| -- |
| -- 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 Span = require('skywalking.span') |
| local TC = require('skywalking.tracing_context') |
| local Layer = require('skywalking.span_layer') |
| local Segment = require('skywalking.segment') |
| local Util = require('skywalking.util') |
| local Const = require('skywalking.constants') |
| local json = require('cjson.safe') |
| |
| local metadata_shdict = ngx.shared.tracing_buffer |
| local ngx = ngx |
| local nginxComponentId = 6000 |
| |
| |
| local Tracer = {} |
| |
| |
| function Tracer:start(upstream_name, correlation) |
| local serviceName = metadata_shdict:get("serviceName") |
| local serviceInstanceName = metadata_shdict:get('serviceInstanceName') |
| local includeHostInEntrySpan = metadata_shdict:get('includeHostInEntrySpan') |
| local tracingContext = TC.new(serviceName, serviceInstanceName) |
| |
| -- Constant pre-defined in SkyWalking main repo |
| -- 6000 represents Nginx |
| |
| local contextCarrier = {} |
| contextCarrier["sw8"] = ngx.var.http_sw8 |
| contextCarrier["sw8-correlation"] = ngx.var.http_sw8_correlation |
| |
| local time_now = ngx.now() * 1000 |
| local entrySpan |
| if (includeHostInEntrySpan) then |
| entrySpan = TC.createEntrySpan(tracingContext, ngx.var.host .. ngx.var.uri, nil, contextCarrier) |
| else |
| entrySpan = TC.createEntrySpan(tracingContext, ngx.var.uri, nil, contextCarrier) |
| end |
| Span.start(entrySpan, time_now) |
| Span.setComponentId(entrySpan, nginxComponentId) |
| Span.setLayer(entrySpan, Layer.HTTP) |
| |
| Span.tag(entrySpan, 'http.method', ngx.req.get_method()) |
| Span.tag(entrySpan, 'http.params', |
| ngx.var.scheme .. '://' .. ngx.var.host .. ngx.var.request_uri ) |
| |
| contextCarrier = {} |
| -- Use the same URI to represent incoming and forwarding requests |
| -- Change it if you need. |
| local upstreamUri = ngx.var.uri |
| local upstreamServerName = upstream_name |
| ------------------------------------------------------ |
| local exitSpan = TC.createExitSpan(tracingContext, upstreamUri, entrySpan, |
| upstreamServerName, contextCarrier, correlation) |
| Span.start(exitSpan, time_now) |
| Span.setComponentId(exitSpan, nginxComponentId) |
| Span.setLayer(exitSpan, Layer.HTTP) |
| |
| for name, value in pairs(contextCarrier) do |
| ngx.req.set_header(name, value) |
| end |
| |
| -- Push the data in the context |
| local ctx = ngx.ctx |
| ctx.tracingContext = tracingContext |
| ctx.entrySpan = entrySpan |
| ctx.exitSpan = exitSpan |
| end |
| |
| function Tracer:finish() |
| -- Finish the exit span when received the first response package from upstream |
| if ngx.ctx.exitSpan ~= nil then |
| local upstream_status = tonumber(ngx.var.upstream_status) |
| if upstream_status then |
| Span.tag(ngx.ctx.exitSpan, 'http.status', upstream_status) |
| end |
| Span.finish(ngx.ctx.exitSpan, ngx.now() * 1000) |
| ngx.ctx.exitSpan = nil |
| end |
| end |
| |
| function Tracer:prepareForReport() |
| local entrySpan = ngx.ctx.entrySpan |
| if not entrySpan then |
| return |
| end |
| |
| local ngxstatus = ngx.var.status |
| Span.tag(entrySpan, 'http.status', ngxstatus) |
| if tonumber(ngxstatus) >= 500 then |
| Span.errorOccurred(entrySpan) |
| end |
| |
| Span.finish(entrySpan, ngx.now() * 1000) |
| |
| local ok, segment = TC.drainAfterFinished(ngx.ctx.tracingContext) |
| if not ok then |
| return |
| end |
| |
| local segmentJson, err = json.encode(Segment.transform(segment)) |
| if not segmentJson then |
| ngx.log(ngx.ERR, "failed to encode segment: ", err) |
| return |
| end |
| ngx.log(ngx.DEBUG, 'segment = ', segmentJson) |
| |
| local length, err = metadata_shdict:lpush(Const.segment_queue, segmentJson) |
| if not length then |
| ngx.log(ngx.ERR, "failed to push segment: ", err) |
| return |
| end |
| ngx.log(ngx.DEBUG, 'segment buffer size = ', length) |
| end |
| |
| return Tracer |