constellation/bootstrapper/internal/kubernetes/k8sapi/k8sutil.go
3u13r e0285c122e
todo responsibilities and cleanup (#1837)
* chore: add TODO responsibilities

* chore: remove not needed TODOs

* chore: remove outdated migrations

* chore: remove resolved goleak exception

* chore: remove not needed cosign env

* config: add link to our Azure snp docs
2023-06-01 12:33:06 +02:00

527 lines
19 KiB
Go

/*
Copyright (c) Edgeless Systems GmbH
SPDX-License-Identifier: AGPL-3.0-only
*/
package k8sapi
import (
"context"
"crypto/rand"
"crypto/x509"
"encoding/pem"
"errors"
"fmt"
"net"
"net/http"
"os"
"os/exec"
"path/filepath"
"strconv"
"strings"
"time"
"github.com/edgelesssys/constellation/v2/bootstrapper/internal/certificate"
"github.com/edgelesssys/constellation/v2/bootstrapper/internal/kubernetes/k8sapi/resources"
"github.com/edgelesssys/constellation/v2/internal/constants"
"github.com/edgelesssys/constellation/v2/internal/role"
"github.com/edgelesssys/constellation/v2/internal/versions/components"
corev1 "k8s.io/api/core/v1"
"k8s.io/apiserver/pkg/authentication/user"
kubeconstants "k8s.io/kubernetes/cmd/kubeadm/app/constants"
"github.com/edgelesssys/constellation/v2/internal/crypto"
"github.com/edgelesssys/constellation/v2/internal/file"
"github.com/edgelesssys/constellation/v2/internal/installer"
"github.com/edgelesssys/constellation/v2/internal/logger"
"github.com/spf13/afero"
"go.uber.org/zap"
)
const (
// kubeletStartTimeout is the maximum time given to the kubelet service to (re)start.
kubeletStartTimeout = 10 * time.Minute
kubeletServicePath = "/usr/lib/systemd/system/kubelet.service"
)
// Client provides the functions to talk to the k8s API.
type Client interface {
Initialize(kubeconfig []byte) error
CreateConfigMap(ctx context.Context, configMap corev1.ConfigMap) error
AddTolerationsToDeployment(ctx context.Context, tolerations []corev1.Toleration, name string, namespace string) error
AddNodeSelectorsToDeployment(ctx context.Context, selectors map[string]string, name string, namespace string) error
ListAllNamespaces(ctx context.Context) (*corev1.NamespaceList, error)
AnnotateNode(ctx context.Context, nodeName, annotationKey, annotationValue string) error
}
type componentsInstaller interface {
Install(
ctx context.Context, kubernetesComponent components.Component,
) error
}
// KubernetesUtil provides low level management of the kubernetes cluster.
type KubernetesUtil struct {
inst componentsInstaller
file file.Handler
}
// NewKubernetesUtil creates a new KubernetesUtil.
func NewKubernetesUtil() *KubernetesUtil {
return &KubernetesUtil{
inst: installer.NewOSInstaller(),
file: file.NewHandler(afero.NewOsFs()),
}
}
// InstallComponents installs the kubernetes components passed from the CLI.
func (k *KubernetesUtil) InstallComponents(ctx context.Context, kubernetesComponents components.Components) error {
for _, component := range kubernetesComponents {
if err := k.inst.Install(ctx, component); err != nil {
return fmt.Errorf("installing kubernetes component from URL %s: %w", component.URL, err)
}
}
return enableSystemdUnit(ctx, kubeletServicePath)
}
// InitCluster instruments kubeadm to initialize the K8s cluster.
// On success an admin kubeconfig file is returned.
