commit 9ad0b6828ff3169ac79753405512cdafee924b2d Author: nmasse Date: Mon Feb 7 09:53:54 2022 +0000 initial commit diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..c8006ba --- /dev/null +++ b/.gitignore @@ -0,0 +1,3 @@ +golang-health-check +__debug_bin +bindata.go diff --git a/.openshiftio/application.yaml b/.openshiftio/application.yaml new file mode 100644 index 0000000..aea86f5 --- /dev/null +++ b/.openshiftio/application.yaml @@ -0,0 +1,158 @@ +apiVersion: v1 +kind: Template +metadata: + name: launchpad-builder + annotations: + description: This template creates a Build Configuration using an S2I builder. + tags: instant-app +parameters: + - name: SUFFIX_NAME + description: The suffix name for the template objects + displayName: Suffix name + value: '' + - name: RELEASE_VERSION + description: The release version number of application + displayName: Release version + value: 1.0.0 + - name: SOURCE_REPOSITORY_URL + description: The source URL for the application + displayName: Source URL + required: true + - name: SOURCE_REPOSITORY_REF + description: The branch name for the application + displayName: Source Branch + value: master + required: true +objects: + - apiVersion: image.openshift.io/v1 + kind: ImageStream + metadata: + name: 'golang-health-check${SUFFIX_NAME}' + labels: + version: '${RELEASE_VERSION}' + app: golang-health-check + spec: {} + - apiVersion: v1 + kind: BuildConfig + metadata: + name: 'golang-health-check-s2i${SUFFIX_NAME}' + labels: + app: golang-health-check + version: '${RELEASE_VERSION}' + spec: + output: + to: + kind: ImageStreamTag + name: 'golang-health-check${SUFFIX_NAME}:${RELEASE_VERSION}' + postCommit: {} + resources: {} + source: + git: + uri: '${SOURCE_REPOSITORY_URL}' + ref: '${SOURCE_REPOSITORY_REF}' + type: Git + strategy: + type: Source + sourceStrategy: + from: + kind: DockerImage + name: 'registry.fedoraproject.org/f29/golang' + incremental: true + status: + lastVersion: 0 + - apiVersion: v1 + kind: Service + spec: + ports: + - protocol: TCP + port: 8080 + targetPort: 8080 + type: ClusterIP + selector: + project: golang-health-check + provider: golang-starters + metadata: + name: 'golang-health-check${SUFFIX_NAME}' + labels: + app: golang-health-check + provider: golang-starters + expose: 'true' + project: golang-health-check + version: '${RELEASE_VERSION}' + - apiVersion: v1 + kind: DeploymentConfig + metadata: + name: 'golang-health-check${SUFFIX_NAME}' + labels: + app: golang-health-check + provider: golang-starters + project: golang-health-check + version: '${RELEASE_VERSION}' + spec: + template: + spec: + containers: + - readinessProbe: + httpGet: + path: /api/health + port: 8080 + scheme: HTTP + failureThreshold: 3 + initialDelaySeconds: 10 + periodSeconds: 5 + successThreshold: 1 + timeoutSeconds: 1 + livenessProbe: + httpGet: + path: /api/health + port: 8080 + scheme: HTTP + failureThreshold: 2 + initialDelaySeconds: 60 + periodSeconds: 3 + successThreshold: 1 + timeoutSeconds: 1 + image: '' + name: golang-health-check + securityContext: + privileged: false + ports: + - containerPort: 8080 + name: http + protocol: TCP + metadata: + labels: + app: golang-health-check + project: golang-health-check + provider: golang-starters + version: '${RELEASE_VERSION}' + replicas: 1 + selector: + app: golang-health-check + project: golang-health-check + provider: golang-starters + triggers: + - type: ConfigChange + - type: ImageChange + imageChangeParams: + automatic: true + containerNames: + - golang-health-check + from: + kind: ImageStreamTag + name: 'golang-health-check${SUFFIX_NAME}:${RELEASE_VERSION}' + - apiVersion: v1 + kind: Route + metadata: + labels: + app: golang-health-check + project: golang-health-check + provider: golang-starters + version: '${RELEASE_VERSION}' + name: 'golang-health-check${SUFFIX_NAME}' + spec: + port: + targetPort: 8080 + to: + kind: Service + name: 'golang-health-check${SUFFIX_NAME}' diff --git a/.theia/launch.json b/.theia/launch.json new file mode 100644 index 0000000..f36b195 --- /dev/null +++ b/.theia/launch.json @@ -0,0 +1,13 @@ +{ + "version": "0.2.0", + "configurations": [ + + { + "name": "Debug current file", + "type": "go", + "request": "launch", + "mode": "auto", + "program": "${fileDirname}" + } +] +} diff --git a/LICENSE b/LICENSE new file mode 100644 index 0000000..261eeb9 --- /dev/null +++ b/LICENSE @@ -0,0 +1,201 @@ + Apache License + Version 2.0, January 2004 + http://www.apache.org/licenses/ + + TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION + + 1. 