/
handler.go
364 lines (302 loc) · 8.4 KB
/
handler.go
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package kube
import (
"github.com/dbschenker/vaultpal/config"
"github.com/dbschenker/vaultpal/vault"
"github.com/hashicorp/vault/api"
"github.com/mitchellh/go-homedir"
"github.com/mitchellh/mapstructure"
"github.com/pkg/errors"
log "github.com/sirupsen/logrus"
"gopkg.in/yaml.v2"
"io"
"os"
"strings"
)
const ENV_VAULTPAL_KUBECONFIG_FILE = "VAULTPAL_KUBECONFIG_FILE"
func contextEntryMap(c []ContextEntry) map[string]ContextEntry {
cm := map[string]ContextEntry{}
for _, ce := range c {
cm[ce.Name] = ce
}
return cm
}
func contextEntrySlice(m map[string]ContextEntry) []ContextEntry {
sl := make([]ContextEntry, len(m))
idx := 0
for _, v := range m {
sl[idx] = v
idx++
}
return sl
}
func clusterEntryMap(c []ClusterEntry) map[string]ClusterEntry {
cm := map[string]ClusterEntry{}
for _, ce := range c {
cm[ce.Name] = ce
}
return cm
}
func clusterEntrySlice(m map[string]ClusterEntry) []ClusterEntry {
sl := make([]ClusterEntry, len(m))
idx := 0
for _, v := range m {
sl[idx] = v
idx++
}
return sl
}
func userEntryMap(u []UserEntry) map[string]UserEntry {
um := map[string]UserEntry{}
for _, ue := range u {
um[ue.Name] = ue
}
return um
}
func userEntrySlice(m map[string]UserEntry) []UserEntry {
sl := make([]UserEntry, len(m))
idx := 0
for _, v := range m {
sl[idx] = v
idx++
}
return sl
}
func getPalKubeConfig(client *api.Client, cluster string) config.KubeCluster {
vaultpath := "kv/data/vaultbro/k8s/clusters/" + cluster
k8s, err := client.Logical().Read(vaultpath)
if err != nil {
log.Fatal("error reading vaultpal config entry for cluster: " + err.Error())
}
if k8s == nil {
log.Fatalf("Cluster %s is undefined", cluster)
}
cf := config.KubeCluster{}
mapstructure.Decode(k8s.Data["data"], &cf)
if cf.Name == "" {
log.Errorf("Vaultpath %s exists but contains no config for cluster %s", vaultpath, cluster)
}
return cf
}
func handleWriteKubeconfig(kconfig []byte, cluster string, role string) ([]byte, error) {
namespace := deriveNamespaceFromRole(role)
log.WithFields(log.Fields{
"Cluster": cluster,
"Role": role,
"Namespace": namespace,
}).Info("write a kubeconfig for")
client, err := vault.NewClient()
if err != nil {
log.Fatal("error creating vault api client: " + err.Error())
}
user, err := vault.GetIdentityName(client)
if err != nil {
return nil, errors.Wrap(err, "error getting own identity")
} else if user == nil || *user == "" {
return nil, errors.New("identity must be not empty/nil")
}
log.WithFields(log.Fields{
"identity": *user,
}).Info("got your identity")
cf := getPalKubeConfig(client, cluster)
err = verifyPalKubeConfig(cf)
if err != nil {
return nil, err
}
log.WithFields(log.Fields{
"Cluster": cf.Name,
"PKI": cf.PKI,
"APIServer": cf.Server,
"Alias": cf.Alias,
}).Info("using k8s definition")
pki := cf.PKI
if cf.Alias != "" {
cfAlias := getPalKubeConfig(client, cf.Alias)
err = verifyPalKubeConfig(cfAlias)
if err != nil {
return nil, err
}
pki = cfAlias.PKI
log.WithFields(log.Fields{
"Alias": cf.Alias,
"PKI": cfAlias.PKI,
}).Infof("[%s] is an alias pointing to [%s]", cf.Name, cfAlias.Name)
}
userName := cf.Name + "_" + *user
secret, err := client.Logical().Write(pki+"/issue/"+role, map[string]interface{}{
"common_name": *user,
"ttl": "3600",
})
if err != nil {
log.Fatal("error creating client key for cluster: " + err.Error())
}
clusterE := ClusterEntry{
Name: cf.Name,
Cluster: Cluster{
Server: cf.Server,
CertificateAuthorityData: StringToBase64String(secret.Data["issuing_ca"].(string)),
},
}
contextE := ContextEntry{
Name: cf.Name,
Context: Context{
Cluster: cf.Name,
Namespace: namespace,
User: userName,
},
}
userE := UserEntry{
Name: userName,
User: User{
ClientCertificateData: StringToBase64String(secret.Data["certificate"].(string)),
ClientKeyData: StringToBase64String(secret.Data["private_key"].(string)),
},
}
k8 := Config{
ApiVersion: "v1",
Kind: "Config",
CurrentContext: cf.Name,
Clusters: []ClusterEntry{},
Contexts: []ContextEntry{},
Users: []UserEntry{},
}
oldk8, err := parseKubeConfig(kconfig)
if err != nil {
