Checkpoint

admin/admin.go

@@ -0,0 +1,146 @@
+package admin
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"io"
+	"net/http"
+	"os"
+	"strconv"
+	"sync"
+
+	"git.maze.io/maze/styx/dataset"
+	"git.maze.io/maze/styx/logger"
+	"git.maze.io/maze/styx/proxy"
+)
+
+type Admin struct {
+	Storage   dataset.Storage
+	setupOnce sync.Once
+	mux       *http.ServeMux
+	api       *http.ServeMux
+}
+
+type apiError struct {
+	Code int
+	Err  error
+}
+
+func (err apiError) Error() string {
+	return err.Err.Error()
+}
+
+func (a *Admin) setup() {
+	a.mux = http.NewServeMux()
+
+	a.api = http.NewServeMux()
+	a.api.HandleFunc("GET /groups", a.apiGroups)
+	a.api.HandleFunc("POST /group", a.apiGroupCreate)
+	a.api.HandleFunc("GET /group/{id}", a.apiGroup)
+	a.api.HandleFunc("PATCH /group/{id}", a.apiGroupUpdate)
+	a.api.HandleFunc("DELETE /group/{id}", a.apiGroupDelete)
+	a.api.HandleFunc("GET /clients", a.apiClients)
+	a.api.HandleFunc("GET /client/{id}", a.apiClient)
+	a.api.HandleFunc("POST /client", a.apiClientCreate)
+	a.api.HandleFunc("PATCH /client/{id}", a.apiClientUpdate)
+	a.api.HandleFunc("DELETE /client/{id}", a.apiClientDelete)
+	a.api.HandleFunc("GET /lists", a.apiLists)
+	a.api.HandleFunc("POST /list", a.apiListCreate)
+	a.api.HandleFunc("GET /list/{id}", a.apiList)
+	a.api.HandleFunc("DELETE /list/{id}", a.apiListDelete)
+}
+
+type Handler interface {
+	Handle(pattern string, handler http.Handler)
+}
+
+func (a *Admin) Install(handler Handler) {
+	a.setupOnce.Do(a.setup)
+	handler.Handle("/api/v1/", http.StripPrefix("/api/v1", a.api))
+}
+
+func (a *Admin) handleAPIError(w http.ResponseWriter, r *http.Request, err error) {
+	code := http.StatusBadRequest
+	switch {
+	case dataset.IsNotExist(err):
+		code = http.StatusNotFound
+	case os.IsPermission(err):
+		code = http.StatusForbidden
+	case errors.Is(err, apiError{}):
+		if c := err.(apiError).Code; c > 0 {
+			code = c
+		}
+	}
+
+	logger.StandardLog.Err(err).Values(logger.Values{
+		"code":   code,
+		"client": r.RemoteAddr,
+		"method": r.Method,
+		"path":   r.URL.Path,
+	}).Warn("Unexpected API error encountered")
+
+	var data []byte
+	if err, ok := err.(apiError); ok {
+		data, _ = json.Marshal(struct {
+			Code  int    `json:"code"`
+			Error string `json:"error"`
+		}{code, err.Error()})
+	} else {
+		data, _ = json.Marshal(struct {
+			Code  int    `json:"code"`
+			Error string `json:"error"`
+		}{code, http.StatusText(code)})
+	}
+
+	res := proxy.NewResponse(code, io.NopCloser(bytes.NewReader(data)), r)
+	res.Header.Set(proxy.HeaderContentType, "application/json")
+
+	for k, vv := range res.Header {
+		if len(vv) >= 1 {
+			w.Header().Set(k, vv[0])
+			for _, v := range vv[1:] {
+				w.Header().Add(k, v)
+			}
+		}
+	}
+	w.WriteHeader(code)
+	io.Copy(w, res.Body)
+}
+
+func (a *Admin) jsonResponse(w http.ResponseWriter, r *http.Request, value any, codes ...int) {
+	var (
+		code = http.StatusNoContent
+		body io.ReadCloser
+		size int64
+	)
+	if value != nil {
+		data, err := json.Marshal(value)
+		if err != nil {
+			a.handleAPIError(w, r, err)
+			return
+		}
+		code = http.StatusOK
+		body = io.NopCloser(bytes.NewReader(data))
+		size = int64(len(data))
+	}
+	if len(codes) > 0 {
+		code = codes[0]
+	}
+
+	res := proxy.NewResponse(code, body, r)
+	res.Close = true
+	res.Header.Set(proxy.HeaderContentLength, strconv.FormatInt(size, 10))
+	res.Header.Set(proxy.HeaderContentType, "application/json")
+
+	for k, vv := range res.Header {
+		if len(vv) >= 1 {
+			w.Header().Set(k, vv[0])
+			for _, v := range vv[1:] {
+				w.Header().Add(k, v)
+			}
+		}
+	}
+	w.WriteHeader(code)
+	io.Copy(w, res.Body)
+}