container_ids"
    container_remove_cmd="sudo docker rm $remove_container_ids"
    $container_remove_cmd
  else
    echo "no containers to remove"
  fi  
}

get_containers
filter_containers
remove_containers

test

$ ./clean.sh 10  //remove containers older than 10 mins
$ ./clean.sh //remove containers older than 30 mins(default)