1// SPDX-License-Identifier: AGPL-3.0-or-later
2
3// Package web is the HTML front of ermite: the pages of the read-only
4// showcase, rendered with templ from the data of the use cases.
5//
6// Like every other inbound adapter, the package reads and writes through the
7// use case interfaces of package ports (ADR 0024), never through the API. The
8// caller of every use case call is passed explicitly: the principal of the
9// request, which is anonymous unless the request carries a valid owner session
10// (ServeHTTP sets it in the context, principal reads it). The use cases then
11// show public repositories only to an anonymous caller; a private repository
12// is indistinguishable from a missing one (domain.ErrNotFound), here as
13// everywhere.
14//
15// Adding a page: a handler on Server, a route in routes, a templ page in
16// pages.templ and its view model in view.go.
17package web
18
19import (
20 "bytes"
21 "context"
22 "crypto/rand"
23 "encoding/hex"
24 "errors"
25 "fmt"
26 "net/http"
27 "net/netip"
28 "net/url"
29 "strings"
30 "time"
31
32 "github.com/a-h/templ"
33 "github.com/bnema/zerowrap"
34
35 "bnema.dev/ermite/internal/domain"
36 "bnema.dev/ermite/internal/ports"
37)
38
39// Patterns are the ServeMux patterns the handler serves: everything. The
40// router of the package answers the paths it does not know with its 404
41// page, and the more specific patterns of the server (health, API, Git) win
42// over this one.
43var Patterns = []string{"/"}
44
45// requestTimeout bounds the use case calls that build one page.
46const requestTimeout = 30 * time.Second
47
48// Config configures a Server.
49type Config struct {
50 // Mirrors answers the push mirror badge shown to repository admins. Without it there is
51 // no badge. Leave it unset rather than assigning a typed nil pointer.
52 Mirrors ports.MirrorWarner
53 // Repos and Browse are the use cases the pages are built from.
54 Repos ports.RepoService
55 Browse ports.BrowseService
56 // MergeRequests serves the merge request pages (ADR 0017). Without it
57 // there are no such pages, nor section for them. Leave it unset rather
58 // than assigning a typed nil pointer.
59 MergeRequests ports.MergeRequestService
60 // Issues serves the issue pages (ADR 0031). Without it there are no such
61 // pages, nor tab for them. Leave it unset rather than assigning a typed
62 // nil pointer.
63 Issues ports.IssueService
64 // IssueNumbers tells whether a number names an issue or a merge request,
65 // so that the page of the wrong kind redirects to the right one. Without
66 // it there is no such redirect. Leave it unset rather than assigning a
67 // typed nil pointer.
68 IssueNumbers ports.IssueNumberResolver
69 // IssueForm serves the public issue form of repositories whose issues
70 // mode is public (GET and POST /<repo>/issues/new for a visitor). Without
71 // it there is no such form. Leave it unset rather than assigning a typed
72 // nil pointer.
73 IssueForm ports.IssueSubmissionService
74 // Moderation serves the Approve, Reject and Reject-and-ban buttons of the
75 // pending issues in the inbox. It needs Inbox. Without it there are no
76 // such routes. Leave it unset rather than assigning a typed nil pointer.
77 Moderation ports.IssueModerationService
78 // Inbox serves the owner's inbox page (/-/inbox) and the button that
79 // leads to it. Without it there is neither. Leave it unset rather than
80 // assigning a typed nil pointer.
81 Inbox ports.InboxService
82 // SigningKey tells the key that signs the squash and merge commits, shown
83 // in the merge box. Without it the box does not name the key. Leave it
84 // unset rather than assigning a typed nil pointer.
85 SigningKey ports.SigningKeyService
86 // Runs serves the CI pages (/<repo>/actions) and the checks shown next to
87 // commits and merge requests. Without it there are no such pages. Leave it
88 // unset rather than assigning a typed nil pointer.
89 Runs ports.RunService
90 // Artifacts serves the artifacts of the runs: a section of the run page,
91 // their download and their deletion. It needs Runs. Without it there is
92 // neither. Leave it unset rather than assigning a typed nil pointer.
93 Artifacts ports.ArtifactService
94 // Events is the source of the event stream behind /-/events. Without
95 // it the pages are not live and the route answers 404. Leave it unset
96 // rather than assigning a typed nil pointer.