func (k *KubernetesUtil) InitCluster(
ctx context.Context, initConfig []byte, nodeName, clusterName string, ips []net.IP, controlPlaneEndpoint string, conformanceMode bool, log *logger.Logger,
) ([]byte, error) {
// TODO(3u13r): audit policy should be user input
auditPolicy, err := resources.NewDefaultAuditPolicy().Marshal()
if err != nil {
return nil, fmt.Errorf("generating default audit policy: %w", err)
}
if err := os.WriteFile(auditPolicyPath, auditPolicy, 0o644); err != nil {
return nil, fmt.Errorf("writing default audit policy: %w", err)
}
initConfigFile, err := os.CreateTemp("", "kubeadm-init.*.yaml")
if err != nil {
return nil, fmt.Errorf("creating init config file %v: %w", initConfigFile.Name(), err)
}
if _, err := initConfigFile.Write(initConfig); err != nil {
return nil, fmt.Errorf("writing kubeadm init yaml config %v: %w", initConfigFile.Name(), err)
}
// preflight
log.Infof("Running kubeadm preflight checks")
cmd := exec.CommandContext(ctx, constants.KubeadmPath, "init", "phase", "preflight", "-v=5", "--config", initConfigFile.Name())
out, err := cmd.CombinedOutput()
if err != nil {
var exitErr *exec.ExitError
if errors.As(err, &exitErr) {
return nil, fmt.Errorf("kubeadm init phase preflight failed (code %v) with: %s", exitErr.ExitCode(), out)
}
return nil, fmt.Errorf("kubeadm init: %w", err)
}
// create CA certs
log.Infof("Creating Kubernetes control-plane certificates and keys")
cmd = exec.CommandContext(ctx, constants.KubeadmPath, "init", "phase", "certs", "all", "-v=5", "--config", initConfigFile.Name())
out, err = cmd.CombinedOutput()
if err != nil {
var exitErr *exec.ExitError
if errors.As(err, &exitErr) {
return nil, fmt.Errorf("kubeadm init phase certs all failed (code %v) with: %s", exitErr.ExitCode(), out)
}
return nil, fmt.Errorf("kubeadm init: %w", err)
}
// create kubelet key and CA signed certificate for the node
log.Infof("Creating signed kubelet certificate")
if err := k.createSignedKubeletCert(nodeName, ips); err != nil {
return nil, fmt.Errorf("creating signed kubelete certificate: %w", err)
}
// Create static pods directory for all nodes (the Kubelets on the worker nodes also expect the path to exist)
log.Infof("Creating static Pod directory /etc/kubernetes/manifests")
if err := os.MkdirAll("/etc/kubernetes/manifests", os.ModePerm); err != nil {
return nil, fmt.Errorf("creating static pods directory: %w", err)
}
log.Infof("Preparing node for Konnectivity")
if err := k.prepareControlPlaneForKonnectivity(ctx, controlPlaneEndpoint); err != nil {
return nil, fmt.Errorf("setup konnectivity: %w", err)
}
// initialize the cluster
log.Infof("Initializing the cluster using kubeadm init")
skipPhases := "--skip-phases=preflight,certs"
if !conformanceMode {
skipPhases += ",addon/kube-proxy"
}
cmd = exec.CommandContext(ctx, constants.KubeadmPath, "init", "-v=5", skipPhases, "--config", initConfigFile.Name())
out, err = cmd.CombinedOutput()
if err != nil {
var exitErr *exec.ExitError
if errors.As(err, &exitErr) {
return nil, fmt.Errorf("kubeadm init failed (code %v) with: %s", exitErr.ExitCode(), out)
}
return nil, fmt.Errorf("kubeadm init: %w", err)
}
log.With(zap.String("output", string(out))).Infof("kubeadm init succeeded")
userName := clusterName + "-admin"
log.With(zap.String("userName", userName)).Infof("Creating admin kubeconfig file")
cmd = exec.CommandContext(
ctx, constants.KubeadmPath, "kubeconfig", "user",
"--client-name", userName, "--config", initConfigFile.Name(), "--org", user.SystemPrivilegedGroup,
)
out, err = cmd.Output()
if err != nil {
var exitErr *exec.ExitError
if errors.As(err, &exitErr) {
return nil, fmt.Errorf("kubeadm kubeconfig user failed (code %v) with: %s", exitErr.ExitCode(), out)
}
return nil, fmt.Errorf("kubeadm kubeconfig user: %w", err)
}
log.Infof("kubeadm kubeconfig user succeeded")
return out, nil
}
func (k *KubernetesUtil) prepareControlPlaneForKonnectivity(ctx context.Context, loadBalancerEndpoint string) error {
