diff --git a/API.md b/API.md new file mode 100644 index 0000000..3c65eb6 --- /dev/null +++ b/API.md @@ -0,0 +1,4 @@ +# dn42grcsrv API Description + +tbc + diff --git a/README.md b/README.md index 4a024ee..2d9bd01 100644 --- a/README.md +++ b/README.md @@ -9,6 +9,8 @@ A public instance of the API and explorer web app can be accessed via: ## Features -* tbc +* Includes simple webserver for delivering static content +## Using +See the [API.md](API.md) file for a detailed description of the API. diff --git a/contrib/dn42grcsrv.service b/contrib/dn42grcsrv.service new file mode 100644 index 0000000..a47d1d9 --- /dev/null +++ b/contrib/dn42grcsrv.service @@ -0,0 +1,20 @@ +########################################################################## +# dn42regsrv example systemd service file +########################################################################## + +[Unit] +Description=DN42 GRC API Server +After=network.target + +[Install] +WantedBy=multi-user.target + +[Service] +User=regsrv +Group=registry +Type=simple +Restart=on-failure +ExecStart=/home/grcsrv/go/bin/dn42grcsrv + +######################################################################### +# end of file diff --git a/dn42grcsrv.go b/dn42grcsrv.go new file mode 100644 index 0000000..18de1b5 --- /dev/null +++ b/dn42grcsrv.go @@ -0,0 +1,172 @@ +////////////////////////////////////////////////////////////////////////// +// DN42 GRC API Server +////////////////////////////////////////////////////////////////////////// + +package main + +////////////////////////////////////////////////////////////////////////// + +import ( + "context" + "github.com/gorilla/mux" + log "github.com/sirupsen/logrus" + flag "github.com/spf13/pflag" + "net/http" + "os" + "os/signal" + "time" +) + +////////////////////////////////////////////////////////////////////////// + +var EventBus = make(SimpleEventBus) + +////////////////////////////////////////////////////////////////////////// +// http request logger + +func requestLogger(next http.Handler) http.Handler { + return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { + + log.WithFields(log.Fields{ + "method": r.Method, + "URL": r.URL.String(), + "Remote": r.RemoteAddr, + }).Debug("HTTP Request") + + next.ServeHTTP(w, r) + }) +} + +////////////////////////////////////////////////////////////////////////// +// Install static routes + +func installStaticRoutes(router *mux.Router, staticPath string) { + + // an empty path disables static route serving + if staticPath == "" { + log.Info("Disabling static route serving") + return + } + + // validate that the staticPath exists + stat, err := os.Stat(staticPath) + if err != nil { + log.WithFields(log.Fields{ + "error": err, + "path": staticPath, + }).Fatal("Unable to find static page directory") + } + + // and it is a directory + if !stat.IsDir() { + log.WithFields(log.Fields{ + "error": err, + "path": staticPath, + }).Fatal("Static path is not a directory") + } + + // install a file server for the static route + router.PathPrefix("/").Handler(http.StripPrefix("/", + http.FileServer(http.Dir(staticPath)))).Methods("GET") + + log.WithFields(log.Fields{ + "path": staticPath, + }).Info("Static route installed") + +} + +////////////////////////////////////////////////////////////////////////// +// everything starts here + +func main() { + + // set a default log level, so that logging can be used immediately + // the level will be overidden later on once the command line + // options are loaded + log.SetLevel(log.InfoLevel) + log.Info("DN42 GRC API Server Starting") + + // declare cmd line options + var ( + logLevel = flag.StringP("LogLevel", "l", "Info", "Log level") + bindAddress = flag.StringP("BindAddress", "b", ":80", "Server bind address") + staticRoot = flag.StringP("StaticRoot", "s", "/home/grcsrv/webapp", "Static page directory") + refreshInterval = flag.StringP("Refresh", "i", "60m", "Refresh interval") + ) + flag.Parse() + + // now