build(dockerfile): explicitly disable cgo

Dockerfile

@@ -1,10 +1,14 @@
 # Build the application from source.
 FROM golang:1.22.0-alpine@sha256:8e96e6cff6a388c2f70f5f662b64120941fcd7d4b89d62fec87520323a316bd9 AS go-builder
 
-ENV GOCACHE="/cache/go-build"
-
 WORKDIR /app
 
+ENV \
+    # Maunt as dedicated RUN cache.
+    GOCACHE="/cache/go-build" \
+    # Disable CGO to build a static binary.
+    CGO_ENABLED=0
+
 COPY go.mod go.sum cmd ./
 RUN --mount=type=cache,target=${GOCACHE} \
     go build -o /app/dist/deadnews-template-go ./...

cmd/deadnews-template-go/main.go

@@ -52,7 +52,7 @@ func makeServer() *echo.Echo {
 
 // handleRoot handles the "/" route and returns an HTML response.
 func handleRoot(c echo.Context) error {
-	return c.HTML(http.StatusOK, "Hello, World!")
+	return c.HTML(http.StatusOK, "Hello, World!\n")
 }
 
 // handleHealth handles the "/health" route and returns a JSON response.

cmd/deadnews-template-go/main_test.go

@@ -33,7 +33,7 @@ func TestServerResponseRoot(t *testing.T) {
 	assert.Equal(t, expectedStatus, rec.Code)
 
 	// Check the actual response body against the expected response body.
-	expectedBody := "Hello, World!"
+	expectedBody := "Hello, World!\n"
 	assert.Equal(t, expectedBody, rec.Body.String())
 
 	// Check the response content type header.