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samuelkarpsamuelkarp
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Adjust disallowed CpuShares in /containers/create
Previous versions of libcontainer allowed CpuShares that were greater than the maximum or less than the minimum supported by the kernel, and relied on the kernel to do the right thing. Newer libcontainer fails after creating the container if the requested CpuShares is different from what was actually created by the kernel, which breaks compatibility with earlier Docker Remote API versions. This change explicitly adjusts the requested CpuShares in API versions < 1.20. Signed-off-by: Samuel Karp <[email protected]>
1 parent cd1a1ee commit ed39fbe

4 files changed

Lines changed: 96 additions & 0 deletions

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‎api/server/server.go‎

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Original file line numberDiff line numberDiff line change
@@ -894,6 +894,7 @@ func (s *Server) postContainersCreate(version version.Version, w http.ResponseWr
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if err != nil {
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return err
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}
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adjustCpuShares(version, hostConfig)
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containerId, warnings, err := s.daemon.ContainerCreate(name, config, hostConfig)
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if err != nil {

‎api/server/server_linux.go‎

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@@ -8,12 +8,21 @@ import (
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"net/http"
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"strconv"
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"github.com/Sirupsen/logrus"
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"github.com/docker/docker/daemon"
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"github.com/docker/docker/pkg/sockets"
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"github.com/docker/docker/pkg/systemd"
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"github.com/docker/docker/pkg/version"
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"github.com/docker/docker/runconfig"
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"github.com/docker/libnetwork/portallocator"
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)
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const (
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// See http://git.kernel.org/cgit/linux/kernel/git/tip/tip.git/tree/kernel/sched/sched.h?id=8cd9234c64c584432f6992fe944ca9e46ca8ea76#n269
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linuxMinCpuShares = 2
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linuxMaxCpuShares = 262144
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)
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// newServer sets up the required serverClosers and does protocol specific checking.
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func (s *Server) newServer(proto, addr string) ([]serverCloser, error) {
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var (
@@ -96,3 +105,18 @@ func allocateDaemonPort(addr string) error {
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}
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return nil
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}
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func adjustCpuShares(version version.Version, hostConfig *runconfig.HostConfig) {
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if version.LessThan("1.19") {
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if hostConfig.CpuShares > 0 {
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// Handle unsupported CpuShares
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if hostConfig.CpuShares < linuxMinCpuShares {
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logrus.Warnf("Changing requested CpuShares of %d to minimum allowed of %d", hostConfig.CpuShares, linuxMinCpuShares)
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hostConfig.CpuShares = linuxMinCpuShares
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} else if hostConfig.CpuShares > linuxMaxCpuShares {
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logrus.Warnf("Changing requested CpuShares of %d to maximum allowed of %d", hostConfig.CpuShares, linuxMaxCpuShares)
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hostConfig.CpuShares = linuxMaxCpuShares
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}
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}
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}
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}

‎api/server/server_linux_test.go‎

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,68 @@
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// +build linux
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package server
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import (
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"testing"
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"github.com/docker/docker/pkg/version"
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"github.com/docker/docker/runconfig"
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)
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func TestAdjustCpuSharesOldApi(t *testing.T) {
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apiVersion := version.Version("1.18")
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hostConfig := &runconfig.HostConfig{
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CpuShares: linuxMinCpuShares - 1,
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}
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adjustCpuShares(apiVersion, hostConfig)
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if hostConfig.CpuShares != linuxMinCpuShares {
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t.Errorf("Expected CpuShares to be %d", linuxMinCpuShares)
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}
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hostConfig.CpuShares = linuxMaxCpuShares + 1
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adjustCpuShares(apiVersion, hostConfig)
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if hostConfig.CpuShares != linuxMaxCpuShares {
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t.Errorf("Expected CpuShares to be %d", linuxMaxCpuShares)
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}
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hostConfig.CpuShares = 0
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adjustCpuShares(apiVersion, hostConfig)
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if hostConfig.CpuShares != 0 {
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t.Error("Expected CpuShares to be unchanged")
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}
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hostConfig.CpuShares = 1024
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adjustCpuShares(apiVersion, hostConfig)
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if hostConfig.CpuShares != 1024 {
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t.Error("Expected CpuShares to be unchanged")
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}
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}
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func TestAdjustCpuSharesNoAdjustment(t *testing.T) {
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apiVersion := version.Version("1.19")
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hostConfig := &runconfig.HostConfig{
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CpuShares: linuxMinCpuShares - 1,
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}
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adjustCpuShares(apiVersion, hostConfig)
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if hostConfig.CpuShares != linuxMinCpuShares-1 {
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t.Errorf("Expected CpuShares to be %d", linuxMinCpuShares-1)
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}
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hostConfig.CpuShares = linuxMaxCpuShares + 1
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adjustCpuShares(apiVersion, hostConfig)
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if hostConfig.CpuShares != linuxMaxCpuShares+1 {
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t.Errorf("Expected CpuShares to be %d", linuxMaxCpuShares+1)
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}
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hostConfig.CpuShares = 0
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adjustCpuShares(apiVersion, hostConfig)
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if hostConfig.CpuShares != 0 {
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t.Error("Expected CpuShares to be unchanged")
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}
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hostConfig.CpuShares = 1024
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adjustCpuShares(apiVersion, hostConfig)
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if hostConfig.CpuShares != 1024 {
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t.Error("Expected CpuShares to be unchanged")
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}
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}

‎api/server/server_windows.go‎

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Original file line numberDiff line numberDiff line change
@@ -54,3 +54,6 @@ func (s *Server) AcceptConnections(d *daemon.Daemon) {
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func allocateDaemonPort(addr string) error {
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return nil
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}
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func adjustCpuShares(version version.Version, hostConfig *runconfig.HostConfig) {
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}

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