feat: option to run github-notifier as a daemon that you call

Dockerfile

@@ -15,4 +15,5 @@ FROM scratch
 COPY --from=builder /go/bin/ci-github-notifier /go/bin/ci-github-notifier
 COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
 
+EXPOSE 8080
 ENTRYPOINT ["/go/bin/ci-github-notifier"]

README.md

@@ -66,3 +66,6 @@ docker run \
 
 # Argo Workflows example
 A simple Argo Workflows template can be found in the examples directory.
+
+# Run as a daemon
+You may wish to run as a permanent service in your Kubernetes cluster and then call the service using curl or similar to send your message. An example of how to do this can be found in the examples directory.

ci-github-notifier/main.go

@@ -2,44 +2,103 @@ package main
 
 import (
 	"encoding/json"
-	"fmt"
 	"github.com/imroc/req"
-	"io/ioutil"
-	"log"
-	"os"
+	"strings"
+    "flag"
+    "fmt"
+    "log"
+    "net/http"
+    "os"
 )
 
 func main() {
-	fmt.Printf("Notifiying Github: %s:%s\n", getValidatedEnvVar("context"), getValidatedEnvVar("state"))
+	var webServerModeFlag = flag.Bool("webServerMode", false, "Run in web server (daemon service) mode")
+	flag.Parse()
 
-	header := req.Header{
-		"Authorization": fmt.Sprintf("token %s", getToken(os.Getenv("tokenFile"), "access_token")),
-	}
+    // Flag can be overridden by environment variable
+    webServerModeEnv := strings.ToLower(os.Getenv("WEBSERVER_MODE")) == "true"
 
-	values := map[string]string{"state": getValidatedEnvVar("state"), "target_url": getValidatedEnvVar("target_url"), "description": getValidatedEnvVar("description"), "context": getValidatedEnvVar("context")}
-	jsonData, err := json.Marshal(values)
+    // Determine web server mode by combining the flag and the environment variable
+    webServerMode := *webServerModeFlag || webServerModeEnv
 
-	r, err := req.Post(fmt.Sprintf("https://%s/repos/%s/%s/statuses/%s", getUrl("gh_url", "api.github.com"), getValidatedEnvVar("organisation"), getValidatedEnvVar("app_repo"), getValidatedEnvVar("git_sha")), header, req.BodyJSON(jsonData))
+    if webServerMode {
+		fmt.Println("Running in web server mode")
+        startWebServer()
+    } else {
+		fmt.Println("Running in standalone mode")
+        notifyGitHub(nil, nil)
+    }
+}
 
-	if err != nil {
-		log.Fatal(err)
-	}
-	resp := r.Response()
-	fmt.Println("HTTP response from github:", resp.StatusCode)
+func startWebServer() {
+    http.HandleFunc("/notify", func(w http.ResponseWriter, r *http.Request) {
+		notifyGitHub(w, r)
+	})
+    fmt.Println("Server is listening on :8080")
+    log.Fatal(http.ListenAndServe(":8080", nil))
+}
+
+func notifyGitHub(w http.ResponseWriter, r *http.Request) {
+    // Helper function to get parameter value: first tries URL query, then falls back to environment variable.
+    getParamValue := func(paramName, envVarName string) string {
+        if r != nil { // Check if http.Request is available
+            values := r.URL.Query()
+            if value, found := values[paramName]; found && len(value) > 0 {
+                return value[0]
+            }
+        }
+        return getValidatedEnvVar(envVarName)
+    }
+
+    // Parameters
+    state := getParamValue("state", "state")
+    targetURL := getParamValue("target_url", "target_url")
+    description := getParamValue("description", "description")
+    context := getParamValue("context", "context")
+    organisation := getParamValue("organisation", "organisation")
+    appRepo := getParamValue("app_repo", "app_repo")
+    gitSha := getParamValue("git_sha", "git_sha")
+    ghURL := getParamValue("gh_url", "gh_url")
+
+    // Notification logic
+    fmt.Printf("Notifying Github: %s:%s\n", context, state)
+
+    header := req.Header{
+        "Authorization": fmt.Sprintf("token %s", getToken(os.Getenv("tokenFile"), "access_token")),
+    }
+
+    values := map[string]string{"state": state, "target_url": targetURL, "description": description, "context": context}
+    jsonData, err := json.Marshal(values)
+
+    resp, err := req.Post(fmt.Sprintf("https://%s/repos/%s/%s/statuses/%s", getUrl(ghURL, "api.github.com"), organisation, appRepo, gitSha), header, req.BodyJSON(jsonData))
+    if err != nil {
+        if w != nil { // Check if http.ResponseWriter is available
+            http.Error(w, err.Error(), http.StatusInternalServerError)
+        } else {
+            fmt.Println("Error notifying GitHub:", err)
+        }
+        return
+    }
+
+    httpResponse := resp.Response()
+    if w != nil {
+        fmt.Fprintf(w, "HTTP response from github: %d", httpResponse.StatusCode)
+    } else {
+        fmt.Printf("HTTP response from github: %d\n", httpResponse.StatusCode)
+    }
 }
 
