haproxy: deploy script can update existing certificate over stats socket

Since version 2.2, HAProxy is able to update dynamically certificates,
without a reload.

This patch uses socat to push the certificate into HAProxy in order to
achieve hot update. With this method, reloading is not required.
This should be used only to update an existing certificate in haproxy.

2 new variables are available:

- DEPLOY_HAPROXY_HOT_UPDATE="yes" update over the stats socket instead
  of reloading

- DEPLOY_HAPROXY_STATS_SOCKET="UNIX:/run/haproxy/admin.sock" set the path on
  the stats socket.

deploy/haproxy.sh

@@ -36,6 +36,14 @@
 # Note: This functionality requires HAProxy was compiled against
 # a version of OpenSSL that supports this.
 #
+# export DEPLOY_HAPROXY_HOT_UPDATE="yes"
+# export DEPLOY_HAPROXY_STATS_SOCKET="UNIX:/run/haproxy/admin.sock"
+#
+# OPTIONAL: Deploy the certificate over the HAProxy stats socket without
+# needing to reload HAProxy. Default is "no".
+#
+# Require the socat binary. DEPLOY_HAPROXY_STATS_SOCKET variable uses the socat
+# address format.
 
 ########  Public functions #####################
 
@@ -53,6 +61,8 @@ haproxy_deploy() {
   DEPLOY_HAPROXY_BUNDLE_DEFAULT="no"
   DEPLOY_HAPROXY_ISSUER_DEFAULT="no"
   DEPLOY_HAPROXY_RELOAD_DEFAULT="true"
+  DEPLOY_HAPROXY_HOT_UPDATE_DEFAULT="no"
+  DEPLOY_HAPROXY_STATS_SOCKET_DEFAULT="UNIX:/run/haproxy/admin.sock"
 
   _debug _cdomain "${_cdomain}"
   _debug _ckey "${_ckey}"
@@ -118,6 +128,26 @@ haproxy_deploy() {
     Le_Deploy_haproxy_reload="${DEPLOY_HAPROXY_RELOAD_DEFAULT}"
   fi
 
+  # HOT_UPDATE is optional. If not provided then assume "${DEPLOY_HAPROXY_HOT_UPDATE_DEFAULT}"
+  _getdeployconf DEPLOY_HAPROXY_HOT_UPDATE
+  _debug2 DEPLOY_HAPROXY_HOT_UPDATE "${DEPLOY_HAPROXY_HOT_UPDATE}"
+  if [ -n "${DEPLOY_HAPROXY_HOT_UPDATE}" ]; then
+    Le_Deploy_haproxy_hot_update="${DEPLOY_HAPROXY_HOT_UPDATE}"
+    _savedomainconf Le_Deploy_haproxy_hot_update "${Le_Deploy_haproxy_hot_update}"
+  elif [ -z "${Le_Deploy_haproxy_hot_update}" ]; then
+    Le_Deploy_haproxy_hot_update="${DEPLOY_HAPROXY_HOT_UPDATE_DEFAULT}"
+  fi
+
+  # STATS_SOCKET is optional. If not provided then assume "${DEPLOY_HAPROXY_STATS_SOCKET_DEFAULT}"
+  _getdeployconf DEPLOY_HAPROXY_STATS_SOCKET
+  _debug2 DEPLOY_HAPROXY_STATS_SOCKET "${DEPLOY_HAPROXY_STATS_SOCKET}"
+  if [ -n "${DEPLOY_HAPROXY_STATS_SOCKET}" ]; then
+    Le_Deploy_haproxy_stats_socket="${DEPLOY_HAPROXY_STATS_SOCKET}"
+    _savedomainconf Le_Deploy_haproxy_stats_socket "${Le_Deploy_haproxy_stats_socket}"
+  elif [ -z "${Le_Deploy_haproxy_stats_socket}" ]; then
+    Le_Deploy_haproxy_stats_socket="${DEPLOY_HAPROXY_STATS_SOCKET_DEFAULT}"
+  fi
+
   # Set the suffix depending if we are creating a bundle or not
   if [ "${Le_Deploy_haproxy_bundle}" = "yes" ]; then
     _info "Bundle creation requested"
@@ -142,6 +172,7 @@ haproxy_deploy() {
   _issuer="${_pem}.issuer"
   _ocsp="${_pem}.ocsp"
   _reload="${Le_Deploy_haproxy_reload}"
+  _statssock="${Le_Deploy_haproxy_stats_socket}"
 
   _info "Deploying PEM file"
   # Create a temporary PEM file
@@ -265,6 +296,38 @@ haproxy_deploy() {
     fi
   fi
 
+  if [ "${Le_Deploy_haproxy_hot_update}" = "yes" ]; then
+    # Update certificate over HAProxy stats socket.
+    _info "Update the certificate over HAProxy stats socket."
+    if _exists socat; then
+      _socat_cert_cmd="echo 'show ssl cert' | socat '${_statssock}' - | grep -q '^${_pem}$'"
+      _debug _socat_cert_cmd "${_socat_cert_cmd}"
+      eval "${_socat_cert_cmd}"
+      _ret=$?
+      if [ "${_ret}" != "0" ]; then
+        _err "Couldn't find '${_pem}' in haproxy 'show ssl cert'"
+        return "${_ret}"
+      fi
+      _socat_cert_set_cmd="echo -e 'set ssl cert ${_pem} <<\n$(cat "${_pem}")\n' | socat '${_statssock}' - | grep -q 'Transaction created'"
+      _debug _socat_cert_set_cmd "${_socat_cert_set_cmd}"
+      eval "${_socat_cert_set_cmd}"
+      _ret=$?
+      if [ "${_ret}" != "0" ]; then
+        _err "Can't update '${_pem}' in haproxy"
+        return "${_ret}"
+      fi
+      _socat_cert_commit_cmd="echo 'commit ssl cert ${_pem}' | socat '${_statssock}' - | grep -q '^Success!$'"
+      _debug _socat_cert_commit_cmd "${_socat_cert_commit_cmd}"
+      eval "${_socat_cert_commit_cmd}"
+      _ret=$?
+      if [ "${_ret}" != "0" ]; then
+        _err "Can't commit '${_pem}' in haproxy"
+        return ${_ret}
+      fi
+    else
+      _err "'socat' is not available, couldn't update over stats socket"
+    fi
+  else
     # Reload HAProxy
     _debug _reload "${_reload}"
     eval "${_reload}"
@@ -275,6 +338,7 @@ haproxy_deploy() {
     else
       _info "Reload successful"
     fi
+  fi
 
   return 0
 }