73 lines
1.9 KiB
Go
73 lines
1.9 KiB
Go
package overlay
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import (
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"io/ioutil"
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"path"
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"strconv"
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"strings"
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"github.com/sirupsen/logrus"
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)
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type conditionalCheck func(val1, val2 string) bool
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type osValue struct {
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value string
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checkFn conditionalCheck
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}
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var osConfig = map[string]osValue{
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"net.ipv4.neigh.default.gc_thresh1": {"8192", checkHigher},
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"net.ipv4.neigh.default.gc_thresh2": {"49152", checkHigher},
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"net.ipv4.neigh.default.gc_thresh3": {"65536", checkHigher},
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}
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func propertyIsValid(val1, val2 string, check conditionalCheck) bool {
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if check == nil || check(val1, val2) {
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return true
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}
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return false
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}
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func checkHigher(val1, val2 string) bool {
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val1Int, _ := strconv.ParseInt(val1, 10, 32)
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val2Int, _ := strconv.ParseInt(val2, 10, 32)
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return val1Int < val2Int
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}
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// writeSystemProperty writes the value to a path under /proc/sys as determined from the key.
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// For e.g. net.ipv4.ip_forward translated to /proc/sys/net/ipv4/ip_forward.
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func writeSystemProperty(key, value string) error {
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keyPath := strings.Replace(key, ".", "/", -1)
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return ioutil.WriteFile(path.Join("/proc/sys", keyPath), []byte(value), 0644)
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}
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func readSystemProperty(key string) (string, error) {
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keyPath := strings.Replace(key, ".", "/", -1)
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value, err := ioutil.ReadFile(path.Join("/proc/sys", keyPath))
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if err != nil {
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return "", err
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}
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return string(value), nil
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}
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func applyOStweaks() {
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for k, v := range osConfig {
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// read the existing property from disk
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oldv, err := readSystemProperty(k)
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if err != nil {
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logrus.Errorf("error reading the kernel parameter %s, error: %s", k, err)
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continue
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}
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if propertyIsValid(oldv, v.value, v.checkFn) {
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// write new prop value to disk
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if err := writeSystemProperty(k, v.value); err != nil {
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logrus.Errorf("error setting the kernel parameter %s = %s, (leaving as %s) error: %s", k, v.value, oldv, err)
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continue
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}
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logrus.Debugf("updated kernel parameter %s = %s (was %s)", k, v.value, oldv)
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}
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}
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}
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