.gitignore

@@ -0,0 +1,20 @@
+# Binaries for programs and plugins
+artifacts
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+
+# Test binary, built with `go test -c`
+*.test
+
+# Output of the go coverage tool, specifically when used with LiteIDE
+*.out
+
+# Dependency directories (remove the comment below to include it)
+# vendor/
+
+# Go workspace file
+go.work
+go.work.sum

README.md

@@ -1,6 +1,32 @@
-# Testing
+# GocustomUrls
 
-With the go-get command
+This is a homespun implementation of the practice of [using custom import paths for go modules](https://pkg.go.dev/cmd/go#hdr-Remote_import_paths).
+
+This package basically returns a html document with a prefilled meta tag
+
+```html
+<meta name="go-import" content="{package} git {url location of the package}">
+```
+
+There are ways to do this with [nginx](https://www.nirenjan.com/2019/golang-vanity-urls-in-nginx/) or [hugo](https://blog.jbowen.dev/2020/07/using-go-vanity-urls-with-hugo/) but I wanted to:
+
+* host on a subdomain
+* not muck up my ngnix config
+
+So I used golang for this project.
+
+## Testing
+
+You can test with 
+
+(a) [httpie](https://httpie.io/)
+
+```sh
+$ http --body "https://{domain.name}/{package}?go-get=1"
+...truncated output
+```
+
+(b) With the go-get command
 
 ```sh
 $ go get -v -u jbowen.dev/cereal
@@ -8,9 +34,8 @@ get "jbowen.dev/cereal": found meta tag get.metaImport{Prefix:"jbowen.dev/cereal
 jbowen.dev/cereal (download)
 ```
 
-With the httpie command
+## TODOs
 
-```sh
+* [x] Fix permission errors around opening the app.log and rules.json.
-$ http --body "https://gopkg.in/yaml.v3?go-get=1"
+* [x] Make the flags (config, rules) required instead of optional.
-...
+* [ ] Figure how to use logrotate (a linux utility)
-```

conf.go

@@ -41,8 +41,10 @@ func (c *Config) LoadMappingFile(fp string) error {
 	if len(c.MappingFilePath) == 0 {
 		ok := isFile(mappingFilePath)
 		if !ok {
-			return fmt.Errorf("%s is not found", mappingFilePath)
+			return fmt.Errorf("mappingfile %s is not found", mappingFilePath)
 		}
+	} else {
+		mappingFilePath = c.MappingFilePath
 	}
 	mappingFile, err := os.Open(mappingFilePath)
 	if err != nil {

embed.go

@@ -5,15 +5,26 @@ import (
 	"html/template"
 )
 
-// go:embed templates/*
+// https://stackoverflow.com/questions/70193820/why-isnt-go-embedding-files
+//
+//go:embed templates/*
 var tmpls embed.FS
 
-func GetServeHtml() *template.Template {
+func GetServeHtml() (*template.Template, error) {
-	data, _ := tmpls.ReadFile("success.html")
+	var t *template.Template
-	return template.Must(template.New("main").Parse(string(data)))
+	data, err := tmpls.ReadFile("templates/success.html")
+	if err != nil {
+		return t, err
+	}
+	return template.New("").Parse(string(data))
 }
 
-func GetDefaultHtml() []byte {
+func GetDefaultHtml() ([]byte, error) {
-	data, _ := tmpls.ReadFile("default.html")
+	var data []byte
-	return data
+	var err error
+	data, err = tmpls.ReadFile("templates/default.html")
+	if err != nil {
+		return data, err
+	}
+	return data, nil
 }

handlers.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"bytes"
+	"fmt"
 	"net/http"
 	"strings"
 )
@@ -14,8 +15,9 @@ func reloadRules(c *Config) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		err := c.LoadMappingFile("")
 		if err != nil {
-			errorLog.Printf("Cannot reload rules: %+v", err)
+			e := fmt.Errorf("annot reload rules: %+v", err)
-			http.Error(w, err.Error(), http.StatusInternalServerError)
+			// errorLog.Printf("Cannot reload rules: %+v", err)
+			http.Error(w, e.Error(), http.StatusInternalServerError)
 			return
 		}
 		w.Write([]byte("ok"))
@@ -31,7 +33,12 @@ func serveRules(c *Config) http.HandlerFunc {
 
