helmfile/pkg/helmexec/runner.go

100 lines
2.4 KiB
Go

package helmexec
import (
"bytes"
"errors"
"fmt"
"go.uber.org/zap"
"os"
"os/exec"
"strings"
"syscall"
)
const (
tmpPrefix = "helmfile-"
tmpSuffix = "-exec"
)
// Runner interface for shell commands
type Runner interface {
Execute(cmd string, args []string, env map[string]string) ([]byte, error)
}
// ShellRunner implemention for shell commands
type ShellRunner struct {
Dir string
Logger *zap.SugaredLogger
}
// Execute a shell command
func (shell ShellRunner) Execute(cmd string, args []string, env map[string]string) ([]byte, error) {
preparedCmd := exec.Command(cmd, args...)
preparedCmd.Dir = shell.Dir
preparedCmd.Env = mergeEnv(os.Environ(), env)
return combinedOutput(preparedCmd, shell.Logger)
}
func combinedOutput(c *exec.Cmd, logger *zap.SugaredLogger) ([]byte, error) {
if c.Stdout != nil {
return nil, errors.New("exec: Stdout already set")
}
if c.Stderr != nil {
return nil, errors.New("exec: Stderr already set")
}
var stdout bytes.Buffer
var stderr bytes.Buffer
c.Stdout = &stdout
c.Stderr = &stderr
err := c.Run()
o := stdout.Bytes()
e := stderr.Bytes()
if err != nil {
// TrimSpace is necessary, because otherwise helmfile prints the redundant new-lines after each error like:
//
// err: release "envoy2" in "helmfile.yaml" failed: exit status 1: Error: could not find a ready tiller pod
// <redundant new line!>
// err: release "envoy" in "helmfile.yaml" failed: exit status 1: Error: could not find a ready tiller pod
switch ee := err.(type) {
case *exec.ExitError:
// Propagate any non-zero exit status from the external command, rather than throwing it away,
// so that helmfile could return its own exit code accordingly
waitStatus := ee.Sys().(syscall.WaitStatus)
exitStatus := waitStatus.ExitStatus()
err = newExitError(c.Path, exitStatus, string(e))
default:
panic(fmt.Sprintf("unexpected error: %v", err))
}
}
return o, err
}
func mergeEnv(orig []string, new map[string]string) []string {
wanted := env2map(orig)
for k, v := range new {
wanted[k] = v
}
return map2env(wanted)
}
func map2env(wanted map[string]string) []string {
result := []string{}
for k, v := range wanted {
result = append(result, k+"="+v)
}
return result
}
func env2map(env []string) map[string]string {
wanted := map[string]string{}
for _, cur := range env {
pair := strings.SplitN(cur, "=", 2)
wanted[pair[0]] = pair[1]
}
return wanted
}