cmd/atlas: Implement server command

1 files changed, 100 insertions, 0 deletions

diff --git a/cmd/atlas/main.go b/cmd/atlas/main.go
new file mode 100644
index 0000000..a9251b5
--- /dev/null
+++ b/cmd/atlas/main.go
@@ -0,0 +1,100 @@
+// Command atlas TODO.
+package main
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"os"
+	"os/signal"
+	"syscall"
+
+	"github.com/hashicorp/go-envparse"
+	_ "github.com/mattn/go-sqlite3"
+	"github.com/pg9182/atlas/pkg/atlas"
+	"github.com/spf13/pflag"
+)
+
+var opt struct {
+	Help bool
+}
+
+func init() {
+	pflag.BoolVarP(&opt.Help, "help", "h", false, "Show this help text")
+}
+
+func main() {
+	pflag.Parse()
+
+	if pflag.NArg() > 1 || opt.Help {
+		fmt.Printf("usage: %s [options] [env_file]\n\noptions:\n%s\nnote: if env_file is provided, config from the environment is ignored\n", os.Args[0], pflag.CommandLine.FlagUsages())
+		if opt.Help {
+			os.Exit(2)
+		}
+		os.Exit(0)
+	}
+
+	var e []string
+	if pflag.NArg() == 0 {
+		e = os.Environ()
+	} else {
+		if x, err := readEnv(pflag.Arg(0)); err == nil {
+			e = x
+		} else {
+			fmt.Fprintf(os.Stderr, "error: read env file: %v\n", err)
+			os.Exit(1)
+		}
+		if v, ok := os.LookupEnv("NOTIFY_SOCKET"); ok {
+			e = append(e, "NOTIFY_SOCKET="+v)
+		}
+	}
+
+	var c atlas.Config
+	if err := c.UnmarshalEnv(e, false); err != nil {
+		fmt.Fprintf(os.Stderr, "error: parse config: %v\n", err)
+		os.Exit(1)
+	}
+
+	s, err := atlas.NewServer(&c)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "error: initialize server: %v\n", err)
+		os.Exit(1)
+	}
+
+	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
+	defer stop()
+
+	hch := make(chan os.Signal, 1)
+	signal.Notify(hch, syscall.SIGHUP)
+
+	go func() {
+		for range hch {
+			fmt.Println("got SIGHUP")
+			s.HandleSIGHUP()
+		}
+	}()
+
+	if err := s.Run(ctx); err != nil && !errors.Is(err, context.Canceled) {
+		fmt.Fprintf(os.Stderr, "error: run server: %v\n", err)
+		os.Exit(1)
+	}
+}
+
+func readEnv(name string) ([]string, error) {
+	f, err := os.Open(name)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	m, err := envparse.Parse(f)
+	if err != nil {
+		return nil, err
+	}
+
+	var r []string
+	for k, v := range m {
+		r = append(r, k+"="+v)
+	}
+	return r, nil
+}