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Certmaster automates the process of renewing and installing SSL certificates.

  1. Creates an SSL cert from Let's Encrypt
  2. Validates certs using DNS
  3. Uploads or installs SSL certs to multiple destinations

Supported DNS

Certmaster uses the excellent go-acme/lego repository to generate certificates and automate DNS validation. They support 100+ providers, which are listed here.

Supported Destinations

  1. Email
  2. SFTP
  3. Hetzner Load Balancer


Start with the example config.json and modify it.

  • To configure DNS providers, create JSON of the form:

        "provider": "route53",

    Here, provider is the provider name from go-acme/lego's documentation. The rest of the fields are configs specific to your DNS provider.

  • Similarly, you configure destinations with all details required to upload.


To update the certificate, just run:

$ ./certmaster create --config config.json

AWS Lambda

The Docker file is to use with AWS Lambda. When you invoke the function, you send the same JSON payload as the normal config.