feat: boot.img.lz4

cmd/dkl-local-server/initrd.go

@@ -0,0 +1,152 @@
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"log"
+	"net/http"
+	"os"
+	"time"
+
+	cpio "github.com/cavaliercoder/go-cpio"
+	yaml "gopkg.in/yaml.v2"
+)
+
+func renderConfig(w http.ResponseWriter, r *http.Request, ctx *renderContext) error {
+	log.Printf("sending config for %q", ctx.Host.Name)
+
+	_, cfg, err := ctx.Config()
+	if err != nil {
+		return err
+	}
+
+	ba, err := yaml.Marshal(cfg)
+	if err != nil {
+		return err
+	}
+
+	w.Header().Set("Content-Type", "application/yaml")
+	http.ServeContent(w, r, "config.yaml", time.Unix(0, 0), bytes.NewReader(ba))
+
+	return nil
+}
+
+func renderStaticPods(w http.ResponseWriter, r *http.Request, ctx *renderContext) error {
+	log.Printf("sending static-pods for %q", ctx.Host.Name)
+
+	ba, err := ctx.StaticPods()
+	if err != nil {
+		return err
+	}
+
+	w.Header().Set("Content-Type", "application/yaml") // XXX can also be JSON
+	http.ServeContent(w, r, "static-pods", time.Unix(0, 0), bytes.NewReader(ba))
+
+	return nil
+}
+
+func renderCtx(w http.ResponseWriter, r *http.Request, ctx *renderContext, what string,
+	create func(out io.Writer, ctx *renderContext) error) error {
+	log.Printf("sending %s for %q", what, ctx.Host.Name)
+
+	tag, err := ctx.Tag()
+	if err != nil {
+		return err
+	}
+
+	// get it or create it
+	content, meta, err := casStore.GetOrCreate(tag, what, func(out io.Writer) error {
+		log.Printf("building %s for %q", what, ctx.Host.Name)
+		return create(out, ctx)
+	})
+
+	if err != nil {
+		return err
+	}
+
+	// serve it
+	http.ServeContent(w, r, what, meta.ModTime(), content)
+	return nil
+}
+
+func buildInitrd(out io.Writer, ctx *renderContext) error {
+	_, cfg, err := ctx.Config()
+
+	if err != nil {
+		return err
+	}
+
+	// send initrd basis
+	initrdPath, err := ctx.distFetch("initrd", ctx.Group.Initrd)
+	if err != nil {
+		return err
+	}
+
+	err = writeFile(out, initrdPath)
+	if err != nil {
+		return err
+	}
+
+	// and our extra archive
+	archive := cpio.NewWriter(out)
+
+	// - required dirs
+	for _, dir := range []string{
+		"boot",
+		"boot/current",
+		"boot/current/layers",
+	} {
+		archive.WriteHeader(&cpio.Header{
+			Name: dir,
+			Mode: 0600 | cpio.ModeDir,
+		})
+	}
+
+	// - the layers
+	for _, layer := range cfg.Layers {
+		layerVersion := ctx.Group.Versions[layer]
+		if layerVersion == "" {
+			return fmt.Errorf("layer %q not mapped to a version", layer)
+		}
+
+		path, err := ctx.distFetch("layers", layer, layerVersion)
+		if err != nil {
+			return err
+		}
+
+		stat, err := os.Stat(path)
+		if err != nil {
+			return err
+		}
+
+		archive.WriteHeader(&cpio.Header{
+			Name: "boot/current/layers/" + layer + ".fs",
+			Mode: 0600,
+			Size: stat.Size(),
+		})
+
+		if err = writeFile(archive, path); err != nil {
+			return err
+		}
+	}
+
+	// - the configuration
+	ba, err := yaml.Marshal(cfg)
+	if err != nil {
+		return err
+	}
+
+	archive.WriteHeader(&cpio.Header{
+		Name: "boot/config.yaml",
+		Mode: 0600,
+		Size: int64(len(ba)),
+	})
+
+	archive.Write(ba)
+
+	// finalize the archive
+	archive.Flush()
+	archive.Close()
+	return nil
+}