created hws module

hws/errors.go

@@ -0,0 +1,39 @@
+package hws
+
+import "net/http"
+
+type HWSError struct {
+	statusCode int    // HTTP Status code
+	message    string // Error message
+	error      error  // Error
+}
+
+type ErrorPage func(statusCode int, w http.ResponseWriter, r *http.Request) error
+
+func NewError(statusCode int, msg string, err error) *HWSError {
+	return &HWSError{
+		statusCode: statusCode,
+		message:    msg,
+		error:      err,
+	}
+}
+
+func (server *Server) AddErrorPage(page ErrorPage) {
+	server.errorPage = page
+}
+
+func (server *Server) ThrowError(w http.ResponseWriter, r *http.Request, error *HWSError) {
+	w.WriteHeader(error.statusCode)
+	server.logger.logger.Error().Err(error.error).Msg(error.message)
+	if server.errorPage != nil {
+		err := server.errorPage(error.statusCode, w, r)
+		if err != nil {
+			server.logger.logger.Error().Err(err).Msg("Failed to render error page")
+		}
+	}
+}
+
+func (server *Server) ThrowWarn(w http.ResponseWriter, error *HWSError) {
+	w.WriteHeader(error.statusCode)
+	server.logger.logger.Warn().Err(error.error).Msg(error.message)
+}

hws/go.mod

@@ -0,0 +1,14 @@
+module git.haelnorr.com/h/golib/hws
+
+go 1.25.5
+
+require (
+	github.com/pkg/errors v0.9.1
+	github.com/rs/zerolog v1.34.0
+)
+
+require (
+	github.com/mattn/go-colorable v0.1.13 // indirect
+	github.com/mattn/go-isatty v0.0.19 // indirect
+	golang.org/x/sys v0.12.0 // indirect
+)

hws/go.sum

@@ -0,0 +1,16 @@
+github.com/coreos/go-systemd/v22 v22.5.0/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSVTIJ3seZv2GcEnc=
+github.com/godbus/dbus/v5 v5.0.4/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
+github.com/mattn/go-colorable v0.1.13 h1:fFA4WZxdEF4tXPZVKMLwD8oUnCTTo08duU7wxecdEvA=
+github.com/mattn/go-colorable v0.1.13/go.mod h1:7S9/ev0klgBDR4GtXTXX8a3vIGJpMovkB8vQcUbaXHg=
+github.com/mattn/go-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/yFXSvRLM=
+github.com/mattn/go-isatty v0.0.19 h1:JITubQf0MOLdlGRuRq+jtsDlekdYPia9ZFsB8h/APPA=
+github.com/mattn/go-isatty v0.0.19/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
+github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
+github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/rs/xid v1.6.0/go.mod h1:7XoLgs4eV+QndskICGsho+ADou8ySMSjJKDIan90Nz0=
+github.com/rs/zerolog v1.34.0 h1:k43nTLIwcTVQAncfCw4KZ2VY6ukYoZaBPNOE8txlOeY=
+github.com/rs/zerolog v1.34.0/go.mod h1:bJsvje4Z08ROH4Nhs5iH600c3IkWhwp44iRc54W6wYQ=
+golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.12.0 h1:CM0HF96J0hcLAwsHPJZjfdNzs0gftsLfgKt57wWHJ0o=
+golang.org/x/sys v0.12.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=

hws/gzip.go

@@ -0,0 +1,31 @@
+package hws
+
+import (
+	"compress/gzip"
+	"io"
+	"net/http"
+	"strings"
+)
+
+func addgzip(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if !strings.Contains(r.Header.Get("Accept-Encoding"), "gzip") {
+			next.ServeHTTP(w, r)
+			return
+		}
+		w.Header().Set("Content-Encoding", "gzip")
+		gz := gzip.NewWriter(w)
+		defer gz.Close()
+		gzw := gzipResponseWriter{Writer: gz, ResponseWriter: w}
+		next.ServeHTTP(gzw, r)
+	})
+}
+
+type gzipResponseWriter struct {
+	io.Writer
+	http.ResponseWriter
+}
+
+func (w gzipResponseWriter) Write(b []byte) (int, error) {
+	return w.Writer.Write(b)
+}

