feat(plugins): Datadog for metrics collection (#5372)

apisix/plugins/datadog.lua

@@ -0,0 +1,277 @@
+--
+-- Licensed to the Apache Software Foundation (ASF) under one or more
+-- contributor license agreements.  See the NOTICE file distributed with
+-- this work for additional information regarding copyright ownership.
+-- The ASF licenses this file to You 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 core = require("apisix.core")
+local plugin = require("apisix.plugin")
+local batch_processor = require("apisix.utils.batch-processor")
+local fetch_log = require("apisix.utils.log-util").get_full_log
+local ngx = ngx
+local udp = ngx.socket.udp
+local format = string.format
+local concat = table.concat
+local buffers = {}
+local ipairs = ipairs
+local tostring = tostring
+local stale_timer_running = false
+local timer_at = ngx.timer.at
+
+local plugin_name = "datadog"
+local defaults = {
+    host = "127.0.0.1",
+    port = 8125,
+    namespace = "apisix",
+    constant_tags = {"source:apisix"}
+}
+
+local schema = {
+    type = "object",
+    properties = {
+        buffer_duration = {type = "integer", minimum = 1, default = 60},
+        inactive_timeout = {type = "integer", minimum = 1, default = 5},
+        batch_max_size = {type = "integer", minimum = 1, default = 5000},
+        max_retry_count = {type = "integer", minimum = 1, default = 1},
+    }
+}
+
+local metadata_schema = {
+    type = "object",
+    properties = {
+        host = {type = "string", default= defaults.host},
+        port = {type = "integer", minimum = 0, default = defaults.port},
+        namespace = {type = "string", default = defaults.namespace},
+        constant_tags = {
+            type = "array",
+            items = {type = "string"},
+            default = defaults.constant_tags
+        }
+    },
+}
+
+local _M = {
+    version = 0.1,
+    priority = 495,
+    name = plugin_name,
+    schema = schema,
+    metadata_schema = metadata_schema,
+}
+
+function _M.check_schema(conf, schema_type)
+    if schema_type == core.schema.TYPE_METADATA then
+        return core.schema.check(metadata_schema, conf)
+    end
+    return core.schema.check(schema, conf)
+end
+
+local function generate_tag(entry, const_tags)
+    local tags
+    if const_tags and #const_tags > 0 then
+        tags = core.table.clone(const_tags)
+    else
+        tags = {}
+    end
+
+    -- priority on route name, if not found using the route id.
+    if entry.route_name ~= "" then
+        core.table.insert(tags, "route_name:" .. entry.route_name)
+    elseif entry.route_id and entry.route_id ~= "" then
+        core.table.insert(tags, "route_name:" .. entry.route_id)
+    end
+
+    if entry.service_id and entry.service_id ~= "" then
+        core.table.insert(tags, "service_id:" .. entry.service_id)
+    end
+
+    if entry.consumer and entry.consumer ~= "" then
+        core.table.insert(tags, "consumer:" .. entry.consumer)
+    end
+    if entry.balancer_ip ~= "" then
+        core.table.insert(tags, "balancer_ip:" .. entry.balancer_ip)
+    end
+    if entry.response.status then
+        core.table.insert(tags, "response_status:" .. entry.response.status)
+    end
+    if entry.scheme ~= "" then
+        core.table.insert(tags, "scheme:" .. entry.scheme)
+    end
+
+    if #tags > 0 then
+        return "|#" .. concat(tags, ',')
+    end
+
+    return ""
+end
+
+-- remove stale objects from the memory after timer expires
+local function remove_stale_objects(premature)
+    if premature then
+        return
+    end
+
+    for key, batch in ipairs(buffers) do
+        if #batch.entry_buffer.entries == 0 and #batch.batch_to_process == 0 then
+            core.log.warn("removing batch processor stale object, conf: ",
+                          core.json.delay_encode(key))
+            buffers[key] = nil
+        end
+    end
+
+    stale_timer_running = false
+end
+
+function _M.log(conf, ctx)
+
+    if not stale_timer_running then
+        -- run the timer every 30 mins if any log is present
+        timer_at(1800, remove_stale_objects)
+        stale_timer_running = true
+    end
+
+    local entry = fetch_log(ngx, {})
+    entry.upstream_latency = ctx.var.upstream_response_time * 1000
+    entry.balancer_ip = ctx.balancer_ip or ""
+    entry.route_name = ctx.route_name or ""
+    entry.scheme = ctx.upstream_scheme or ""
+
+    local log_buffer = buffers[conf]
+    if log_buffer then
+        log_buffer:push(entry)
+        return
+    end
+
+    -- Generate a function to be executed by the batch processor
+    local func = function(entries, batch_max_size)
+        -- Fetching metadata details
+        local metadata = plugin.plugin_metadata(plugin_name)
+        if not metadata then
+            core.log.info("received nil metadata: using metadata defaults: ",
+                                core.json.delay_encode(defaults, true))
+            metadata = {}
+            metadata.value = defaults
+        end
+
+        -- Creating a udp socket
+        local sock = udp()
+        local host, port = metadata.value.host, metadata.value.port
+        core.log.info("sending batch metrics to dogstatsd: ", host, ":", port)
+
+        local ok, err = sock:setpeername(host, port)
+
+        if not ok then
