letsencrypt-kubernetes

A docker image suitable for requesting new certificates from letsencrypt, and storing them in a secret on kubernetes.

Available on docker hub as ployst/letsencrypt

Purpose

To provide an application that owns certificate requesting and storing.

• To serve acme requests to letsencrypt (given that you direct them to this container)
• To regularly (monthly) ask for new certificates.
• To store those new certificates in a secret on kubernetes.

Useful commands

Generate a new set of certs

Once this container is running you can generate new certificates using:

kubectl exec -it <pod> -- bash -c 'EMAIL=fred@fred.com DOMAINS=example.com foo.example.com ./fetch_certs.sh'

Save the set of certificates as a secret

kubectl exec -it <pod> -- bash -c 'DOMAINS=example.com foo.example.com ./save_certs.sh'

Refresh the certificates

kubectl exec -it <pod> -- bash -c 'EMAIL=fred@fred.com DOMAINS=example.com foo.example.com SECRET_NAME=foo DEPLOYMENTS=bar ./refresh_certs.sh'

Environment variables:

• EMAIL - the email address to obtain certificates on behalf of.
• DOMAINS - a space separated list of domains to obtain a certificate for.
• LETSENCRYPT_ENDPOINT
  • If set, will be used to populate the /etc/letsencrypt/cli.ini file with the given server value. For testing use https://acme-staging.api.letsencrypt.org/directory
• DEPLOYMENTS - a space separated list of deployments whose pods should be refreshed after a certificate save
• SECRET_NAME - the name to save the secrets under
• NAMESPACE - the namespace under which the secrets should be available
• CRON_FREQUENCY - the 5-part frequency of the cron job. Default is a random time in the range 0-59 0-23 1-27 * *