-- Copyright 2015-2016 Mirantis, Inc.
--
-- Licensed under the Apache License, Version 2.0 (the "License");
-- you may not use this file except in compliance with the License.
-- You may obtain a copy of the License at
--
--     http://www.apache.org/licenses/LICENSE-2.0
--
-- Unless required by applicable law or agreed to in writing, software
-- distributed under the License is distributed on an "AS IS" BASIS,
-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-- See the License for the specific language governing permissions and
-- limitations under the License.
local dt     = require "date_time"
local l      = require 'lpeg'
l.locale(l)

local patt   = require 'os_patterns'
local utils  = require 'os_utils'

local msg = {
    Timestamp   = nil,
    Type        = 'log',
    Hostname    = nil,
    Payload     = nil,
    Pid         = nil,
    Fields      = nil,
    Severity    = nil,
}

-- RabbitMQ message logs are formatted like this:
--   =ERROR REPORT==== 2-Jan-2015::09:17:22 ===
--   Blabla
--   Blabla
--
local message   = l.Cg(patt.Message / utils.chomp, "Message")
-- The token before 'REPORT' isn't standardized so it can be a valid severity
-- level as 'INFO' or 'ERROR' but also 'CRASH' or 'SUPERVISOR'.
local severity  = l.Cg(l.R"AZ"^1, "SeverityLabel")
local day = l.R"13" * l.R"09" + l.R"19"
local datetime = l.Cg(day, "day") * patt.dash * dt.date_mabbr * patt.dash * dt.date_fullyear *
                 "::" * dt.rfc3339_partial_time
local timestamp = l.Cg(l.Ct(datetime)/ dt.time_to_ns, "Timestamp")

local grammar = l.Ct("=" * severity * " REPORT==== " * timestamp * " ===" * l.P'\n' * message)

function process_message ()
    local log = read_message("Payload")

    local m = grammar:match(log)
    if not m then
        return -1
    end

    msg.Timestamp = m.Timestamp
    msg.Payload = m.Message
    if utils.label_to_severity_map[m.SeverityLabel] then
        msg.Severity = utils.label_to_severity_map[m.SeverityLabel]
    elseif m.SeverityLabel == 'CRASH' then
        msg.Severity = 2 -- CRITICAL
    else
        msg.Severity = 5 -- NOTICE
    end

    msg.Fields = {}
    msg.Fields.severity_label = utils.severity_to_label_map[msg.Severity]
    msg.Fields.programname = 'rabbitmq'

    return utils.safe_inject_message(msg)
end

Add Heka log decoder for RabbitMQ
Add Heka log decoder for RabbitMQ

In the future the Heka Lua sandboxes will be moved out of Kolla, and
installed in the Heka container using a deb or rpm package.

Partially implements: blueprint heka
Change-Id: I1aa27048d22f1a5ed385180696d320af9a961389
