Merge pull request #2392 from rn/p2

Better kernel cmdline handling on packet.net

src/cmd/linuxkit/run_packet.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"flag"
 	"fmt"
+	"io/ioutil"
 	"net"
 	"net/http"
 	"os"
@@ -88,13 +89,34 @@ func runPacket(args []string) {
 	name := getStringValue(packetNameVar, *nameFlag, prefix)
 	osType := "custom_ipxe"
 	billing := "hourly"
-	// TODO(rn): Extract the kernel commandline from the file generated by moby build
-	userData := fmt.Sprintf("#!ipxe\n\ndhcp\nset base-url %s\nset kernel-params ip=dhcp nomodeset ro serial console=ttyS1,115200\nkernel ${base-url}/%s-kernel ${kernel-params}\ninitrd ${base-url}/%s-initrd.img\nboot", url, name, name)
+
+	// Read kernel command line
+	var cmdline string
+	if c, err := ioutil.ReadFile(prefix + "-cmdline"); err != nil {
+		log.Fatalf("Cannot open cmdline file: %v", err)
+	} else {
+		cmdline = string(c)
+	}
+
+	// Build the iPXE script
+	// Note, we *append* the <prefix>-cmdline. iXPE booting will
+	// need the first set of "kernel-params" and we don't want to
+	// require these to be added to every YAML file.
+	userData := "#!ipxe\n\n"
+	userData += "dhcp\n"
+	userData += fmt.Sprintf("set base-url %s\n", url)
+	userData += fmt.Sprintf("set kernel-params ip=dhcp nomodeset ro serial console=ttyS1,115200 %s\n", cmdline)
+	userData += fmt.Sprintf("kernel ${base-url}/%s-kernel ${kernel-params}\n", name)
+	userData += fmt.Sprintf("initrd ${base-url}/%s-initrd.img\n", name)
+	userData += "boot"
 	log.Debugf("Using userData of:\n%s\n", userData)
+
+	// Make sure the URL works
 	initrdURL := fmt.Sprintf("%s/%s-initrd.img", url, name)
 	kernelURL := fmt.Sprintf("%s/%s-kernel", url, name)
 	validateHTTPURL(kernelURL)
 	validateHTTPURL(initrdURL)
+
 	client := packngo.NewClient("", apiKey, nil)
 	tags := []string{}
 	req := packngo.DeviceCreateRequest{