add api endpoints for pow and mailinglist, plus some framework improvements

srv/.gitignore

@@ -0,0 +1 @@
+mailinglist.sqlite3

srv/cmd/mediocre-blog/api.go

@@ -1,24 +0,0 @@
-package main
-
-import (
-	"encoding/json"
-	"log"
-	"net/http"
-)
-
-func internalServerError(rw http.ResponseWriter, r *http.Request, err error) {
-	http.Error(rw, "internal server error", 500)
-	log.Printf("%s %s: internal server error: %v", r.Method, r.URL, err)
-}
-
-func jsonResult(rw http.ResponseWriter, r *http.Request, v interface{}) {
-	b, err := json.Marshal(v)
-	if err != nil {
-		internalServerError(rw, r, err)
-		return
-	}
-	b = append(b, '\n')
-
-	rw.Header().Set("Content-Type", "application/json")
-	rw.Write(b)
-}

srv/cmd/mediocre-blog/mailinglist.go

@@ -0,0 +1,67 @@
+package main
+
+import (
+	"errors"
+	"net/http"
+	"strings"
+
+	"github.com/mediocregopher/blog.mediocregopher.com/srv/mailinglist"
+)
+
+func mailingListSubscribeHandler(ml mailinglist.MailingList) http.Handler {
+	return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
+		email := r.PostFormValue("email")
+		if parts := strings.Split(email, "@"); len(parts) != 2 ||
+			parts[0] == "" ||
+			parts[1] == "" ||
+			len(email) >= 512 {
+			badRequest(rw, r, errors.New("invalid email"))
+		}
+
+		if err := ml.BeginSubscription(email); errors.Is(err, mailinglist.ErrAlreadyVerified) {
+			// just eat the error, make it look to the user like the
+			// verification email was sent.
+		} else if err != nil {
+			internalServerError(rw, r, err)
+		}
+	})
+}
+
+func mailingListFinalizeHandler(ml mailinglist.MailingList) http.Handler {
+	return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
+		subToken := r.PostFormValue("subToken")
+		if l := len(subToken); l == 0 || l > 128 {
+			badRequest(rw, r, errors.New("invalid subToken"))
+			return
+		}
+
+		err := ml.FinalizeSubscription(subToken)
+		if errors.Is(err, mailinglist.ErrNotFound) ||
+			errors.Is(err, mailinglist.ErrAlreadyVerified) {
+			badRequest(rw, r, err)
+			return
+		} else if err != nil {
+			internalServerError(rw, r, err)
+			return
+		}
+	})
+}
+
+func mailingListUnsubscribeHandler(ml mailinglist.MailingList) http.Handler {
+	return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
+		unsubToken := r.PostFormValue("unsubToken")
+		if l := len(unsubToken); l == 0 || l > 128 {
+			badRequest(rw, r, errors.New("invalid unsubToken"))
+			return
+		}
+
+		err := ml.Unsubscribe(unsubToken)
+		if errors.Is(err, mailinglist.ErrNotFound) {
+			badRequest(rw, r, err)
+			return
+		} else if err != nil {
+			internalServerError(rw, r, err)
+			return
+		}
+	})
+}

srv/cmd/mediocre-blog/main.go

@@ -1,58 +1,140 @@
 package main
 
 import (
+	"context"
 	"flag"
-	"log"
+	"fmt"
 	"net/http"
+	"path"
 	"strconv"
+	"strings"
 
+	"github.com/emersion/go-sasl"
+	"github.com/mediocregopher/blog.mediocregopher.com/srv/mailinglist"
 	"github.com/mediocregopher/blog.mediocregopher.com/srv/pow"
+	"github.com/mediocregopher/mediocre-go-lib/v2/mctx"
+	"github.com/mediocregopher/mediocre-go-lib/v2/mlog"
 	"github.com/tilinna/clock"
 )
 