if !strings.Contains(loadBalancerEndpoint, ":") {
loadBalancerEndpoint = net.JoinHostPort(loadBalancerEndpoint, strconv.Itoa(constants.KubernetesPort))
}
konnectivityServerYaml, err := resources.NewKonnectivityServerStaticPod().Marshal()
if err != nil {
return fmt.Errorf("generating konnectivity server static pod: %w", err)
}
if err := os.WriteFile("/etc/kubernetes/manifests/konnectivity-server.yaml", konnectivityServerYaml, 0o644); err != nil {
return fmt.Errorf("writing konnectivity server pod: %w", err)
}
egressConfigYaml, err := resources.NewEgressSelectorConfiguration().Marshal()
if err != nil {
return fmt.Errorf("generating egress selector configuration: %w", err)
}
if err := os.WriteFile("/etc/kubernetes/egress-selector-configuration.yaml", egressConfigYaml, 0o644); err != nil {
return fmt.Errorf("writing egress selector config: %w", err)
}
if err := k.createSignedKonnectivityCert(); err != nil {
return fmt.Errorf("generating konnectivity server certificate: %w", err)
}
if out, err := exec.CommandContext(ctx, constants.KubectlPath, "config", "set-credentials", "--kubeconfig", "/etc/kubernetes/konnectivity-server.conf", "system:konnectivity-server",
"--client-certificate", "/etc/kubernetes/konnectivity.crt", "--client-key", "/etc/kubernetes/konnectivity.key", "--embed-certs=true").CombinedOutput(); err != nil {
return fmt.Errorf("konnectivity kubeconfig set-credentials: %w, %s", err, string(out))
}
if out, err := exec.CommandContext(ctx, constants.KubectlPath, "--kubeconfig", "/etc/kubernetes/konnectivity-server.conf", "config", "set-cluster", "kubernetes", "--server", "https://"+loadBalancerEndpoint,
"--certificate-authority", "/etc/kubernetes/pki/ca.crt", "--embed-certs=true").CombinedOutput(); err != nil {
return fmt.Errorf("konnectivity kubeconfig set-cluster: %w, %s", err, string(out))
}
if out, err := exec.CommandContext(ctx, constants.KubectlPath, "--kubeconfig", "/etc/kubernetes/konnectivity-server.conf", "config", "set-context", "system:konnectivity-server@kubernetes",
"--cluster", "kubernetes", "--user", "system:konnectivity-server").CombinedOutput(); err != nil {
return fmt.Errorf("konnectivity kubeconfig set-context: %w, %s", err, string(out))
}
if out, err := exec.CommandContext(ctx, constants.KubectlPath, "--kubeconfig", "/etc/kubernetes/konnectivity-server.conf", "config", "use-context", "system:konnectivity-server@kubernetes").CombinedOutput(); err != nil {
return fmt.Errorf("konnectivity kubeconfig use-context: %w, %s", err, string(out))
}
// cleanup
if err := os.Remove("/etc/kubernetes/konnectivity.crt"); err != nil {
return fmt.Errorf("removing konnectivity certificate: %w", err)
}
if err := os.Remove("/etc/kubernetes/konnectivity.key"); err != nil {
return fmt.Errorf("removing konnectivity key: %w", err)
}
return nil
}
// SetupPodNetworkInput holds all configuration options to setup the pod network.
type SetupPodNetworkInput struct {
CloudProvider string
NodeName string
FirstNodePodCIDR string
SubnetworkPodCIDR string
LoadBalancerEndpoint string
}
// WaitForCilium waits until Cilium reports a healthy status over its /healthz endpoint.
func (k *KubernetesUtil) WaitForCilium(ctx context.Context, log *logger.Logger) error {
// wait for cilium pod to be healthy
client := http.Client{}
for {
select {
case <-ctx.Done():
return ctx.Err()
default:
time.Sleep(5 * time.Second)
req, err := http.NewRequestWithContext(ctx, http.MethodGet, "http://127.0.0.1:9879/healthz", http.NoBody)
if err != nil {
return fmt.Errorf("unable to create request: %w", err)
}
resp, err := client.Do(req)
if err != nil {
log.With(zap.Error(err)).Infof("Waiting for local Cilium DaemonSet - Pod not healthy yet")
continue
}
resp.Body.Close()
if resp.StatusCode == 200 {
return nil
}
}
}
}
// FixCilium fixes https://github.com/cilium/cilium/issues/19958
// Instead of a rollout restart of the Cilium DaemonSet, it only restarts the local Cilium Pod.
