Suppose you want your own self-hosted Minecraft server on EC2 because you want to save money; you have a Route 53 DNS that needs updating, too...

minecraft-server.sh

#
# AWS EC2 Minecraft Server Functions!
# These functions will work for any EC2 you want to start and stop on-demand.
# Save even MORE money with a spot instance.
#

# You will need:
# 1. An AWS account.
# 2. A domain/DNS for the host, preferably in Route 53.
# 3. An EC2 with the minecraft server installed on it (possibly launched on boot?)
# 4. A configured IAM role with the following permissions on the above resources:
#    - ec2.describe-instances
#    - ec2.start-instances
#    - ec2.stop-instances
#    - budgets.describe-budgets
#    - route53.change-record-resource-sets
#    - route53.get-change


#
# 5. Set these variables.
#
INSTANCE_ID= # AWS Instance ID
HOST_DNS=    # DNS name of minecraft server
ZONEID=      # DNS Zone ID
ACCOUNT_ID=  # Your account ID (for billing updates)
# 6. If you don't have ~/.aws/config set for this IAM profile, also set these:
# AWS_ACCESS_KEY_ID= 
# AWS_SECRET_ACCESS_KEY=
# AWS_DEFAULT_REGION=



#
# Status and this month's billing
#
minecraft-status() {
    server_status=$(aws ec2 describe-instances --instance-ids ${INSTANCE_ID} | jq -r .Reservations[].Instances[].State.Name)
    budget_status=$(aws budgets describe-budgets --account-id ${ACCOUNT_ID})

    actual_spend=$(echo ${budget_status} | jq -r .Budgets[].CalculatedSpend.ActualSpend.Amount)
    future_spend=$(echo ${budget_status} | jq -r .Budgets[].CalculatedSpend.ForecastedSpend.Amount)

    echo "Minecraft host is currently: ${server_status}."
    echo "Current  monthly spend is:   \$${actual_spend}."
    echo "Expected monthly spend is:   \$${future_spend}."
}


#
# Bring up the server and update DNS
#
minecraft-up() {
    echo "Launching the server."
    aws ec2 start-instances --instance-ids ${INSTANCE_ID}

    echo -n "Waiting for it to be alive..."
    while [ $(aws ec2 describe-instances --instance-ids ${INSTANCE_ID} | jq -r .Reservations[].Instances[].State.Name) != "running" ] ; do
	sleep 5
	echo -n '.'
    done

    echo "And we're awake."
    server_ip=$(aws ec2 describe-instances --instance-ids ${INSTANCE_ID} | jq -r .Reservations[].Instances[].PublicIpAddress)
    echo "Server IP: ${server_ip}"

    cat <<EOF > /tmp/changeset.json
{
    "Comment": "Update record to reflect new IP address of minecraft server",
    "Changes": [
        {
            "Action": "UPSERT",
            "ResourceRecordSet": {
                "Name": "${HOST_DNS}",
                "Type": "A",
                "TTL": 300,
                "ResourceRecords": [
                    {
                        "Value": "${server_ip}"
                    }
                ]
            }
        }
    ]
}
EOF

    echo "Updating DNS record."
    long_changeid=$(aws route53 change-resource-record-sets --hosted-zone-id ${ZONEID} --change-batch file:///tmp/changeset.json | jq -r .ChangeInfo.Id)
    changeid=$(echo $long_changeid |sed -e 's/\/change\///')
    echo "Change ID: ${changeid}"

    echo -n "Waiting for DNS update..."
    while [ $(aws route53 get-change --id ${changeid} | jq -r .ChangeInfo.Status) != 'INSYNC' ] ; do
	sleep 5
	echo -n '.'
    done

    echo "updated."
    echo "You may now connect to the host with ssh."
}


#
# Shut down the server.
#
minecraft-down() {
    echo "Stopping the server."
    aws ec2 stop-instances --instance-ids ${INSTANCE_ID}

    echo -n "Waiting for it to be down..."
    while [ $(aws ec2 describe-instances --instance-ids ${INSTANCE_ID} | jq -r .Reservations[].Instances[].State.Name) != "stopped" ] ; do sleep 5 ; echo -n '.' ; done

    echo "And we're dead."
}