97 Events ports.EventService
98 // Heartbeat is how often an idle event stream gets a comment line;
99 // DefaultHeartbeat when zero.
100 Heartbeat time.Duration
101 // Owner is the owner login the GitHub-shaped URLs of CI show
102 // (<server>/<owner>/<repo>/...). A GET or HEAD of /<owner>/<rest> is
103 // redirected to /<rest> unless a repository named like the owner is
104 // visible to the caller. Empty: no redirect.
105 Owner string
106 // PublicURL is the base URL of the instance, without a trailing slash:
107 // the clone URLs are built on it, and its host is the instance name.
108 PublicURL string
109 // SourceURL is the link to the source of the running version (AGPL §13).
110 SourceURL string
111 // Version is the version of the running server.
112 Version string
113 // Now is the clock of relative dates; time.Now when nil.
114 Now func() time.Time
115 // Sessions signs the owner in (ADR 0018). Without it there are no login
116 // routes and every visitor is anonymous.
117 Sessions ports.WebSessionService
118 // Passkeys signs the owner in with a passkey and manages the passkeys
119 // (ADR 0026). Without it, or without Sessions, there are no passkey
120 // routes and no link to them. Leave it unset rather than assigning a typed
121 // nil pointer.
122 Passkeys ports.WebPasskeyService
123 // Limiter counts the failed logins; required with Sessions. Share it with
124 // the API and Git, so that a client has one budget of failures.
125 Limiter ports.FailureLimiter
126 // TrustedProxies are the networks allowed to set X-Forwarded-For, to find
127 // the address of the client that fails a login.
128 TrustedProxies []netip.Prefix
129}
130
131// Server serves the pages. It is an http.Handler.
132type Server struct {
133 cfg Config
134 instance string
135 origin string // scheme://host of the public URL, what a POST must come from
136 assets *assetSet
137 md *markdown
138 // pathCache holds the path lists the file finder fetches.
139 pathCache *pathCache
140 // hl holds the colours of highlighted diffs.
141 hl *hlCache
142 mux *http.ServeMux
143 // ownerRepo is the owner login as a repository name, zero when it is not
144 // a valid one (then no repository can be named like the owner).
145 ownerRepo domain.RepoName
146 // refsFan shares the fragments of the refs page between the watchers of
147 // a push; entries are few and short-lived.
148 refsFan fanout
149 // pulses holds the activity curves of the home rows.
150 pulses pulseCache
151}
152
153// New builds the web handler.
154func New(cfg Config) (*Server, error) {
155 if cfg.Repos == nil || cfg.Browse == nil {
156 return nil, errors.New("web: the repository and browse use cases are required")
157 }
158 u, err := url.Parse(cfg.PublicURL)
159 if err != nil || u.Host == "" {
160 return nil, fmt.Errorf("web: public URL %q is not a valid base URL", cfg.PublicURL)
161 }
162 if cfg.Now == nil {
163 cfg.Now = time.Now
164 }
165 assets, err := loadAssets()
166 if err != nil {
167 return nil, fmt.Errorf("web: load assets: %w", err)
168 }
169 if cfg.Sessions != nil && cfg.Limiter == nil {
170 return nil, errors.New("web: sessions need a failure limiter")
171 }
172 s := &Server{
173 cfg: cfg, instance: u.Host, assets: assets, md: newMarkdown(),
174 pathCache: newPathCache(pathCacheBytes, pathBuilds),
175 hl: newHLCache(hlCacheBytes),
176 origin: originOf(u),
177 }
178 s.ownerRepo, _ = domain.ParseRepoName(cfg.Owner)
179 s.mux = s.routes()
180 return s, nil
181}
182
183// routes is the router of the web. Any path that is not a page is the 404
184// page.
