initial commit

.gitignore

@@ -0,0 +1,36 @@
+# Compiled Object files, Static and Dynamic libs (Shared Objects)
+*.o
+*.a
+*.so
+
+# Folders
+_obj
+_test
+
+# Architecture specific extensions/prefixes
+*.[568vq]
+[568vq].out
+
+*.cgo1.go
+*.cgo2.c
+_cgo_defun.c
+_cgo_gotypes.go
+_cgo_export.*
+
+_testmain.go
+
+*.exe
+*.test
+*.prof
+
+# Output of the go coverage tool, specifically when used with LiteIDE
+*.out
+*.bin
+
+config.ini
+crossbuild.bat
+safelinks.txt
+
+testfolder/*
+
+deploy.sh

Dockerfile

@@ -0,0 +1,17 @@
+FROM golang:1.14 as builder
+
+WORKDIR /app
+
+COPY go.* ./
+RUN go mod download
+
+COPY . ./
+
+RUN CGO_ENABLED=0 GOOS=linux go build -mod=readonly -v -o server
+
+FROM alpine:3
+RUN apk add --no-cache ca-certificates tzdata
+
+COPY --from=builder /app/server /server
+
+CMD ["/server"]

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2016 Sebastian Stefan Winkler
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

function.go

@@ -0,0 +1,23 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+	"os"
+
+	"github.com/Seklfreak/youtube-opml-exporter/pkg"
+)
+
+func main() {
+	http.HandleFunc("/", pkg.ExportHandler)
+	http.HandleFunc("/login", pkg.LoginHandler)
+	http.HandleFunc("/exchange", pkg.ExchangeHandler)
+
+	port := os.Getenv("PORT")
+	if port == "" {
+		port = "8080"
+	}
+
+	log.Fatal(http.ListenAndServe(fmt.Sprintf(":%s", port), nil))
+}

go.mod

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+module github.com/Seklfreak/youtube-opml-exporter
+
+go 1.14
+
+require (
+	cloud.google.com/go v0.54.0 // indirect
+	github.com/kelseyhightower/envconfig v1.4.0
+	go.uber.org/zap v1.14.0
+	golang.org/x/oauth2 v0.0.0-20200107190931-bf48bf16ab8d
+	google.golang.org/api v0.20.0
+	google.golang.org/genproto v0.0.0-20200306153348-d950eab6f860 // indirect
+)

pkg/common.go

@@ -0,0 +1,70 @@
+package pkg
+
+import (
+	"errors"
+	"net/http"
+	"time"
+
+	"github.com/kelseyhightower/envconfig"
+	"go.uber.org/zap"
+	"golang.org/x/oauth2"
+	"google.golang.org/api/option"
+	"google.golang.org/api/youtube/v3"
+)
+
+type config struct {
+	GoogleClientID     string `envconfig:"GOOGLE_CLIENT_ID" required:"true"`
+	GoogleClientSecret string `envconfig:"GOOGLE_CLIENT_SECRET" required:"true"`
+}
+
+var (
+	logger *zap.Logger
+
+	cfg config
+
+	oauthConfig = &oauth2.Config{
+		ClientID:     "", // filled by config
+		ClientSecret: "", // filled by config
+		Endpoint: oauth2.Endpoint{
+			AuthURL:  "https://accounts.google.com/o/oauth2/auth",
+			TokenURL: "https://oauth2.googleapis.com/token",
+		},
+		RedirectURL: "urn:ietf:wg:oauth:2.0:oob",
+		Scopes:      []string{youtube.YoutubeReadonlyScope},
+	}
+)
+
+func init() {
+	var err error
+
+	logger, err = zap.NewProduction()
+	if err != nil {
+		panic(err)
+	}
+
+	err = envconfig.Process("", &cfg)
+	if err != nil {
+		logger.Fatal("failure reading config", zap.Error(err))
+	}
+
+	oauthConfig.ClientID = cfg.GoogleClientID
+	oauthConfig.ClientSecret = cfg.GoogleClientSecret
+}
+
+func ytServiceViaBasicAuth(r *http.Request) (*youtube.Service, error) {
+	_, password, ok := r.BasicAuth()
+	if !ok || password == "" {
+		return nil, errors.New("please provide refresh token")
+	}
+
+	oauthToken := &oauth2.Token{
+		Expiry:       time.Now(),
+		TokenType:    "Bearer",
+		RefreshToken: password,
+	}
+
+	return youtube.NewService(
+		r.Context(),
+		option.WithTokenSource(oauthConfig.TokenSource(r.Context(), oauthToken)),
+	)
+}

pkg/exchange.go

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+package pkg
+
+import (
+	"fmt"
+	"net/http"
+)
+
+func ExchangeHandler(w http.ResponseWriter, r *http.Request) {
+	token, err := oauthConfig.Exchange(r.Context(), r.URL.Query().Get("token"))
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
+	w.Header().Set("X-Content-Type-Options", "nosniff")
+	fmt.Fprintf(w, "Refresh Token: %s", token.RefreshToken)
+}

pkg/feed.go

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+package pkg
+
+import (
+	"fmt"
+	"net/http"
+
+	"go.uber.org/zap"
+	"google.golang.org/api/youtube/v3"
+)
+
+const (
+	documentFmt string = `
+<opml version="1.1">
+    <body>
+        <outline text="YouTube Subscriptions" title="YouTube Subscriptions">
+%s
+        </outline>
+    </body>
+</opml>
+`
+	itemFmt string = `
+            <outline text="%s" title="%s" type="rss"
+                     xmlUrl="https://www.youtube.com/feeds/videos.xml?channel_id=%s"/>
+`
+)
+
+func ExportHandler(w http.ResponseWriter, r *http.Request) {
+	yt, err := ytServiceViaBasicAuth(r)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusUnauthorized)
+		return
+	}
+
+	var items []*youtube.Subscription
+
+	var pageToken string
+	for {
+		logger.Info("making YouTube API request", zap.String("page_token", pageToken))
+
+		resp, err := yt.Subscriptions.
+			List("snippet").
+			MaxResults(50).
+			Order("alphabetical").
+			Mine(true).
+			PageToken(pageToken).
+			Do()
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+
+		items = append(items, resp.Items...)
+
+		pageToken = resp.NextPageToken
+		if resp.NextPageToken == "" {
+			break
+		}
+	}
+
+	logger.Info("found items", zap.Int("amount", len(items)))
+
+	var result string
+	for _, item := range items {
+		if item == nil || item.Snippet == nil || item.Snippet.ResourceId == nil ||
+			item.Snippet.ResourceId.ChannelId == "" {
+			logger.Warn("skipping item because it does not have all required fields", zap.Any("item", item))
+			continue
+		}
+
+		result += fmt.Sprintf(itemFmt, item.Snippet.Title, item.Snippet.Title, item.Snippet.ResourceId.ChannelId)
+	}
+
+	result = fmt.Sprintf(documentFmt, result)
+
+	w.Header().Set("Content-Type", "application/xml")
+	fmt.Fprint(w, result)
+}

pkg/login.go

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+package pkg
+
+import (
+	"net/http"
+
+	"golang.org/x/oauth2"
+)
+
+func LoginHandler(w http.ResponseWriter, r *http.Request) {
+	authURL := oauthConfig.AuthCodeURL("state-token", oauth2.AccessTypeOffline)
+
+	http.Redirect(w, r, authURL, http.StatusFound)
+}