Made changes to handle pause container so that k8s can use runnc (min…

…us network) (#34)

* Made changes so that k8s can use runnc (minus network)

Signed-off-by: Brandon Lum <[email protected]>

* Updated travis to use proper golint path

Signed-off-by: Brandon Lum <[email protected]>

.travis.yml

@@ -24,7 +24,7 @@ before_install:
   - echo "deb http://archive.ubuntu.com/ubuntu trusty-backports main restricted universe multiverse" | sudo tee -a /etc/apt/sources.list
   - sudo apt-get -qq update
   - sudo apt-get install -y libseccomp-dev/trusty-backports genisoimage
-  - go get -u github.com/golang/lint/golint
+  - go get -u golang.org/x/lint/golint
   - go get -u github.com/vbatts/git-validation
   - go get -u github.com/golang/dep/cmd/dep
   - env | grep TRAVIS_

libcontainer/factory_nabla.go

@@ -34,6 +34,7 @@ import (
 const (
 	stateFilename    = "state.json"
 	execFifoFilename = "exec.fifo"
+	pauseNablaName   = "pause.nabla"
 )
 
 var (
@@ -68,6 +69,19 @@ type NablaFactory struct {
 	Root string
 }
 
+func isPauseContainer(config *configs.Config) bool {
+	return len(config.Args) == 1 && config.Args[0] == "/pause"
+}
+
+func applyPauseHack(config *configs.Config, containerRoot string) (*configs.Config, error) {
+	if !isPauseContainer(config) {
+		return nil, errors.New("Trying to make pause changes on non-pause container")
+	}
+
+	config.Args = []string{pauseNablaName}
+	return config, nil
+}
+
 func createRootfsISO(config *configs.Config, containerRoot string) (string, error) {
 	rootfsPath := config.Rootfs
 	targetISOPath := filepath.Join(containerRoot, "rootfs.iso")
@@ -93,6 +107,7 @@ func (l *NablaFactory) Create(id string, config *configs.Config) (Container, err
 	if err := l.validateID(id); err != nil {
 		return nil, err
 	}
+
 	//if err := l.Validator.Validate(config); err != nil {
 	//    return nil, err
 	//}
@@ -128,14 +143,26 @@ func (l *NablaFactory) Create(id string, config *configs.Config) (Container, err
 		return nil, err
 	}
 
-	fsPath, err := createRootfsISO(config, containerRoot)
-	if err != nil {
-		return nil, err
+	// If it is a pause container for kubernetes, set config so that init
+	// will just pause instead of executing a nabla
+	fsPath := ""
+	if isPauseContainer(config) {
+		config, err = applyPauseHack(config, containerRoot)
+		if err != nil {
+			return nil, err
+		}
+	} else {
+		fsPath, err = createRootfsISO(config, containerRoot)
+		if err != nil {
+			return nil, err
+		}
 	}
 
 	err = network.CreateTapInterface(nablaTapName(id), nil, nil)
 	if err != nil {
-		os.Remove(fsPath)
+		if fsPath != "" {
+			os.Remove(fsPath)
+		}
 		return nil, fmt.Errorf("Unable to create tap interface: %v", err)
 	}
 

libcontainer/init_nabla.go

@@ -53,7 +53,7 @@ func nablaRunArgs(cfg *initConfig) ([]string, error) {
 	args = append(args, "--")
 	args = append(args, cfg.Args[1:]...)
 
-	fmt.Printf("Running with args: %v", args)
+	fmt.Fprintf(os.Stderr, "Running with args: %v", args)
 	return args, nil
 }
 
@@ -108,6 +108,11 @@ func initNabla() error {
 	syscall.Close(fd)
 	syscall.Close(rootfd)
 
+	// Check if it is a pause container, if it is, just pause
+	if len(config.Args) == 1 && config.Args[0] == pauseNablaName {
+		select {}
+	}
+
 	runArgs, err := nablaRunArgs(config)
 	if err != nil {
 		return newSystemErrorWithCause(err, "Unable to construct nabla run args")

nabla-lib/storage/storage_linux.go

@@ -20,6 +20,7 @@
 package storage
 
 import (
+	"github.com/pkg/errors"
 	"io/ioutil"
 	"os/exec"
 	"path/filepath"
@@ -52,20 +53,20 @@ func CreateIso(dir string, target *string) (string, error) {
 		var err error
 		fname, err = filepath.Abs(*target)
 		if err != nil {
-			return "", err
+			return "", errors.Wrap(err, "Unable to resolve abs target path")
 		}
 	}
 
 	absDir, err := filepath.Abs(dir)
 	if err != nil {
-		return "", err
+		return "", errors.Wrap(err, "Unable to resolve abs dir path")
 	}
 
 	cmd := exec.Command("genisoimage", "-m", "dev", "-m", "sys",
 		"-m", "proc", "-l", "-r", "-o", fname, absDir)
 	err = cmd.Run()
 	if err != nil {
-		return "", err
+		return "", errors.Wrap(err, "Unable to run geniso command")
 	}
 
 	return fname, nil

runnc-cli/util.go

@@ -21,6 +21,8 @@ import (
 	"github.com/sirupsen/logrus"
 	"github.com/urfave/cli"
 	"os"
+	"path/filepath"
+	"strings"
 )
 
 // fatal prints the error's details if it is a libcontainer specific error type
@@ -44,6 +46,11 @@ func setupSpec(context *cli.Context) (*specs.Spec, error) {
 	if err != nil {
 		return nil, err
 	}
+
+	if spec.Root != nil && !strings.HasPrefix(spec.Root.Path, "/") {
+		spec.Root.Path = filepath.Join(bundle, spec.Root.Path)
+	}
+
 	notifySocket := os.Getenv("NOTIFY_SOCKET")
 	if notifySocket != "" {
 		setupSdNotify(spec, notifySocket)