From 0d2628cdf19783106ae8723f51fae0a7c7f361c6 Mon Sep 17 00:00:00 2001 From: Antonio Murdaca Date: Thu, 6 Aug 2015 13:55:56 +0200 Subject: [PATCH] Add hostConfig check before starting a container It may happen that host system settings are changed while the daemon is running. This will cause errors at libcontainer level when starting a container with a particular hostConfig (e.g. hostConfig with memory swappiness but the memory cgroup was umounted). This patch adds an hostConfig check on container start to prevent the daemon from even calling libcontainer with the wrong configuration as we're already doing on container's creation). Signed-off-by: Antonio Murdaca --- daemon/daemon_unix.go | 7 ++++++- daemon/start.go | 10 ++++++---- runconfig/parse.go | 8 ++++---- 3 files changed, 16 insertions(+), 9 deletions(-) diff --git a/daemon/daemon_unix.go b/daemon/daemon_unix.go index 13ac51843b..9e2d6736d5 100644 --- a/daemon/daemon_unix.go +++ b/daemon/daemon_unix.go @@ -155,6 +155,8 @@ func verifyPlatformContainerSettings(daemon *Daemon, hostConfig *runconfig.HostC if hostConfig.LxcConf.Len() > 0 && !strings.Contains(daemon.ExecutionDriver().Name(), "lxc") { return warnings, fmt.Errorf("Cannot use --lxc-conf with execdriver: %s", daemon.ExecutionDriver().Name()) } + + // memory subsystem checks and adjustments if hostConfig.Memory != 0 && hostConfig.Memory < 4194304 { return warnings, fmt.Errorf("Minimum memory limit allowed is 4MB") } @@ -162,6 +164,7 @@ func verifyPlatformContainerSettings(daemon *Daemon, hostConfig *runconfig.HostC warnings = append(warnings, "Your kernel does not support memory limit capabilities. Limitation discarded.") logrus.Warnf("Your kernel does not support memory limit capabilities. Limitation discarded.") hostConfig.Memory = 0 + hostConfig.MemorySwap = -1 } if hostConfig.Memory > 0 && hostConfig.MemorySwap != -1 && !sysInfo.SwapLimit { warnings = append(warnings, "Your kernel does not support swap limit capabilities, memory limited without swap.") @@ -174,7 +177,7 @@ func verifyPlatformContainerSettings(daemon *Daemon, hostConfig *runconfig.HostC if hostConfig.Memory == 0 && hostConfig.MemorySwap > 0 { return warnings, fmt.Errorf("You should always set the Memory limit when using Memoryswap limit, see usage.") } - if hostConfig.MemorySwappiness != nil && !sysInfo.MemorySwappiness { + if hostConfig.MemorySwappiness != nil && *hostConfig.MemorySwappiness != -1 && !sysInfo.MemorySwappiness { warnings = append(warnings, "Your kernel does not support memory swappiness capabilities, memory swappiness discarded.") logrus.Warnf("Your kernel does not support memory swappiness capabilities, memory swappiness discarded.") hostConfig.MemorySwappiness = nil @@ -198,10 +201,12 @@ func verifyPlatformContainerSettings(daemon *Daemon, hostConfig *runconfig.HostC if hostConfig.BlkioWeight > 0 && (hostConfig.BlkioWeight < 10 || hostConfig.BlkioWeight > 1000) { return warnings, fmt.Errorf("Range of blkio weight is from 10 to 1000.") } + if hostConfig.OomKillDisable && !sysInfo.OomKillDisable { hostConfig.OomKillDisable = false return warnings, fmt.Errorf("Your kernel does not support oom kill disable.") } + if sysInfo.IPv4ForwardingDisabled { warnings = append(warnings, "IPv4 forwarding is disabled. Networking will not work.") logrus.Warnf("IPv4 forwarding is disabled. Networking will not work") diff --git a/daemon/start.go b/daemon/start.go index 9df56c5a34..2dc05d613c 100644 --- a/daemon/start.go +++ b/daemon/start.go @@ -21,10 +21,6 @@ func (daemon *Daemon) ContainerStart(name string, hostConfig *runconfig.HostConf return fmt.Errorf("Container already started") } - if _, err = daemon.verifyContainerSettings(hostConfig, nil); err != nil { - return err - } - // Windows does not have the backwards compatibilty issue here. if runtime.GOOS != "windows" { // This is kept for backward compatibility - hostconfig should be passed when @@ -40,6 +36,12 @@ func (daemon *Daemon) ContainerStart(name string, hostConfig *runconfig.HostConf } } + // check if hostConfig is in line with the current system settings. + // It may happen cgroups are umounted or the like. + if _, err = daemon.verifyContainerSettings(container.hostConfig, nil); err != nil { + return err + } + if err := container.Start(); err != nil { return fmt.Errorf("Cannot start container %s: %s", name, err) } diff --git a/runconfig/parse.go b/runconfig/parse.go index 5528d7af76..6488817cfd 100644 --- a/runconfig/parse.go +++ b/runconfig/parse.go @@ -188,16 +188,16 @@ func Parse(cmd *flag.FlagSet, args []string) (*Config, *HostConfig, *flag.FlagSe flMemory = parsedMemory } - var MemorySwap int64 + var memorySwap int64 if *flMemorySwap != "" { if *flMemorySwap == "-1" { - MemorySwap = -1 + memorySwap = -1 } else { parsedMemorySwap, err := units.RAMInBytes(*flMemorySwap) if err != nil { return nil, nil, cmd, err } - MemorySwap = parsedMemorySwap + memorySwap = parsedMemorySwap } } @@ -354,7 +354,7 @@ func Parse(cmd *flag.FlagSet, args []string) (*Config, *HostConfig, *flag.FlagSe ContainerIDFile: *flContainerIDFile, LxcConf: lxcConf, Memory: flMemory, - MemorySwap: MemorySwap, + MemorySwap: memorySwap, CPUShares: *flCPUShares, CPUPeriod: *flCPUPeriod, CpusetCpus: *flCpusetCpus,