Change REUSE_KEY to REUSE_PRIVATE_KEYS

REUSE_KEY might be confusing now that there is a REUSE_ACCOUNT_KEYS env var

README.md

@@ -204,7 +204,7 @@ $ docker run -d \
 
 * `REUSE_ACCOUNT_KEYS` - Set it to `false` to disable the account keys reutilization (see [ACME account keys](#acme-account-keys)).
 
-* `REUSE_KEY` - Set it to `true` to make simp_le reuse previously generated private key instead of creating a new one on certificate renewal. Recommended if you intend to use HPKP.
+* `REUSE_PRIVATE_KEYS` - Set it to `true` to make simp_le reuse previously generated private key for each certificate instead of creating a new one on certificate renewal. Recommended if you intend to use HPKP.
 
 * The `com.github.jrcs.letsencrypt_nginx_proxy_companion.nginx_proxy` label - set this label on the nginx-proxy container to tell the docker-letsencrypt-nginx-proxy-companion container to use it as the proxy.
 

app/letsencrypt_service

@@ -9,6 +9,7 @@ seconds_to_wait=3600
 ACME_CA_URI="${ACME_CA_URI:-https://acme-v01.api.letsencrypt.org/directory}"
 DEFAULT_KEY_SIZE=4096
 REUSE_ACCOUNT_KEYS="$(lc ${REUSE_ACCOUNT_KEYS:-true})"
+REUSE_PRIVATE_KEYS="$(lc ${REUSE_PRIVATE_KEYS:-false})"
 
 create_link() {
     local -r target=${1?missing target argument}
@@ -78,7 +79,7 @@ update_certs() {
         params_d_str=""
         [[ $DEBUG == true ]] && params_d_str+=" -v"
         [[ -n $ACME_TOS_HASH ]] && params_d_str+=" --tos_sha256 $ACME_TOS_HASH"
-        [[ $REUSE_KEY == true ]] && params_d_str+=" --reuse_key"
+        [[ $REUSE_PRIVATE_KEYS == true ]] && params_d_str+=" --reuse_key"
         [[ "${1}" == "--force-renew" ]] && params_d_str+=" --valid_min 7776000"
 
         hosts_array_expanded=("${!hosts_array}")