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Commit 08606b53 authored by Kubernetes Submit Queue's avatar Kubernetes Submit Queue Committed by GitHub
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Merge pull request #45148 from rickypai/rpai/use_host_aliases

Automatic merge from submit-queue (batch tested with PRs 45110, 45148) write HostAliases to hosts file **What this PR does / why we need it**: using the PodSpec's `HostAliases`, we write entries into the Kubernetes-managed hosts file. **Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #43632 **Special notes for your reviewer**: Previous PRs in this series: - https://github.com/kubernetes/kubernetes/pull/44572 isolates the logic of creating the file and writing the file - https://github.com/kubernetes/kubernetes/pull/44641 introduces the `HostAliases` field in PodSpec along with validations **Release note**: ```release-note PodSpec's `HostAliases` now write entries into the Kubernetes-managed hosts file. ``` @thockin @yujuhong Thanks for reviewing!
parents 6480bc70 407fe8b3
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Showing with 61 additions and 7 deletions
pkg/kubelet/kubelet_pods.go
View file @ 08606b53
...@@ -181,7 +181,8 @@ func makeMounts(pod *v1.Pod, podDir string, container *v1.Container, hostName, h ...@@ -181,7 +181,8 @@ func makeMounts(pod *v1.Pod, podDir string, container *v1.Container, hostName, h
}) })
} }
if mountEtcHostsFile { if mountEtcHostsFile {
hostsMount, err := makeHostsMount(podDir, podIP, hostName, hostDomain) hostAliases := pod.Spec.HostAliases
hostsMount, err := makeHostsMount(podDir, podIP, hostName, hostDomain, hostAliases)
if err != nil { if err != nil {
return nil, err return nil, err
} }
...@@ -192,9 +193,9 @@ func makeMounts(pod *v1.Pod, podDir string, container *v1.Container, hostName, h ...@@ -192,9 +193,9 @@ func makeMounts(pod *v1.Pod, podDir string, container *v1.Container, hostName, h
// makeHostsMount makes the mountpoint for the hosts file that the containers // makeHostsMount makes the mountpoint for the hosts file that the containers
// in a pod are injected with. // in a pod are injected with.
func makeHostsMount(podDir, podIP, hostName, hostDomainName string) (*kubecontainer.Mount, error) { func makeHostsMount(podDir, podIP, hostName, hostDomainName string, hostAliases []v1.HostAlias) (*kubecontainer.Mount, error) {
hostsFilePath := path.Join(podDir, "etc-hosts") hostsFilePath := path.Join(podDir, "etc-hosts")
if err := ensureHostsFile(hostsFilePath, podIP, hostName, hostDomainName); err != nil { if err := ensureHostsFile(hostsFilePath, podIP, hostName, hostDomainName, hostAliases); err != nil {
return nil, err return nil, err
} }
return &kubecontainer.Mount{ return &kubecontainer.Mount{
...@@ -208,17 +209,17 @@ func makeHostsMount(podDir, podIP, hostName, hostDomainName string) (*kubecontai ...@@ -208,17 +209,17 @@ func makeHostsMount(podDir, podIP, hostName, hostDomainName string) (*kubecontai
// ensureHostsFile ensures that the given host file has an up-to-date ip, host // ensureHostsFile ensures that the given host file has an up-to-date ip, host
// name, and domain name. // name, and domain name.
func ensureHostsFile(fileName, hostIP, hostName, hostDomainName string) error { func ensureHostsFile(fileName, hostIP, hostName, hostDomainName string, hostAliases []v1.HostAlias) error {
if _, err := os.Stat(fileName); os.IsExist(err) { if _, err := os.Stat(fileName); os.IsExist(err) {
glog.V(4).Infof("kubernetes-managed etc-hosts file exits. Will not be recreated: %q", fileName) glog.V(4).Infof("kubernetes-managed etc-hosts file exits. Will not be recreated: %q", fileName)
return nil return nil
} }
content := hostsFileContent(hostIP, hostName, hostDomainName) content := hostsFileContent(hostIP, hostName, hostDomainName, hostAliases)
return ioutil.WriteFile(fileName, content, 0644) return ioutil.WriteFile(fileName, content, 0644)
} }
// hostsFileContent is the content of the managed etc hosts // hostsFileContent is the content of the managed etc hosts
func hostsFileContent(hostIP, hostName, hostDomainName string) []byte { func hostsFileContent(hostIP, hostName, hostDomainName string, hostAliases []v1.HostAlias) []byte {
var buffer bytes.Buffer var buffer bytes.Buffer
buffer.WriteString("# Kubernetes-managed hosts file.\n") buffer.WriteString("# Kubernetes-managed hosts file.\n")
buffer.WriteString("127.0.0.1\tlocalhost\n") // ipv4 localhost buffer.WriteString("127.0.0.1\tlocalhost\n") // ipv4 localhost
...@@ -232,6 +233,12 @@ func hostsFileContent(hostIP, hostName, hostDomainName string) []byte { ...@@ -232,6 +233,12 @@ func hostsFileContent(hostIP, hostName, hostDomainName string) []byte {
} else { } else {
buffer.WriteString(fmt.Sprintf("%s\t%s\n", hostIP, hostName)) buffer.WriteString(fmt.Sprintf("%s\t%s\n", hostIP, hostName))
} }
// write each IP/hostname pair as an entry into hosts file
for _, hostAlias := range hostAliases {
for _, hostname := range hostAlias.Hostnames {
buffer.WriteString(fmt.Sprintf("%s\t%s\n", hostAlias.IP, hostname))
}
}
return buffer.Bytes() return buffer.Bytes()
} }
......
