/
main.go
157 lines (142 loc) · 3.17 KB
/
main.go
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package main
import (
"flag"
"fmt"
"os"
"path"
"runtime"
"runtime/debug"
"k8s.io/client-go/tools/clientcmd"
"k8s.io/client-go/tools/clientcmd/api"
)
var (
inPlaceFlag bool
restoreFlag bool
replaceCmd string = "kcc-cache"
)
func main() {
// flag
flag.Usage = func() {
fmt.Fprintf(flag.CommandLine.Output(), "Usage: %s [flags] <kubeconfig-filepath>\n", path.Base(os.Args[0]))
flag.PrintDefaults()
}
flag.BoolVar(&inPlaceFlag, "i", false, "edit file in-place")
flag.BoolVar(&restoreFlag, "r", false, "restore kubeconfig to original")
flag.StringVar(&replaceCmd, "c", replaceCmd, "injection command")
flag.Parse()
// read input
var filename string
var bytes []byte
{
if args := flag.Args(); len(args) > 0 {
filename = args[0]
}
if filename == "" {
fmt.Fprintln(os.Stderr, "filename required")
flag.Usage()
os.Exit(1)
}
b, err := os.ReadFile(filename)
if err != nil {
fatal("read error: %s", err)
}
bytes = b
}
// parse as kubeconfig
var kubeConfig api.Config
{
clientConfig, err := clientcmd.NewClientConfigFromBytes(bytes)
if err != nil {
fatal("%v", err)
}
apiConfig, err := clientConfig.RawConfig()
if err != nil {
fatal("%v", err)
}
kubeConfig = apiConfig
}
// kubeconfig manipulation
if restoreFlag {
// restore to original
for _, user := range kubeConfig.AuthInfos {
if user.Exec == nil {
continue
}
if user.Exec.Command == replaceCmd {
user.Exec.Command = user.Exec.Args[0]
user.Exec.Args = user.Exec.Args[1:]
}
search := func() (index int) {
for i, e := range user.Exec.Env {
if e.Name == "KUBE_CREDENTIAL_CACHE_USER" {
return i
}
}
return -1
}
for {
i := search()
if i == -1 {
break
}
user.Exec.Env = append(user.Exec.Env[:i], user.Exec.Env[i+1:]...)
}
}
} else {
// enable cache
for name, user := range kubeConfig.AuthInfos {
if user.Exec == nil {
continue
}
if user.Exec.Command != replaceCmd {
user.Exec.Args = append([]string{user.Exec.Command}, user.Exec.Args...)
user.Exec.Command = replaceCmd
}
found := false
userEnv := api.ExecEnvVar{
Name: "KUBE_CREDENTIAL_CACHE_USER",
Value: name,
}
for i, e := range user.Exec.Env {
if e.Name == "KUBE_CREDENTIAL_CACHE_USER" {
found = true
user.Exec.Env[i] = userEnv
}
}
if !found {
user.Exec.Env = append(user.Exec.Env, userEnv)
}
}
}
// output
if inPlaceFlag {
// in-place
err := clientcmd.WriteToFile(kubeConfig, filename)
if err != nil {
fatal("%v", err)
}
} else {
// stdout
b, err := clientcmd.Write(kubeConfig)
if err != nil {
fatal("%v", err)
}
fmt.Println(string(b))
}
}
func fatal(format string, v ...any) {
var commit string = "main"
if i, ok := debug.ReadBuildInfo(); ok {
for _, v := range i.Settings {
if v.Key == "vcs.revision" {
commit = v.Value
}
}
}
_, _, line, _ := runtime.Caller(1)
fmt.Fprintf(os.Stderr, "%s: ", path.Base(os.Args[0]))
fmt.Fprintf(os.Stderr, format+"\n", v...)
fmt.Fprintf(os.Stderr, "error occurred at: https://github.com/ryodocx/kube-credential-cache/blob/%s/cmd/kcc-injector/main.go#L%d\n", commit, line)
flag.Usage()
os.Exit(1)
}