A simple sidecar, that mimics an acme-dns API server and allows to easily automate LetsEncrypt DNS-01 challenge for domains with Timeweb Cloud managed nameservers

Written with FastAPI, AioHTTP and AioTinyDB

To obtain a wildcard TLS Let's Encrypt certificate with a minimal effort using managed cloud DNS, without messing up with deploying own nameservers - it's your only choice if you don't want to deploy your own DNS server, as at the moment cloud managed DNS API does not give you an option to add NS records for subdomains, and therefore you cannot delegate it to acme-dns.

This sidecar automatically manage acme challenge TXT records for a single domain and optionally its subdomains: it keeps created TXT records IDs in a small database and deletes old records automatically during the next renewal. Moreover, it mimics acme-dns API semantic, and therefore you don't need to reinvent a new plugin for certbot.

1. Build it with docker:

docker build . -t ${DOCKER_IMAGE_FULL_NAME}

2. Fill env file (see .env.example)

Security warning: keep cloud access token as safe as possible, as the PaaS currently have no option to limit its permissions and allows access to all cloud infrastructure of your account, not just DNS

3. Start:

docker run -d --env-file .env -p 8000:8000 -v ./data/:/data/ ${DOCKER_IMAGE_FULL_NAME} --name 'acme-dns-timeweb-sidecar'

4. Then fill your registration.json with pattern below, according to configuration:

{
	"${MANAGED_DOMAIN}": {
		"username":"${UPDATE_USERNAME}",
		"password":"${UPDATE_PASSWORD}",
		"fulldomain":"_acme-challenge.${MANAGED_DOMAIN}",
		"subdomain":"${MANAGED_DOMAIN}",
		"allowfrom":["0.0.0.0/0"]
	}
}

Notice: You can use it for subdomains of ${MANAGED_DOMAIN} as well - just set subdomain key's value to something like foo.bar.example.com assuming ${MANAGED_DOMAIN} is example.com.

Just keep in mind, you'll need to add additional records to those subdomains if it was set via wildcard, as once this automation will create TXT record for subdomain, it will no longer be resolved via parent wildcard's records. For example, if you've added foo.example.com, and earlier had it via A record for *.example.com pointing to somewhere, foo.example.com will no longer resolve unless you explicitly add A records foo.example.com and optionally *.foo.example.com

5. Use a standard acme-dns plugin for certbot (or whatever you use) to obtain the certificate
6. Enjoy a wildcard certificate