consul-cluster

This repo is designed to work with the CloudCoreo engine.

Description

Highly Available, self-healing consul cluster configuration and setup

Consul is an awesome product from the guys over at Hashicorp. It is a key/value store and service discovery mechanism (like zookeeper) as well as health-checker and DNS provider. It's also ready to support multiple datacenters out of the box.

This CloudCoreo stack provides a production-ready Consul Server Cluster that is self-healing and highly available. If defaults are left as is, your environment will launch a cluster of 3 t2.small instances.

How does it work?

You must provide a route53 dns zone for us to add an entry to. This will be a CNAME pointing to an internal ELB. The internal ELB will provide healthchecks for the consul servers and automatically replace failed nodes. The url will be dictated by the variable: CONSUL_NAME which defaults to "consul".

i.e. if your CONSUL_NAME is left as the default "consul", your consul cluster UI will be available at http://consul.<dns_name>

This is a private ELB so you can only access via VPN or bastion depending on how your network is set up.

When a failre even takes place, the Autoscaling group will replace the failed node. The addition of a new node triggers a clean up process approximately 60 seconds after boot is complete.

REQUIRED VARIABLES

DNS_ZONE:

• required: true
• description: the route53 dns zone to add the consul entry to.

OVERRIDE OPTIONAL VARIABLES

CONSUL_INGRESS_CIDRS:

• default:
  • 10.11.0.0/16
• description: cidrs that can access the consul server
• type: array
• required: true

CONSUL_NAME:

• default: consul
• description: name of the consul server
• required: true

CONSUL_AMI:

• default: ami-1ecae776
• description: the ami to launch for consul - default is Amazon Linux AMI 2015.03 (HVM), SSD Volume Type
• type: string
• required: true

CONSUL_SIZE:

• default: t2.small
• description: the image size to launch
• required: true

CONSUL_KEY:

• default: ""
• description: the ssh key to associate with the instance(s) - blank will disable ssh
• type: string
• required: false

CONSUL_GROUP_SIZE_MIN:

• default: 3
• description: the minimum number of instances to launch
• type: number
• required: true

CONSUL_GROUP_SIZE_MAX:

• default: 5
• description: the maxmium number of instances to launch
• type: number
• required: true

Tags

1. Service Discovery
2. DNS
3. Monitoring
4. Hashicorp
5. High Availability

Diagram

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