Refactored internals more

README.md

@@ -49,6 +49,7 @@ The `ratchetd` cmd binary uses Oauth so you will need to create a new Oauth App.
 - [Understand Mutexs in Go](https://www.alexedwards.net/blog/understanding-mutexes)
 - [Structured Logging in Go with log/slog](https://pkg.go.dev/log/slog)
 - [Exit Codes with special meaning](https://tldp.org/LDP/abs/html/exitcodes.html)
+- [Organizing Database Access in Go](https://www.alexedwards.net/blog/organising-database-access)
 
 ### Go http.FileServer
 

cmd/ratchetd/main.go

@@ -6,33 +6,37 @@ import (
 	"log/slog"
 	"net/http"
 	"os"
-	"strings"
 
-	"git.runcible.io/learning/ratchet"
-	ratchethttp "git.runcible.io/learning/ratchet/internal"
+	"git.runcible.io/learning/ratchet/internal/logging"
+	"git.runcible.io/learning/ratchet/internal/server"
+	// "git.runcible.io/learning/ratchet"
+	// ratchethttp "git.runcible.io/learning/ratchet/internal"
 )
 
-var (
-	version string
-	commit  string
-)
+// var (
+// 	version string
+// 	commit  string
+// )
 
 func main() {
-	// Commandline options
+	// CONFIGURATION
+	// Parse command line options
 	addr := flag.String("addr", "0.0.0.0", "HTTP network address")
 	port := flag.String("port", "5001", "HTTP port")
 	logLevel := flag.String("logging", "INFO", "Logging Level. Valid values [INFO, DEBUG, WARN, ERROR].")
 	// must call parse or all values will be the defaults
 	flag.Parse()
 
+	// DEPENDENCY INJECTION FOR HANDLERS
 	// Setup Logging
-	ratchethttp.InitLogging(*logLevel)
+	logger := logging.InitLogging(*logLevel)
 
 	// Propagate build information to root package to share globally
-	ratchet.Version = strings.TrimPrefix(version, "")
-	ratchet.Commit = commit
+	// ratchet.Version = strings.TrimPrefix(version, "")
+	// ratchet.Commit = commit
+	server := server.NewRatchetServer(logger)
 
-	server := ratchethttp.NewRatchetServer()
+	// START SERVING REQUESTS
 	slog.Debug("Herp dirp!")
 	slog.Info(fmt.Sprintf("Listening on http://%s:%s", *addr, *port))
 	//log.Fatal(http.ListenAndServe(fmt.Sprintf("%s:%s", *addr, *port), server))

internal/apperror/apperror.go

@@ -1,4 +1,4 @@
-package ratchet
+package apperror
 
 import (
 	"errors"

internal/apperror/apperror_test.go

@@ -1,4 +1,4 @@
-package ratchet
+package apperror
 
 import (
 	"errors"

internal/domain/user/user.go

@@ -1,8 +1,10 @@
-package ratchet
+package user
 
 import (
 	"context"
 	"time"
+
+	"git.runcible.io/learning/ratchet/internal/apperror"
 )
 
 type User struct {
@@ -27,7 +29,7 @@ type User struct {
 
 func (u *User) Validate() error {
 	if u.Name == "" {
-		return Errorf(EINVALID, "User name required.")
+		return apperror.Errorf(apperror.EINVALID, "User name required.")
 	}
 	return nil
 }

internal/domain/user/user_test.go

@@ -1,11 +1,15 @@
-package ratchet
+package user
 
-import "testing"
+import (
+	"testing"
+
+	"git.runcible.io/learning/ratchet/internal/apperror"
+)
 
 func TestUserValidation(t *testing.T) {
 	t.Run("user should return invalid", func(t *testing.T) {
 		u := &User{}
-		if ErrorCode(u.Validate()) != EINVALID {
+		if apperror.ErrorCode(u.Validate()) != apperror.EINVALID {
 			t.Errorf("User validation should have failed but passed instead.")
 		}
 	})

