From 0197d9cd493b5785bca05f476856540ec64da64a Mon Sep 17 00:00:00 2001 From: Brian Picciano Date: Sat, 7 Aug 2021 20:38:37 -0600 Subject: split configuration parsing out into separate packages, split api out as well --- srv/api/api.go | 174 +++++++++++++++++++++++++++++++++++++++++++++++++ srv/api/mailinglist.go | 87 +++++++++++++++++++++++++ srv/api/middleware.go | 78 ++++++++++++++++++++++ srv/api/pow.go | 51 +++++++++++++++ srv/api/utils.go | 60 +++++++++++++++++ 5 files changed, 450 insertions(+) create mode 100644 srv/api/api.go create mode 100644 srv/api/mailinglist.go create mode 100644 srv/api/middleware.go create mode 100644 srv/api/pow.go create mode 100644 srv/api/utils.go (limited to 'srv/api') diff --git a/srv/api/api.go b/srv/api/api.go new file mode 100644 index 0000000..ae0970b --- /dev/null +++ b/srv/api/api.go @@ -0,0 +1,174 @@ +// Package api implements the HTTP-based api for the mediocre-blog. +package api + +import ( + "context" + "errors" + "fmt" + "net" + "net/http" + "net/http/httputil" + "net/url" + "os" + + "github.com/mediocregopher/blog.mediocregopher.com/srv/cfg" + "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" +) + +// Params are used to instantiate a new API instance. All fields are required +// unless otherwise noted. +type Params struct { + Logger *mlog.Logger + PowManager pow.Manager + MailingList mailinglist.MailingList + + // ListenProto and ListenAddr are passed into net.Listen to create the + // API's listener. Both "tcp" and "unix" protocols are explicitly + // supported. + ListenProto, ListenAddr string + + // StaticDir and StaticProxy are mutually exclusive. + // + // If StaticDir is set then that directory on the filesystem will be used to + // serve the static site. + // + // Otherwise if StaticProxy is set all requests for the static site will be + // reverse-proxied there. + StaticDir string + StaticProxy *url.URL +} + +// SetupCfg implement the cfg.Cfger interface. +func (p *Params) SetupCfg(cfg *cfg.Cfg) { + + cfg.StringVar(&p.ListenProto, "listen-proto", "tcp", "Protocol to listen for HTTP requests with") + cfg.StringVar(&p.ListenAddr, "listen-addr", ":4000", "Address/path to listen for HTTP requests on") + + cfg.StringVar(&p.StaticDir, "static-dir", "", "Directory from which static files are served (mutually exclusive with -static-proxy-url)") + staticProxyURLStr := cfg.String("static-proxy-url", "", "HTTP address from which static files are served (mutually exclusive with -static-dir)") + + cfg.OnInit(func(ctx context.Context) error { + if *staticProxyURLStr != "" { + var err error + if p.StaticProxy, err = url.Parse(*staticProxyURLStr); err != nil { + return fmt.Errorf("parsing -static-proxy-url: %w", err) + } + + } else if p.StaticDir == "" { + return errors.New("-static-dir or -static-proxy-url is required") + } + + return nil + }) +} + +// Annotate implements mctx.Annotator interface. +func (p *Params) Annotate(a mctx.Annotations) { + a["listenProto"] = p.ListenProto + a["listenAddr"] = p.ListenAddr + + if p.StaticProxy != nil { + a["staticProxy"] = p.StaticProxy.String() + return + } + + a["staticDir"] = p.StaticDir +} + +// API will listen on the port configured for it, and serve HTTP requests for +// the mediocre-blog. +type API interface { + Shutdown(ctx context.Context) error +} + +type api struct { + params Params + srv *http.Server +} + +// New initializes and returns a new API instance, including setting up all +// listening ports. +func New(params Params) (API, error) { + + l, err := net.Listen(params.ListenProto, params.ListenAddr) + if err != nil { + return nil, fmt.Errorf("creating listen socket: %w", err) + } + + if params.ListenProto == "unix" { + if err := os.Chmod(params.ListenAddr, 0777); err != nil { + return nil, fmt.Errorf("chmod-ing unix socket: %w", err) + } + } + + a := &api{ + params: params, + } + + a.srv = &http.Server{Handler: a.handler()} + + go func() { + + err := a.srv.Serve(l) + if err != nil && !errors.Is(err, http.ErrServerClosed) { + ctx := mctx.Annotate(context.Background(), a.params) + params.Logger.Fatal(ctx, fmt.Sprintf("%s: %v", "serving http server", err)) + } + }() + + return a, nil +} + +func (a *api) Shutdown(ctx context.Context) error { + if err := a.srv.Shutdown(ctx); err != nil { + return err + } + + return nil +} + +func (a *api) handler() http.Handler { + + var staticHandler http.Handler + if a.params.StaticDir != "" { + staticHandler = http.FileServer(http.Dir(a.params.StaticDir)) + } else { + staticHandler = httputil.NewSingleHostReverseProxy(a.params.StaticProxy) + } + + // sugar + requirePow := func(h http.Handler) http.Handler { + return a.requirePowMiddleware(h) + } + + mux := http.NewServeMux() + + mux.Handle("/", staticHandler) + + apiMux := http.NewServeMux() + apiMux.Handle("/pow/challenge", a.newPowChallengeHandler()) + apiMux.Handle("/pow/check", + requirePow( + http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {}), + ), + ) + + apiMux.Handle("/mailinglist/subscribe", requirePow(a.mailingListSubscribeHandler())) + apiMux.Handle("/mailinglist/finalize", a.mailingListFinalizeHandler()) + apiMux.Handle("/mailinglist/unsubscribe", a.mailingListUnsubscribeHandler()) + + apiHandler := logMiddleware(a.params.Logger, apiMux) + apiHandler = annotateMiddleware(apiHandler) + apiHandler = addResponseHeaders(map[string]string{ + "Cache-Control": "no-store, max-age=0", + "Pragma": "no-cache", + "Expires": "0", + }, apiHandler) + + mux.Handle("/api/", http.StripPrefix("/api", apiHandler)) + + return mux +} diff --git a/srv/api/mailinglist.go b/srv/api/mailinglist.go new file mode 100644 index 0000000..2ddfbe6 --- /dev/null +++ b/srv/api/mailinglist.go @@ -0,0 +1,87 @@ +package api + +import ( + "errors" + "net/http" + "strings" + + "github.com/mediocregopher/blog.mediocregopher.com/srv/mailinglist" +) + +func (a *api) mailingListSubscribeHandler() 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")) + return + } + + err := a.params.MailingList.BeginSubscription(email) + + if 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) + return + } + + jsonResult(rw, r, struct{}{}) + }) +} + +func (a *api) mailingListFinalizeHandler() http.Handler { + var errInvalidSubToken = errors.New("invalid subToken") + + 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, errInvalidSubToken) + return + } + + err := a.params.MailingList.FinalizeSubscription(subToken) + + if errors.Is(err, mailinglist.ErrNotFound) { + badRequest(rw, r, errInvalidSubToken) + return + + } else if errors.Is(err, mailinglist.ErrAlreadyVerified) { + // no problem + + } else if err != nil { + internalServerError(rw, r, err) + return + } + + jsonResult(rw, r, struct{}{}) + }) +} + +func (a *api) mailingListUnsubscribeHandler() http.Handler { + var errInvalidUnsubToken = errors.New("invalid unsubToken") + + 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, errInvalidUnsubToken) + return + } + + err := a.params.MailingList.Unsubscribe(unsubToken) + + if errors.Is(err, mailinglist.ErrNotFound) { + badRequest(rw, r, errInvalidUnsubToken) + return + + } else if err != nil { + internalServerError(rw, r, err) + return + } + + jsonResult(rw, r, struct{}{}) + }) +} diff --git a/srv/api/middleware.go b/srv/api/middleware.go new file mode 100644 index 0000000..e3e85bb --- /dev/null +++ b/srv/api/middleware.go @@ -0,0 +1,78 @@ +package api + +import ( + "net" + "net/http" + "time" + + "github.com/mediocregopher/mediocre-go-lib/v2/mctx" + "github.com/mediocregopher/mediocre-go-lib/v2/mlog" +) + +func addResponseHeaders(headers map[string]string, h http.Handler) http.Handler { + return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) { + for k, v := range headers { + rw.Header().Set(k, v) + } + h.ServeHTTP(rw, r) + }) +} + +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") + }) +} diff --git a/srv/api/pow.go b/srv/api/pow.go new file mode 100644 index 0000000..096e252 --- /dev/null +++ b/srv/api/pow.go @@ -0,0 +1,51 @@ +package api + +import ( + "encoding/hex" + "errors" + "fmt" + "net/http" +) + +func (a *api) newPowChallengeHandler() http.Handler { + return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) { + + challenge := a.params.PowManager.NewChallenge() + + jsonResult(rw, r, struct { + Seed string `json:"seed"` + Target uint32 `json:"target"` + }{ + Seed: hex.EncodeToString(challenge.Seed), + Target: challenge.Target, + }) + }) +} + +func (a *api) requirePowMiddleware(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 + } + + err = a.params.PowManager.CheckSolution(seed, solution) + + if err != nil { + badRequest(rw, r, fmt.Errorf("checking proof-of-work solution: %w", err)) + return + } + + h.ServeHTTP(rw, r) + }) +} diff --git a/srv/api/utils.go b/srv/api/utils.go new file mode 100644 index 0000000..8e2a63b --- /dev/null +++ b/srv/api/utils.go @@ -0,0 +1,60 @@ +package api + +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", + }) +} -- cgit v1.2.3