Hello, I would like to share with a sample AWS Cloudformation template used to provision and configure a EC2 instance as you can see it is a parametrized template in order to allow the Operator to modify specific values at runtime. Beside that the manifest it is performing various task like the configuration of the Security Group and the attachment to the nearly created instance (the rules for ingress need fine tuning). Of course we are leveraging Cloud-Init to execute the configuration steps needed to modify the new instance after the provisioning has been completed and finally the Template is retrieving/creating also values to SSM and to Route53 in order to update the internal Dns Zone.
References to the tools used:
AWS Cloudformation Docs: https://docs.aws.amazon.com/cloudformation/?icmpid=docs_homepage_mgmtgov
AWS Cloudformation Templates: https://aws.amazon.com/cloudformation/resources/templates/
AWS::CloudFormation::Init (cfn-init).
AWS SSM: https://docs.aws.amazon.com/systems-manager/latest/userguide/what-is-systems-manager.html
AWS ROUTE53: https://docs.aws.amazon.com/route53/?icmpid=docs_homepage_networking
AWSTemplateFormatVersion: 2010-09-09
Description: This template creates a new ec2 EC2
Parameters:
Environment:
Type: String
Description: 'staging, preproduction, or production'
Default: staging
AllowedValues:
- staging
- preproduction
- production
PrivateSubnet:
Description: Specify the Subnet Id e.g. id-a for SubnetA
Type: String
Default: id-a
AllowedValues:
- id-a
- id-b
- id-c
InstanceType:
Description: EC2 instance type
Type: String
Default: t3.medium
NodeName:
Description: "Specify the Node's Name keep in mind that the resulting name will follow this convention: staging-infrastructure-ec2-1"
Type: String
Default: ec2
NodeId:
Description: Specify the Node Number Id e.g. 1 for Node1
Type: String
Default: 1
DiskSize:
Description: EC2 Selected Disk Size
Type: String
Default: 40
DNSZoneId:
Description: Specify the DNSZone Id e.g. Z0177864RGEW5HYK40Z5
Type: String
DNSDomainName:
Description: Specify the DNSZone Name e.g.
Type: String
Default: staging.internal.services.com
Mappings:
RegionToAmazonAMI:
eu-central-1:
HVM64: ami-image-id
Resources:
SecurityGroup:
Type: AWS::EC2::SecurityGroup
Properties:
GroupDescription: !Join [ "-", [ !Ref Environment, !Ref "AWS::Region", infrastructure-security-group-ec2-all] ]
GroupName: !Join [ "-", [ !Ref Environment, !Ref "AWS::Region", infrastructure-security-group-ec2-all] ]
SecurityGroupEgress:
- CidrIp: 0.0.0.0/0
IpProtocol: "-1"
SecurityGroupIngress:
- CidrIp: 0.0.0.0/0
IpProtocol: icmp
FromPort: -1
ToPort: -1
- CidrIp: 0.0.0.0/0
IpProtocol: tcp
FromPort: 22
ToPort: 22
- CidrIp: 0.0.0.0/0
IpProtocol: tcp
FromPort: 80
ToPort: 80
- CidrIp: 0.0.0.0/0
IpProtocol: tcp
FromPort: 443
ToPort: 443
- CidrIp: 0.0.0.0/0
IpProtocol: tcp
FromPort: 1936
ToPort: 1936
Tags:
- Key: "Environment"
Value: !Ref Environment
VpcId: !ImportValue ExportedVpcId
# One Node ec2 Linux Instance
InfraHAProxyNode:
Type: AWS::EC2::Instance
DependsOn: SecurityGroup
CreationPolicy:
ResourceSignal:
Count: 1
Timeout: PT30M
Metadata:
'AWS::CloudFormation::Init':
configSets:
Provisioning:
- PrepHaproxySteps
PrepHaproxySteps:
files:
/root/prep-ec2-script.sh:
content: !Sub |
#!/bin/bash
ip=$(hostname -I)
echo "$ip $HOSTNAME " >>/etc/hosts
chmod 0700 /root/.ssh/
echo "$SSHKEY" > /root/.ssh/HAProxy_ssh_key
echo "$PUBSSHKEY" >> /root/.ssh/authorized_keys
chmod 0600 /root/.ssh/HAProxy_ssh_key
chmod 0600 /root/.ssh/authorized_keys
env:
SSHKEY: !Sub "{{resolve:ssm:/${Environment}/infrastructure/aws/ec2/rabbitmq_ssh_key}}"
PUBSSHKEY: !Sub "{{resolve:ssm:/${Environment}/infrastructure/aws/ec2/rabbitmq_ssh_key-pub}}"
HOSTNAME: !Sub "${Environment}-${AWS::Region}-infrastructure-${NodeName}-node-${NodeId}"
mode: '000755'