185func (s *Server) routes() *http.ServeMux {
186 mux := http.NewServeMux()
187 mux.HandleFunc("GET "+StaticPrefix, s.assets.serve)
188 mux.HandleFunc("GET /-/events", s.events)
189 mux.HandleFunc("GET "+ServiceWorkerPath, s.assets.sw.serve)
190 if s.cfg.Sessions != nil {
191 mux.HandleFunc("GET "+loginPrefix+"{nonce}", s.loginConfirm)
192 mux.HandleFunc("POST "+loginPrefix+"{nonce}", s.loginPost)
193 mux.HandleFunc("POST /-/logout", s.logout)
194 }
195 if s.passkeysOn() {
196 s.passkeyRoutes(mux)
197 }
198 if s.cfg.Inbox != nil {
199 mux.HandleFunc("GET "+inboxPath, s.page(s.inbox))
200 if s.cfg.Moderation != nil {
201 mux.HandleFunc("POST "+inboxPath+"/pending/{repo}/{id}/approve", s.mrAction(s.pendingApprove))
202 mux.HandleFunc("POST "+inboxPath+"/pending/{repo}/{id}/reject", s.mrAction(s.pendingReject(false)))
203 mux.HandleFunc("POST "+inboxPath+"/pending/{repo}/{id}/ban", s.mrAction(s.pendingReject(true)))
204 }
205 }
206 mux.HandleFunc("GET /{$}", s.page(s.home))
207 mux.HandleFunc("GET /{repo}", s.page(s.summary))
208 mux.HandleFunc("GET /{repo}/{$}", s.page(s.summary))
209 mux.HandleFunc("GET /{repo}/refs", s.page(s.refs))
210 mux.HandleFunc("GET /{repo}/commits", s.page(s.commits))
211 mux.HandleFunc("GET /{repo}/commits/{rest...}", s.page(s.commits))
212 mux.HandleFunc("GET /{repo}/commit/{sha}", s.page(s.commit))
213 mux.HandleFunc("GET /{repo}/commit/{sha}/files", s.page(s.commitFiles))
214 mux.HandleFunc("GET /{repo}/tree", s.page(s.tree))
215 mux.HandleFunc("GET /{repo}/tree/{rest...}", s.page(s.tree))
216 mux.HandleFunc("GET /{repo}/blob/{rest...}", s.page(s.blob))
217 mux.HandleFunc("GET /{repo}/raw/{rest...}", s.raw)
218 mux.HandleFunc("GET /{repo}/paths/{sha}", s.paths)
219 mux.HandleFunc("GET /{repo}/context/{sha}", s.page(s.diffContext))
220 if s.cfg.MergeRequests != nil {
221 mux.HandleFunc("GET /{repo}/merge-requests", s.page(s.mrList))
222 mux.HandleFunc("GET /{repo}/merge-requests/{$}", s.page(s.mrList))
223 mux.HandleFunc("GET /{repo}/merge-requests/{n}", s.pageOrRedirect(s.mrShow, s.mrToIssue))
224 mux.HandleFunc("GET /{repo}/merge-requests/{n}/since", s.page(s.mrSince))
225 mux.HandleFunc("GET /{repo}/merge-requests/{n}/files", s.page(s.mrFiles))
226 mux.HandleFunc("GET /{repo}/compare/{rest...}", s.page(s.compare))
227 // The writes: POST only, behind the gate (ServeHTTP).
228 mux.HandleFunc("POST /{repo}/merge-requests", s.mrAction(s.mrCreate))
229 mux.HandleFunc("POST /{repo}/merge-requests/{n}/comments", s.mrAction(s.mrComment))
230 mux.HandleFunc("POST /{repo}/merge-requests/{n}/comments/{id}/resolve", s.mrAction(s.mrResolve))
231 mux.HandleFunc("POST /{repo}/merge-requests/{n}/comments/{id}/edit", s.mrAction(s.mrEditComment))
232 mux.HandleFunc("POST /{repo}/merge-requests/{n}/comments/{id}/delete", s.mrAction(s.mrDeleteComment))
233 mux.HandleFunc("POST /{repo}/merge-requests/{n}/merge", s.mrAction(s.mrMerge))
234 mux.HandleFunc("POST /{repo}/merge-requests/{n}/close", s.mrAction(s.mrClose))
235 mux.HandleFunc("POST /{repo}/merge-requests/{n}/ready", s.mrAction(s.mrReady))
236 mux.HandleFunc("POST /{repo}/merge-requests/{n}/read", s.mrAction(s.mrRead))
237 }
238 if s.cfg.Issues != nil {
239 mux.HandleFunc("GET /{repo}/issues", s.page(s.issueList))
240 mux.HandleFunc("GET /{repo}/issues/{$}", s.page(s.issueList))
241 mux.HandleFunc("GET /{repo}/issues/new", s.issueNewRoute)
242 mux.HandleFunc("GET /{repo}/issues/{n}", s.pageOrRedirect(s.issueShow, s.issueToMR))
243 // The writes: POST only, behind the gate (ServeHTTP).
