packer-cn/provisioner/powershell/provisioner.go

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// This package implements a provisioner for Packer that executes
// shell scripts within the remote machine.
package powershell
import (
"bufio"
"bytes"
"errors"
"fmt"
"io/ioutil"
"log"
"os"
"sort"
"strings"
"time"
"github.com/mitchellh/packer/common"
"github.com/mitchellh/packer/common/uuid"
"github.com/mitchellh/packer/helper/config"
"github.com/mitchellh/packer/packer"
"github.com/mitchellh/packer/template/interpolate"
)
const DefaultRemotePath = "c:/Windows/Temp/script.ps1"
var retryableSleep = 2 * time.Second
type Config struct {
common.PackerConfig `mapstructure:",squash"`
// If true, the script contains binary and line endings will not be
// converted from Windows to Unix-style.
Binary bool
// An inline script to execute. Multiple strings are all executed
// in the context of a single shell.
Inline []string
// The local path of the shell script to upload and execute.
Script string
// An array of multiple scripts to run.
Scripts []string
// An array of environment variables that will be injected before
// your command(s) are executed.
Vars []string `mapstructure:"environment_vars"`
// The remote path where the local shell script will be uploaded to.
// This should be set to a writable file that is in a pre-existing directory.
RemotePath string `mapstructure:"remote_path"`
// The command used to execute the script. The '{{ .Path }}' variable
// should be used to specify where the script goes, {{ .Vars }}
// can be used to inject the environment_vars into the environment.
ExecuteCommand string `mapstructure:"execute_command"`
// The command used to execute the elevated script. The '{{ .Path }}' variable
// should be used to specify where the script goes, {{ .Vars }}
// can be used to inject the environment_vars into the environment.
ElevatedExecuteCommand string `mapstructure:"elevated_execute_command"`
// The timeout for retrying to start the process. Until this timeout
// is reached, if the provisioner can't start a process, it retries.
// This can be set high to allow for reboots.
StartRetryTimeout time.Duration `mapstructure:"start_retry_timeout"`
// This is used in the template generation to format environment variables
// inside the `ExecuteCommand` template.
EnvVarFormat string
// This is used in the template generation to format environment variables
// inside the `ElevatedExecuteCommand` template.
ElevatedEnvVarFormat string `mapstructure:"elevated_env_var_format"`
// Instructs the communicator to run the remote script as a
// Windows scheduled task, effectively elevating the remote
// user by impersonating a logged-in user
ElevatedUser string `mapstructure:"elevated_user"`
ElevatedPassword string `mapstructure:"elevated_password"`
// Valid Exit Codes - 0 is not always the only valid error code!
// See http://www.symantec.com/connect/articles/windows-system-error-codes-exit-codes-description for examples
// such as 3010 - "The requested operation is successful. Changes will not be effective until the system is rebooted."
ValidExitCodes []int `mapstructure:"valid_exit_codes"`
ctx interpolate.Context
}
type Provisioner struct {
config Config
communicator packer.Communicator
}
type ExecuteCommandTemplate struct {
Vars string
Path string
}
func (p *Provisioner) Prepare(raws ...interface{}) error {
err := config.Decode(&p.config, &config.DecodeOpts{
Interpolate: true,
InterpolateContext: &p.config.ctx,
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InterpolateFilter: &interpolate.RenderFilter{
Exclude: []string{
"execute_command",
},
},
}, raws...)
if err != nil {
return err
}
if p.config.EnvVarFormat == "" {
p.config.EnvVarFormat = `$env:%s=\"%s\"; `
}
if p.config.ElevatedEnvVarFormat == "" {
p.config.ElevatedEnvVarFormat = `$env:%s="%s"; `
}
if p.config.ExecuteCommand == "" {
p.config.ExecuteCommand = `powershell "& { {{.Vars}}{{.Path}}; exit $LastExitCode}"`
}
if p.config.ElevatedExecuteCommand == "" {
p.config.ElevatedExecuteCommand = `{{.Vars}}{{.Path}}`
}
if p.config.Inline != nil && len(p.config.Inline) == 0 {
p.config.Inline = nil
}
if p.config.StartRetryTimeout == 0 {
p.config.StartRetryTimeout = 5 * time.Minute
}
if p.config.RemotePath == "" {
p.config.RemotePath = DefaultRemotePath
}
if p.config.Scripts == nil {
p.config.Scripts = make([]string, 0)
}
if p.config.Vars == nil {
p.config.Vars = make([]string, 0)
}
if p.config.ValidExitCodes == nil {
p.config.ValidExitCodes = []int{0}
}
var errs error
if p.config.Script != "" && len(p.config.Scripts) > 0 {
errs = packer.MultiErrorAppend(errs,
errors.New("Only one of script or scripts can be specified."))
