CloudFormation template for an S3-backed private Docker Registry with password protection and HTTPS.

Prerequisites:

• SSL certificate (if it's untrusted, you'll need to add it to the system keystore or pass use Docker's --insecure option)
• (Optional) Route 53 hosted zone for the desired registry address (e.g., mycompany.com for docker.mycompany.com)

Overview

This template bootstraps a private Docker Registry.

Registry servers are launched in an auto scaling group using public AMIs running Ubuntu 14.04 LTS and pre-reloaded with Docker and Runit. If you wish to use your own image, simply modify RegionMap in the template file.

The servers register with an Elastic Load Balancer, an Alias for which is created in Route 53 (if you pass DnsZone and DnsPrefix). When tagging repositories, use this (or a higher-level record) instead of the ELB's raw DNS record as your registry address instead (e.g., docker.mycompany.com/myimage instead of mystack-do-ElasticL-AJK...elb.amazonaws.com/myimage).

The ELB listens on HTTPS using the specified SSL cert. Each registry server is password-protected by an nginx proxy. The ELB performs health checks against /v1/_ping. If an instance fails these health checks for several minutes, the ASG will terminate the instance and bring up a replacement.

The registry is run via a Docker image specified as a Parameter. You can use the default or provide your own.

To adjust registry capacity, simply increment or decrement the auto scaling group. Node addition/removal should be handled transparently by the ASG and ELB.

Note that this template must be used with Amazon VPC. New AWS accounts automatically use VPC, but if you have an old account and are still using EC2-Classic, you'll need to modify this template or make the switch.

Usage

1. Clone the repository

git clone https://github.com/mbabineau/cloudformation-docker-registry.git

2. Create an Admin security group

This is a VPC security group containing access rules for cluster administration, and should be locked down to your IP range, a bastion host, or similar. This security group will be associated with the Registry servers.

Inbound rules are at your discretion, but you may want to include access to:

• 22 [tcp] - SSH port
• 80 [tcp] - Private nginx proxy port (troubleshooting only)
• 5000 [tcp] - Private registry port (troubleshooting only)

3. Upload an SSL certificate

Upload an SSL certificate to IAM (instructions). This certificate must be valid for the registry DNS address and be trusted by the clients (if self-signed, you must add it to the clients' keystores or use Docker's --insecure flag).

Once uploaded, you'll need the ARN for this certificate. You can do this via aws-cli:

$ aws iam list-server-certificates
{
    "ServerCertificateMetadataList": [
        {
            "Path": "/", 
            "Arn": "arn:aws:iam::123456789:server-certificate/docker.mycompany.com", 
            "ServerCertificateId": "AAAAAIZG21OOT4VVVVV", 
            "ServerCertificateName": "docker.mycompany.com", 
            "UploadDate": "2014-06-05T20:06:43Z"
        }
    ]
}

4. Generate the auth strings

Docker will be password-protected using an htpasswd file. The RegistryAuth parameter takes a comma-delimited list of these auth strings. You can generate an auth string using htpasswd:

$ htpasswd -bn admin docker
admin:$apr1$SteyXrya$20Smsae8n4EkGTX2u17ou0

5. Launch the stack

Launch the stack via the AWS console, a script, or aws-cli.

See docker-registry.json for the full list of parameters, descriptions, and default values.

Example using aws-cli:

aws cloudformation create-stack \
    --template-body file://docker-registry.json \
    --stack-name <stack> \
    --capabilities CAPABILITY_IAM \
    --parameters \
        ParameterKey=KeyName,ParameterValue=<key> \
        ParameterKey=RegistryAuth,ParameterValue='<auth_string_1>,<auth_string_2>' \
        ParameterKey=S3Bucket,ParameterValue=<bucket> \
        ParameterKey=SslCertificate,ParameterValue=<cert_arn> \
        ParameterKey=DnsZone,ParameterValue=<dns_zone> \
        ParameterKey=VpcId,ParameterValue=<vpc_id> \
        ParameterKey=Subnets,ParameterValue='<subnet_id_1>\,<subnet_id_2>' \
        ParameterKey=AdminSecurityGroup,ParameterValue=<sg_id>

6. Test your registry

Once the stack has been provisioned, try calling the registry using credentials associated with one of the auth strings. You should get a text response with the server version:

$ curl -u <user>:<password> https://docker.mycompany.com
"docker-registry server (prod) (v0.8.0)"

Note: if you didn't pass DnsZone and DnsPrefix, you'll want to set up a CNAME or Alias for the created ELB

To use the new registry, just generate a new ~/.dockercfg by hand (details) or via docker login:

$ docker login docker.mycompany.com
Username: admin
Password: 
Email: [email protected]
Login Succeeded
$ cat ~/.dockercfg
{"docker.mycompany.com":{"auth":"YWRtaW46ZG9ja2Vy","email":"[email protected]"}}

You can now tag and push images to your new registry:

$ docker tag 31bd83ec56f3 docker.mycompany.com/myimage
$ docker push docker.mycompany.com/myimage
The push refers to a repository [docker.mycompany.com/myimage] (len: 1)
Sending image list
Pushing repository docker.mycompany.com/myimage (1 tags)
Image 511136ea3c5a already pushed, skipping
9e0876577d2f: Image successfully pushed 
60d8d9423165: Image successfully pushed 
31bd83ec56f3: Image successfully pushed 
Pushing tag for rev [31bd83ec56f3] on {https://docker.mycompany.com/v1/repositories/myimage/tags/latest}