+func loggerFatalErr(ctx context.Context, logger *mlog.Logger, descr string, err error) {
+	logger.Fatal(ctx, fmt.Sprintf("%s: %v", descr, err))
+}
+
 func main() {
+
+	logger := mlog.NewLogger(nil)
+
+	hostname := flag.String("hostname", "localhost:4000", "Hostname to advertise this server as")
 	staticDir := flag.String("static-dir", "", "Directory from which static files are served")
 	listenAddr := flag.String("listen-addr", ":4000", "Address to listen for HTTP requests on")
+	dataDir := flag.String("data-dir", ".", "Directory to use for long term storage")
+
 	powTargetStr := flag.String("pow-target", "0x000FFFF", "Proof-of-work target, lower is more difficult")
 	powSecret := flag.String("pow-secret", "", "Secret used to sign proof-of-work challenge seeds")
 
+	smtpAddr := flag.String("ml-smtp-addr", "", "Address of SMTP server to use for sending emails for the mailing list")
+	smtpAuthStr := flag.String("ml-smtp-auth", "", "user:pass to use when authenticating with the mailing list SMTP server. The given user will also be used as the From address.")
+
 	// parse config
 
 	flag.Parse()
 
 	switch {
 	case *staticDir == "":
-		log.Fatal("-static-dir is required")
+		logger.Fatal(context.Background(), "-static-dir is required")
 	case *powSecret == "":
-		log.Fatal("-pow-secret is required")
+		logger.Fatal(context.Background(), "-pow-secret is required")
+	case *smtpAddr == "":
+		logger.Fatal(context.Background(), "-ml-smtp-addr is required")
+	case *smtpAuthStr == "":
+		logger.Fatal(context.Background(), "-ml-smtp-auth is required")
 	}
 
 	powTargetUint, err := strconv.ParseUint(*powTargetStr, 0, 32)
 	if err != nil {
-		log.Fatalf("parsing -pow-target: %v", err)
+		loggerFatalErr(context.Background(), logger, "parsing -pow-target", err)
 	}
 	powTarget := uint32(powTargetUint)
 
+	smtpAuthParts := strings.SplitN(*smtpAuthStr, ":", 2)
+	if len(smtpAuthParts) < 2 {
+		logger.Fatal(context.Background(), "invalid -ml-smtp-auth")
+	}
+	smtpAuth := sasl.NewPlainClient("", smtpAuthParts[0], smtpAuthParts[1])
+	smtpSendAs := smtpAuthParts[0]
+
 	// initialization
 
+	ctx := mctx.Annotate(context.Background(),
+		"hostname", *hostname,
+		"staticDir", *staticDir,
+		"listenAddr", *listenAddr,
+		"dataDir", *dataDir,
+		"powTarget", fmt.Sprintf("%x", powTarget),
+		"smtpAddr", *smtpAddr,
+		"smtpSendAs", smtpSendAs,
+	)
+
 	clock := clock.Realtime()
 
 	powStore := pow.NewMemoryStore(clock)
 	defer powStore.Close()
 
-	mgr := pow.NewManager(pow.ManagerParams{
+	powMgr := pow.NewManager(pow.ManagerParams{
 		Clock:  clock,
 		Store:  powStore,
 		Secret: []byte(*powSecret),
 		Target: powTarget,
 	})
 
+	// sugar
+	requirePow := func(h http.Handler) http.Handler { return requirePowMiddleware(powMgr, h) }
+
+	mailer := mailinglist.NewMailer(mailinglist.MailerParams{
+		SMTPAddr: *smtpAddr,
+		SMTPAuth: smtpAuth,
+		SendAs:   smtpSendAs,
+	})
+
+	mlStore, err := mailinglist.NewStore(path.Join(*dataDir, "mailinglist.sqlite3"))
+	if err != nil {
+		loggerFatalErr(ctx, logger, "initializing mailing list storage", err)
+	}
+	defer mlStore.Close()
+
+	ml := mailinglist.New(mailinglist.Params{
+		Store:          mlStore,
+		Mailer:         mailer,
+		Clock:          clock,
+		FinalizeSubURL: *hostname + "/mailinglist/finalize.html",
+		UnsubURL:       *hostname + "/mailinglist/unsubscribe.html",
+	})
+
 	mux := http.NewServeMux()
 	mux.Handle("/", http.FileServer(http.Dir(*staticDir)))
-	mux.Handle("/api/pow/challenge", newPowChallengeHandler(mgr))
+
+	apiMux := http.NewServeMux()
+	apiMux.Handle("/pow/challenge", newPowChallengeHandler(powMgr))
+	apiMux.Handle("/pow/check",
+		requirePow(
+			http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {}),
+		),
+	)
+
+	apiMux.Handle("/mailinglist/subscribe", requirePow(mailingListSubscribeHandler(ml)))
+	apiMux.Handle("/mailinglist/finalize", mailingListFinalizeHandler(ml))
+	apiMux.Handle("/mailinglist/unsubscribe", mailingListUnsubscribeHandler(ml))
+
+	apiHandler := logMiddleware(logger.WithNamespace("api"), apiMux)
+	apiHandler = annotateMiddleware(apiHandler)
+	mux.Handle("/api/", http.StripPrefix("/api", apiHandler))
 
