feat: handler for HTTP requests

network.go

@@ -0,0 +1,66 @@
+package manifesto
+
+import (
+	"bytes"
+	"encoding/json"
+	"net/http"
+)
+
+const (
+	headerContentType = "Content-Type"
+	headerUserAgent   = "User-Agent"
+
+	mimeJson = "application/json"
+	mimeText = "plain/text"
+)
+
+// HandleManifest adds a POST endpoint for the given path and spec/status types.
+func HandleManifest(path string, pool *Pool, spec any, status any) {
+	http.HandleFunc(path, func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodPost {
+			w.WriteHeader(http.StatusMethodNotAllowed)
+			w.Write([]byte("this endpoint only allows POST requests"))
+			return
+		}
+
+		manifest := ParseReader(r.Body, spec, status)
+		pool.Apply(*manifest)
+
+		b, err := json.Marshal(manifest)
+		if err != nil {
+			w.Header().Add(headerContentType, mimeText)
+			w.WriteHeader(http.StatusInternalServerError)
+			w.Write([]byte(err.Error()))
+			return
+		} else {
+			w.Header().Add(headerContentType, mimeJson)
+			w.WriteHeader(http.StatusOK)
+			w.Write(b)
+			return
+		}
+	})
+}
+
+// SendManifest sends a manifest to a given endpoint (blocking) and returns the new manifest.
+func SendManifestSilent(endpoint string, manifest *Manifest, userAgent string) (*Manifest, error) {
+	b, err := json.Marshal(manifest)
+	if err != nil {
+		return nil, err
+	}
+
+	req, err := http.NewRequest(http.MethodPost, endpoint+"/"+manifest.ApiVersion+"/"+manifest.Kind, bytes.NewBuffer(b))
+	if err != nil {
+		return nil, err
+	}
+
+	req.Header.Set(headerContentType, mimeJson)
+	req.Header.Set(headerUserAgent, userAgent)
+
+	res, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return nil, err
+	}
+
+	defer res.Body.Close()
+	return ParseReader(res.Body, manifest.Spec, manifest.Status), nil
+}