downloads API, UI

cmd/dkl-local-server/ws-downloads.go

@@ -0,0 +1,150 @@
+package main
+
+import (
+	"crypto/rand"
+	"encoding/base32"
+	"log"
+	"net/http"
+	"strconv"
+	"time"
+
+	restful "github.com/emicklei/go-restful"
+	"m.cluseau.fr/go/cow"
+)
+
+type DownloadSpec struct {
+	Kind   string
+	Name   string
+	Assets []string
+
+	createdAt time.Time
+}
+
+func wsAuthorizeDownload(req *restful.Request, resp *restful.Response) {
+	var spec DownloadSpec
+
+	if err := req.ReadEntity(&spec); err != nil {
+		wsError(resp, err)
+		return
+	}
+
+	if spec.Kind == "" || spec.Name == "" || len(spec.Assets) == 0 {
+		resp.WriteErrorString(http.StatusBadRequest, "missing data")
+		return
+	}
+
+	randBytes := make([]byte, 32)
+	_, err := rand.Read(randBytes)
+	if err != nil {
+		wsError(resp, err)
+		return
+	}
+
+	token := base32.StdEncoding.WithPadding(base32.NoPadding).EncodeToString(randBytes)
+
+	spec.createdAt = time.Now()
+
+	wState.Change(func(v *State) {
+		cow.MapSet(&v.Downloads, token, spec)
+	})
+
+	log.Printf("download token created for %s %q, assets %q", spec.Kind, spec.Name, spec.Assets)
+
+	resp.WriteAsJson(token)
+}
+
+func wsDownload(req *restful.Request, resp *restful.Response) {
+	token := req.PathParameter("token")
+	asset := req.PathParameter("asset")
+
+	if token == "" || asset == "" {
+		wsNotFound(req, resp)
+		return
+	}
+
+	var spec DownloadSpec
+	found := false
+	wState.Change(func(v *State) {
+		var ok bool
+		spec, ok = v.Downloads[token]
+		if !ok {
+			return
+		}
+
+		newAssets := make([]string, 0, len(spec.Assets))
+		for _, a := range spec.Assets {
+			if a == asset {
+				found = true
+			} else {
+				newAssets = append(newAssets, a)
+			}
+		}
+
+		if !found {
+			return
+		}
+
+		cow.Map(&v.Downloads)
+
+		if len(newAssets) == 0 {
+			delete(v.Downloads, token)
+		} else {
+			spec.Assets = newAssets
+			v.Downloads[token] = spec
+		}
+	})
+
+	if !found {
+		wsNotFound(req, resp)
+		return
+	}
+
+	log.Printf("download via token %q", token)
+
+	cfg, err := readConfig()
+	if err != nil {
+		wsError(resp, err)
+		return
+	}
+
+	setHeader := func(ext string) {
+		resp.AddHeader("Content-Disposition", "attachment; filename="+strconv.Quote(spec.Kind+"_"+spec.Name+"_"+asset+ext))
+	}
+
+	switch spec.Kind {
+	case "cluster":
+		cluster := cfg.ClusterByName(spec.Name)
+		if cluster == nil {
+			wsNotFound(req, resp)
+			return
+		}
+
+		switch asset {
+		case "addons":
+			setHeader(".yaml")
+			resp.Write([]byte(cluster.Addons))
+
+		default:
+			wsNotFound(req, resp)
+		}
+
+	case "host":
+		host := cfg.Host(spec.Name)
+		if host == nil {
+			wsNotFound(req, resp)
+			return
+		}
+
+		switch asset {
+		case "config", "bootstrap-config":
+			setHeader(".yaml")
+		default:
+			setHeader("")
+		}
+
+		renderHost(resp.ResponseWriter, req.Request, asset, host, cfg)
+
+	default:
+		wsNotFound(req, resp)
+	}
+}