Continuing this short series of writing a simple echo service web API along with the docker and k8s requirements, we’re now going to turn our attention to a Go implementation.<\/p>\n
Implementation<\/strong><\/p>\n I’m using JetBrains GoLand for this project, so I created a project named echo_service<\/em>.<\/p>\n If it doesn’t exist add the go.mod file or update it to have following<\/p>\n add a main.go file with the following<\/p>\n Dockerfile<\/strong><\/p>\n Next up we need to create our Dockerfile<\/p>\n Note: In Linux port 80 might be locked down, hence we use port 8080 by default.<\/em><\/p>\n To build this, run <\/p>\n Don’t forget to change the name to your preferred name.<\/em><\/p>\n and to test this, run<\/p>\n Kubernetes<\/strong><\/p>\n If all wen well we’ve not tested our application and see it working from a docker image, so now we need to create the deployment etc. for Kubernete’s. Let’s assume you’ve pushed you image to Docker or another container registry such as Azure – I’m call my container registry putridparrotreg<\/em>.<\/p>\n I’m also not going to use helm at this point as I just want a (relatively) simple yaml file to run from kubectl, so create a deployment.yaml file, we’ll store all the configurations, deployment, service and ingress in this one file jus for simplicity.<\/p>\n\r\nmodule echo_service\r\n\r\ngo 1.24\r\n<\/pre>\n
\r\npackage main\r\n\r\nimport (\r\n\t"fmt"\r\n\t"net\/http"\r\n)\r\n\r\nfunc livezHandler(w http.ResponseWriter, r *http.Request) {\r\n\tw.WriteHeader(http.StatusOK)\r\n\tw.Write([]byte("ok\\n"))\r\n}\r\n\r\nfunc readyzHandler(w http.ResponseWriter, r *http.Request) {\r\n\tw.WriteHeader(http.StatusOK)\r\n\tw.Write([]byte("ok\\n"))\r\n}\r\n\r\nfunc echoHandler(w http.ResponseWriter, r *http.Request) {\r\n\ttext := r.URL.Query().Get("text")\r\n\tfmt.Fprintf(w, "Go Echo: %s\\n", text)\r\n}\r\n\r\nfunc main() {\r\n\thttp.HandleFunc("\/echo", echoHandler)\r\n\thttp.HandleFunc("\/livez", livezHandler)\r\n\thttp.HandleFunc("\/readyz", readyzHandler)\r\n\r\n\tfmt.Println("Echo service running on port 8080...")\r\n\terr := http.ListenAndServe(":8080", nil)\r\n\tif err != nil {\r\n\t\tfmt.Println("Failed to start the service")\r\n\t\treturn\r\n\t}\r\n}\r\n<\/pre>\n\r\nFROM golang:1.24-alpine\r\nWORKDIR \/app\r\nCOPY . .\r\nRUN go build -o echo_service .\r\nCMD [".\/echo_service"]\r\n<\/pre>\n
\r\ndocker build -t putridparrot.echo_service:v1 .\r\n<\/pre>\n
\r\ndocker run -p 8080:8080 putridparrot.echo_service:v1\r\n<\/pre>\n
\r\napiVersion: apps\/v1\r\nkind: Deployment\r\nmetadata:\r\n name: echo\r\n namespace: dev\r\n labels:\r\n app: echo\r\nspec:\r\n replicas: 1\r\n selector:\r\n matchLabels:\r\n app: echo\r\n template:\r\n metadata:\r\n labels:\r\n app: echo\r\n spec:\r\n containers:\r\n - name: echo\r\n image: putridparrotreg\/putridparrot.echo_service:v1\r\n ports:\r\n - containerPort: 8080\r\n resources:\r\n requests:\r\n memory: "100Mi"\r\n cpu: "100m"\r\n limits:\r\n memory: "200Mi"\r\n cpu: "200m"\r\n livenessProbe:\r\n httpGet:\r\n path: \/livez\r\n port: 8080\r\n initialDelaySeconds: 30\r\n periodSeconds: 10\r\n readinessProbe:\r\n httpGet:\r\n path: \/readyz\r\n port: 8080\r\n initialDelaySeconds: 5\r\n periodSeconds: 5\r\n\r\n---\r\napiVersion: v1\r\nkind: Service\r\nmetadata:\r\n name: echo_service\r\n namespace: dev\r\n labels:\r\n app: echo\r\nspec:\r\n type: ClusterIP\r\n selector:\r\n app: echo \r\n ports:\r\n - name: http\r\n port: 80\r\n targetPort: 8080\r\n protocol: TCP\r\n---\r\napiVersion: networking.k8s.io\/v1\r\nkind: Ingress\r\nmetadata:\r\n name: echo-ingress\r\n namespace: dev\r\n annotations:\r\n kubernetes.io\/ingress.class: "nginx"\r\n nginx.ingress.kubernetes.io\/rewrite-target: \/\r\nspec:\r\n rules:\r\n - host: mydomain.com\r\n http:\r\n paths:\r\n - path: \/\r\n pathType: Prefix\r\n backend:\r\n service:\r\n name: echo_service\r\n port:\r\n number: 80\r\n<\/pre>\n