Use Lager to log RabbitMQ messages

By default, RabbitMQ now logs messages to a single file
($RABBITMQ_LOGS). The $RABBITMQ_SASL_LOGS variable is unused. To
configure how and which messages are logged, it's recommended to do it
from rabbitmq.config, not from the environment variable.

The old `log_levels` parameter is unsupported and categories are
replaced by Lager extra sinks. If you had in your rabbitmq.config:
    {rabbit, [
        {log_levels, [{connection, info}]}
      ]}
You can now configure Lager like this:
    {lager, [
        {extra_sinks, [
            {rabbit_connection_lager_event, [
                {handlers, [{lager_forwarder_backend, [lager_event, info]}]}
              ]}
          ]}
      ]}

rabbitmq-build.mk from rabbitmq-common is included in the top-level
Makefile. It sets the appropriate compiler options to enable Lager's
lager_transform parse_transform module.

rabbit_log calls are now converted by this parse_transform to direct
calls to lager:log(). To keep backward compatibility with other plugins,
the rabbit_log module still implements all the <level>() functions.
Compared to the parse_transformed calls, the main difference is the
logged message does not carry the file:line metadata.

Fixes #94.

1 files changed, 6 insertions, 13 deletions

diff --git a/scripts/rabbitmq-server b/scripts/rabbitmq-server
index 69c2b7ff6c..303383eb1b 100755
--- a/scripts/rabbitmq-server
+++ b/scripts/rabbitmq-server
@@ -76,22 +76,15 @@ RABBITMQ_CONFIG_ARG=
 RABBITMQ_LISTEN_ARG=
 [ "x" != "x$RABBITMQ_NODE_PORT" ] && [ "x" != "x$RABBITMQ_NODE_IP_ADDRESS" ] && RABBITMQ_LISTEN_ARG="-rabbit tcp_listeners [{\""${RABBITMQ_NODE_IP_ADDRESS}"\","${RABBITMQ_NODE_PORT}"}]"
 
-# If $RABBITMQ_LOGS is '-', send all log messages to stdout. Likewise
-# for RABBITMQ_SASL_LOGS. This is particularily useful for Docker
-# images.
+# If $RABBITMQ_LOGS is '-', send all log messages to stdout. This is
+# particularily useful for Docker images.
 
 if [ "$RABBITMQ_LOGS" = '-' ]; then
-    RABBIT_ERROR_LOGGER='tty'
-else
-    RABBIT_ERROR_LOGGER='{file,"'${RABBITMQ_LOGS}'"}'
-fi
-
-if [ "$RABBITMQ_SASL_LOGS" = '-' ]; then
     SASL_ERROR_LOGGER=tty
-    RABBIT_SASL_ERROR_LOGGER='tty'
+    RABBIT_LAGER_HANDLER=tty
 else
     SASL_ERROR_LOGGER=false
-    RABBIT_SASL_ERROR_LOGGER='{file,"'${RABBITMQ_SASL_LOGS}'"}'
+    RABBIT_LAGER_HANDLER='"'${RABBITMQ_LOGS}'"'
 fi
 
 # we need to turn off path expansion because some of the vars, notably
@@ -116,8 +109,8 @@ start_rabbitmq_server() {
         ${RABBITMQ_LISTEN_ARG} \
         -sasl errlog_type error \
         -sasl sasl_error_logger "$SASL_ERROR_LOGGER" \
-        -rabbit error_logger "$RABBIT_ERROR_LOGGER" \
-        -rabbit sasl_error_logger "$RABBIT_SASL_ERROR_LOGGER" \
+        -rabbit lager_log_root "\"$RABBITMQ_LOG_BASE\"" \
+        -rabbit lager_handler "$RABBIT_LAGER_HANDLER" \
         -rabbit enabled_plugins_file "\"$RABBITMQ_ENABLED_PLUGINS_FILE\"" \
         -rabbit plugins_dir "\"$RABBITMQ_PLUGINS_DIR\"" \
         -rabbit plugins_expand_dir "\"$RABBITMQ_PLUGINS_EXPAND_DIR\"" \