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We also recommend that a + file or class name and description of purpose be included on the + same "printed page" as the copyright notice for easier + identification within third-party archives. + + Copyright [yyyy] [name of copyright owner] + + 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. diff --git a/README.md b/README.md new file mode 100644 index 0000000..1cd96d2 --- /dev/null +++ b/README.md @@ -0,0 +1,16 @@ +# Golang Health Check +A booster demonstrating health checks and recovery using the kubernetes/openshift +`liveliness` and `readiness` probes. + + +# How to run +The project uses openshift s2i to build docker image. Run the following command +to build the docker image + +```s2i build . registry.fedoraproject.org/f29/golang golang-health-check``` + +To start the web service, run + +```docker run -p 8080:8080 golang-health-check``` + +The web service should now be accessible on `http://localhost:8080` diff --git a/go.mod b/go.mod new file mode 100644 index 0000000..bcbd56a --- /dev/null +++ b/go.mod @@ -0,0 +1,3 @@ +module github.com/golang-starters/golang-health-check + +require github.com/elazarl/go-bindata-assetfs v1.0.0 diff --git a/go.sum b/go.sum new file mode 100644 index 0000000..32c6846 --- /dev/null +++ b/go.sum @@ -0,0 +1,2 @@ +github.com/elazarl/go-bindata-assetfs v1.0.0 h1:G/bYguwHIzWq9ZoyUQqrjTmJbbYn3j3CKKpKinvZLFk= +github.com/elazarl/go-bindata-assetfs v1.0.0/go.mod h1:v+YaWX3bdea5J/mo8dSETolEo7R71Vk1u8bnjau5yw4= diff --git a/main.go b/main.go new file mode 100644 index 0000000..14b55d9 --- /dev/null +++ b/main.go @@ -0,0 +1,45 @@ +package main + +import ( + "fmt" + "log" + "net/http" +) + +var isOnline = true + +func main() { + http.HandleFunc("/api/greeting", greeting) + http.HandleFunc("/api/stop", stop) + http.HandleFunc("/api/health", health) + http.Handle("/", http.FileServer(assetFS())) + fmt.Println("Web server running on port 8080") + + log.Fatal(http.ListenAndServe(":8080", nil)) +} + +func greeting(w http.ResponseWriter, r *http.Request) { + if isOnline { + message := "World" + if m := r.FormValue("name"); m != "" { + message = m + } + fmt.Fprintf(w, "Hello %s!", message) + return + } + w.WriteHeader(503) + w.Write([]byte("Not Online")) +} + +func stop(w http.ResponseWriter, r *http.Request) { + isOnline = false + w.Write([]byte("Stopping HTTP Server")) +} + +func health(w http.ResponseWriter, r *http.Request) { + if isOnline { + w.WriteHeader(200) + return + } + w.WriteHeader(500) +} diff --git a/public/index.html b/public/index.html new file mode 100644 index 0000000..903f89f --- /dev/null +++ b/public/index.html @@ -0,0 +1,102 @@ + + + + Health Check Mission - Golang + + + + +
+
+
+

Health Check Booster

+
+
+

Demonstrates how the Kubernetes/Openshift health checks work to determine if a container is still alive (the liveness + of the container) and ready to serve the traffic for the HTTP endpoints of the application (the readiness + of the container).

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+

To demonstrate this behavior, the application configures a /health HTTP endpoint, which is + used + by Kubernetes/Openshift to issue HTTP requests. If the container is still alive—​which means the Health HTTP + endpoint + is able to reply—​the management platform will receive HTTP code 200 as a response, and no further action + is taken. After you click the + Stop Service button, the HTTP endpoint starts + returning a 500 response, and the platform then + restarts + the pod with the failed container. While the pod is down, the booster UI polls the service + periodically + until the pod is restarted. In the meantime, do not refresh the page because it will + not be served until the pod finishes restarting.

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+

Using the greeting service

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+ +
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+ + +
+ + +
+ +

Result:

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Invoke the service to see the result.
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+
+ + + + + + + \ No newline at end of file