 func getValidatedEnvVar(e string) string {
-	c := os.Getenv(e)
-	if os.Getenv(e) == "" {
-		fmt.Printf("Error: No environment variable called %s available. Exiting.\n", e)
-		os.Exit(1)
-	}
-	return c
+    c := os.Getenv(e)
+    if os.Getenv(e) == "" {
+        log.Fatalf("Error: No environment variable called %s available. Exiting.\n", e)
+    }
+    return c
 }
 
 func getToken(f string, e string) string {
 	if os.Getenv(e) == "" {
-		data, err := ioutil.ReadFile(f)
+		data, err := os.ReadFile(f)
 		if err != nil {
 			fmt.Println("No tokenFile found. Falling back to Environment Variable")
 		}
@@ -50,8 +109,8 @@ func getToken(f string, e string) string {
 }
 
 func getUrl(e, fallback string) string {
-	if value, ok := os.LookupEnv(e); ok {
-		return value
-	}
-	return fallback
+    if value, ok := os.LookupEnv(e); ok {
+        return value
+    }
+    return fallback
 }

examples/daemon-deployment/README.md

@@ -0,0 +1,8 @@
+# Web server mode (daemon) deployment
+
+This example demonstrates how to deploy the CI GitHub Notifier in web server mode (daemon) in Kubernetes. You deploy the CI GitHub Notifier as a Kubernetes Deployment and expose it as a Kubernetes Service. Then you can call it from other services in the same Kubernetes cluster (eg a running Argo Workflow).
+
+Call it with:
+```bash
+curl http://localhost:8080/notify?state=success&target_url=http%3A%2F%2Fexample.com&description=Deployment+successful&context=deployment&tokenFile=/path/to/tokenfile&organisation=myorg&app_repo=myrepo&git_sha=abc123&gh_url=api.github.com
+```

examples/daemon-deployment/argo-workflow.yaml

@@ -0,0 +1,40 @@
+apiVersion: argoproj.io/v1alpha1
+kind: Workflow
+metadata:
+  generateName: ci-github-notifier-example-
+spec:
+  entrypoint: main
+  serviceAccountName: valid-sa-name-here #https://argo-workflows.readthedocs.io/en/latest/http-template/#argo-agent
+  templates:
+    - name: main
+      dag:
+        tasks:
+          - name: post-pending
+            template: ci-github-notifier
+            arguments:
+              parameters:
+                - name: base_url
+                  value: "http://ci-github-notifier.ci-github-notifier.svc.cluster.local:8080/notify"
+                - name: git_sha
+                  value: "12345"
+                - name: state
+                  value: "pending"
+                - name: context
+                  value: "UI Checks"
+                - name: description
+                  value: "In progress — This check has started..."
+                - name: target_url
+                  value: "https://pipekit.io/"
+
+    - name: ci-github-notifier
+      inputs:
+        parameters:
+          - name: base_url
+          - name: git_sha
+          - name: state
+          - name: context
+          - name: description
+          - name: target_url
+      http:
+        url: "{{inputs.parameters.base_url}}?app_repo=foo&organisation=bar&git_sha={{inputs.parameters.git_sha}}&state={{inputs.parameters.state}}&context={{inputs.parameters.context}}&description={{inputs.parameters.description}}&target_url={{inputs.parameters.target_url}}"
+        successCondition: "response.body contains \"200\""

examples/daemon-deployment/deployment.yaml

@@ -0,0 +1,76 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  labels:
+    app: ci-github-notifier
+  name: ci-github-notifier
+spec:
+  replicas: 2
+  strategy:
+    type: RollingUpdate
+    rollingUpdate:
+      maxUnavailable: 1
+  selector:
+    matchLabels:
+      app: ci-github-notifier
+  template:
+    metadata:
+      labels:
+        app: ci-github-notifier
+    spec:
+      containers:
+      - image: ghcr.io/crumbhole/ci-github-notifier
+        imagePullPolicy: Always
+        name: ci-github-notifier
+        ports:
+        - containerPort: 8080
+          name: http
+          protocol: TCP
+        resources:
+          requests:
+            memory: 20Mi
+            cpu: 10m
+        env:
+        - name: WEBSERVER_MODE
+          value: "true"
+        - name: access_token
+          valueFrom:
+            secretKeyRef:
+              name: ci-github-notifier-access-token
+              key: access_token
+      affinity:
+        podAntiAffinity:
+          preferredDuringSchedulingIgnoredDuringExecution:
+          - weight: 100
+            podAffinityTerm:
+              labelSelector:
+                matchExpressions:
+                - key: "app"
+                  operator: In
+                  values:
+                  - ci-github-notifier
+              topologyKey: "topology.kubernetes.io/zone"
+---
+apiVersion: v1
+kind: Secret
+metadata:
+  name: ci-github-notifier-access-token
+type: Opaque
+data:
+  access_token: <base64 encoded access token>
+---
+apiVersion: v1
+kind: Service
+metadata:
+  labels:
+    app: ci-github-notifier
+  name: ci-github-notifier
+spec:
+  ports:
+  - name: ci-github-notifier
+    port: 8080
+    protocol: TCP
+    targetPort: 8080
+  selector:
+    app: ci-github-notifier
+  type: ClusterIP