244 mux.HandleFunc("POST /{repo}/issues", s.issueAction(s.issueCreate))
245 mux.HandleFunc("POST /{repo}/issues/{n}/comments", s.issueAction(s.issueComment))
246 mux.HandleFunc("POST /{repo}/issues/{n}/close", s.issueAction(s.issueClose))
247 mux.HandleFunc("POST /{repo}/issues/{n}/reopen", s.issueAction(s.issueReopen))
248 }
249 if s.cfg.IssueForm != nil {
250 mux.HandleFunc("GET /{repo}/issues/submitted", s.issueSubmittedPage)
251 mux.HandleFunc("POST /{repo}/issues/new", s.issueFormPost)
252 }
253 if s.cfg.Runs != nil {
254 mux.HandleFunc("GET /{repo}/actions", s.page(s.actions))
255 mux.HandleFunc("GET /{repo}/actions/{$}", s.page(s.actions))
256 mux.HandleFunc("GET /{repo}/actions/runs/{id}", s.page(s.run))
257 mux.HandleFunc("GET /{repo}/actions/runs/{id}/job/{job}", s.page(s.job))
258 mux.HandleFunc("GET /{repo}/actions/runs/{id}/job/{job}/raw", s.rawLog)
259 mux.HandleFunc("GET /{repo}/actions/runs/{id}/job/{job}/stream", s.logStream)
260 mux.HandleFunc("POST /{repo}/actions/runs/{id}/cancel", s.ciAction(s.runCancel))
261 mux.HandleFunc("POST /{repo}/actions/runs/{id}/rerun", s.ciAction(s.runRerun(false)))
262 mux.HandleFunc("POST /{repo}/actions/runs/{id}/rerun-failed", s.ciAction(s.runRerun(true)))
263 if s.cfg.Artifacts != nil {
264 mux.HandleFunc("GET /{repo}/actions/runs/{id}/artifacts/{artifact}", s.artifactDownload)
265 mux.HandleFunc("POST /{repo}/actions/runs/{id}/artifacts/{artifact}/delete", s.ciAction(s.artifactDelete))
266 }
267 }
268 mux.HandleFunc(catchAll, s.page(s.notFound))
269 return mux
270}
271
272// ServeHTTP implements http.Handler.
273func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
274 // Whatever the context carried, the caller is anonymous until a valid
275 // session says otherwise (withSession).
276 r = r.WithContext(domain.ContextWithPrincipal(r.Context(), domain.Anonymous()))
277 r = s.withSession(w, r)
278 if !s.gate(w, r) {
279 return
280 }
281 if to, ok := s.ownerRedirect(r); ok {
282 http.Redirect(w, r, to, http.StatusPermanentRedirect)
283 return
284 }
285 s.mux.ServeHTTP(w, r)
286}
287
288// catchAll is the pattern of the paths that are no page.
289const catchAll = "GET /{repo}/{rest...}"
290
291// ownerRedirect maps /<owner>/<repo>[.git][/rest] to /<repo>[.git][/rest]: the
292// URLs that the github context of CI shows (html_url, commit and compare
293// URLs, clone_url) have the owner of the instance in front, like GitHub's.
294//
295// The rule is by repository, not by route: when no repository named like the
296// owner is visible to the caller, every GET or HEAD of /<owner>/<rest> is
297// redirected, so /<owner>/actions reaches the repository named "actions". A
298// repository named like the owner keeps its own pages. A private one is seen
299// as missing by an anonymous caller (the use case answers ErrNotFound), so the
300// redirect is the same as for a name nobody has and tells nothing.
301//
302// The target is built from a segment that parses as a repository name, which
303// has no slash, backslash, percent sign or dot-dot: it can only be a path on
304// this origin, never a "//host" one.
