CloudFormation to demo etcd-aws-cluster

gistfile1.json

{
  "AWSTemplateFormatVersion": "2010-09-09",
  "Description": "An etcd cluster based off an auto scaling group",
  "Mappings" : {
      "RegionMap" : {
          "eu-central-1" : {
              "AMI" : "ami-840a0899"
          },
          "ap-northeast-1" : {
              "AMI" : "ami-6c5ac56c"
          },
          "us-gov-west-1" : {
          	  "AMI" : "ami-796a085a"
          },
          "sa-east-1" : {
              "AMI" : "ami-3396012e"
          },
          "ap-southeast-2" : {
              "AMI" : "ami-f5ace5cf"
          },
          "ap-southeast-1" : {
              "AMI" : "ami-46819614"
          },
          "us-east-1" : {
              "AMI" : "ami-05783d60"
          },
          "us-west-2" : {
              "AMI" : "ami-ed8b90dd"
          },
          "us-west-1" : {
              "AMI" : "ami-2b29ee6f"
          },
          "eu-west-1" : {
              "AMI" : "ami-eb97bc9c"
          }
      }
  },
  "Parameters": {
    "InstanceType" : {
      "Description" : "EC2 HVM instance type (m3.medium, etc).",
      "Type" : "String",
      "Default" : "t2.micro",
      "ConstraintDescription" : "Must be a valid EC2 HVM instance type."
    },
    "ClusterSize": {
      "Default": "3",
      "MinValue": "3",
      "MaxValue": "9",
      "Description": "Number of nodes in cluster (3-9).",
      "Type": "Number"
    },
    "ProxyClusterSize": {
      "Default": "1",
      "MinValue": "0",
      "MaxValue": "9",
      "Description": "Number of nodes in cluster (0-9).",
      "Type": "Number"
    },
    "AdvertisedIPAddress": {
      "Description": "Use 'private' if your etcd cluster is within one region or 'public' if it spans regions or cloud providers.",
      "Default": "private",
      "AllowedValues": ["private", "public"],
      "Type": "String"
    },
    "AllowSSHFrom": {
      "Description": "The net block (CIDR) that SSH is available to.",
      "Default": "0.0.0.0/0",
      "Type": "String"
    },
    "KeyPair" : {
      "Description" : "The name of an EC2 Key Pair to allow SSH access to the instance.",
      "Type" : "String"
    }
  },
  "Resources": {
    "CoreOSSecurityGroup": {
      "Type": "AWS::EC2::SecurityGroup",
      "Properties": {
        "GroupDescription": "CoreOS SecurityGroup",
        "SecurityGroupIngress": [
          {"IpProtocol": "tcp", "FromPort": "22", "ToPort": "22", "CidrIp": {"Ref": "AllowSSHFrom"}}
        ]
      }
    },
    "Ingress2379": {
      "Type": "AWS::EC2::SecurityGroupIngress",
      "Properties": {
        "GroupName": {"Ref": "CoreOSSecurityGroup"}, "IpProtocol": "tcp", "FromPort": "2379", "ToPort": "2379", "SourceSecurityGroupId": {
          "Fn::GetAtt" : [ "CoreOSSecurityGroup", "GroupId" ]
        }
      }
    },
    "Ingress2380": {
      "Type": "AWS::EC2::SecurityGroupIngress",
      "Properties": {
        "GroupName": {"Ref": "CoreOSSecurityGroup"}, "IpProtocol": "tcp", "FromPort": "2380", "ToPort": "2380", "SourceSecurityGroupId": {
          "Fn::GetAtt" : [ "CoreOSSecurityGroup", "GroupId" ]
        }
      }
    },
    "cliROrole": {
      "Type": "AWS::IAM::Role",
      "Properties": {
        "AssumeRolePolicyDocument": {
          "Statement": [
            {
              "Effect": "Allow",
              "Principal": {
                "Service": [
                  "ec2.amazonaws.com"
                ]
              },
              "Action": [
                "sts:AssumeRole"
              ]
            }
          ]
        },
        "Policies": [
          {
            "PolicyName": "CLIROAccess",
            "PolicyDocument": {
              "Statement": [
                {
                  "Effect": "Allow",
                  "Action": [
                    "ec2:Describe*"
                  ],
                  "Resource": "*"
                },
                {
                  "Effect": "Allow",
                  "Action": [
                    "autoscaling:Describe*"
                  ],
                  "Resource": "*"
                }
              ]
            }
          }
        ],
        "Path": "/"
      }
    },
    "CLIROAccessProfile": {
      "Type": "AWS::IAM::InstanceProfile",
      "Properties": {
        "Path": "/",
        "Roles": [
          {
            "Ref": "cliROrole"
          }
        ]
      }
    },
    "CoreOSServerAutoScale": {
      "Type": "AWS::AutoScaling::AutoScalingGroup",
      "Properties": {
        "AvailabilityZones": {"Fn::GetAZs": ""},
        "LaunchConfigurationName": {"Ref": "CoreOSServerLaunchConfig"},
        "MinSize": "3",
        "MaxSize": "9",
        "DesiredCapacity": {"Ref": "ClusterSize"},
        "Tags": [
            {"Key": "Name", "Value": { "Ref" : "AWS::StackName" }, "PropagateAtLaunch": true}
        ]
      }
    },
    "CoreOSServerLaunchConfig": {
      "Type": "AWS::AutoScaling::LaunchConfiguration",
      "Properties": {
        "ImageId" : { "Fn::FindInMap" : [ "RegionMap", { "Ref" : "AWS::Region" }, "AMI" ]},
