briceburg/swarm53 repository overview

⁠swarm53

registers swarm nodes with a route53 hostedzone.

⁠usage

Example Zone: acme.tld

docker run --rm \
  -e SWARM_NAME=alpha \
  -e AWS_DEFAULT_REGION=us-east-2 \
  -e HOSTED_ZONE_ID=Z3463YG518IZIW \
  -e SWARM_DOMAIN=swarms.acme.tld \
  swarm53

⁠effect

⁠monitoring for topology changes

The swarm53 container can be invoked in monitor mode. When the swarm topology changes, swarm53 will update DNS records after a brief 30 second delay to allow instance termination.

• Set the entrypoint to swarm53-monitor enable monitor mode.
• Bind the required host's docker socket.
• Run on a manager node only.

docker run --rm .... \
  -v /var/run/docker.sock:/var/run/docker.sock \
  --entrypoint swarm53-monitor \
  swarm53

⁠requirements

⁠AWS tags on all swarm EC2 instances

⁠IAM instance role

Policy must grant ec2:DescribeInstances and route53:ChangeResourceRecordSets prermissions.

Example policy JSON granting access explicitly to the hosted zone Z3463YG518IZIW:

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "route53:ChangeResourceRecordSets",
            ],
            "Resource": [
                "arn:aws:route53:::hostedzone/Z3463YG518IZIW",
            ]
        },
        {
            "Effect": "Allow",
            "Action": "ec2:DescribeInstances",
            "Resource": "*"
        }
    ]
}

⁠TODO

• use r53 healthchecks and multivalue answers