305func (s *Server) ownerRedirect(r *http.Request) (string, bool) {
306 if s.cfg.Owner == "" || (r.Method != http.MethodGet && r.Method != http.MethodHead) {
307 return "", false
308 }
309 first, rest, ok := strings.Cut(strings.TrimPrefix(r.URL.EscapedPath(), "/"), "/")
310 if !ok || !domain.OwnerMatches(s.cfg.Owner, first) || rest == "" {
311 return "", false
312 }
313 repo, _, _ := strings.Cut(rest, "/")
314 if _, err := domain.ParseRepoPath(repo); err != nil {
315 return "", false
316 }
317 if s.ownerNamesARepo(r) {
318 return "", false
319 }
320 to := "/" + rest
321 if r.URL.RawQuery != "" {
322 to += "?" + r.URL.RawQuery
323 }
324 return to, true
325}
326
327// ownerNamesARepo tells whether the caller can see a repository named like
328// the owner. A lookup that fails otherwise counts as yes: the request is then
329// served as it was before, without a redirect.
330func (s *Server) ownerNamesARepo(r *http.Request) bool {
331 if s.ownerRepo.IsZero() {
332 return false // the owner login is not a repository name
333 }
334 ctx := r.Context()
335 _, err := s.cfg.Repos.Get(ctx, principal(ctx), s.ownerRepo)
336 switch {
337 case err == nil:
338 return true
339 case errors.Is(err, domain.ErrNotFound):
340 return false
341 }
342 log := zerowrap.FromCtx(ctx)
343 log.Debug().Err(err).Msg("owner redirect: the lookup of the repository named like the owner failed")
344 return true
345}
346
347// handler builds a page. It returns the component and its status, or an
348// error, which becomes the 404 or 500 page.
349type handler func(ctx context.Context, r *http.Request) (templ.Component, int, error)
350
351// page adapts a handler: it bounds the use case calls, renders the component into
352// a buffer (so that a failure never leaves half a page), and maps errors to
353// the state pages.
354func (s *Server) page(h handler) http.HandlerFunc {
355 return func(w http.ResponseWriter, r *http.Request) {
356 ctx, cancel := context.WithTimeout(r.Context(), requestTimeout)
357 defer cancel()
358 c, status, err := h(ctx, r)
359 if err != nil {
360 s.fail(ctx, w, r, err)
361 return
362 }
363 s.write(ctx, w, r, status, c)
364 }
365}
366
367// write renders c with the given status.
368func (s *Server) write(ctx context.Context, w http.ResponseWriter, r *http.Request, status int, c templ.Component) {
369 var buf bytes.Buffer
370 if err := c.Render(ctx, &buf); err != nil {
371 // The error page itself failed: a bare answer is all that is left.
372 log := zerowrap.FromCtx(ctx)
373 log.Error().Err(err).Str("path", logPath(r.URL.Path)).Msg("render page")
374 http.Error(w, "internal error", http.StatusInternalServerError)
375 return
376 }
377 h := w.Header()
378 h.Set("Content-Type", "text/html; charset=utf-8")
379 // Links on this origin are prefetched on hover, so a click shows the page
380 // at once. Every GET page is safe to load (nothing is marked read on GET).
381 h.Set("Speculation-Rules", `"`+s.assets.urls.Rules+`"`)
382 // Public pages: the browser and any proxy revalidate each time. A page
383 // rendered for the owner is private and never stored; a handler that set
384 // its own Cache-Control keeps it.
385 if h.Get("Cache-Control") == "" {
386 cacheHeaders(ctx, h, "no-cache", sessionCache)
387 }
388 body := buf.Bytes()
389 // Whether the body is sent gzipped follows from its size and the request
390 // alone, so that the tag is known before the compression is spent.
391 gz := len(body) >= minCompress && acceptsGzip(r.Header) &&
392 !noTransform(h) && h.Get("Content-Encoding") == ""
393 addVary(h, "Accept-Encoding")
394 readOnly := r.Method == http.MethodGet || r.Method == http.MethodHead
395 // A page that may be stored gets a validator: the browser then
396 // revalidates with If-None-Match and a page that did not change costs a
397 // 304. A no-store page (the owner's) is never revalidated.