return nil, err
}
contextM := contextEntryMap(oldk8.Contexts)
contextM[contextE.Name] = contextE
clusterM := clusterEntryMap(oldk8.Clusters)
clusterM[clusterE.Name] = clusterE
userM := userEntryMap(oldk8.Users)
userM[userE.Name] = userE
k8.Contexts = contextEntrySlice(contextM)
k8.Clusters = clusterEntrySlice(clusterM)
k8.Users = userEntrySlice(userM)
out, err := yaml.Marshal(k8)
if err != nil {
return nil, errors.Wrap(err, "cannot marshal kubeconfig file")
}
log.WithFields(log.Fields{
"Cluster": cf.Name,
"API": cf.Server,
"Role": role,
}).Info("Let's kube 🛀")
return out, nil
}
func verifyPalKubeConfig(cluster config.KubeCluster) error {
if cluster.Name == "" {
return errors.New("cluster name must not be empty")
}
if cluster.Server == "" {
return errors.New("server must not be empty")
}
if cluster.Alias == "" {
if cluster.PKI == "" {
return errors.New("pki must not be empty")
}
} else {
if cluster.PKI != "" {
return errors.New("pki must be empty")
}
}
return nil
}
func ensurePalKubeConfigFile() (string, error) {
kubeconfigFile := ""
if envPalKFile := os.Getenv(ENV_VAULTPAL_KUBECONFIG_FILE); envPalKFile == "" {
home, err := homedir.Dir()
if err != nil {
return "", err
}
kubeconfigPath := home + "/.vaultpal/kube"
kubeconfigFile = kubeconfigPath + "/config"
// Make sure pal kube dir exists
err = os.MkdirAll(kubeconfigPath, 0740)
if err != nil {
log.WithError(err).Fatal("cannot create dir")
}
} else {
kubeconfigFile = envPalKFile
}
return kubeconfigFile, nil
}
func WriteKubeconfig(cluster string, role string) error {
kubeconfigFile, err := ensurePalKubeConfigFile()
if err != nil {
return err
}
err = createPalKubeConfigFile(kubeconfigFile)
if err != nil {
return err
}
kubeConfigR, err := kubeConfigReader(kubeconfigFile)
if err != nil {
kubeConfigR.Close()
return err
}
kubeConfigRaw, err := readKubeConfigRaw(kubeConfigR)
if err != nil {
kubeConfigR.Close()
return err
}
kubeConfigR.Close()
newKubeConfig, err := handleWriteKubeconfig(kubeConfigRaw, cluster, role)
if err != nil {
return err
}
err = os.WriteFile(kubeconfigFile, newKubeConfig, 0600)
if err != nil {
return errors.Wrapf(err, "cannot write kubeconfig to [%s]", kubeconfigFile)
}
log.Infof("Enable kubeconfig with: KUBECONFIG=%s", kubeconfigFile)
return nil
}
func createPalKubeConfigFile(file string) error {
if _, err := os.Stat(file); err == nil {
return nil
} else if os.IsNotExist(err) {
log.Info("create empty bro kube config")
err = os.WriteFile(file, []byte{}, 0600)
if err != nil {
return errors.Wrapf(err, "cannot write kubeconfig to [%s]", file)
}
return nil
} else {
return err
}
}
func kubeConfigReader(configFile string) (*os.File, error) {
kconfigReader, err := os.Open(configFile)
if err != nil {
return nil, errors.Wrapf(err, "unable to read existing kube config [%s]", configFile)
}
return kconfigReader, nil
}
func readKubeConfigRaw(configFile io.Reader) ([]byte, error) {
yamlRaw, err := io.ReadAll(configFile)
if err != nil {
return nil, errors.Wrapf(err, "unable to read existing kube config [%s]", configFile)
}
return yamlRaw, nil
}
func parseKubeConfig(configRaw []byte) (*Config, error) {
kconfig := &Config{}
err := yaml.Unmarshal(configRaw, kconfig)
if err != nil {
return nil, errors.Wrap(err, "unable to unmarshal kube config")
}
return kconfig, nil
}
// Traditionally role and namespace have been treated as the same value, e.g. "ttb-int"
// However with the advent of different roles types for the same topic/environment such as ttb-int-user
// We need to strip those suffixes to ensure that the default kubeconfig points to a namespace that actually exists
// Similar to -user we may introduce -admin and additional more fine grained suffixed in future
func deriveNamespaceFromRole(role string) (namespace string) {
roleSuffixes := [...]string{"-user", "-admin"} // also support -admin, even though it's currently not used
for _, suffix := range roleSuffixes {
if strings.HasSuffix(role, suffix) {
return role[0 : len(role)-len(suffix)]
}
}
return role // traditional behaviour (role == namespace): if no known suffix matches, just return the role input
}