        "InstanceType": {"Ref": "InstanceType"},
        "KeyName": {"Ref": "KeyPair"},
        "SecurityGroups": [{"Ref": "CoreOSSecurityGroup"}],
        "IamInstanceProfile": {"Ref": "CLIROAccessProfile"},
        "UserData" : { "Fn::Base64":
          { "Fn::Join": [ "", [
            "#cloud-config\n\n",
            "coreos:\n",
            "  etcd2:\n",
			"    advertise-client-urls: http://$", { "Ref": "AdvertisedIPAddress" }, "_ipv4:2379\n",
			"    initial-advertise-peer-urls: http://$", { "Ref": "AdvertisedIPAddress" }, "_ipv4:2380\n",
			"    listen-client-urls: http://0.0.0.0:2379\n",
			"    listen-peer-urls: http://$", { "Ref": "AdvertisedIPAddress" }, "_ipv4:2380\n",
            "  units:\n",
            "    - name: etcd2.service\n",
            "      command: stop\n",
            "    - name: etcd-peers.service\n",
			"      command: start\n",
      		"      content: |\n",
      		"        [Unit]\n",
      		"        Description=Write a file with the etcd peers that we should bootstrap to\n",
      		"        [Service]\n",
      		"        Restart=on-failure\n",
      		"        RestartSec=10\n",
      		"        ExecStartPre=/usr/bin/docker pull monsantoco/etcd-aws-cluster:latest\n",
      		"        ExecStartPre=/usr/bin/docker run --rm=true -v /etc/sysconfig/:/etc/sysconfig/ monsantoco/etcd-aws-cluster:latest\n",
      		"        ExecStart=/usr/bin/systemctl start etcd2\n",
            "    - name: fleet.service\n",
            "      command: start\n",
            "write_files:\n",
            "  - path: /etc/systemd/system/etcd2.service.d/30-etcd_peers.conf\n",
			"    permissions: 0644\n",
			"    content: |\n",
			"      [Service]\n",
			"      # Load the other hosts in the etcd leader autoscaling group from file\n",
			"      EnvironmentFile=/etc/sysconfig/etcd-peers\n"
            ] ]
          }
        }
      }
    },
        "CoreOSProxyAutoScale": {
      "Type": "AWS::AutoScaling::AutoScalingGroup",
      "Properties": {
        "AvailabilityZones": {"Fn::GetAZs": ""},
        "LaunchConfigurationName": {"Ref": "CoreOSProxyLaunchConfig"},
        "MinSize": "0",
        "MaxSize": "9",
        "DesiredCapacity": {"Ref": "ProxyClusterSize"},
        "Tags": [
            {"Key": "Name", "Value": { "Ref" : "AWS::StackName" }, "PropagateAtLaunch": true}
        ]
      }
    },
    "CoreOSProxyLaunchConfig": {
      "Type": "AWS::AutoScaling::LaunchConfiguration",
      "Properties": {
        "ImageId" : { "Fn::FindInMap" : [ "RegionMap", { "Ref" : "AWS::Region" }, "AMI" ]},
        "InstanceType": {"Ref": "InstanceType"},
        "KeyName": {"Ref": "KeyPair"},
        "SecurityGroups": [{"Ref": "CoreOSSecurityGroup"}],
        "IamInstanceProfile": {"Ref": "CLIROAccessProfile"},
        "UserData" : { "Fn::Base64":
          { "Fn::Join": [ "", [
            "#cloud-config\n\n",
            "coreos:\n",
            "  etcd2:\n",
			"    advertise-client-urls: http://$", { "Ref": "AdvertisedIPAddress" }, "_ipv4:2379\n",
			"    initial-advertise-peer-urls: http://$", { "Ref": "AdvertisedIPAddress" }, "_ipv4:2380\n",
			"    listen-client-urls: http://0.0.0.0:2379\n",
			"    listen-peer-urls: http://$", { "Ref": "AdvertisedIPAddress" }, "_ipv4:2380\n",
            "  units:\n",
            "    - name: etcd2.service\n",
            "      command: stop\n",
            "    - name: etcd-peers.service\n",
			"      command: start\n",
      		"      content: |\n",
      		"        [Unit]\n",
      		"        Description=Write a file with the etcd peers that we should bootstrap to\n",
      		"        [Service]\n",
      		"        Restart=on-failure\n",
      		"        RestartSec=10\n",
      		"        ExecStartPre=/usr/bin/docker pull monsantoco/etcd-aws-cluster:latest\n",
      		"        ExecStartPre=/usr/bin/docker run -e PROXY_ASG=", { "Ref": "CoreOSServerAutoScale" } ," --rm=true -v /etc/sysconfig/:/etc/sysconfig/ monsantoco/etcd-aws-cluster:latest\n",
      		"        ExecStart=/usr/bin/systemctl start etcd2\n",
            "    - name: fleet.service\n",
            "      command: start\n",
            "write_files:\n",
            "  - path: /etc/systemd/system/etcd2.service.d/30-etcd_peers.conf\n",
			"    permissions: 0644\n",
			"    content: |\n",
			"      [Service]\n",
			"      # Load the other hosts in the etcd leader autoscaling group from file\n",
			"      EnvironmentFile=/etc/sysconfig/etcd-peers\n"
            ] ]
          }
        }
      }
    }
  }
}

Line 31, the eu-west-1 AMI mapping contains a typo: "mi-...."

Hey there, thanks for this! As a note, I think your docker pull's are pulling from an invalid organization in your unit definitions. I believe monsanto should be monsantoco

sorry we changed org names at some point, I've updated this to now work and include an example of using an etcd proxy

Cloudformation refuses to create t2 class instances unless a VPC is specified but this template does not support VPC - any chance to update it?