func (k *KubernetesUtil) FixCilium(ctx context.Context) error {
// get cilium container id
out, err := exec.CommandContext(ctx, "/run/state/bin/crictl", "ps", "--name", "cilium-agent", "-q").CombinedOutput()
if err != nil {
return fmt.Errorf("getting cilium container id failed: %s", out)
}
outLines := strings.Split(string(out), "\n")
if len(outLines) < 2 {
return fmt.Errorf("getting cilium container id returned invalid output: %s", out)
}
containerID := outLines[len(outLines)-2]
// get cilium pod id
out, err = exec.CommandContext(ctx, "/run/state/bin/crictl", "inspect", "-o", "go-template", "--template", "{{ .info.sandboxID }}", containerID).CombinedOutput()
if err != nil {
return fmt.Errorf("getting Cilium Pod ID failed: %s", out)
}
outLines = strings.Split(string(out), "\n")
if len(outLines) < 2 {
return fmt.Errorf("getting Cilium Pod ID returned invalid output: %s", out)
}
podID := outLines[len(outLines)-2]
// stop and delete pod
out, err = exec.CommandContext(ctx, "/run/state/bin/crictl", "stopp", podID).CombinedOutput()
if err != nil {
return fmt.Errorf("stopping Cilium agent Pod failed: %s", out)
}
out, err = exec.CommandContext(ctx, "/run/state/bin/crictl", "rmp", podID).CombinedOutput()
if err != nil {
return fmt.Errorf("removing Cilium agent Pod failed: %s", out)
}
return nil
}
// JoinCluster joins existing Kubernetes cluster using kubeadm join.
func (k *KubernetesUtil) JoinCluster(ctx context.Context, joinConfig []byte, peerRole role.Role, controlPlaneEndpoint string, log *logger.Logger) error {
// TODO(3u13r): audit policy should be user input
auditPolicy, err := resources.NewDefaultAuditPolicy().Marshal()
if err != nil {
return fmt.Errorf("generating default audit policy: %w", err)
}
if err := os.WriteFile(auditPolicyPath, auditPolicy, 0o644); err != nil {
return fmt.Errorf("writing default audit policy: %w", err)
}
joinConfigFile, err := os.CreateTemp("", "kubeadm-join.*.yaml")
if err != nil {
return fmt.Errorf("creating join config file %v: %w", joinConfigFile.Name(), err)
}
if _, err := joinConfigFile.Write(joinConfig); err != nil {
return fmt.Errorf("writing kubeadm init yaml config %v: %w", joinConfigFile.Name(), err)
}
// Create static pods directory for all nodes (the Kubelets on the worker nodes also expect the path to exist)
log.Infof("Creating static Pod directory /etc/kubernetes/manifests")
if err := os.MkdirAll("/etc/kubernetes/manifests", os.ModePerm); err != nil {
return fmt.Errorf("creating static pods directory: %w", err)
}
if peerRole == role.ControlPlane {
log.Infof("Prep Init Kubernetes cluster")
if err := k.prepareControlPlaneForKonnectivity(ctx, controlPlaneEndpoint); err != nil {
return fmt.Errorf("setup konnectivity: %w", err)
}
}
// run `kubeadm join` to join a worker node to an existing Kubernetes cluster
cmd := exec.CommandContext(ctx, constants.KubeadmPath, "join", "-v=5", "--config", joinConfigFile.Name())
out, err := cmd.CombinedOutput()
if err != nil {
var exitErr *exec.ExitError
if errors.As(err, &exitErr) {
return fmt.Errorf("kubeadm join failed (code %v) with: %s (full err: %s)", exitErr.ExitCode(), out, err)
}
return fmt.Errorf("kubeadm join: %w", err)
}
log.With(zap.String("output", string(out))).Infof("kubeadm join succeeded")
return nil
}
// StartKubelet enables and starts the kubelet systemd unit.
func (k *KubernetesUtil) StartKubelet() error {
ctx, cancel := context.WithTimeout(context.TODO(), kubeletStartTimeout)
defer cancel()
if err := enableSystemdUnit(ctx, kubeletServicePath); err != nil {
return fmt.Errorf("enabling kubelet systemd unit: %w", err)
}
return startSystemdUnit(ctx, "kubelet.service")
}
// createSignedKubeletCert manually creates a Kubernetes CA signed kubelet certificate for the bootstrapper node.
