Port kubernetes package to supervisor
This replaces the ad-hoc goroutine and process management
previously in the kubernetes package with a nice supervisor-based
implementation which should make it easier to understand and more
reliable. It also prevents creation of more ad-hoc launching code
for future features (like CSI & Provisioning).
Since porting SmalltownNode is rather involved I just instantiated a
new supervision tree in the Kubernetes main service and wired it
up to the old interface. Once we port SmalltownNode we can just
remove the legacy Start() method and directly call Run().
Test Plan:
Passes Bazel tests, Kubernetes functionality was manually
tested by running `bazel run //core/cmd/dbg -- kubectl run -i --image alpine:edge sh`
to verify that Kubernetes still works properly. Automated tests for this
are being worked on.
X-Origin-Diff: phab/D534
GitOrigin-RevId: 001de38eaa5c7ee661bf5db9a7c3d0125c1b6af2
diff --git a/core/internal/kubernetes/kubelet.go b/core/internal/kubernetes/kubelet.go
index b7d8157..3b1a123 100644
--- a/core/internal/kubernetes/kubelet.go
+++ b/core/internal/kubernetes/kubelet.go
@@ -22,17 +22,18 @@
"encoding/json"
"encoding/pem"
"fmt"
- "go.uber.org/zap"
+ "io"
"io/ioutil"
+ "net"
"os"
"os/exec"
- "net"
-
- "git.monogon.dev/source/nexantic.git/core/pkg/fileargs"
"go.etcd.io/etcd/clientv3"
v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
- "k8s.io/kubelet/config/v1beta1"
+ kubeletconfig "k8s.io/kubelet/config/v1beta1"
+
+ "git.monogon.dev/source/nexantic.git/core/internal/common/supervisor"
+ "git.monogon.dev/source/nexantic.git/core/pkg/fileargs"
)
type KubeletSpec struct {
@@ -77,65 +78,63 @@
return nil
}
-func (s *Service) runKubelet(ctx context.Context, spec *KubeletSpec) error {
- fargs, err := fileargs.New()
- if err != nil {
- return err
- }
- var clusterDNS []string
- for _, dnsIP := range spec.clusterDNS {
- clusterDNS = append(clusterDNS, dnsIP.String())
- }
+func runKubelet(spec *KubeletSpec, output io.Writer) supervisor.Runnable {
+ return func(ctx context.Context) error {
+ fargs, err := fileargs.New()
+ if err != nil {
+ return err
+ }
+ var clusterDNS []string
+ for _, dnsIP := range spec.clusterDNS {
+ clusterDNS = append(clusterDNS, dnsIP.String())
+ }
- kubeletConf := &v1beta1.KubeletConfiguration{
- TypeMeta: v1.TypeMeta{
- Kind: "KubeletConfiguration",
- APIVersion: v1beta1.GroupName + "/v1beta1",
- },
- TLSCertFile: "/data/kubernetes/kubelet.crt",
- TLSPrivateKeyFile: "/data/kubernetes/kubelet.key",
- TLSMinVersion: "VersionTLS13",
- ClusterDNS: clusterDNS,
- Authentication: v1beta1.KubeletAuthentication{
- X509: v1beta1.KubeletX509Authentication{
- ClientCAFile: "/data/kubernetes/ca.crt",
+ kubeletConf := &kubeletconfig.KubeletConfiguration{
+ TypeMeta: v1.TypeMeta{
+ Kind: "KubeletConfiguration",
+ APIVersion: kubeletconfig.GroupName + "/v1beta1",
},
- },
- ClusterDomain: "cluster.local",
- EnableControllerAttachDetach: False(),
- HairpinMode: "none",
- MakeIPTablesUtilChains: False(), // We don't have iptables
- FailSwapOn: False(), // Our kernel doesn't have swap enabled which breaks Kubelet's detection
- KubeReserved: map[string]string{
- "cpu": "200m",
- "memory": "300Mi",
- },
- // We're not going to use this, but let's make it point to a known-empty directory in case anybody manages to
- // trigger it.
- VolumePluginDir: "/kubernetes/conf/flexvolume-plugins",
- }
+ TLSCertFile: "/data/kubernetes/kubelet.crt",
+ TLSPrivateKeyFile: "/data/kubernetes/kubelet.key",
+ TLSMinVersion: "VersionTLS13",
+ ClusterDNS: clusterDNS,
+ Authentication: kubeletconfig.KubeletAuthentication{
+ X509: kubeletconfig.KubeletX509Authentication{
+ ClientCAFile: "/data/kubernetes/ca.crt",
+ },
+ },
+ ClusterDomain: "cluster.local", // cluster.local is hardcoded in the certificate too currently
+ EnableControllerAttachDetach: False(),
+ HairpinMode: "none",
+ MakeIPTablesUtilChains: False(), // We don't have iptables
+ FailSwapOn: False(), // Our kernel doesn't have swap enabled which breaks Kubelet's detection
+ KubeReserved: map[string]string{
+ "cpu": "200m",
+ "memory": "300Mi",
+ },
+ // We're not going to use this, but let's make it point to a known-empty directory in case anybody manages to
+ // trigger it.
+ VolumePluginDir: "/kubernetes/conf/flexvolume-plugins",
+ }
- configRaw, err := json.Marshal(kubeletConf)
- if err != nil {
+ configRaw, err := json.Marshal(kubeletConf)
+ if err != nil {
+ return err
+ }
+ cmd := exec.CommandContext(ctx, "/kubernetes/bin/kube", "kubelet",
+ fargs.FileOpt("--config", "config.json", configRaw),
+ "--container-runtime=remote",
+ "--container-runtime-endpoint=unix:///containerd/run/containerd.sock",
+ "--kubeconfig=/data/kubernetes/kubelet.kubeconfig",
+ "--root-dir=/data/kubernetes/kubelet",
+ )
+ cmd.Env = []string{"PATH=/kubernetes/bin"}
+ cmd.Stdout = output
+ cmd.Stderr = output
+
+ supervisor.Signal(ctx, supervisor.SignalHealthy)
+ err = cmd.Run()
+ fmt.Fprintf(output, "kubelet stopped: %v\n", err)
return err
}
- cmd := exec.CommandContext(ctx, "/kubernetes/bin/kube", "kubelet",
- fargs.FileOpt("--config", "config.json", configRaw),
- "--container-runtime=remote",
- "--container-runtime-endpoint=unix:///containerd/run/containerd.sock",
- "--kubeconfig=/data/kubernetes/kubelet.kubeconfig",
- "--root-dir=/data/kubernetes/kubelet",
- )
- cmd.Env = []string{"PATH=/kubernetes/bin"}
- cmd.Stdout = s.kubeletLogs
- cmd.Stderr = s.kubeletLogs
-
- err = cmd.Run()
- fmt.Fprintf(s.kubeletLogs, "kubelet stopped: %v\n", err)
- if ctx.Err() == context.Canceled {
- s.logger.Info("kubelet stopped", zap.Error(err))
- } else {
- s.logger.Warn("kubelet stopped unexpectedly", zap.Error(err))
- }
- return err
}