hws/logger.go

@@ -0,0 +1,44 @@
+package hws
+
+import (
+	"errors"
+	"fmt"
+	"net/url"
+
+	"github.com/rs/zerolog"
+)
+
+type logger struct {
+	logger       *zerolog.Logger
+	ignoredPaths []string
+}
+
+// Server.AddLogger adds a logger to the server to use for request logging.
+func (server *Server) AddLogger(zlogger *zerolog.Logger) error {
+	if zlogger == nil {
+		return errors.New("Unable to add logger, no logger provided")
+	}
+	server.logger = &logger{
+		logger: zlogger,
+	}
+	return nil
+}
+
+// Server.LoggerIgnorePaths sets a list of URL paths to ignore logging for.
+// Path should match the url.URL.Path field, see https://pkg.go.dev/net/url#URL
+// Useful for ignoring requests to CSS files or favicons
+func (server *Server) LoggerIgnorePaths(paths ...string) error {
+	for _, path := range paths {
+		u, err := url.Parse(path)
+		valid := err == nil &&
+			u.Scheme == "" &&
+			u.Host == "" &&
+			u.RawQuery == "" &&
+			u.Fragment == ""
+		if !valid {
+			return fmt.Errorf("Invalid path: '%s'", path)
+		}
+	}
+	server.logger.ignoredPaths = paths
+	return nil
+}

hws/middleware.go

@@ -0,0 +1,51 @@
+package hws
+
+import (
+	"errors"
+	"net/http"
+)
+
+type Middleware func(h http.Handler) http.Handler
+type MiddlewareFunc func(w http.ResponseWriter, r *http.Request) (*http.Request, *HWSError)
+
+// Server.AddMiddleware registers all the middleware.
+// Middleware will be run in the order that they are provided.
+func (server *Server) AddMiddleware(middleware ...Middleware) error {
+	if !server.routes {
+		return errors.New("Server.AddRoutes must be called before Server.AddMiddleware")
+	}
+
+	// RUN LOGGING MIDDLEWARE FIRST
+	server.server.Handler = logging(server.server.Handler, server.logger)
+
+	// LOOP PROVIDED MIDDLEWARE IN REVERSE order
+	for i := len(middleware); i > 0; i-- {
+		server.server.Handler = middleware[i-1](server.server.Handler)
+	}
+
+	// RUN GZIP
+	if server.gzip {
+		server.server.Handler = addgzip(server.server.Handler)
+	}
+	// RUN TIMER MIDDLEWARE LAST
+	server.server.Handler = startTimer(server.server.Handler)
+
+	server.middleware = true
+
+	return nil
+}
+
+func (server *Server) NewMiddleware(
+	middlewareFunc MiddlewareFunc,
+) Middleware {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			newReq, herr := middlewareFunc(w, r)
+			if herr != nil {
+				server.ThrowError(w, r, herr)
+				return
+			}
+			next.ServeHTTP(w, newReq)
+		})
+	}
+}

hws/middleware_logging.go

@@ -0,0 +1,38 @@
+package hws
+
+import (
+	"net/http"
+	"slices"
+	"time"
+)
+
+// Middleware to add logs to console with details of the request
+func logging(next http.Handler, logger *logger) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if logger == nil {
+			next.ServeHTTP(w, r)
+			return
+		}
+		if slices.Contains(logger.ignoredPaths, r.URL.Path) {
+			next.ServeHTTP(w, r)
+			return
+		}
+		start, err := getStartTime(r.Context())
+		if err != nil {
+			logger.logger.Error().Err(err)
+			return
+		}
+		wrapped := &wrappedWriter{
+			ResponseWriter: w,
+			statusCode:     http.StatusOK,
+		}
+		next.ServeHTTP(wrapped, r)
+		logger.logger.Info().
+			Int("status", wrapped.statusCode).
+			Str("method", r.Method).
+			Str("resource", r.URL.Path).
+			Dur("time_elapsed", time.Since(start)).
+			Str("remote_addr", r.Header.Get("X-Forwarded-For")).
+			Msg("Served")
+	})
+}

