bootstrap a go application

planning to make this some kind of unhinged microfrontend hotwired mess.

this is basically the setup walked through in "Lets Go", but pared down.

since we plan to ship this in k8s behind nginx and cert-manager, there's no need
to do TLS termination in go.

i like httprouter and alice, so i'm including them here early.

use `go:embed` to get our templates and static assets (neither of which exist
yet) into the binary so we can ship this whole thing to a commodity `go`
container.

README.md

@@ -0,0 +1,15 @@
+replication.systems
+===================
+
+it's a [`go`][golang] + [`hotwire`][hotwire] mess!
+
+[wtf.replication.tech][wtf]
+---------------------------
+
+TK: planning to put some stuff about how this made and deployed at the above
+address.
+
+
+[golang]: https://go.dev/
+[hotwire]: https://hotwired.dev/
+[wtf]: wtf.replication.tech

cmd/web/handlers.go

@@ -0,0 +1,15 @@
+package main
+
+import (
+	"net/http"
+)
+
+// home ...
+func (app *application) home(w http.ResponseWriter, r *http.Request) {
+	if r.URL.Path != "/" {
+		http.NotFound(w, r)
+		return
+	}
+
+	w.Write([]byte("Hello from replication.systems"))
+}

cmd/web/logger.go

@@ -0,0 +1,26 @@
+package main
+
+import (
+	"log/slog"
+	"os"
+)
+
+// loggerBuilder ...
+func loggerBuilder(logfmt *string, loglevel *string) *slog.Logger {
+	var logger *slog.Logger
+	var handler_options slog.HandlerOptions
+
+	switch *loglevel {
+        case "DEBUG": handler_options = slog.HandlerOptions{Level: slog.LevelDebug}
+	case "INFO": handler_options = slog.HandlerOptions{Level: slog.LevelInfo}
+	case "WARN": handler_options = slog.HandlerOptions{Level: slog.LevelWarn}
+	case "ERROR": handler_options = slog.HandlerOptions{Level: slog.LevelError}
+	}
+
+	switch *logfmt {
+	case "json": logger = slog.New(slog.NewJSONHandler(os.Stdout, &handler_options))
+	default: logger = slog.New(slog.NewTextHandler(os.Stdout, &handler_options))
+	}
+
+	return logger
+}

cmd/web/main.go

@@ -0,0 +1,44 @@
+package main
+
+import (
+	"flag"
+	"log/slog"
+	"net/http"
+	"os"
+	"time"
+)
+
+type application struct {
+	logger *slog.Logger
+}
+
+// main run the webserverrrrr
+func main() {
+	// configuration
+	addr := flag.String("addr", ":4000", "HTTP network address")
+	logfmt := flag.String("logfmt", "text", "Log output format")
+	loglevel := flag.String("loglevel", "INFO", "Log level: DEBUG, INFO, WARN, or ERROR")
+	flag.Parse()
+
+	// setup the application
+	app := &application{
+		logger: loggerBuilder(logfmt, loglevel),
+	}
+
+
+	srv := &http.Server{
+		Addr:         *addr,
+		Handler:      app.routes(),
+		ErrorLog:     slog.NewLogLogger(app.logger.Handler(), slog.LevelError),
+		IdleTimeout:  time.Minute,
+		ReadTimeout:  5 * time.Second,
+		WriteTimeout: 10 * time.Second,
+	}
+
+	app.logger.Info("starting server", slog.String("addr", *addr))
+
+	err := srv.ListenAndServe()
+
+	app.logger.Error(err.Error())
+	os.Exit(1)
+}

cmd/web/routes.go

@@ -0,0 +1,25 @@
+package main
+
+import (
+	"net/http"
+
+	"github.com/julienschmidt/httprouter"
+	"github.com/justinas/alice"
+
+	"replication-systems.estradiol.cloud/ui"
+)
+
+// routes ...
+func (app *application) routes() http.Handler {
+	router := httprouter.New()
+
+	// setup server for static files
+	fileServer := http.FileServer(http.FS(ui.Files))
+	router.Handler(http.MethodGet, "/static/*filepath", fileServer)
+
+	router.HandlerFunc(http.MethodGet, "/", app.home)
+
+	standard := alice.New()
+
+	return standard.Then(router)
+}

go.mod

@@ -0,0 +1,8 @@
+module replication-systems.estradiol.cloud
+
+go 1.21.4
+
+require (
+	github.com/julienschmidt/httprouter v1.3.0
+	github.com/justinas/alice v1.2.0
+)

go.sum

@@ -0,0 +1,4 @@
+github.com/julienschmidt/httprouter v1.3.0 h1:U0609e9tgbseu3rBINet9P48AI/D3oJs4dN7jwJOQ1U=
+github.com/julienschmidt/httprouter v1.3.0/go.mod h1:JR6WtHb+2LUe8TCKY3cZOxFyyO8IZAc4RVcycCCAKdM=
+github.com/justinas/alice v1.2.0 h1:+MHSA/vccVCF4Uq37S42jwlkvI2Xzl7zTPCN5BnZNVo=
+github.com/justinas/alice v1.2.0/go.mod h1:fN5HRH/reO/zrUflLfTN43t3vXvKzvZIENsNEe7i7qA=

ui/efs.go

@@ -0,0 +1,8 @@
+package ui
+
+import (
+	"embed"
+)
+
+//go:embed "html" "static"
+var Files embed.FS