}
if p.config.ElevatedUser != "" && p.config.ElevatedPassword == "" {
errs = packer.MultiErrorAppend(errs,
errors.New("Must supply an 'elevated_password' if 'elevated_user' provided"))
}
if p.config.ElevatedUser == "" && p.config.ElevatedPassword != "" {
errs = packer.MultiErrorAppend(errs,
errors.New("Must supply an 'elevated_user' if 'elevated_password' provided"))
}
if p.config.Script != "" {
p.config.Scripts = []string{p.config.Script}
}
if len(p.config.Scripts) == 0 && p.config.Inline == nil {
errs = packer.MultiErrorAppend(errs,
errors.New("Either a script file or inline script must be specified."))
} else if len(p.config.Scripts) > 0 && p.config.Inline != nil {
errs = packer.MultiErrorAppend(errs,
errors.New("Only a script file or an inline script can be specified, not both."))
}
for _, path := range p.config.Scripts {
if _, err := os.Stat(path); err != nil {
errs = packer.MultiErrorAppend(errs,
fmt.Errorf("Bad script '%s': %s", path, err))
}
}
// Do a check for bad environment variables, such as '=foo', 'foobar'
for _, kv := range p.config.Vars {
vs := strings.SplitN(kv, "=", 2)
if len(vs) != 2 || vs[0] == "" {
errs = packer.MultiErrorAppend(errs,
fmt.Errorf("Environment variable not in format 'key=value': %s", kv))
}
}
if errs != nil {
return errs
}
return nil
}
// Takes the inline scripts, concatenates them
// into a temporary file and returns a string containing the location
// of said file.
func extractScript(p *Provisioner) (string, error) {
temp, err := ioutil.TempFile(os.TempDir(), "packer-powershell-provisioner")
if err != nil {
return "", err
}
defer temp.Close()
writer := bufio.NewWriter(temp)
for _, command := range p.config.Inline {
log.Printf("Found command: %s", command)
if _, err := writer.WriteString(command + "\n"); err != nil {
return "", fmt.Errorf("Error preparing shell script: %s", err)
}
}
if err := writer.Flush(); err != nil {
return "", fmt.Errorf("Error preparing shell script: %s", err)
}
return temp.Name(), nil
}
func (p *Provisioner) Provision(ui packer.Ui, comm packer.Communicator) error {
ui.Say(fmt.Sprintf("Provisioning with Powershell..."))
p.communicator = comm
scripts := make([]string, len(p.config.Scripts))
copy(scripts, p.config.Scripts)
// Build our variables up by adding in the build name and builder type
envVars := make([]string, len(p.config.Vars)+2)
envVars[0] = "PACKER_BUILD_NAME=" + p.config.PackerBuildName
envVars[1] = "PACKER_BUILDER_TYPE=" + p.config.PackerBuilderType
copy(envVars, p.config.Vars)
if p.config.Inline != nil {
temp, err := extractScript(p)
if err != nil {
ui.Error(fmt.Sprintf("Unable to extract inline scripts into a file: %s", err))
}
scripts = append(scripts, temp)
}
for _, path := range scripts {
ui.Say(fmt.Sprintf("Provisioning with shell script: %s", path))
log.Printf("Opening %s for reading", path)
f, err := os.Open(path)
if err != nil {
return fmt.Errorf("Error opening shell script: %s", err)
}
defer f.Close()
command, err := p.createCommandText()
if err != nil {
return fmt.Errorf("Error processing command: %s", err)
}
// Upload the file and run the command. Do this in the context of
// a single retryable function so that we don't end up with
// the case that the upload succeeded, a restart is initiated,
// and then the command is executed but the file doesn't exist
// any longer.
var cmd *packer.RemoteCmd
err = p.retryable(func() error {
if _, err := f.Seek(0, 0); err != nil {
return err
}
if err := comm.Upload(p.config.RemotePath, f, nil); err != nil {
return fmt.Errorf("Error uploading script: %s", err)
}
cmd = &packer.RemoteCmd{Command: command}
return cmd.StartWithUi(comm, ui)
})
if err != nil {
return err
}
// Close the original file since we copied it
f.Close()
// Check exit code against allowed codes (likely just 0)
validExitCode := false
for _, v := range p.config.ValidExitCodes {
if cmd.ExitStatus == v {
validExitCode = true
}
}
if !validExitCode {
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return fmt.Errorf(
"Script exited with non-zero exit status: %d. Allowed exit codes are: %v",
cmd.ExitStatus, p.config.ValidExitCodes)
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}
}
return nil
}
func (p *Provisioner) Cancel() {
// Just hard quit. It isn't a big deal if what we're doing keeps
// running on the other side.
os.Exit(0)
}
// retryable will retry the given function over and over until a
// non-error is returned.
