Create lkl config json

Both Rumprun and LKL can have json config at run time, but no
compatibility. This commit adds LKL specific config builder.

Signed-off-by: Akira Moroo <retrage01@gmail.com>

llruntimes/nabla/runnc-cont/lkl.go

@@ -0,0 +1,101 @@
+// Copyright (c) 2018, IBM
+// Author(s): Brandon Lum, Ricardo Koller, Dan Williams
+//
+// Permission to use, copy, modify, and/or distribute this software for
+// any purpose with or without fee is hereby granted, provided that the
+// above copyright notice and this permission notice appear in all
+// copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
+// WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
+// WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
+// AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
+// DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA
+// OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+// TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+// +build linux
+
+package runnc_cont
+
+import (
+	"encoding/json"
+	"fmt"
+	"net"
+	"strconv"
+	"strings"
+
+	"github.com/retrage/runnc/nabla-lib/network"
+)
+
+type lklArgsNetwork struct {
+	Type    string `json:"type,omitempty"`
+	Name    string `json:"name,omitempty"`
+	Param   string `json:"param,omitempty"`
+	Mtu     string `json:"mtu,omitempty"`
+	Ip      string `json:"ip,omitempty"`
+	Ipv6    string `json:"ipv6,omitempty"`
+	IfGw    string `json:"ifgateway,omitempty"`
+	IfGw6   string `json:"ifgateway6,omitempty"`
+	Mac     string `json:"mac,omitempty"`
+	Mask    string `json:"masklen,omitempty"`
+	Mask6   string `json:"masklen6,omitempty"`
+	Neigh   string `json:"neigh,omitempty"`
+	Qdisc   string `json:"qdisc,omitempty"`
+    Offload string `json:"offload,omitempty"`
+}
+
+type lklArgs struct {
+	If      []lklArgsNetwork `json:"interfaces"`
+	Gw      string `json:"gateway,omitempty"`
+	Gw6     string `json:"gateway6,omitempty"`
+	Debug   string `json:"debug,omitempty"`
+	Mount   string `json:"mount,omitempty"`
+	Cpu     string `json:"singlecpu,omitempty"`
+	Sysctl  string `json:"sysctl,omitempty"`
+	Cmdline string `json:"boot_cmdline,omitempty"`
+	Dump    string `json:"dump,omitempty"`
+	Delay   string `json:"delay_main,omitempty"`
+}
+
+// CreateLklArgs returns the config string for lkl (a json)
+func CreateLklArgs(ip net.IP, mask net.IPMask, gw net.IP, mac string) (string, error) {
+
+	// XXX: Due to bug in: https://github.com/nabla-containers/runnc/issues/40
+	// If we detect a /32 mask, we set it to 1 as a "fix", and hope we are in
+	// the same subnet... (working on a fix for mask:0)
+	cidr := strconv.Itoa(network.MaskCIDR(mask))
+	if cidr == "32" {
+		fmt.Printf("WARNING: Changing CIDR from 32 to 1 due to Issue https://github.com/nabla-containers/runnc/issues/40\n")
+		cidr = "1"
+	}
+
+	net := lklArgsNetwork{
+		Type: "rumpfd",
+		Name: "tap",
+		Ip:   ip.String(),
+		Mask: cidr,
+		IfGw: gw.String(),
+		Mac:  mac,
+	}
+
+	la := &lklArgs{
+		If:       []lklArgsNetwork{net},
+		Debug:    "1",
+		Cpu:      "1",
+		Delay:    "50000",
+		Sysctl:   "net.ipv4.tcp_wmem=4096 87380 2147483647",
+	}
+
+	b, err := json.Marshal(la)
+	if err != nil {
+		return "", fmt.Errorf("error with lkl config json: %v", err)
+	}
+
+    s := string(b)
+	s = strings.Replace(s, "\"", "\\\"", -1)
+	s = strings.Replace(s, " ", "\\ ", -1)
+
+	return s, nil
+}

llruntimes/nabla/runnc-cont/runnc_cont.go

@@ -133,7 +133,10 @@ func setupDisk(path string) (string, error) {
 }
 
 func (r *RunncCont) Run() error {
-	var err error
+	var (
+		mac string
+		err error
+	)
 
 	disk, err := setupDisk(r.Disk)
 	if err != nil {
@@ -150,14 +153,21 @@ func (r *RunncCont) Run() error {
 		r.UniKernelBin = unikernel
 	}
 
+	unikernelArgs, err := CreateLklArgs(r.IPAddress, r.IPMask, r.Gateway, mac)
+	if err != nil {
+		return fmt.Errorf("could not create the unikernel cmdline: %v\n", err)
+	}
+
 	var args []string
-    args = []string{r.NablaRunBin,
-        "--mem=" + strconv.FormatInt(r.Memory, 10),
-        "--net:tap=" + r.Tap,
-        "--block:rootfs=" + disk,
-        r.UniKernelBin}
-    args = append(args, "__RUMP_FDINFO_NET_tap=4")
+	args = []string{r.NablaRunBin,
+		"--mem=" + strconv.FormatInt(r.Memory, 10),
+		"--net:tap=" + r.Tap,
+		"--block:rootfs=" + disk,
+		r.UniKernelBin}
+	args = append(args, "__RUMP_FDINFO_NET_tap=4")
 	args = append(args, r.Env...)
+	args = append(args, "--config")
+	args = append(args, unikernelArgs)
 	args = append(args, "--")
 	args = append(args, r.NablaRunArgs...)