 		// if go-get param is absent, return nothing
 		if r.FormValue("go-get") != "1" {
-			w.Write(GetDefaultHtml())
+			data, err := GetDefaultHtml()
+			if err != nil {
+				http.Error(w, err.Error(), http.StatusInternalServerError)
+				return
+			}
+			w.Write(data)
 			return
 		}
 
@@ -39,12 +46,9 @@ func serveRules(c *Config) http.HandlerFunc {
 
 		var vanityUrl, proto, repoUrl string
 		for _, rule := range c.MappingRules.Mappings {
-			if strings.HasPrefix(strings.ToLower(nameOfPkg), strings.ToLower(rule.VanityUrl+"/")) {
+			if strings.HasPrefix(strings.ToLower(rule.VanityUrl+"/"), strings.Trim(strings.ToLower(nameOfPkg), " ")) {
-				repo := strings.Replace(strings.ToLower(nameOfPkg), strings.ToLower(rule.VanityUrl), "", -1)
+				vanityUrl = rule.VanityUrl
-				repo = strings.Split(repo, "/")[1]
+				repoUrl = rule.RealUrl
-
-				vanityUrl = rule.VanityUrl + "/" + repo
-				repoUrl = rule.RealUrl + "/" + repo
 				proto = rule.Protocol
 
 				break
@@ -56,10 +60,14 @@ func serveRules(c *Config) http.HandlerFunc {
 			Proto:     proto,
 			RepoUrl:   repoUrl,
 		}
-		tmpl := GetServeHtml()
+		tmpl, err := GetServeHtml()
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
 
 		var buf bytes.Buffer
-		err := tmpl.Execute(&buf, &d)
+		err = tmpl.Execute(&buf, &d)
 		if err != nil {
 			http.Error(w, err.Error(), http.StatusInternalServerError)
 			return

logger.go

@@ -5,7 +5,9 @@ import (
 	"log"
 	"net/http"
 	"os"
+	"path/filepath"
 	"strings"
+	"time"
 )
 
 // some headers not worth logging
@@ -50,7 +52,13 @@ type LogFileRec struct {
 }
 
 func newFileLogger(path string) (*LogFile, error) {
-	f, err := os.OpenFile(path, os.O_WRONLY|os.O_APPEND|os.O_CREATE, 0666)
+	requestedFile := filepath.Clean(filepath.Join("/", path))
+	parentDir := filepath.Dir(requestedFile)
+	err := os.MkdirAll(parentDir, 0777)
+	if err != nil {
+		return nil, err
+	}
+	f, err := os.OpenFile(requestedFile, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0666)
 	if err != nil {
 		return nil, err
 	}
@@ -123,6 +131,11 @@ func shouldLogHeader(s string) bool {
 	return !hdrsToNotLogMap[s]
 }
 
+func getCurrentDate() string {
+	dt := time.Now()
+	return dt.Format(time.RFC3339Nano)
+}
+
 func (f *LogFile) WriteLog(r *http.Request) error {
 	if f == nil {
 		return nil
@@ -132,6 +145,7 @@ func (f *LogFile) WriteLog(r *http.Request) error {
 	rec["requestUri"] = r.RequestURI
 	rec["Host"] = r.Host
 	rec["ipAddr"] = extractIpAddress(r)
+	rec["requestDate"] = getCurrentDate()
 	if !canSkipExtraHeaders(r) {
 		for key, val := range r.Header {
 			if shouldLogHeader(key) && len(val) > 0 {

main.go

@@ -9,16 +9,18 @@ import (
 	"net/http"
 	"os"
 	"os/signal"
+	"path/filepath"
+	"strconv"
 	"syscall"
 	"time"
 )
 
 var errorLog *log.Logger = log.New(os.Stderr, "", log.LstdFlags)
 
-const (
+// const (
-	DEFAULT_RULES_FILE string = "/var/lib/gocustomurls/rules.json"
+// 	DEFAULT_RULES_FILE string = "/var/lib/gocustomurls/rules.json"
-	DEFAULT_LOG_FILE   string = "/var/log/gocustomurls/app.log"
+// 	DEFAULT_LOG_FILE   string = "/var/log/gocustomurls/app.log"
-)
+// )
 
 // flagsSet returns a set of all the flags what were actually set on the
 // command line.
@@ -30,6 +32,35 @@ func flagsSet(flags *flag.FlagSet) map[string]bool {
 	return s
 }
 
