From 0bd8bd6f2366e60212dd0305a584427b7b1aab26 Mon Sep 17 00:00:00 2001 From: Brian Picciano Date: Thu, 19 Jan 2023 18:03:20 +0100 Subject: Slight cleanup in http package --- src/http/http.go | 286 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 286 insertions(+) create mode 100644 src/http/http.go (limited to 'src/http/http.go') diff --git a/src/http/http.go b/src/http/http.go new file mode 100644 index 0000000..e5ca3f1 --- /dev/null +++ b/src/http/http.go @@ -0,0 +1,286 @@ +// Package http implements the HTTP-based api for the mediocre-blog. +package http + +import ( + "context" + "embed" + "encoding/json" + "errors" + "fmt" + "html/template" + "net" + "net/http" + "net/url" + "os" + "strings" + "time" + + lru "github.com/hashicorp/golang-lru" + "github.com/mediocregopher/blog.mediocregopher.com/srv/cfg" + "github.com/mediocregopher/blog.mediocregopher.com/srv/http/apiutil" + "github.com/mediocregopher/blog.mediocregopher.com/srv/mailinglist" + "github.com/mediocregopher/blog.mediocregopher.com/srv/post" + "github.com/mediocregopher/blog.mediocregopher.com/srv/pow" + "github.com/mediocregopher/mediocre-go-lib/v2/mctx" + "github.com/mediocregopher/mediocre-go-lib/v2/mlog" +) + +//go:embed static +var staticFS embed.FS + +// 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 + + PostStore post.Store + PostAssetStore post.AssetStore + PostDraftStore post.DraftStore + + MailingList mailinglist.MailingList + + // PublicURL is the base URL which site visitors can navigate to. + PublicURL *url.URL + + // 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 + + // AuthUsers keys are usernames which are allowed to edit server-side data, + // and the values are the password hash which accompanies those users. The + // password hash must have been produced by NewPasswordHash. + AuthUsers map[string]string + + // AuthRatelimit indicates how much time must pass between subsequent auth + // attempts. + AuthRatelimit time.Duration +} + +// SetupCfg implement the cfg.Cfger interface. +func (p *Params) SetupCfg(cfg *cfg.Cfg) { + + publicURLStr := cfg.String("http-public-url", "http://localhost:4000", "URL this service is accessible at") + + cfg.StringVar(&p.ListenProto, "http-listen-proto", "tcp", "Protocol to listen for HTTP requests with") + cfg.StringVar(&p.ListenAddr, "http-listen-addr", ":4000", "Address/path to listen for HTTP requests on") + + httpAuthUsersStr := cfg.String("http-auth-users", "{}", "JSON object with usernames as values and password hashes (produced by the hash-password binary) as values. Denotes users which are able to edit server-side data") + + httpAuthRatelimitStr := cfg.String("http-auth-ratelimit", "5s", "Minimum duration which must be waited between subsequent auth attempts") + + cfg.OnInit(func(context.Context) error { + + err := json.Unmarshal([]byte(*httpAuthUsersStr), &p.AuthUsers) + + if err != nil { + return fmt.Errorf("unmarshaling -http-auth-users: %w", err) + } + + if p.AuthRatelimit, err = time.ParseDuration(*httpAuthRatelimitStr); err != nil { + return fmt.Errorf("unmarshaling -http-auth-ratelimit: %w", err) + } + + *publicURLStr = strings.TrimSuffix(*publicURLStr, "/") + if p.PublicURL, err = url.Parse(*publicURLStr); err != nil { + return fmt.Errorf("parsing -http-public-url: %w", err) + } + + return nil + }) +} + +// Annotate implements mctx.Annotator interface. +func (p *Params) Annotate(a mctx.Annotations) { + a["httpPublicURL"] = p.PublicURL + a["httpListenProto"] = p.ListenProto + a["httpListenAddr"] = p.ListenAddr + a["httpAuthRatelimit"] = p.AuthRatelimit +} + +// 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 + + redirectTpl *template.Template + auther Auther +} + +// 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, + auther: NewAuther(params.AuthUsers, params.AuthRatelimit), + } + + a.redirectTpl = a.mustParseTpl("redirect.html") + + 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, "serving http server", err) + } + }() + + return a, nil +} + +func (a *api) Shutdown(ctx context.Context) error { + defer a.auther.Close() + if err := a.srv.Shutdown(ctx); err != nil { + return err + } + + return nil +} + +func (a *api) apiHandler() http.Handler { + mux := http.NewServeMux() + + mux.Handle("/pow/challenge", a.newPowChallengeHandler()) + mux.Handle("/pow/check", + a.requirePowMiddleware( + http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {}), + ), + ) + + mux.Handle("/mailinglist/subscribe", a.requirePowMiddleware(a.mailingListSubscribeHandler())) + mux.Handle("/mailinglist/finalize", a.mailingListFinalizeHandler()) + mux.Handle("/mailinglist/unsubscribe", a.mailingListUnsubscribeHandler()) + + return apiutil.MethodMux(map[string]http.Handler{ + "POST": mux, + }) +} + +func (a *api) blogHandler() http.Handler { + + cache, err := lru.New(5000) + + // instantiating the lru cache can't realistically fail + if err != nil { + panic(err) + } + + mux := http.NewServeMux() + + mux.Handle("/posts/", http.StripPrefix("/posts", + apiutil.MethodMux(map[string]http.Handler{ + "GET": a.getPostsHandler(), + "EDIT": a.editPostHandler(false), + "MANAGE": a.managePostsHandler(), + "POST": a.postPostHandler(), + "DELETE": a.deletePostHandler(false), + "PREVIEW": a.previewPostHandler(), + }), + )) + + mux.Handle("/assets/", http.StripPrefix("/assets", + apiutil.MethodMux(map[string]http.Handler{ + "GET": a.getPostAssetHandler(), + "MANAGE": a.managePostAssetsHandler(), + "POST": a.postPostAssetHandler(), + "DELETE": a.deletePostAssetHandler(), + }), + )) + + mux.Handle("/drafts/", http.StripPrefix("/drafts", + + // everything to do with drafts is protected + authMiddleware(a.auther)( + + apiutil.MethodMux(map[string]http.Handler{ + "EDIT": a.editPostHandler(true), + "MANAGE": a.manageDraftPostsHandler(), + "POST": a.postDraftPostHandler(), + "DELETE": a.deletePostHandler(true), + "PREVIEW": a.previewPostHandler(), + }), + ), + )) + + mux.Handle("/static/", http.FileServer(http.FS(staticFS))) + mux.Handle("/follow", a.renderDumbTplHandler("follow.html")) + mux.Handle("/admin", a.renderDumbTplHandler("admin.html")) + mux.Handle("/mailinglist/unsubscribe", a.renderDumbTplHandler("unsubscribe.html")) + mux.Handle("/mailinglist/finalize", a.renderDumbTplHandler("finalize.html")) + mux.Handle("/feed.xml", a.renderFeedHandler()) + mux.Handle("/", a.renderIndexHandler()) + + readOnlyMiddlewares := []middleware{ + logReqMiddleware, // only log GETs on cache miss + cacheMiddleware(cache), + } + + readWriteMiddlewares := []middleware{ + purgeCacheOnOKMiddleware(cache), + authMiddleware(a.auther), + } + + h := apiutil.MethodMux(map[string]http.Handler{ + "GET": applyMiddlewares(mux, readOnlyMiddlewares...), + "MANAGE": applyMiddlewares(mux, readOnlyMiddlewares...), + "EDIT": applyMiddlewares(mux, readOnlyMiddlewares...), + "*": applyMiddlewares(mux, readWriteMiddlewares...), + }) + + return h +} + +func (a *api) handler() http.Handler { + + mux := http.NewServeMux() + + mux.Handle("/api/", applyMiddlewares( + http.StripPrefix("/api", a.apiHandler()), + logReqMiddleware, + )) + + mux.Handle("/", a.blogHandler()) + + noCacheMiddleware := addResponseHeadersMiddleware(map[string]string{ + "Cache-Control": "no-store, max-age=0", + "Pragma": "no-cache", + "Expires": "0", + }) + + h := applyMiddlewares( + apiutil.MethodMux(map[string]http.Handler{ + "GET": applyMiddlewares(mux), + "MANAGE": applyMiddlewares(mux, noCacheMiddleware), + "EDIT": applyMiddlewares(mux, noCacheMiddleware), + "*": applyMiddlewares( + mux, + a.checkCSRFMiddleware, + noCacheMiddleware, + ), + }), + setLoggerMiddleware(a.params.Logger), + ) + + return h +} -- cgit v1.2.3