dcos-gen-masterlist.service

[Unit]
Description=Update master_list for DCOS services
[Service]
Type=simple
StandardOutput=journal
StandardError=journal
EnvironmentFile=/etc/environment
EnvironmentFile=/opt/mesosphere/environment
ExecStart=/home/core/mesos-systemd/dcos/util/dcos-gen-masterlist.sh /opt/mesosphere/etc/master_list

dcos-gen-masterlist.sh

#!/bin/bash
# This script uses the IP addresses assigned to the master's autoscaling group to populate the master_list entries.
# It should be run from each master via the included systemd units/timers

pkg=dcos-gen-masterlist
AWS_REGION=$(curl -s http://169.254.169.254/latest/meta-data/placement/availability-zone | sed 's/[a-z]$//')

if [ -z "$1" ]; then
  echo "$pkg: master_list file not specified.  Use fully qualified path as an arument (e.g., $pkg /opt/mesosphere/etc/master_list)"
  exit 1
fi

ec2_instance_id=$(curl -s http://169.254.169.254/latest/meta-data/instance-id)

ec2_instance_ip=$(curl -s http://169.254.169.254/latest/meta-data/local-ipv4)

asg_name=$(docker run behance/utility:latest aws autoscaling describe-auto-scaling-groups --region ${AWS_REGION} \
  | jq --raw-output ".[] | map(select(.Instances[].InstanceId | contains(\"$ec2_instance_id\"))) | .[].AutoScalingGroupName")

master_list_ips=$(docker run behance/utility:latest aws ec2 describe-instances --region ${AWS_REGION} --instance-ids \
  $(docker run  behance/utility:latest aws autoscaling describe-auto-scaling-groups --region ${AWS_REGION} --auto-scaling-group-name $asg_name | jq .AutoScalingGroups[0].Instances[].InstanceId | xargs) \
  | jq -r '.Reservations[].Instances | map("\\\"" + .NetworkInterfaces[].PrivateIpAddress + "\\\"")[]')

output=$(echo \"[${master_list_ips}]\" | sed -r  s/\ /,/g)

echo ${output} > $1

dcos-gen-masterlist.timer

[Unit]
Description=Periodically update master_list
[Timer]
OnBootSec=0min
OnUnitActiveSec=1min