github.com/jwhonce/docker@v0.6.7-0.20190327063223-da823cf3a5a3/rootless/specconv/specconv_linux.go (about)

     1  package specconv
     2  
     3  import (
     4  	"io/ioutil"
     5  	"strconv"
     6  
     7  	"github.com/opencontainers/runtime-spec/specs-go"
     8  )
     9  
    10  // ToRootless converts spec to be compatible with "rootless" runc.
    11  // * Remove cgroups (will be supported in separate PR when delegation permission is configured)
    12  // * Fix up OOMScoreAdj
    13  func ToRootless(spec *specs.Spec) error {
    14  	return toRootless(spec, getCurrentOOMScoreAdj())
    15  }
    16  
    17  func getCurrentOOMScoreAdj() int {
    18  	b, err := ioutil.ReadFile("/proc/self/oom_score_adj")
    19  	if err != nil {
    20  		return 0
    21  	}
    22  	i, err := strconv.Atoi(string(b))
    23  	if err != nil {
    24  		return 0
    25  	}
    26  	return i
    27  }
    28  
    29  func toRootless(spec *specs.Spec, currentOOMScoreAdj int) error {
    30  	// Remove cgroup settings.
    31  	spec.Linux.Resources = nil
    32  	spec.Linux.CgroupsPath = ""
    33  
    34  	if spec.Process.OOMScoreAdj != nil && *spec.Process.OOMScoreAdj < currentOOMScoreAdj {
    35  		*spec.Process.OOMScoreAdj = currentOOMScoreAdj
    36  	}
    37  	return nil
    38  }