pkg/kubelet/kubelet_pods_test.go
View file @ 08606b53
...@@ -119,12 +119,14 @@ func TestHostsFileContent(t *testing.T) { ...@@ -119,12 +119,14 @@ func TestHostsFileContent(t *testing.T) {
hostIP string hostIP string
hostName string hostName string
hostDomainName string hostDomainName string
hostAliases []v1.HostAlias
expectedContent string expectedContent string
}{ }{
{ {
"123.45.67.89", "123.45.67.89",
"podFoo", "podFoo",
"", "",
[]v1.HostAlias{},
`# Kubernetes-managed hosts file. `# Kubernetes-managed hosts file.
127.0.0.1 localhost 127.0.0.1 localhost
::1 localhost ip6-localhost ip6-loopback ::1 localhost ip6-localhost ip6-loopback
...@@ -139,6 +141,7 @@ fe00::2 ip6-allrouters ...@@ -139,6 +141,7 @@ fe00::2 ip6-allrouters
"203.0.113.1", "203.0.113.1",
"podFoo", "podFoo",
"domainFoo", "domainFoo",
[]v1.HostAlias{},
`# Kubernetes-managed hosts file. `# Kubernetes-managed hosts file.
127.0.0.1 localhost 127.0.0.1 localhost
::1 localhost ip6-localhost ip6-loopback ::1 localhost ip6-localhost ip6-loopback
...@@ -149,10 +152,54 @@ fe00::2 ip6-allrouters ...@@ -149,10 +152,54 @@ fe00::2 ip6-allrouters
203.0.113.1 podFoo.domainFoo podFoo 203.0.113.1 podFoo.domainFoo podFoo
`, `,
}, },
{
"203.0.113.1",
"podFoo",
"domainFoo",
[]v1.HostAlias{
{IP: "123.45.67.89", Hostnames: []string{"foo", "bar", "baz"}},
},
`# Kubernetes-managed hosts file.
127.0.0.1 localhost
::1 localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
fe00::0 ip6-mcastprefix
fe00::1 ip6-allnodes
fe00::2 ip6-allrouters
203.0.113.1 podFoo.domainFoo podFoo
123.45.67.89 foo
123.45.67.89 bar
123.45.67.89 baz
`,
},
{
"203.0.113.1",
"podFoo",
"domainFoo",
[]v1.HostAlias{
{IP: "123.45.67.89", Hostnames: []string{"foo", "bar", "baz"}},
{IP: "456.78.90.123", Hostnames: []string{"park", "doo", "boo"}},
},
`# Kubernetes-managed hosts file.
127.0.0.1 localhost
::1 localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
fe00::0 ip6-mcastprefix
fe00::1 ip6-allnodes
fe00::2 ip6-allrouters
203.0.113.1 podFoo.domainFoo podFoo
123.45.67.89 foo
123.45.67.89 bar
123.45.67.89 baz
456.78.90.123 park
456.78.90.123 doo
456.78.90.123 boo
`,
},
} }
for _, testCase := range testCases { for _, testCase := range testCases {
actualContent := string(hostsFileContent(testCase.hostIP, testCase.hostName, testCase.hostDomainName)) actualContent := string(hostsFileContent(testCase.hostIP, testCase.hostName, testCase.hostDomainName, testCase.hostAliases))
assert.Equal(t, testCase.expectedContent, actualContent, "hosts file content not expected") assert.Equal(t, testCase.expectedContent, actualContent, "hosts file content not expected")
} }
} }
......
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