// This is necessary because this node does not request a certificate from the join service.
func (k *KubernetesUtil) createSignedKubeletCert(nodeName string, ips []net.IP) error {
// Create CSR
certRequestRaw, kubeletKey, err := certificate.GetKubeletCertificateRequest(nodeName, ips)
if err != nil {
return err
}
if err := k.file.Write(certificate.KeyFilename, kubeletKey, file.OptMkdirAll); err != nil {
return err
}
certRequest, err := x509.ParseCertificateRequest(certRequestRaw)
if err != nil {
return err
}
// Prepare certificate signing
serialNumber, err := crypto.GenerateCertificateSerialNumber()
if err != nil {
return err
}
now := time.Now()
// Create the kubelet certificate
// For a reference on the certificate fields, see: https://kubernetes.io/docs/setup/best-practices/certificates/
certTmpl := &x509.Certificate{
SerialNumber: serialNumber,
NotBefore: now.Add(-2 * time.Hour),
NotAfter: now.Add(24 * 365 * time.Hour),
Subject: certRequest.Subject,
KeyUsage: x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
ExtKeyUsage: []x509.ExtKeyUsage{
x509.ExtKeyUsageClientAuth,
x509.ExtKeyUsageServerAuth,
},
IsCA: false,
BasicConstraintsValid: true,
IPAddresses: certRequest.IPAddresses,
}
parentCert, parentKey, err := k.getKubernetesCACertAndKey()
if err != nil {
return err
}
// Sign the certificate
certRaw, err := x509.CreateCertificate(rand.Reader, certTmpl, parentCert, certRequest.PublicKey, parentKey)
if err != nil {
return err
}
// Write the certificate
kubeletCert := pem.EncodeToMemory(&pem.Block{
Type: "CERTIFICATE",
Bytes: certRaw,
})
return k.file.Write(certificate.CertificateFilename, kubeletCert, file.OptMkdirAll)
}
// createSignedKonnectivityCert manually creates a Kubernetes CA signed certificate for the Konnectivity server.
func (k *KubernetesUtil) createSignedKonnectivityCert() error {
// Create CSR
certRequestRaw, keyPem, err := resources.GetKonnectivityCertificateRequest()
if err != nil {
return err
}
if err := k.file.Write(resources.KonnectivityKeyFilename, keyPem, file.OptMkdirAll); err != nil {
return err
}
certRequest, err := x509.ParseCertificateRequest(certRequestRaw)
if err != nil {
return err
}
// Prepare certificate signing
serialNumber, err := crypto.GenerateCertificateSerialNumber()
if err != nil {
return err
}
now := time.Now()
// Create the kubelet certificate
// For a reference on the certificate fields, see: https://kubernetes.io/docs/setup/best-practices/certificates/
certTmpl := &x509.Certificate{
SerialNumber: serialNumber,
NotBefore: now.Add(-2 * time.Hour),
NotAfter: now.Add(24 * 365 * time.Hour),
Subject: certRequest.Subject,
}
parentCert, parentKey, err := k.getKubernetesCACertAndKey()
if err != nil {
return err
}
// Sign the certificate
certRaw, err := x509.CreateCertificate(rand.Reader, certTmpl, parentCert, certRequest.PublicKey, parentKey)
if err != nil {
return err
}
// Write the certificate
konnectivityCert := pem.EncodeToMemory(&pem.Block{
Type: "CERTIFICATE",
Bytes: certRaw,
})
return k.file.Write(resources.KonnectivityCertificateFilename, konnectivityCert, file.OptMkdirAll)
}
// getKubernetesCACertAndKey returns the Kubernetes CA certificate and key.
// The key of type `any` can be consumed by `x509.CreateCertificate()`.
func (k *KubernetesUtil) getKubernetesCACertAndKey() (*x509.Certificate, any, error) {
parentCertRaw, err := k.file.Read(filepath.Join(
kubeconstants.KubernetesDir,
kubeconstants.DefaultCertificateDir,
kubeconstants.CACertName,
))
if err != nil {
return nil, nil, err
}
parentCert, err := crypto.PemToX509Cert(parentCertRaw)
if err != nil {
return nil, nil, err
}
parentKeyRaw, err := k.file.Read(filepath.Join(
kubeconstants.KubernetesDir,
kubeconstants.DefaultCertificateDir,
kubeconstants.CAKeyName,
))
if err != nil {
return nil, nil, err
}
parentKeyPEM, _ := pem.Decode(parentKeyRaw)
var parentKey any
switch parentKeyPEM.Type {
case "EC PRIVATE KEY":
parentKey, err = x509.ParseECPrivateKey(parentKeyPEM.Bytes)
case "RSA PRIVATE KEY":
parentKey, err = x509.ParsePKCS1PrivateKey(parentKeyPEM.Bytes)
case "PRIVATE KEY":
parentKey, err = x509.ParsePKCS8PrivateKey(parentKeyPEM.Bytes)
default:
err = fmt.Errorf("unsupported key type %q", parentKeyPEM.Type)
}
if err != nil {
return nil, nil, err
}
return parentCert, parentKey, nil
}