If an error occurs when attempting to acquire a certificate, a flag file (block_acquisitions.flag) is written into /etc/letsencrypt to stop further auto acquisition attempts. This is done to avoid hitting Certbot rate limits which can occur if we keep retrying due to a permanent failure. If you are are sure you deployments never fail and don't want temporary errors to stop auto acquisition then you can pass this environment variable (with a value of true) in which case the normal auto acquisition will occur regardless of the existence of the flag. The block flag file automatically times out after 15 minutes. Running 'nginx-le acquire' also clears the block flag.