discourse/lib/discourse_logstash_logger.rb
Alan Guo Xiang Tan 8e10878e1a
DEV: Redo DiscourseLogstashLogger to not rely on logstash-logger (#27663)
This commit rewrites `DiscourseLogstashLogger` to not be an instance
of `LogstashLogger`. The reason we don't want it to be an instance of
`LogstashLogger` is because we want the new logger to be chained to
Logster's logger which can then pass down useful information like the
request's env and error backtraces which Logster has already gathered.

Note that this commit does not bother to maintain backwards
compatibility and drops the `LOGSTASH_URI` and `UNICORN_LOGSTASH_URI`
ENV variables which were previously used to configure the destination in
which `logstash-logger` would send the logs to. Instead, we introduce
the `ENABLE_LOGSTASH_LOGGER` ENV variable to replace both ENV and remove
the need for the log paths to be specified. Note that the previous
feature was considered experimental as stated in d888d3c54c
and the new feature should be considered experimental as well. The code
may be moved into a plugin in the future.
2024-07-05 09:41:52 +08:00

105 lines
3.0 KiB
Ruby

# frozen_string_literal: true
require "json"
require "socket"
require_relative "git_utils"
class DiscourseLogstashLogger < Logger
PROCESS_PID = Process.pid
HOST = Socket.gethostname
GIT_VERSION = GitUtils.git_version
attr_accessor :customize_event, :type
# Creates a new logger instance.
#
# @param logdev [String, IO, nil] The log device. This can be one of:
# - A string filepath: entries are written to the file at that path. If the file exists, new entries are appended.
# - An IO stream (typically +$stdout+, +$stderr+, or an open file): entries are written to the given stream.
# - nil or File::NULL: no entries are written.
# @param type [String] The type of log messages. This will add a `type` field to all log messages.
# @param customize_event [Proc, nil] A proc that customizes the log event before it is written to the log device.
# The proc is called with a hash of log event data and can be modified in place.
#
# @return [Logger] A new logger instance with the specified log device and type.
def self.logger(logdev:, type:, customize_event: nil)
logger = self.new(logdev)
logger.type = type
logger.customize_event = customize_event if customize_event
logger
end
# :nodoc:
def add(*args, &block)
add_with_opts(*args, &block)
end
ALLOWED_HEADERS_FROM_ENV = %w[
REQUEST_URI
REQUEST_METHOD
HTTP_HOST
HTTP_USER_AGENT
HTTP_ACCEPT
HTTP_REFERER
HTTP_X_FORWARDED_FOR
HTTP_X_REAL_IP
]
# :nodoc:
def add_with_opts(severity, message = nil, progname = nil, opts = {}, &block)
return true if @logdev.nil? || severity < @level
progname = @progname if progname.nil?
if message.nil?
if block_given?
message = yield
else
message = progname
progname = @progname
end
end
event = {
"message" => message,
"severity" => severity,
"severity_name" => Logger::SEV_LABEL[severity],
"pid" => PROCESS_PID,
"type" => @type.to_s,
"host" => HOST,
"git_version" => GitUtils.git_version,
}
# Only log backtrace and env for Logger::WARN and above.
# Backtrace is just noise for anything below that.
if severity >= Logger::WARN
if (backtrace = opts&.dig(:backtrace)).present?
event["backtrace"] = backtrace
end
if (env = opts&.dig(:env)).present?
ALLOWED_HEADERS_FROM_ENV.each do |header|
event["request.headers.#{header.downcase}"] = opts[:env][header]
end
end
end
if message.start_with?("{") && message.end_with?("}")
begin
parsed = JSON.parse(message)
event["message"] = parsed.delete("message") if parsed["message"]
event.merge!(parsed)
event
rescue JSON::ParserError
# Do nothing
end
end
@customize_event.call(event) if @customize_event
@logdev.write("#{event.to_json}\n")
rescue Exception => e
STDERR.puts "Error logging message in DiscourseLogstashLogger: #{message} (#{e.message})\n#{e.backtrace.join("\n")}"
end
end