398 if readOnly && status == http.StatusOK && h.Get("ETag") == "" && !hasCacheDirective(h, noStore) {
399 tag := pageETag(body, SignedIn(ctx), gz)
400 h.Set("ETag", tag)
401 if etagMatches(strings.Join(r.Header.Values("If-None-Match"), ","), tag) {
402 h.Del("Content-Type")
403 w.WriteHeader(http.StatusNotModified)
404 return
405 }
406 }
407 if gz {
408 if z, err := gzipPage(body); err == nil && len(z) < len(body) {
409 body = z
410 h.Set("Content-Encoding", "gzip")
411 }
412 }
413 h.Set("Content-Length", itoa(len(body)))
414 w.WriteHeader(status)
415 if r.Method != http.MethodHead {
416 _, _ = w.Write(body)
417 }
418}
419
420// fail answers an error of a use case: not found (and a name or revision the
421// use case refuses, which no page can show either) gives the 404 page, a
422// visitor that left gives nothing, anything else gives the 500 page with an id
423// to find the cause in the log.
424func (s *Server) fail(ctx context.Context, w http.ResponseWriter, r *http.Request, err error) {
425 switch {
426 case errors.Is(err, domain.ErrNotFound), domain.IsInvalid(err):
427 s.write(ctx, w, r, http.StatusNotFound, s.notFoundPage())
428 case errors.Is(err, context.Canceled):
429 // The client is gone; there is nobody to answer.
430 default:
431 id := requestID()
432 log := zerowrap.FromCtx(ctx)
433 log.Error().Err(err).Str("request_id", id).Str("path", logPath(r.URL.Path)).Msg("web request failed")
434 s.write(ctx, w, r, http.StatusInternalServerError, s.errorPage(id))
435 }
436}
437
438// errNotFound is returned by handlers for a resource that does not exist
439// although the use case did not say so (a ref or a path that is not there).
440var errNotFound = domain.ErrNotFound
441
442// requestID is a short random id, shown on the 500 page and logged.
443func requestID() string {
444 var b [4]byte
445 _, _ = rand.Read(b[:])
446 return hex.EncodeToString(b[:])
447}
448
449// notFound is the handler of the paths without a page.
450func (s *Server) notFound(context.Context, *http.Request) (templ.Component, int, error) {
451 return nil, 0, errNotFound
452}
453
454// base is the Layout every page starts from.
455func (s *Server) base() Layout {
456 return Layout{
457 Owner: s.cfg.Owner,
458 Version: s.cfg.Version,
459 SourceURL: s.cfg.SourceURL,
460 Assets: s.assets.urls,
461 Passkeys: s.passkeysOn(),
462 }
463}
464
465// stateLayout is the layout of a state page: only the way home.
466func (s *Server) stateLayout(title string, crumbs []Crumb) Layout {
467 l := s.base()
468 l.Title = title + " · " + s.instance
469 l.Crumbs = crumbs
470 l.Cmd = []CmdItem{{Kind: "go", Label: "home", Href: "/"}}
471 return l
472}
473
474func (s *Server) notFoundPage() templ.Component {
475 l := s.stateLayout("404", []Crumb{{Label: "not found", Current: true}})
476 return State(l, StatePage{
477 Code: "404", Title: "not found",
478 Lines: []string{"no such page, ref or path.", "check the URL, or start from the repo list."},
479 Back: []Link{{Label: "home", Href: "/"}},
480 })
481}
482
483func (s *Server) errorPage(id string) templ.Component {
484 l := s.stateLayout("error", []Crumb{{Label: "error", Current: true}})
485 return State(l, StatePage{
486 Code: "500", Title: "internal error",
487 Lines: []string{
488 "the server failed to answer this request.",
489 "request id: " + id,
490 "retry in a moment; if it persists, the owner has the log.",
491 },
492 Back: []Link{{Label: "home", Href: "/"}},
493 })
494}
495
496// originOf is the origin of a URL as a browser writes it in the Origin
497// header: scheme and host in lower case, the port only when it is not the
498// default of the scheme.
499func originOf(u *url.URL) string {
500 scheme, host, port := strings.ToLower(u.Scheme), strings.ToLower(u.Hostname()), u.Port()
501 if strings.Contains(host, ":") {
502 host = "[" + host + "]"
503 }
504 defaultPort := (scheme == "http" && port == "80") || (scheme == "https" && port == "443")
505 if port != "" && !defaultPort {
506 host += ":" + port
507 }
508 return scheme + "://" + host
509}