Brian Picciano
3 years ago
parent
dce39b836a
commit
0197d9cd49
@ -0,0 +1,174 @@ |
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// Package api implements the HTTP-based api for the mediocre-blog.
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package api |
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import ( |
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"context" |
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"errors" |
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"fmt" |
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"net" |
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"net/http" |
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"net/http/httputil" |
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"net/url" |
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"os" |
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"github.com/mediocregopher/blog.mediocregopher.com/srv/cfg" |
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"github.com/mediocregopher/blog.mediocregopher.com/srv/mailinglist" |
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"github.com/mediocregopher/blog.mediocregopher.com/srv/pow" |
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"github.com/mediocregopher/mediocre-go-lib/v2/mctx" |
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"github.com/mediocregopher/mediocre-go-lib/v2/mlog" |
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) |
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// Params are used to instantiate a new API instance. All fields are required
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// unless otherwise noted.
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type Params struct { |
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Logger *mlog.Logger |
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PowManager pow.Manager |
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MailingList mailinglist.MailingList |
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// ListenProto and ListenAddr are passed into net.Listen to create the
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// API's listener. Both "tcp" and "unix" protocols are explicitly
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// supported.
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ListenProto, ListenAddr string |
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// StaticDir and StaticProxy are mutually exclusive.
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//
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// If StaticDir is set then that directory on the filesystem will be used to
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// serve the static site.
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//
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// Otherwise if StaticProxy is set all requests for the static site will be
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// reverse-proxied there.
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StaticDir string |
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StaticProxy *url.URL |
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} |
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// SetupCfg implement the cfg.Cfger interface.
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func (p *Params) SetupCfg(cfg *cfg.Cfg) { |
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cfg.StringVar(&p.ListenProto, "listen-proto", "tcp", "Protocol to listen for HTTP requests with") |
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cfg.StringVar(&p.ListenAddr, "listen-addr", ":4000", "Address/path to listen for HTTP requests on") |
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cfg.StringVar(&p.StaticDir, "static-dir", "", "Directory from which static files are served (mutually exclusive with -static-proxy-url)") |
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staticProxyURLStr := cfg.String("static-proxy-url", "", "HTTP address from which static files are served (mutually exclusive with -static-dir)") |
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cfg.OnInit(func(ctx context.Context) error { |
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if *staticProxyURLStr != "" { |
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var err error |
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if p.StaticProxy, err = url.Parse(*staticProxyURLStr); err != nil { |
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return fmt.Errorf("parsing -static-proxy-url: %w", err) |
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} |
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} else if p.StaticDir == "" { |
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return errors.New("-static-dir or -static-proxy-url is required") |
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} |
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return nil |
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}) |
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} |
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// Annotate implements mctx.Annotator interface.
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func (p *Params) Annotate(a mctx.Annotations) { |
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a["listenProto"] = p.ListenProto |
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a["listenAddr"] = p.ListenAddr |
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if p.StaticProxy != nil { |
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a["staticProxy"] = p.StaticProxy.String() |
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return |
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} |
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a["staticDir"] = p.StaticDir |
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} |
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// API will listen on the port configured for it, and serve HTTP requests for
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// the mediocre-blog.
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type API interface { |
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Shutdown(ctx context.Context) error |
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} |
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type api struct { |
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params Params |
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srv *http.Server |
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} |
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// New initializes and returns a new API instance, including setting up all
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// listening ports.
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func New(params Params) (API, error) { |
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l, err := net.Listen(params.ListenProto, params.ListenAddr) |
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if err != nil { |
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return nil, fmt.Errorf("creating listen socket: %w", err) |
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} |
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if params.ListenProto == "unix" { |
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if err := os.Chmod(params.ListenAddr, 0777); err != nil { |
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return nil, fmt.Errorf("chmod-ing unix socket: %w", err) |
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} |
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} |
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a := &api{ |
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params: params, |
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} |
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a.srv = &http.Server{Handler: a.handler()} |
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go func() { |
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err := a.srv.Serve(l) |
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if err != nil && !errors.Is(err, http.ErrServerClosed) { |
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ctx := mctx.Annotate(context.Background(), a.params) |
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params.Logger.Fatal(ctx, fmt.Sprintf("%s: %v", "serving http server", err)) |
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} |
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}() |
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return a, nil |
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} |
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func (a *api) Shutdown(ctx context.Context) error { |
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if err := a.srv.Shutdown(ctx); err != nil { |
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return err |
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} |
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return nil |
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} |
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func (a *api) handler() http.Handler { |
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var staticHandler http.Handler |
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if a.params.StaticDir != "" { |
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staticHandler = http.FileServer(http.Dir(a.params.StaticDir)) |
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} else { |
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staticHandler = httputil.NewSingleHostReverseProxy(a.params.StaticProxy) |
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} |
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// sugar
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requirePow := func(h http.Handler) http.Handler { |
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return a.requirePowMiddleware(h) |
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} |
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mux := http.NewServeMux() |
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mux.Handle("/", staticHandler) |
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apiMux := http.NewServeMux() |
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apiMux.Handle("/pow/challenge", a.newPowChallengeHandler()) |
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apiMux.Handle("/pow/check", |
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requirePow( |
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http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {}), |
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), |
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) |
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apiMux.Handle("/mailinglist/subscribe", requirePow(a.mailingListSubscribeHandler())) |
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apiMux.Handle("/mailinglist/finalize", a.mailingListFinalizeHandler()) |
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apiMux.Handle("/mailinglist/unsubscribe", a.mailingListUnsubscribeHandler()) |
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apiHandler := logMiddleware(a.params.Logger, apiMux) |
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apiHandler = annotateMiddleware(apiHandler) |
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apiHandler = addResponseHeaders(map[string]string{ |
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"Cache-Control": "no-store, max-age=0", |
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"Pragma": "no-cache", |
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"Expires": "0", |
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}, apiHandler) |
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mux.Handle("/api/", http.StripPrefix("/api", apiHandler)) |
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return mux |
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} |
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@ -1,4 +1,4 @@ |
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package main |
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package api |
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import ( |
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"net" |
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@ -1,4 +1,4 @@ |
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package main |
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package api |
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import ( |
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"context" |
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@ -0,0 +1,52 @@ |
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// Package cfg implements a simple wrapper around go's flag package, in order to
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// implement initialization hooks.
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package cfg |
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import ( |
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"context" |
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"flag" |
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"os" |
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) |
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// Cfger is a component which can be used with Cfg to setup its initialization.
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type Cfger interface { |
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SetupCfg(*Cfg) |
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} |
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// Cfg is a wrapper around the stdlib's FlagSet and a set of initialization
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// hooks.
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type Cfg struct { |
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*flag.FlagSet |
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hooks []func(ctx context.Context) error |
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} |
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// New initializes and returns a new instance of *Cfg.
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func New() *Cfg { |
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return &Cfg{ |
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FlagSet: flag.NewFlagSet("", flag.ExitOnError), |
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} |
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} |
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// OnInit appends the given callback to the sequence of hooks which will run on
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// a call to Init.
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func (c *Cfg) OnInit(cb func(context.Context) error) { |
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c.hooks = append(c.hooks, cb) |
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} |
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// Init runs all hooks registered using OnInit, in the same order OnInit was
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// called. If one returns an error that error is returned and no further hooks
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// are run.
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func (c *Cfg) Init(ctx context.Context) error { |
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if err := c.FlagSet.Parse(os.Args[1:]); err != nil { |
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return err |
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} |
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for _, h := range c.hooks { |
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if err := h(ctx); err != nil { |
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return err |
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} |
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} |
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return nil |
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} |
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