 	// run
 
-	log.Printf("listening on %q", *listenAddr)
+	logger.Info(ctx, "listening")
-	log.Fatal(http.ListenAndServe(*listenAddr, mux))
+
+	// TODO graceful shutdown
+	err = http.ListenAndServe(*listenAddr, mux)
+	loggerFatalErr(ctx, logger, "listening", err)
 }

srv/cmd/mediocre-blog/middleware.go

@@ -0,0 +1,69 @@
+package main
+
+import (
+	"net"
+	"net/http"
+	"time"
+
+	"github.com/mediocregopher/mediocre-go-lib/v2/mctx"
+	"github.com/mediocregopher/mediocre-go-lib/v2/mlog"
+)
+
+func annotateMiddleware(h http.Handler) http.Handler {
+	return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
+
+		type reqInfoKey string
+
+		ip, _, _ := net.SplitHostPort(r.RemoteAddr)
+
+		ctx := r.Context()
+		ctx = mctx.Annotate(ctx,
+			reqInfoKey("remote_ip"), ip,
+			reqInfoKey("url"), r.URL,
+			reqInfoKey("method"), r.Method,
+		)
+
+		r = r.WithContext(ctx)
+		h.ServeHTTP(rw, r)
+	})
+}
+
+type logResponseWriter struct {
+	http.ResponseWriter
+	statusCode int
+}
+
+func newLogResponseWriter(rw http.ResponseWriter) *logResponseWriter {
+	return &logResponseWriter{
+		ResponseWriter: rw,
+		statusCode:     200,
+	}
+}
+
+func (lrw *logResponseWriter) WriteHeader(statusCode int) {
+	lrw.statusCode = statusCode
+	lrw.ResponseWriter.WriteHeader(statusCode)
+}
+
+func logMiddleware(logger *mlog.Logger, h http.Handler) http.Handler {
+	return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
+
+		r = setRequestLogger(r, logger)
+
+		lrw := newLogResponseWriter(rw)
+
+		started := time.Now()
+		h.ServeHTTP(lrw, r)
+		took := time.Since(started)
+
+		type logCtxKey string
+
+		ctx := r.Context()
+		ctx = mctx.Annotate(ctx,
+			logCtxKey("took"), took.String(),
+			logCtxKey("response_code"), lrw.statusCode,
+		)
+
+		logger.Info(ctx, "handled HTTP request")
+	})
+}

srv/cmd/mediocre-blog/pow.go

@@ -2,6 +2,8 @@ package main
 
 import (
 	"encoding/hex"
+	"errors"
+	"fmt"
 	"net/http"
 
 	"github.com/mediocregopher/blog.mediocregopher.com/srv/pow"
@@ -20,3 +22,28 @@ func newPowChallengeHandler(mgr pow.Manager) http.Handler {
 		})
 	})
 }
+
+func requirePowMiddleware(mgr pow.Manager, h http.Handler) http.Handler {
+	return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
+		seedHex := r.PostFormValue("powSeed")
+		seed, err := hex.DecodeString(seedHex)
+		if err != nil || len(seed) == 0 {
+			badRequest(rw, r, errors.New("invalid powSeed"))
+			return
+		}
+
+		solutionHex := r.PostFormValue("powSolution")
+		solution, err := hex.DecodeString(solutionHex)
+		if err != nil || len(seed) == 0 {
+			badRequest(rw, r, errors.New("invalid powSolution"))
+			return
+		}
+
+		if err := mgr.CheckSolution(seed, solution); err != nil {
+			badRequest(rw, r, fmt.Errorf("checking proof-of-work solution: %w", err))
+			return
+		}
+
+		h.ServeHTTP(rw, r)
+	})
+}

