Test

knative/helloworld.yaml → knative/picalc2.yaml

@@ -1,7 +1,7 @@
 apiVersion: serving.knative.dev/v1alpha1
 kind: Service
 metadata:
-  name: helloworld
+  name: picalc2
   namespace: default
 spec:
   runLatest:

src/Dockerfile

@@ -5,25 +5,24 @@ FROM golang:1.12 as builder
 
 # Copy local code to the container image.
 WORKDIR /go/src/github.com/bluebosh/knap-example
-COPY helloworld.go helloworld_test.go .
+COPY picalc2.go picalc2_test.go .
 
 # Run unit tests
 RUN CGO_ENABLED=0 GOOS=linux go test
 
 # Build the code inside the container.
-RUN CGO_ENABLED=0 GOOS=linux go build -v -o helloworld
+RUN CGO_ENABLED=0 GOOS=linux go build -v -o picalc2
 
 # Use a Docker multi-stage build to create a lean production image.
 # https://docs.docker.com/develop/develop-images/multistage-build/#use-multi-stage-builds
 FROM alpine
 
 # Copy the binary to the production image from the builder stage.
-COPY --from=builder /go/src/github.com/bluebosh/knap-example /helloworld
-RUN chmod a+x /helloworld/*
+COPY --from=builder /go/src/github.com/bluebosh/knap-example /picalc2
 
 # Service must listen to $PORT environment variable.
 # This default value facilitates local development.
 ENV PORT 8080
 
 # Run the web service on container startup.
-CMD ["/helloworld"]
+CMD ["/picalc2"]

src/picalc2.go

@@ -0,0 +1,45 @@
+package main
+
+import (
+    "fmt"
+    "log"
+    "net/http"
+    "os"
+    "strconv"
+)
+
+// Calculate pi using Gregory-Leibniz series:   (4/1) - (4/3) + (4/5) - (4/7) + (4/9) - (4/11) + (4/13) - (4/15) ...
+func calculatePi(iterations int) float64 {
+    var result float64 = 0.0
+    var sign float64 = 1.0
+    var denominator float64 = 1.0
+    for i := 0; i < iterations; i++ {
+        result = result + (sign * 4/denominator)
+        denominator = denominator + 2
+        sign = -sign
+    }
+    return result
+}
+
+func handler(w http.ResponseWriter, r *http.Request) {
+    log.Print("Pi calculator received a request.")
+    iterations, err := strconv.Atoi(r.URL.Query()["iterations"][0])
+    if err != nil {
+        fmt.Fprintf(w, "iterations parameter not valid\n")
+        return
+    }
+    fmt.Fprintf(w, "%.10f\n", calculatePi(iterations))
+}
+
+func main() {
+    log.Print("Pi calculator started.")
+
+    http.HandleFunc("/", handler)
+
+    port := os.Getenv("PORT")
+    if port == "" {
+        port = "8080"
+    }
+
+    log.Fatal(http.ListenAndServe(fmt.Sprintf(":%s", port), nil))
+}

src/picalc2_test.go

@@ -0,0 +1,11 @@
+package main
+
+import "testing"
+
+func TestCalculatePi(t *testing.T) {
+    var pi float64
+    pi = calculatePi(20000000)
+    if pi < 3.1415926 || pi >= 3.1415927 {
+       t.Errorf("Value %.10f is incorrect", pi)
+    }
+}