github/kubernetes
1
0
Fork 0
mirror of https://github.com/k3s-io/kubernetes.git synced 2025-07-23 11:50:44 +00:00
Code Issues Projects Releases Wiki Activity

Merge pull request #43925 from Random-Liu/fix-dockershim-dns-options

Browse Source 
Automatic merge from submit-queue

[CRI] Use DNSOptions passed by CRI in dockershim.

When @xlgao-zju is working on the CRI validation test, he found that dockershim is not using the DNSOptions passed in CRI. https://github.com/kubernetes-incubator/cri-tools/pull/30#issuecomment-290644357

This PR fixed the issue. I've manually tried, for `ClusterFirst` DNSPolicy, the resolv.conf will be:
```
nameserver 8.8.8.8
search corp.google.com prod.google.com prodz.google.com google.com
options ndots:5
```

For `Default` DNSPolicy, the resolv.conf will be:
```
nameserver 127.0.1.1
search corp.google.com prod.google.com prodz.google.com google.com
```

@xlgao-zju You should be able to test after this PR is merged.

/cc @yujuhong @feiskyer
This commit is contained in:
Kubernetes Submit Queue 2017-04-03 11:58:23 -07:00 committed by GitHub
commit 6c6f4f0185
1 changed files with 52 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

53
pkg/kubelet/dockershim/docker_sandbox.go
View File

@ -18,6 +18,8 @@ package dockershim
import (
"fmt"
"os"
"strings"
dockertypes "github.com/docker/engine-api/types"
dockercontainer "github.com/docker/engine-api/types/container"
@ -105,7 +107,7 @@ func (ds *dockerService) RunPodSandbox(config *runtimeapi.PodSandboxConfig) (str
return createResp.ID, fmt.Errorf("failed to inspect sandbox container for pod %q: %v", config.Metadata.Name, err)
}
if err := dockertools.RewriteResolvFile(containerInfo.ResolvConfPath, dnsConfig.Servers, dnsConfig.Searches, len(dnsConfig.Options) > 0); err != nil {
if err := rewriteResolvFile(containerInfo.ResolvConfPath, dnsConfig.Servers, dnsConfig.Searches, dnsConfig.Options); err != nil {
return createResp.ID, fmt.Errorf("rewrite resolv.conf failed for pod %q: %v", config.Metadata.Name, err)
}
}
@ -587,3 +589,52 @@ func toCheckpointProtocol(protocol runtimeapi.Protocol) Protocol {
glog.Warningf("Unknown protocol %q: defaulting to TCP", protocol)
return protocolTCP
}
// rewriteResolvFile rewrites resolv.conf file generated by docker.
func rewriteResolvFile(resolvFilePath string, dns []string, dnsSearch []string, dnsOptions []string) error {
if len(resolvFilePath) == 0 {
glog.Errorf("ResolvConfPath is empty.")
return nil
}
if _, err := os.Stat(resolvFilePath); os.IsNotExist(err) {
return fmt.Errorf("ResolvConfPath %q does not exist", resolvFilePath)
}
var resolvFileContent []string
for _, srv := range dns {
resolvFileContent = append(resolvFileContent, "nameserver "+srv)
}
if len(dnsSearch) > 0 {
resolvFileContent = append(resolvFileContent, "search "+strings.Join(dnsSearch, " "))
}
if len(dnsOptions) > 0 {
resolvFileContent = append(resolvFileContent, "options "+strings.Join(dnsOptions, " "))
}
if len(resolvFileContent) > 0 {
resolvFileContentStr := strings.Join(resolvFileContent, "\n")
resolvFileContentStr += "\n"
glog.V(4).Infof("Will attempt to re-write config file %s with: \n%s", resolvFilePath, resolvFileContent)
if err := rewriteFile(resolvFilePath, resolvFileContentStr); err != nil {
glog.Errorf("resolv.conf could not be updated: %v", err)
return err
}
}
return nil
}
func rewriteFile(filePath, stringToWrite string) error {
f, err := os.OpenFile(filePath, os.O_TRUNC|os.O_WRONLY, 0644)
if err != nil {
return err
}
defer f.Close()
_, err = f.WriteString(stringToWrite)
return err
}