owner: root
group: root
commands:
runPrepScript:
command: 'sh /root/prep-ec2-script.sh'
env:
SSHKEY: !Sub "{{resolve:ssm:/${Environment}/infrastructure/aws/ec2/rabbitmq_ssh_key}}"
PUBSSHKEY: !Sub "{{resolve:ssm:/${Environment}/infrastructure/aws/ec2/rabbitmq_ssh_key-pub}}"
HOSTNAME: !Sub "${Environment}-${AWS::Region}-infrastructure-${NodeName}-node-${NodeId}"
cwd: "~"
ignoreErrors: "false"
Properties:
ImageId:
Fn::FindInMap:
- RegionToAmazonAMI
- Ref: 'AWS::Region'
- HVM64
InstanceInitiatedShutdownBehavior: stop
InstanceType: !Ref InstanceType
Tags:
- Key: "Name"
Value: !Sub "${Environment}-${AWS::Region}-infrastructure-${NodeName}-node-${NodeId}"
BlockDeviceMappings:
- DeviceName: "/dev/sda1"
Ebs:
DeleteOnTermination: 'true'
VolumeSize: !Ref DiskSize
VolumeType: gp2
Monitoring: 'true'
NetworkInterfaces:
- AssociatePublicIpAddress: 'false'
DeviceIndex: '0'
GroupSet:
- !Ref SecurityGroup
- !Sub "{{resolve:ssm:/${Environment}/infrastructure/aws/vpc/security-group/ec2/all}}"
SubnetId: !Join [ '', [ !Sub '{{resolve:ssm:/', !Sub '${Environment}', '/infrastructure/aws/vpc/subnet/private/', !Sub '${PrivateSubnet}', '}}'] ]
Tenancy: default
UserData:
Fn::Base64: !Sub |
#cloud-config
repo_update: true
repo_upgrade: all
hostname: "${Environment}-${AWS::Region}-infrastructure-${NodeName}-node-${NodeId}"
write_files:
- content: |
#!/bin/bash
/opt/aws/bin/cfn-init -v --stack ${AWS::StackName} --resource InfraHAProxyNode --configsets HAProxyProvisioning --region ${AWS::Region}
/opt/aws/bin/cfn-signal -e $? --stack ${AWS::StackName} --resource InfraHAProxyNode --region ${AWS::Region}
owner: root:root
path: /root/call-cfn-init.sh
permissions: '0700'
runcmd:
- [ sh, -c , "/root/call-cfn-init.sh" ]
InfraHAProxyNodePrivIpOnSSM:
Type: AWS::SSM::Parameter
DependsOn: InfraHAProxyNode
Properties:
Name: !Sub /${Environment}/infrastructure/aws/ec2/node-${NodeId}/ip
Type: String
Value: !Sub ${InfraHAProxyNode.PrivateIp}
InfraHAProxyNodeHostnameOnSSM:
Type: AWS::SSM::Parameter
DependsOn: InfraHAProxyNode
Properties:
Name: !Sub /${Environment}/infrastructure/aws/ec2/node-${NodeId}/hostname
Type: String
Value: !Sub "${Environment}-${AWS::Region}-infrastructure-${NodeName}-node-${NodeId}"
InfraHAProxyNodeEC2IDOnSSM:
Type: AWS::SSM::Parameter
DependsOn: InfraHAProxyNode
Properties:
Name: !Sub /${Environment}/infrastructure/aws/ec2/node-${NodeId}/instance-id
Type: String
Value: !Ref InfraHAProxyNode
InfraHAProxyNodeEC2IDOnSSM:
Type: 'AWS::SSM::Parameter'
DependsOn: InfraHAProxyNode
Properties:
Name: !Sub /${Environment}/infrastructure/aws/ec2/node-${NodeId}/instance-id
Type: String
Value: !Ref InfraHAProxyNode
InfraSecurityGroupOnSSM:
Type: AWS::SSM::Parameter
DependsOn: InfraHAProxyNode
Properties:
Name: !Sub /${Environment}/infrastructure/aws/ec2/security/group/1
Type: String
Value: !Ref SecurityGroup
InfraHAProxyNodeDNSRecord:
Type: AWS::Route53::RecordSet
Properties:
HostedZoneId: !Ref DNSZoneId
Name: !Sub "${Environment}-${AWS::Region}-infrastructure-${NodeName}-node-${NodeId}"
ResourceRecords:
- !Sub ${InfraHAProxyNode.PrivateIp}
TTL: 360
Type: A
Outputs:
InfraHAProxyNodeId:
Description: 'The ID of EC2 Instance'
Value: !Ref InfraHAProxyNode
Export:
Name: !Sub "ExportedHAProxyID-${NodeId}"
InfraHAProxyNodeHostname:
Description: 'The Hostname of ec2 EC2 Instance'
Value: !Sub "${Environment}-${AWS::Region}-infrastructure-${NodeName}-node-${NodeId}"
Export:
Name: !Sub "ExportedHAProxyHostname-${NodeId}"
I hope you like the tutorial, if you do give a thumps up! and follow me in Twitter, also you can subscribe to my Newsletter in order to avoid missing any of the upcoming tutorials.
Media Attribution
I would like to thank Clark Tibbs for designing the awesome photo I am using in my posts.
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