srv/cmd/mediocre-blog/utils.go

@@ -0,0 +1,60 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+
+	"github.com/mediocregopher/mediocre-go-lib/v2/mlog"
+)
+
+type loggerCtxKey int
+
+func setRequestLogger(r *http.Request, logger *mlog.Logger) *http.Request {
+	ctx := r.Context()
+	ctx = context.WithValue(ctx, loggerCtxKey(0), logger)
+	return r.WithContext(ctx)
+}
+
+func getRequestLogger(r *http.Request) *mlog.Logger {
+	ctx := r.Context()
+	logger, _ := ctx.Value(loggerCtxKey(0)).(*mlog.Logger)
+	if logger == nil {
+		logger = mlog.Null
+	}
+	return logger
+}
+
+func jsonResult(rw http.ResponseWriter, r *http.Request, v interface{}) {
+	b, err := json.Marshal(v)
+	if err != nil {
+		internalServerError(rw, r, err)
+		return
+	}
+	b = append(b, '\n')
+
+	rw.Header().Set("Content-Type", "application/json")
+	rw.Write(b)
+}
+
+func badRequest(rw http.ResponseWriter, r *http.Request, err error) {
+	getRequestLogger(r).Warn(r.Context(), "bad request", err)
+
+	rw.WriteHeader(400)
+	jsonResult(rw, r, struct {
+		Error string `json:"error"`
+	}{
+		Error: err.Error(),
+	})
+}
+
+func internalServerError(rw http.ResponseWriter, r *http.Request, err error) {
+	getRequestLogger(r).Error(r.Context(), "internal server error", err)
+
+	rw.WriteHeader(500)
+	jsonResult(rw, r, struct {
+		Error string `json:"error"`
+	}{
+		Error: "internal server error",
+	})
+}

srv/go.mod

@@ -7,6 +7,7 @@ require (
 	github.com/emersion/go-smtp v0.15.0
 	github.com/google/uuid v1.3.0
 	github.com/mattn/go-sqlite3 v1.14.8
+	github.com/mediocregopher/mediocre-go-lib/v2 v2.0.0-beta.0
 	github.com/rubenv/sql-migrate v0.0.0-20210614095031-55d5740dbbcc
 	github.com/stretchr/testify v1.7.0
 	github.com/tilinna/clock v1.1.0

srv/go.sum

@@ -104,6 +104,8 @@ github.com/mattn/go-sqlite3 v1.14.6/go.mod h1:NyWgC/yNuGj7Q9rpYnZvas74GogHl5/Z4A
 github.com/mattn/go-sqlite3 v1.14.8 h1:gDp86IdQsN/xWjIEmr9MF6o9mpksUgh0fu+9ByFxzIU=
 github.com/mattn/go-sqlite3 v1.14.8/go.mod h1:NyWgC/yNuGj7Q9rpYnZvas74GogHl5/Z4A/KQRfk6bU=
 github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
+github.com/mediocregopher/mediocre-go-lib/v2 v2.0.0-beta.0 h1:i9FBkcCaWXxteJ8458AD8dBL2YqSxVlpsHOMWg5N9Dc=
+github.com/mediocregopher/mediocre-go-lib/v2 v2.0.0-beta.0/go.mod h1:wOZVlnKYvIbkzyCJ3dxy1k40XkirvCd1pisX2O91qoQ=
 github.com/mitchellh/cli v1.1.2/go.mod h1:6iaV0fGdElS6dPBx0EApTxHrcWvmJphyh2n8YBLPPZ4=
 github.com/mitchellh/copystructure v1.0.0/go.mod h1:SNtv71yrdKgLRyLFxmLdkAbkKEFWgYaq1OVrnRcwhnw=
 github.com/mitchellh/go-homedir v1.1.0/go.mod h1:SfyaCUpYCn1Vlf4IUYiD9fPX4A5wJrkLzIz1N1q0pr0=

srv/mailinglist/mailinglist.go

@@ -51,6 +51,11 @@ type Params struct {
 	UnsubURL string
 }
 
+// New initializes and returns a MailingList instance using the given Params.
+func New(params Params) MailingList {
+	return &mailingList{params: params}
+}
+
 type mailingList struct {
 	params Params
 }