internal/logging/logging.go

@@ -0,0 +1,36 @@
+package logging
+
+import (
+	"log/slog"
+	"os"
+	"strings"
+)
+
+func parseLogLevel(levelStr string) slog.Level {
+	switch strings.ToUpper(levelStr) {
+	case "DEBUG":
+		return slog.LevelDebug
+	case "INFO":
+		return slog.LevelInfo
+	case "WARN":
+		return slog.LevelWarn
+	case "ERROR":
+		return slog.LevelError
+	default:
+		return slog.LevelInfo // Default level
+	}
+}
+
+// InitLogggin initializes global structured logging for the entire application
+func InitLogging(level string) *slog.Logger {
+	// Use os.Stderr
+	//
+	// Stderr is used for diagnostics and logging. Stdout is used for program
+	// output. Stderr also have greater likely hood of being seen if a programs
+	// output is being redirected.
+	parsedLogLevel := parseLogLevel(level)
+	loggerHandler := slog.NewJSONHandler(os.Stderr, &slog.HandlerOptions{Level: parsedLogLevel, AddSource: true})
+	logger := slog.New(loggerHandler)
+	slog.SetDefault(logger)
+	return logger
+}

internal/server/base_server.go

@@ -1,52 +1,26 @@
-package ratchet
+package server
 
 import (
 	"fmt"
 	"html/template"
 	"log/slog"
 	"net/http"
-	"os"
 	"strconv"
-	"strings"
+
+	"git.runcible.io/learning/ratchet/internal/domain/user"
 )
 
 type RatchetServer struct {
 	http.Handler
 
+	logger *slog.Logger
 	//Services used by HTTP routes
-	UserService UserService
-}
-
-func parseLogLevel(levelStr string) slog.Level {
-	switch strings.ToUpper(levelStr) {
-	case "DEBUG":
-		return slog.LevelDebug
-	case "INFO":
-		return slog.LevelInfo
-	case "WARN":
-		return slog.LevelWarn
-	case "ERROR":
-		return slog.LevelError
-	default:
-		return slog.LevelInfo // Default level
-	}
+	UserService user.UserService
 }
 
-func InitLogging(level string) {
-	// Use os.Stderr
-	//
-	// Stderr is used for diagnostics and logging. Stdout is used for program
-	// output. Stderr also have greater likely hood of being seen if a programs
-	// output is being redirected.
-	parsedLogLevel := parseLogLevel(level)
-	loggerHandler := slog.NewJSONHandler(os.Stderr, &slog.HandlerOptions{Level: parsedLogLevel, AddSource: true})
-	logger := slog.New(loggerHandler)
-	slog.SetDefault(logger)
-}
-
-func NewRatchetServer() *RatchetServer {
-	r := new(RatchetServer)
-
+func NewRatchetServer(logger *slog.Logger) *RatchetServer {
+	rs := new(RatchetServer)
+	rs.logger = logger
 	// TODO implement middleware that disables directory listings
 	fileServer := http.FileServer(http.Dir("./ui/static/"))
 	router := http.NewServeMux()
@@ -58,22 +32,22 @@ func NewRatchetServer() *RatchetServer {
 	// resulting in this route requiring an exact match on "/" only
 	// You can only include one HTTP method in a route pattern if you choose
 	// GET will match GET & HEAD http request methods
-	router.HandleFunc("GET /{$}", home)
-	router.HandleFunc("GET /snippet/view/{id}", snippetView)
-	router.HandleFunc("GET /snippet/create", snippetCreate)
+	router.HandleFunc("GET /{$}", rs.home)
+	router.HandleFunc("GET /snippet/view/{id}", rs.snippetView)
+	router.HandleFunc("GET /snippet/create", rs.snippetCreate)
 