+            return false, "failed to connect to UDP server: host[" .. host
+                        .. "] port[" .. tostring(port) .. "] err: " .. err
+        end
+
+        -- Generate prefix & suffix according dogstatsd udp data format.
+        local prefix = metadata.value.namespace
+        if prefix ~= "" then
+            prefix = prefix .. "."
+        end
+
+        core.log.info("datadog batch_entry: ", core.json.delay_encode(entries, true))
+        for _, entry in ipairs(entries) do
+            local suffix = generate_tag(entry, metadata.value.constant_tags)
+
+            -- request counter
+            local ok, err = sock:send(format("%s:%s|%s%s", prefix ..
+                                            "request.counter", 1, "c", suffix))
+            if not ok then
+                core.log.error("failed to report request count to dogstatsd server: host[" .. host
+                        .. "] port[" .. tostring(port) .. "] err: " .. err)
+            end
+
+
+            -- request latency histogram
+            local ok, err = sock:send(format("%s:%s|%s%s", prefix ..
+                                        "request.latency", entry.latency, "h", suffix))
+            if not ok then
+                core.log.error("failed to report request latency to dogstatsd server: host["
+                        .. host .. "] port[" .. tostring(port) .. "] err: " .. err)
+            end
+
+            -- upstream latency
+            local apisix_latency = entry.latency
+            if entry.upstream_latency then
+                local ok, err = sock:send(format("%s:%s|%s%s", prefix ..
+                                        "upstream.latency", entry.upstream_latency, "h", suffix))
+                if not ok then
+                    core.log.error("failed to report upstream latency to dogstatsd server: host["
+                                .. host .. "] port[" .. tostring(port) .. "] err: " .. err)
+                end
+                apisix_latency =  apisix_latency - entry.upstream_latency
+                if apisix_latency < 0 then
+                    apisix_latency = 0
+                end
+            end
+
+            -- apisix_latency
+            local ok, err = sock:send(format("%s:%s|%s%s", prefix ..
+                                            "apisix.latency", apisix_latency, "h", suffix))
+            if not ok then
+                core.log.error("failed to report apisix latency to dogstatsd server: host[" .. host
+                        .. "] port[" .. tostring(port) .. "] err: " .. err)
+            end
+
+            -- request body size timer
+            local ok, err = sock:send(format("%s:%s|%s%s", prefix ..
+                                            "ingress.size", entry.request.size, "ms", suffix))
+            if not ok then
+                core.log.error("failed to report req body size to dogstatsd server: host[" .. host
+                        .. "] port[" .. tostring(port) .. "] err: " .. err)
+            end
+
+            -- response body size timer
+            local ok, err = sock:send(format("%s:%s|%s%s", prefix ..
+                                            "egress.size", entry.response.size, "ms", suffix))
+            if not ok then
+                core.log.error("failed to report response body size to dogstatsd server: host["
+                        .. host .. "] port[" .. tostring(port) .. "] err: " .. err)
+            end
+        end
+
+        -- Releasing the UDP socket desciptor
+        ok, err = sock:close()
+        if not ok then
+            core.log.error("failed to close the UDP connection, host[",
+                            host, "] port[", port, "] ", err)
+        end
+
+        -- Returning at the end and ensuring the resource has been released.
+        return true
+    end
+    local config = {
+        name = plugin_name,
+        retry_delay = conf.retry_delay,
+        batch_max_size = conf.batch_max_size,
+        max_retry_count = conf.max_retry_count,
+        buffer_duration = conf.buffer_duration,
+        inactive_timeout = conf.inactive_timeout,
+        route_id = ctx.var.route_id,
+        server_addr = ctx.var.server_addr,
+    }
+
+    local err
+    log_buffer, err = batch_processor:new(func, config)
+
+    if not log_buffer then
+        core.log.error("error when creating the batch processor: ", err)
+        return
+    end
+
+    buffers[conf] = log_buffer
+    log_buffer:push(entry)
+end
+
+return _M

conf/config-default.yaml

@@ -341,6 +341,7 @@ plugins:                          # plugin list (sorted by priority)
   #- dubbo-proxy                   # priority: 507
   - grpc-transcode                 # priority: 506
   - prometheus                     # priority: 500
+  - datadog                        # priority: 495
   - echo                           # priority: 412
   - http-logger                    # priority: 410
   - sls-logger                     # priority: 406

docs/en/latest/config.json

@@ -105,7 +105,8 @@
             "plugins/prometheus",
             "plugins/zipkin",
             "plugins/skywalking",
-            "plugins/node-status"
+            "plugins/node-status",
+            "plugins/datadog"
           ]
         },
         {