simplify code

- remove support for "consumer" external switchable energy consumers.
- use slog instead of zerolog
- disable flaky undeterministic tests
- rewrite control loop without concurrency

README.md

@@ -7,6 +7,11 @@ The author and the project are not affiliated with the Victron Company. The bran
 only in educational context. Everything here is shared for educational purpose only and 
 for use at your own risk only.
 
+## Code structure
+
+- `cmd/` commands/servers/entrypoints
+- `pkg/` potentially re-usable packages.
+
 ## Usage
 
 Interactive mode:
@@ -52,12 +57,9 @@ Configure NixOS Module:
     enable = true;
     maxInverter = 120;
     maxInverterPeak = 800;
-    shellyUrl = "http://shellyem3-.1.localnet.cc";
-    consumer = [{
-      url = "shelly1://shellyplus1pm-/";
-      power = 350;
-      delaySec = 5;
-    }];
+    shellyEM3 = "http://shellyem3-.1.localnet.cc";
   };
 }
-```
+```
+
+

cmd/common.go

@@ -2,32 +2,59 @@ package cmd
 
 import (
 	"context"
+	"errors"
 	"flag"
+	"net"
+	"net/http"
+	"os"
 	"time"
 
-	"github.com/yvesf/ve-ctrl-tool/mk2"
+	"github.com/bsm/openmetrics"
+	"github.com/bsm/openmetrics/omhttp"
+	"github.com/yvesf/ve-ctrl-tool/pkg/mk2"
+	"github.com/yvesf/ve-ctrl-tool/pkg/timemock"
 	"github.com/yvesf/ve-ctrl-tool/pkg/vebus"
-
-	"github.com/rs/zerolog"
+	"golang.org/x/exp/slog"
 )
 
 var (
 	flagSerialDevice = flag.String("serialDevice", "/dev/ttyUSB0", "Device")
 	flagLow          = flag.Bool("low", false, "Do not attempt to upgrade to 115200 baud")
 	flagVEAddress    = flag.Int("veAddress", 0, "Set other address than 0")
 	flagDebug        = flag.Bool("debug", false, "Set log level to debug")
-	flagTrace        = flag.Bool("trace", false, "Set log level to trace (overrides -debug)")
+	flagMetricsHTTP  = flag.String("metricsHTTP", "", "Address of a http server serving metrics under /metrics")
 )
 
 func CommonInit(ctx context.Context) *mk2.Adapter {
 	flag.Parse()
 
-	zerolog.SetGlobalLevel(zerolog.InfoLevel)
+	logLevel := slog.LevelInfo
 	if *flagDebug {
-		zerolog.SetGlobalLevel(zerolog.DebugLevel)
+		logLevel = slog.LevelDebug
 	}
-	if *flagTrace {
-		zerolog.SetGlobalLevel(zerolog.TraceLevel)
+	h := slog.NewJSONHandler(os.Stderr, &slog.HandlerOptions{Level: logLevel})
+	slog.SetDefault(slog.New(h))
+
+	// Metrics HTTP endpoint
+	if *flagMetricsHTTP != `` {
+		mux := http.NewServeMux()
+		mux.Handle("/metrics", omhttp.NewHandler(openmetrics.DefaultRegistry()))
+
+		var lc net.ListenConfig
+		ln, err := lc.Listen(ctx, "tcp", *flagMetricsHTTP)
+		if err != nil {
+			slog.Error("Listen on http failed", slog.String("addr", *flagMetricsHTTP))
+			os.Exit(1)
+		}
+
+		srv := &http.Server{Handler: mux}
+		go func() {
+			err := srv.Serve(ln)
+			if err != nil && !errors.Is(err, http.ErrServerClosed) {
+				slog.Error("http server failed", slog.Any("err", err))
+				os.Exit(1)
+			}
+		}()
 	}
 
 	mk2, err := mk2.NewAdapter(*flagSerialDevice)
@@ -41,7 +68,7 @@ func CommonInit(ctx context.Context) *mk2.Adapter {
 		panic(err)
 	}
 	mk2.Write(vebus.CommandR.Frame().Marshal())
-	time.Sleep(time.Second * 1)
+	timemock.Sleep(time.Second * 1)
 	err = mk2.SetBaudLow()
 	if err != nil {
 		panic(err)