hws/middleware_timer.go

@@ -0,0 +1,33 @@
+package hws
+
+import (
+	"context"
+	"errors"
+	"net/http"
+	"time"
+)
+
+func startTimer(next http.Handler) http.Handler {
+	return http.HandlerFunc(
+		func(w http.ResponseWriter, r *http.Request) {
+			start := time.Now()
+			ctx := setStart(r.Context(), start)
+			newReq := r.WithContext(ctx)
+			next.ServeHTTP(w, newReq)
+		},
+	)
+}
+
+// Set the start time of the request
+func setStart(ctx context.Context, time time.Time) context.Context {
+	return context.WithValue(ctx, "hws context key request-timer", time)
+}
+
+// Get the start time of the request
+func getStartTime(ctx context.Context) (time.Time, error) {
+	start, ok := ctx.Value("hws context key request-timer").(time.Time)
+	if !ok {
+		return time.Time{}, errors.New("Failed to get start time of request")
+	}
+	return start, nil
+}

hws/responsewriter.go

@@ -0,0 +1,15 @@
+package hws
+
+import "net/http"
+
+// Wraps the http.ResponseWriter, adding a statusCode field
+type wrappedWriter struct {
+	http.ResponseWriter
+	statusCode int
+}
+
+// Extends WriteHeader to the ResponseWriter to add the status code
+func (w *wrappedWriter) WriteHeader(statusCode int) {
+	w.ResponseWriter.WriteHeader(statusCode)
+	w.statusCode = statusCode
+}

hws/routes.go

@@ -0,0 +1,62 @@
+package hws
+
+import (
+	"errors"
+	"fmt"
+	"net/http"
+)
+
+type Route struct {
+	Path    string       // Absolute path to the requested resource
+	Method  Method       // HTTP Method
+	Handler http.Handler // Handler to use for the request
+}
+
+type Method string
+
+const (
+	MethodGET     Method = "GET"
+	MethodPOST    Method = "POST"
+	MethodPUT     Method = "PUT"
+	MethodHEAD    Method = "HEAD"
+	MethodDELETE  Method = "DELETE"
+	MethodCONNECT Method = "CONNECT"
+	MethodOPTIONS Method = "OPTIONS"
+	MethodTRACE   Method = "TRACE"
+	MethodPATCH   Method = "PATCH"
+)
+
+// Server.AddRoutes registers the page handlers for the server.
+// At least one route must be provided.
+func (server *Server) AddRoutes(routes ...Route) error {
+	if len(routes) == 0 {
+		return errors.New("No routes provided")
+	}
+	mux := http.NewServeMux()
+	mux.HandleFunc("GET /healthz", func(http.ResponseWriter, *http.Request) {})
+	for _, route := range routes {
+		if !validMethod(route.Method) {
+			return fmt.Errorf("Invalid method %s for path %s", route.Method, route.Path)
+		}
+		if route.Handler == nil {
+			return fmt.Errorf("No handler provided for %s %s", route.Method, route.Path)
+		}
+		pattern := fmt.Sprintf("%s %s", route.Method, route.Path)
+		mux.Handle(pattern, route.Handler)
+	}
+
+	server.server.Handler = mux
+	server.routes = true
+
+	return nil
+}
+
+func validMethod(m Method) bool {
+	switch m {
+	case MethodGET, MethodPOST, MethodPUT, MethodHEAD,
+		MethodDELETE, MethodCONNECT, MethodOPTIONS, MethodTRACE, MethodPATCH:
+		return true
+	default:
+		return false
+	}
+}

