From eb24514cb108eb95fd46f33ba2a9a3cdf9b969dc Mon Sep 17 00:00:00 2001 From: Krzesimir Nowak Date: Tue, 21 Apr 2020 14:17:55 +0200 Subject: [PATCH] Add an example use of the gin-gonic instrumentation --- plugins/gin-gonic/gin/example/Dockerfile | 20 +++++ plugins/gin-gonic/gin/example/README.md | 28 +++++++ .../gin-gonic/gin/example/docker-compose.yml | 39 +++++++++ plugins/gin-gonic/gin/example/server.go | 79 +++++++++++++++++++ 4 files changed, 166 insertions(+) create mode 100644 plugins/gin-gonic/gin/example/Dockerfile create mode 100644 plugins/gin-gonic/gin/example/README.md create mode 100644 plugins/gin-gonic/gin/example/docker-compose.yml create mode 100644 plugins/gin-gonic/gin/example/server.go diff --git a/plugins/gin-gonic/gin/example/Dockerfile b/plugins/gin-gonic/gin/example/Dockerfile new file mode 100644 index 00000000000..591128b6cf6 --- /dev/null +++ b/plugins/gin-gonic/gin/example/Dockerfile @@ -0,0 +1,20 @@ +# Copyright The OpenTelemetry Authors +# +# 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. +FROM golang:alpine AS base +COPY . /src/ +WORKDIR /src/plugins/gin-gonic/gin + +FROM base AS gin-server +RUN go install ./example/server.go +CMD ["/go/bin/server"] diff --git a/plugins/gin-gonic/gin/example/README.md b/plugins/gin-gonic/gin/example/README.md new file mode 100644 index 00000000000..c0bb042b672 --- /dev/null +++ b/plugins/gin-gonic/gin/example/README.md @@ -0,0 +1,28 @@ +# gin-gonic instrumentation example + +An HTTP server using gin-gonic and instrumentation. The server has a +`/users/:id` endpoint. The server generates span information to +`stdout`. + +These instructions expect you have +[docker-compose](https://docs.docker.com/compose/) installed. + +Bring up the `gin-server` and `gin-client` services to run the +example: + +```sh +docker-compose up --detach gin-server gin-client +``` + +The `gin-client` service sends just one HTTP request to `gin-server` +and then exits. View the span generated by `gin-server` in the logs: + +```sh +docker-compose logs gin-server +``` + +Shut down the services when you are finished with the example: + +```sh +docker-compose down +``` diff --git a/plugins/gin-gonic/gin/example/docker-compose.yml b/plugins/gin-gonic/gin/example/docker-compose.yml new file mode 100644 index 00000000000..46aa7e43918 --- /dev/null +++ b/plugins/gin-gonic/gin/example/docker-compose.yml @@ -0,0 +1,39 @@ +# Copyright The OpenTelemetry Authors +# +# 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. +version: "3.7" +services: + gin-client: + image: golang:alpine + networks: + - example + command: + - "/bin/sh" + - "-c" + - "wget http://gin-server:8080/users/123 && cat 123" + depends_on: + - gin-server + gin-server: + build: + dockerfile: $PWD/Dockerfile + context: ../../../.. + ports: + - "8080:80" + command: + - "/bin/sh" + - "-c" + - "/go/bin/server" + networks: + - example +networks: + example: diff --git a/plugins/gin-gonic/gin/example/server.go b/plugins/gin-gonic/gin/example/server.go new file mode 100644 index 00000000000..6a55f745ddf --- /dev/null +++ b/plugins/gin-gonic/gin/example/server.go @@ -0,0 +1,79 @@ +// Copyright The OpenTelemetry Authors +// +// 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. + +package main + +import ( + "context" + "html/template" + "log" + "net/http" + + "github.com/gin-gonic/gin" + + gintrace "go.opentelemetry.io/contrib/plugins/gin-gonic/gin" + otelglobal "go.opentelemetry.io/otel/api/global" + otelkey "go.opentelemetry.io/otel/api/key" + oteltrace "go.opentelemetry.io/otel/api/trace" + oteltracestdout "go.opentelemetry.io/otel/exporters/trace/stdout" + sdktrace "go.opentelemetry.io/otel/sdk/trace" +) + +var tracer = otelglobal.Tracer("gin-server") + +func main() { + initTracer() + r := gin.New() + r.Use(gintrace.Middleware("my-server")) + tmplName := "user" + tmplStr := "user {{ .name }} (id {{ .id }})\n" + tmpl := template.Must(template.New(tmplName).Parse(tmplStr)) + r.SetHTMLTemplate(tmpl) + r.GET("/users/:id", func(c *gin.Context) { + id := c.Param("id") + name := getUser(c.Request.Context(), id) + gintrace.HTML(c, http.StatusOK, tmplName, gin.H{ + "name": name, + "id": id, + }) + }) + _ = r.Run(":8080") +} + +func initTracer() { + exporter, err := oteltracestdout.NewExporter(oteltracestdout.Options{PrettyPrint: true}) + if err != nil { + log.Fatal(err) + } + cfg := sdktrace.Config{ + DefaultSampler: sdktrace.AlwaysSample(), + } + tp, err := sdktrace.NewProvider( + sdktrace.WithConfig(cfg), + sdktrace.WithSyncer(exporter), + ) + if err != nil { + log.Fatal(err) + } + otelglobal.SetTraceProvider(tp) +} + +func getUser(ctx context.Context, id string) string { + _, span := tracer.Start(ctx, "getUser", oteltrace.WithAttributes(otelkey.String("id", id))) + defer span.End() + if id == "123" { + return "gintrace tester" + } + return "unknown" +}