#! /bin/bash

cat <<EOF
This script doesn't work currently, it is obsoleted by
the script 'cleanup-vms-aws-resalloc'.  It is kept for documentation purposes or
future reference.
EOF
exit 1

set -e

help_output()
{
    cat >&2 <<EOF
Usage: $0 [--kill-also-unused]

This script terminates all VMs started in AWS which are "probably" started by
this instance of Copr, but are no more relevant for us.

Normal mode (no --kill-also-unused) only terminates VMs which
- are in running state,
- are named properly (e.g. copr-builder-<instance>....)
- and are not in our redis database.
Such leftover VM usually occurs by manual spawning of bulider, during image
creation.  But bug in VM spawner can cause this, etc.  That's why we run this
mode periodically in cron job.

The --kill-also-unused mode is useful when we need to re-distribute new
mock/rpmbuild configuration to all builders.  All unused builders are
terminated (so we don't kill running builds) and respawned.
EOF
}

die ()
{
    echo >&2 "$*"
    echo >&2
    help_output
    exit 1
}

test "$UID" != "0" || die "execute as copr user"

kill_unused=false

for arg; do
    case $arg in
    -h|--help)
        help_output
        exit 1
        ;;
    --kill-also-unused)
        kill_unused=true
        ;;
    *)
        die "unknown arg $arg"
        ;;
    esac
done

something_found=false

dump_command ()
{
        echo >&2 " -> $*"
        "$@"
}

tracked()
{
        name=$(redis-cli --scan --pattern "copr:backend:vm_instance:hset::$1")
        test -n "$name"
}

used()
{
    task=$(redis-cli hget "copr:backend:vm_instance:hset::$1" task_id)
    test -n "$task"
}

old_enough()
{
    # give them 1 hour
    started=$(date --date="$1" +%s)
    now=$(date +%s)
    old_enough=$(( now - 3600 ))
    test "$started" -le "$old_enough"
}

aws_command=(
    aws ec2 describe-instances
        --query "Reservations[].Instances[].{Id:InstanceId,Name:Tags[?Key=='Name']|[0].Value,Time:LaunchTime}"
        --filters "Name=tag:FedoraGroup,Values=copr"
                  "Name=instance-state-name,Values=running"
                  "Name=tag:CoprPurpose,Values=builder"
        --output text
)

something_found=false

prefix=dev
case $(hostname) in
    copr-be.*)
        prefix=prod
        ;;
esac

while read -r aws_id vm_name launch_time; do
    case $vm_name in
    aws_*_normal_${prefix}_*)
        something_found=true

        if tracked "$vm_name"; then
            # skip known VMs
            ! $kill_unused && continue
            used "$vm_name" && continue
        fi

        # skip recently started VMs
        if ! $kill_unused && ! old_enough "$launch_time"; then
            echo >&2 "$vm_name is not yet old enough: $launch_time"
            continue
        fi

        # delete the rest
        dump_command aws ec2 terminate-instances --instance-ids "$aws_id"
        ;;
    *)
        continue ;;
    esac
done < <( "${aws_command[@]}" )

# fail if no VM was found (weird situation)
$something_found