Initial commit

vendor/github.com/hyperhq/hypercli/daemon/execdriver/native/exec.go

@@ -0,0 +1,87 @@
+// +build linux
+
+package native
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"strings"
+	"syscall"
+
+	"github.com/hyperhq/hypercli/daemon/execdriver"
+	"github.com/opencontainers/runc/libcontainer"
+	// Blank import 'nsenter' so that init in that package will call c
+	// function 'nsexec()' to do 'setns' before Go runtime take over,
+	// it's used for join to exist ns like 'docker exec' command.
+	_ "github.com/opencontainers/runc/libcontainer/nsenter"
+	"github.com/opencontainers/runc/libcontainer/utils"
+)
+
+// Exec implements the exec driver Driver interface,
+// it calls libcontainer APIs to execute a container.
+func (d *Driver) Exec(c *execdriver.Command, processConfig *execdriver.ProcessConfig, pipes *execdriver.Pipes, hooks execdriver.Hooks) (int, error) {
+	active := d.activeContainers[c.ID]
+	if active == nil {
+		return -1, fmt.Errorf("No active container exists with ID %s", c.ID)
+	}
+
+	user := processConfig.User
+	if c.RemappedRoot.UID != 0 && user == "" {
+		//if user namespaces are enabled, set user explicitly so uid/gid is set to 0
+		//otherwise we end up with the overflow id and no permissions (65534)
+		user = "0"
+	}
+
+	p := &libcontainer.Process{
+		Args: append([]string{processConfig.Entrypoint}, processConfig.Arguments...),
+		Env:  c.ProcessConfig.Env,
+		Cwd:  c.WorkingDir,
+		User: user,
+	}
+
+	if processConfig.Privileged {
+		p.Capabilities = execdriver.GetAllCapabilities()
+	}
+	// add CAP_ prefix to all caps for new libcontainer update to match
+	// the spec format.
+	for i, s := range p.Capabilities {
+		if !strings.HasPrefix(s, "CAP_") {
+			p.Capabilities[i] = fmt.Sprintf("CAP_%s", s)
+		}
+	}
+
+	config := active.Config()
+	if err := setupPipes(&config, processConfig, p, pipes); err != nil {
+		return -1, err
+	}
+
+	if err := active.Start(p); err != nil {
+		return -1, err
+	}
+
+	if hooks.Start != nil {
+		pid, err := p.Pid()
+		if err != nil {
+			p.Signal(os.Kill)
+			p.Wait()
+			return -1, err
+		}
+
+		// A closed channel for OOM is returned here as it will be
+		// non-blocking and return the correct result when read.
+		chOOM := make(chan struct{})
+		close(chOOM)
+		hooks.Start(&c.ProcessConfig, pid, chOOM)
+	}
+
+	ps, err := p.Wait()
+	if err != nil {
+		exitErr, ok := err.(*exec.ExitError)
+		if !ok {
+			return -1, err
+		}
+		ps = exitErr.ProcessState
+	}
+	return utils.ExitStatus(ps.Sys().(syscall.WaitStatus)), nil
+}