 	// FYI The http.HandlerFunc() adapter works by automatically adding a ServeHTTP() method to
 	// the passed function
-	router.HandleFunc("POST /snippet/create", snippetCreatePost)
+	router.HandleFunc("POST /snippet/create", rs.snippetCreatePost)
 
 	// Mux Router implements the Handler interface. AKA it has a ServeHTTP receiver.
-	r.Handler = router
-	return r
+	rs.Handler = router
+	return rs
 }
 
-func home(w http.ResponseWriter, r *http.Request) {
+func (rs *RatchetServer) home(w http.ResponseWriter, r *http.Request) {
 	// TODO middleware should be able to print out these lines for all routes
-	slog.Info("request received", "method", "GET", "path", "/")
+	rs.logger.Info("request received", "method", "GET", "path", "/")
 
 	w.Header().Add("Server", "Go")
 
@@ -89,23 +63,25 @@ func home(w http.ResponseWriter, r *http.Request) {
 	// read template file into template set.
 	ts, err := template.ParseFiles(files...)
 	if err != nil {
-		slog.Error(err.Error())
-		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
+		rs.serverError(w, r, err)
 		return
 	}
 	// Write template content to response body
 	err = ts.ExecuteTemplate(w, "base", nil)
 	if err != nil {
-		slog.Error(err.Error())
-		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
+		// This is the older more verbose way of doing what RatchetServer.serverError does
+		// rs.logger.Error(err.Error())
+		// http.Error(w, "Internal Server Error", http.StatusInternalServerError)
+		rs.serverError(w, r, err)
 	}
 }
 
-func snippetView(w http.ResponseWriter, r *http.Request) {
+func (rs *RatchetServer) snippetView(w http.ResponseWriter, r *http.Request) {
 
 	id, err := strconv.Atoi(r.PathValue("id"))
 	if err != nil || id < 1 {
-		http.NotFound(w, r)
+		// http.NotFound(w, r)
+		rs.clientError(w, http.StatusNotFound)
 		return
 	}
 
@@ -124,12 +100,12 @@ func snippetView(w http.ResponseWriter, r *http.Request) {
 }
 
 // snippetCreate handles display of the form used to create snippets
-func snippetCreate(w http.ResponseWriter, r *http.Request) {
+func (rs *RatchetServer) snippetCreate(w http.ResponseWriter, r *http.Request) {
 	w.Write([]byte("Displaying snippetCreate form..."))
 }
 
 // snippetCreate handles display of the form used to create snippets
-func snippetCreatePost(w http.ResponseWriter, r *http.Request) {
+func (rs *RatchetServer) snippetCreatePost(w http.ResponseWriter, r *http.Request) {
 	// example of a custom header. Must be done before calling WriteHeader
 	// or they will fail to take effect.
 	w.Header().Add("Server", "Dirp")

internal/server/helpers.go

@@ -0,0 +1,29 @@
+package server
+
+import (
+	"net/http"
+	"runtime/debug"
+)
+
+// serverError helper writes a log entry at Error level (including the request
+// method and URI as attributes), then sends a generic 500 Internal Server Error
+// response to the user.
+func (rs *RatchetServer) serverError(w http.ResponseWriter, r *http.Request, err error) {
+	var (
+		method = r.Method
+		uri    = r.URL.RequestURI()
+		// Use debug.Stack() to get the stack trace. This returns a byte slice, which
+		// we need to convert to a string so that it's readable in the log entry.
+		trace = string(debug.Stack())
+	)
+
+	rs.logger.Error(err.Error(), "method", method, "uri", uri, "trace", trace)
+	http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
+}
+
+// clientError helper sends a specific status code and corresponding description
+// to the user. We'll use this later in the book to send responses like 400 "Bad
+// Request" when there's a problem with the request that the user sent
+func (rs *RatchetServer) clientError(w http.ResponseWriter, status int) {
+	http.Error(w, http.StatusText(status), status)
+}