func (p *Provisioner) retryable(f func() error) error {
startTimeout := time.After(p.config.StartRetryTimeout)
for {
var err error
if err = f(); err == nil {
return nil
}
// Create an error and log it
err = fmt.Errorf("Retryable error: %s", err)
log.Printf(err.Error())
// Check if we timed out, otherwise we retry. It is safe to
// retry since the only error case above is if the command
// failed to START.
select {
case <-startTimeout:
return err
default:
time.Sleep(retryableSleep)
}
}
}
func (p *Provisioner) createFlattenedEnvVars(elevated bool) (flattened string, err error) {
flattened = ""
envVars := make(map[string]string)
// Always available Packer provided env vars
envVars["PACKER_BUILD_NAME"] = p.config.PackerBuildName
envVars["PACKER_BUILDER_TYPE"] = p.config.PackerBuilderType
// Split vars into key/value components
for _, envVar := range p.config.Vars {
keyValue := strings.Split(envVar, "=")
if len(keyValue) != 2 {
err = errors.New("Shell provisioner environment variables must be in key=value format")
return
}
envVars[keyValue[0]] = keyValue[1]
}
// Create a list of env var keys in sorted order
var keys []string
for k := range envVars {
keys = append(keys, k)
}
sort.Strings(keys)
format := p.config.EnvVarFormat
if elevated {
format = p.config.ElevatedEnvVarFormat
}
// Re-assemble vars using OS specific format pattern and flatten
for _, key := range keys {
flattened += fmt.Sprintf(format, key, envVars[key])
}
return
}
func (p *Provisioner) createCommandText() (command string, err error) {
// Create environment variables to set before executing the command
flattenedEnvVars, err := p.createFlattenedEnvVars(false)
if err != nil {
return "", err
}
p.config.ctx.Data = &ExecuteCommandTemplate{
Vars: flattenedEnvVars,
Path: p.config.RemotePath,
}
command, err = interpolate.Render(p.config.ExecuteCommand, &p.config.ctx)
if err != nil {
return "", fmt.Errorf("Error processing command: %s", err)
}
// Return the interpolated command
if p.config.ElevatedUser == "" {
return command, nil
}
// Can't double escape the env vars, lets create shiny new ones
flattenedEnvVars, err = p.createFlattenedEnvVars(true)
p.config.ctx.Data = &ExecuteCommandTemplate{
Vars: flattenedEnvVars,
Path: p.config.RemotePath,
}
command, err = interpolate.Render(p.config.ExecuteCommand, &p.config.ctx)
if err != nil {
return "", fmt.Errorf("Error processing command: %s", err)
}
// OK so we need an elevated shell runner to wrap our command, this is going to have its own path
// generate the script and update the command runner in the process
path, err := p.generateElevatedRunner(command)
// Return the path to the elevated shell wrapper
command = fmt.Sprintf("powershell -executionpolicy bypass -file \"%s\"", path)
return
}
func (p *Provisioner) generateElevatedRunner(command string) (uploadedPath string, err error) {
log.Printf("Building elevated command wrapper for: %s", command)
// generate command
var buffer bytes.Buffer
err = elevatedTemplate.Execute(&buffer, elevatedOptions{
User: p.config.ElevatedUser,
Password: p.config.ElevatedPassword,
TaskDescription: "Packer elevated task",
TaskName: fmt.Sprintf("packer-%s", uuid.TimeOrderedUUID()),
EncodedCommand: powershellEncode([]byte(command + "; exit $LASTEXITCODE")),
})
if err != nil {
fmt.Printf("Error creating elevated template: %s", err)
return "", err
}
tmpFile, err := ioutil.TempFile(os.TempDir(), "packer-elevated-shell.ps1")
writer := bufio.NewWriter(tmpFile)
if _, err := writer.WriteString(string(buffer.Bytes())); err != nil {
return "", fmt.Errorf("Error preparing elevated shell script: %s", err)
}
if err := writer.Flush(); err != nil {
return "", fmt.Errorf("Error preparing elevated shell script: %s", err)
}
tmpFile.Close()
f, err := os.Open(tmpFile.Name())
if err != nil {
return "", fmt.Errorf("Error opening temporary elevated shell script: %s", err)
}
defer f.Close()
uuid := uuid.TimeOrderedUUID()
path := fmt.Sprintf(`${env:TEMP}\packer-elevated-shell-%s.ps1`, uuid)
log.Printf("Uploading elevated shell wrapper for command [%s] to [%s] from [%s]", command, path, tmpFile.Name())
err = p.communicator.Upload(path, f, nil)
if err != nil {
return "", fmt.Errorf("Error preparing elevated shell script: %s", err)
}
// CMD formatted Path required for this op
path = fmt.Sprintf("%s-%s.ps1", "%TEMP%\\packer-elevated-shell", uuid)
return path, err
}