hws/safefileserver.go

@@ -0,0 +1,52 @@
+package hws
+
+import (
+	"net/http"
+	"os"
+
+	"github.com/pkg/errors"
+)
+
+// Wrapper for default FileSystem
+type justFilesFilesystem struct {
+	fs http.FileSystem
+}
+
+// Wrapper for default File
+type neuteredReaddirFile struct {
+	http.File
+}
+
+// Modifies the behavior of FileSystem.Open to return the neutered version of File
+func (fs justFilesFilesystem) Open(name string) (http.File, error) {
+	f, err := fs.fs.Open(name)
+	if err != nil {
+		return nil, err
+	}
+
+	// Check if the requested path is a directory
+	// and explicitly return an error to trigger a 404
+	fileInfo, err := f.Stat()
+	if err != nil {
+		return nil, err
+	}
+	if fileInfo.IsDir() {
+		return nil, os.ErrNotExist
+	}
+
+	return neuteredReaddirFile{f}, nil
+}
+
+// Overrides the Readdir method of File to always return nil
+func (f neuteredReaddirFile) Readdir(count int) ([]os.FileInfo, error) {
+	return nil, nil
+}
+
+func SafeFileServer(fileSystem *http.FileSystem) (http.Handler, error) {
+	if fileSystem == nil {
+		return nil, errors.New("No file system provided")
+	}
+	nfs := justFilesFilesystem{*fileSystem}
+	fs := http.FileServer(nfs)
+	return fs, nil
+}

hws/server.go

@@ -0,0 +1,84 @@
+package hws
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"net/http"
+	"time"
+
+	"github.com/pkg/errors"
+)
+
+type Server struct {
+	server     *http.Server
+	logger     *logger
+	routes     bool
+	middleware bool
+	gzip       bool
+	errorPage  ErrorPage
+}
+
+// NewServer returns a new hws.Server with the specified parameters.
+// The timeout options are specified in seconds
+func NewServer(
+	host string,
+	port string,
+	readHeaderTimeout time.Duration,
+	writeTimeout time.Duration,
+	idleTimeout time.Duration,
+	gzip bool,
+) (*Server, error) {
+	// TODO: test that host and port are valid values
+	httpServer := &http.Server{
+		Addr:              net.JoinHostPort(host, port),
+		ReadHeaderTimeout: readHeaderTimeout * time.Second,
+		WriteTimeout:      writeTimeout * time.Second,
+		IdleTimeout:       idleTimeout * time.Second,
+	}
+	server := &Server{
+		server: httpServer,
+		routes: false,
+		gzip:   gzip,
+	}
+	return server, nil
+}
+
+func (server *Server) Start() error {
+	if !server.routes {
+		return errors.New("Server.AddRoutes must be run before starting the server")
+	}
+	if !server.middleware {
+		err := server.AddMiddleware()
+		if err != nil {
+			return errors.Wrap(err, "server.AddMiddleware")
+		}
+	}
+
+	go func() {
+		if server.logger == nil {
+			fmt.Printf("Listening for requests on %s", server.server.Addr)
+		} else {
+			server.logger.logger.Info().Str("address", server.server.Addr).Msg("Listening for requests")
+		}
+		if err := server.server.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+			if server.logger == nil {
+				fmt.Printf("Server encountered a fatal error: %s", err.Error())
+			} else {
+				server.logger.logger.Error().Err(err).Msg("Server encountered a fatal error")
+			}
+		}
+	}()
+
+	return nil
+}
+
+func (server *Server) Shutdown(ctx context.Context) {
+	if err := server.server.Shutdown(ctx); err != nil {
+		if server.logger == nil {
+			fmt.Printf("Failed to gracefully shutdown the server: %s", err.Error())
+		} else {
+			server.logger.logger.Error().Err(err).Msg("Failed to gracefully shutdown the server")
+		}
+	}
+}