initialise logging properly based on the cmd line options + setLogLevel(*logLevel) + + // parse the refreshInterval and start data collection + interval, err := time.ParseDuration(*refreshInterval) + if err != nil { + log.WithFields(log.Fields{ + "error": err, + "interval": *refreshInterval, + }).Fatal("Unable to parse registry refresh interval") + } + + interval = interval + + // start data collection here + + // initialise router + router := mux.NewRouter() + // log all access + router.Use(requestLogger) + + // add API routes + subr := router.PathPrefix("/api").Subrouter() + EventBus.Fire("APIEndpoint", subr) + + // initialise static routes + installStaticRoutes(router, *staticRoot) + + // initialise http server + server := &http.Server{ + Addr: *bindAddress, + WriteTimeout: time.Second * 15, + ReadTimeout: time.Second * 15, + IdleTimeout: time.Second * 60, + Handler: router, + } + + // run the server in a non-blocking goroutine + + log.WithFields(log.Fields{ + "BindAddress": *bindAddress, + }).Info("Starting server") + + go func() { + if err := server.ListenAndServe(); err != nil { + log.WithFields(log.Fields{ + "error": err, + "BindAddress": *bindAddress, + }).Fatal("Unable to start server") + } + }() + + // graceful shutdown via SIGINT (^C) + csig := make(chan os.Signal, 1) + signal.Notify(csig, os.Interrupt) + + // and block + <-csig + + log.Info("Server shutting down") + + // deadline for server to shutdown + ctx, cancel := context.WithTimeout(context.Background(), 10) + defer cancel() + + // shutdown the server + server.Shutdown(ctx) + + // nothing left to do + log.Info("Shutdown complete, all done") + os.Exit(0) +} + +////////////////////////////////////////////////////////////////////////// +// end of code diff --git a/util.go b/util.go new file mode 100644 index 0000000..4c24c5d --- /dev/null +++ b/util.go @@ -0,0 +1,82 @@ +////////////////////////////////////////////////////////////////////////// +// DN42 GRC API Server +////////////////////////////////////////////////////////////////////////// + +package main + +////////////////////////////////////////////////////////////////////////// + +import ( + "encoding/json" + log "github.com/sirupsen/logrus" + "net/http" +) + +////////////////////////////////////////////////////////////////////////// +// Simple event bus + +type NotifyFunc func(...interface{}) +type SimpleEventBus map[string][]NotifyFunc + +// add a listener to an event +func (bus SimpleEventBus) Listen(event string, nfunc NotifyFunc) { + bus[event] = append(bus[event], nfunc) +} + +// fire notifications for an event +func (bus SimpleEventBus) Fire(event string, params ...interface{}) { + funcs := bus[event] + if funcs != nil { + for _, nfunc := range funcs { + nfunc(params...) + } + } +} + +////////////////////////////////////////////////////////////////////////// +// Return JSON from an API endpoint + +func ResponseJSON(w http.ResponseWriter, v interface{}) { + + // for response time testing + //time.Sleep(time.Second) + + // marshal the JSON string + data, err := json.Marshal(v) + if err != nil { + log.WithFields(log.Fields{ + "error": err, + }).Error("Failed to marshal JSON") + } + + // write back to http handler + w.Header().Set("Content-Type", "application/json") + w.Header().Set("Access-Control-Allow-Origin", "*") + w.Write(data) +} + +////////////////////////////////////////////////////////////////////////// +// Set the log level + +func setLogLevel(levelStr string) { + + if level, err := log.ParseLevel(levelStr); err != nil { + // failed to set the level + + // set a sensible default and, of course, log the error + log.SetLevel(log.InfoLevel) + log.WithFields(log.Fields{ + "loglevel": levelStr, + "error": err, + }).Error("Failed to set requested log level") + + } else { + + // set the requested level + log.SetLevel(level) + + } +} + +////////////////////////////////////////////////////////////////////////// +// end of code