+// generateDefaults - generate the default values for the rules.json and log files
+func generateDefaults(rulesfp string, logfp string) (string, string, error) {
+	var newlogfp, newrulesfp string
+	var err error
+	newlogfp = logfp
+	newrulesfp = rulesfp
+	if len(newrulesfp) == 0 {
+		dir, err := os.UserConfigDir()
+		if err != nil {
+			return newrulesfp, newlogfp, err
+		}
+		newrulesfp = filepath.Join(dir, "gocustomcurls", "rules.json")
+	}
+	if len(newlogfp) == 0 {
+		dir, err := os.UserHomeDir()
+		if err != nil {
+			return newrulesfp, newlogfp, err
+		}
+		newlogfp = filepath.Join(dir, ".gocustomurls", "logs", "app.log")
+	}
+	return newrulesfp, newlogfp, err
+}
+
+// isValidPort returns true if the port is valid
+// following the RFC https://datatracker.ietf.org/doc/html/rfc6056#section-2.1
+func isValidPort(port int) bool {
+	return port > 0 && port < 65535
+}
+
 func main() {
 	programName := os.Args[0]
 	// errorLog = log.New(os.Stderr, "", log.LstdFlags)
@@ -43,9 +74,9 @@ func main() {
 		flags.PrintDefaults()
 	}
 
-	portFlag := flags.String("port", "7070", "port to listen to")
+	portFlag := flags.String("port", "7070", "Optional. Default port is 7070. Port to listen to")
-	rulesFileFlag := flags.String("config", DEFAULT_RULES_FILE, "contains go-import mapping")
+	rulesFileFlag := flags.String("config", "", "Optional. Contains go-import mapping")
-	logFileFlag := flags.String("logfile", DEFAULT_LOG_FILE, "default log file")
+	logFileFlag := flags.String("logfile", "", "Optional. Default log file")
 	flags.Parse(os.Args[1:])
 
 	if len(flags.Args()) > 1 {
@@ -59,9 +90,23 @@ func main() {
 	var port string
 	if allSetFlags["port"] {
 		port = *portFlag
+	} else {
+		port = "7070"
+	}
+
+	p, err := strconv.Atoi(port)
+	if err != nil {
+		errorLog.Println(err)
+		os.Exit(1)
+	}
+
+	if !isValidPort(p) {
+		errorLog.Println(fmt.Errorf("provided port (%d) is not valid", p))
+		os.Exit(1)
 	}
 
 	var rulesFile string
+
 	if allSetFlags["config"] {
 		rulesFile = *rulesFileFlag
 	}
@@ -71,14 +116,20 @@ func main() {
 		logFile = *logFileFlag
 	}
 
-	// load rules mapping
+	rFile, lFile, err := generateDefaults(logFile, rulesFile)
-	c := &Config{}
-	err := c.LoadMappingFile(rulesFile)
 	if err != nil {
 		errorLog.Println(err)
 		os.Exit(1)
 	}
-	l, err := newFileLogger(logFile)
+
+	// load rules mapping
+	c := &Config{}
+	err = c.LoadMappingFile(rFile)
+	if err != nil {
+		errorLog.Println(err)
+		os.Exit(1)
+	}
+	l, err := newFileLogger(lFile)
 	if err != nil {
 		errorLog.Println(err)
 		os.Exit(1)
@@ -92,12 +143,13 @@ func main() {
 
 	// For graceful shutdowns
 	go func() {
+		app.Log.logger.Printf("%s Starting\n", getCurrentDate())
 		err := srv.ListenAndServe()
 		if !errors.Is(err, http.ErrServerClosed) {
 			errorLog.Printf("HTTP Server error: %+v\n", err)
 			os.Exit(1)
 		}
-		app.Log.logger.Println("Stopped serving new connections.")
+		app.Log.logger.Printf("%s Stopped serving new connections.\n", getCurrentDate())
 	}()
 
 	sigChan := make(chan os.Signal, 1)
@@ -111,5 +163,5 @@ func main() {
 		errorLog.Printf("HTTP shutdown error: %+v\n", err)
 		os.Exit(1)
 	}
-	app.Log.logger.Println("Graceful shutdown complete.")
+	app.Log.logger.Printf("%s Graceful shutdown complete.\n", getCurrentDate())
 }