Add capabilities check to allow docker to run on kernel that does not have all options

commands.go

@@ -907,7 +907,7 @@ func (srv *Server) CmdTag(stdin io.ReadCloser, stdout io.Writer, args ...string)
 }
 
 func (srv *Server) CmdRun(stdin io.ReadCloser, stdout rcli.DockerConn, args ...string) error {
-	config, err := ParseRun(args, stdout)
+	config, err := ParseRun(args, stdout, srv.runtime.capabilities)
 	if err != nil {
 		return err
 	}

container.go

@@ -66,7 +66,7 @@ type Config struct {
 	Image        string // Name of the image as it was passed by the operator (eg. could be symbolic)
 }
 
-func ParseRun(args []string, stdout io.Writer) (*Config, error) {
+func ParseRun(args []string, stdout io.Writer, capabilities *Capabilities) (*Config, error) {
 	cmd := rcli.Subcmd(stdout, "run", "[OPTIONS] IMAGE COMMAND [ARG...]", "Run a command in a new container")
 	if len(args) > 0 && args[0] != "--help" {
 		cmd.SetOutput(ioutil.Discard)
@@ -81,8 +81,8 @@ func ParseRun(args []string, stdout io.Writer) (*Config, error) {
 	flTty := cmd.Bool("t", false, "Allocate a pseudo-tty")
 	flMemory := cmd.Int64("m", 0, "Memory limit (in bytes)")
 
-	if *flMemory > 0 && NO_MEMORY_LIMIT {
-		fmt.Fprintf(stdout, "WARNING: This version of docker has been compiled without memory limit support. Discarding -m.")
+	if *flMemory > 0 && !capabilities.MemoryLimit {
+		fmt.Fprintf(stdout, "WARNING: Your kernel does not support memory limit capabilities. Limitation discarded.\n")
 		*flMemory = 0
 	}
 
@@ -135,6 +135,12 @@ func ParseRun(args []string, stdout io.Writer) (*Config, error) {
 		Dns:          flDns,
 		Image:        image,
 	}
+
+	if *flMemory > 0 && !capabilities.SwapLimit {
+		fmt.Fprintf(stdout, "WARNING: Your kernel does not support swap limit capabilities. Limitation discarded.\n")
+		config.MemorySwap = -1
+	}
+
 	// When allocating stdin in attached mode, close stdin at client disconnect
 	if config.OpenStdin && config.AttachStdin {
 		config.StdinOnce = true

runtime.go

@@ -15,6 +15,11 @@ import (
 	"time"
 )
 
+type Capabilities struct {
+	MemoryLimit bool
+	SwapLimit   bool
+}
+
 type Runtime struct {
 	root           string
 	repository     string
@@ -24,6 +29,7 @@ type Runtime struct {
 	repositories   *TagStore
 	authConfig     *auth.AuthConfig
 	idIndex        *TruncIndex
+	capabilities   *Capabilities
 	kernelVersion  *KernelVersionInfo
 }
 
@@ -299,6 +305,13 @@ func NewRuntime() (*Runtime, error) {
 		log.Printf("WARNING: You are running linux kernel version %s, which might be unstable running docker. Please upgrade your kernel to 3.8.0.", k.String())
 	}
 
+	_, err1 := ioutil.ReadFile("/sys/fs/cgroup/memory/memory.limit_in_bytes")
+	_, err2 := ioutil.ReadFile("/sys/fs/cgroup/memory/memory.soft_limit_in_bytes")
+	runtime.capabilities.MemoryLimit = err1 == nil && err2 == nil
+
+	_, err = ioutil.ReadFile("/sys/fs/cgroup/memory/memeory.memsw.limit_in_bytes")
+	runtime.capabilities.SwapLimit = err == nil
+
 	return runtime, nil
 }
 
@@ -338,6 +351,7 @@ func NewRuntimeFromDirectory(root string) (*Runtime, error) {
 		repositories:   repositories,
 		authConfig:     authConfig,
 		idIndex:        NewTruncIndex(),
+		capabilities:   &Capabilities{},
 	}
 
 	if err := runtime.restore(); err != nil {