Support for only renew operations

README.md

@@ -34,6 +34,16 @@ By default, the container will stay alive and try to renew the
 certificate every 86400 seconds. If you set the environment variable
 `ONLYGETCERT`, then it will only get the certificates and exit.
 
+### Only renewing the certificate
+
+If you only want to trigger renewing existing certificates and skip
+getting the certificates initially, you can set the variable
+`RENEWCERTSONCE`, then it will only renew all certificates and exit.
+
+* If `ONLYRENEWCERTS` is set, only the reguler renew loop will run.
+* If `ONLYRENEWCERTSONCE` is set, renew will be run once and then the
+  container exits
+
 ## Volumes
 
 If you want to keep / use your certificates, you are advised to create

entrypoint.sh

@@ -11,6 +11,8 @@ else
     STAGING="--staging"
 fi
 
+# Skip getting certs if requested
+if [ -z "$ONLYRENEWCERTS" -a -z "$ONLYRENEWCERTSONCE" ]; then
     # Try to get a certificate, accept failures
     while [ ! -f "/etc/letsencrypt/live/${DOMAIN}/fullchain.pem" ]; do
         certbot certonly --agree-tos --cert-name "${DOMAIN}" \
@@ -25,6 +27,7 @@ while [ ! -f "/etc/letsencrypt/live/${DOMAIN}/fullchain.pem" ]; do
             find /etc/letsencrypt -type f -exec chmod 0644 {} \;
         fi
     done
+fi
 
 if [ "$ONLYGETCERT" ]; then
     exit 0
@@ -34,10 +37,14 @@ fi
 while true; do
     /usr/bin/certbot renew
 
+
     # And again, correct permissions if not told otherwise
     if [ -z "$LEAVE_PERMISSIONS_AS_IS" ]; then
         find /etc/letsencrypt -type d -exec chmod 0755 {} \;
         find /etc/letsencrypt -type f -exec chmod 0644 {} \;
     fi
+
+    [ "$ONLYRENEWCERTSONCE" ] && exit 0
+
     sleep 86400
 done