packer-cn/packer/plugin/discover.go

309 lines
9.2 KiB
Go

package plugin
import (
"encoding/json"
"log"
"os"
"os/exec"
"path/filepath"
"runtime"
"sort"
"strings"
packersdk "github.com/hashicorp/packer-plugin-sdk/packer"
"github.com/hashicorp/packer-plugin-sdk/pathing"
pluginsdk "github.com/hashicorp/packer-plugin-sdk/plugin"
)
// PACKERSPACE is used to represent the spaces that separate args for a command
// without being confused with spaces in the path to the command itself.
const PACKERSPACE = "-PACKERSPACE-"
type Config struct {
PluginMinPort int
PluginMaxPort int
builders packersdk.MapOfBuilder
provisioners packersdk.MapOfProvisioner
postProcessors packersdk.MapOfPostProcessor
}
func (c *Config) GetPlugins() (packersdk.MapOfBuilder, packersdk.MapOfProvisioner, packersdk.MapOfPostProcessor) {
return c.builders, c.provisioners, c.postProcessors
}
// Discover discovers plugins.
//
// Search the directory of the executable, then the plugins directory, and
// finally the CWD, in that order. Any conflicts will overwrite previously
// found plugins, in that order.
// Hence, the priority order is the reverse of the search order - i.e., the
// CWD has the highest priority.
func (c *Config) Discover() error {
if c.builders == nil {
c.builders = packersdk.MapOfBuilder{}
}
if c.provisioners == nil {
c.provisioners = packersdk.MapOfProvisioner{}
}
if c.postProcessors == nil {
c.postProcessors = packersdk.MapOfPostProcessor{}
}
// If we are already inside a plugin process we should not need to
// discover anything.
if os.Getenv(pluginsdk.MagicCookieKey) == pluginsdk.MagicCookieValue {
return nil
}
// Next, look in the same directory as the executable.
exePath, err := os.Executable()
if err != nil {
log.Printf("[ERR] Error loading exe directory: %s", err)
} else {
if err := c.discoverExternalComponents(filepath.Dir(exePath)); err != nil {
return err
}
}
// Next, look in the default plugins directory inside the configdir/.packer.d/plugins.
dir, err := pathing.ConfigDir()
if err != nil {
log.Printf("[ERR] Error loading config directory: %s", err)
} else {
if err := c.discoverExternalComponents(filepath.Join(dir, "plugins")); err != nil {
return err
}
}
// Next, look in the CWD.
if err := c.discoverExternalComponents("."); err != nil {
return err
}
// Check whether there is a custom Plugin directory defined. This gets
// absolute preference.
if packerPluginPath := os.Getenv("PACKER_PLUGIN_PATH"); packerPluginPath != "" {
sep := ":"
if runtime.GOOS == "windows" {
// on windows, PATH is semicolon-separated
sep = ";"
}
plugPaths := strings.Split(packerPluginPath, sep)
for _, plugPath := range plugPaths {
if err := c.discoverExternalComponents(plugPath); err != nil {
return err
}
}
}
return nil
}
func (c *Config) discoverExternalComponents(path string) error {
var err error
if !filepath.IsAbs(path) {
path, err = filepath.Abs(path)
if err != nil {
return err
}
}
var externallyUsed []string
pluginPaths, err := c.discoverSingle(filepath.Join(path, "packer-builder-*"))
if err != nil {
return err
}
for pluginName, pluginPath := range pluginPaths {
newPath := pluginPath // this needs to be stored in a new variable for the func below
c.builders[pluginName] = func() (packersdk.Builder, error) {
return c.Client(newPath).Builder()
}
externallyUsed = append(externallyUsed, pluginName)
}
if len(externallyUsed) > 0 {
sort.Strings(externallyUsed)
log.Printf("using external builders %v", externallyUsed)
externallyUsed = nil
}
pluginPaths, err = c.discoverSingle(filepath.Join(path, "packer-post-processor-*"))
if err != nil {
return err
}
for pluginName, pluginPath := range pluginPaths {
newPath := pluginPath // this needs to be stored in a new variable for the func below
c.postProcessors[pluginName] = func() (packersdk.PostProcessor, error) {
return c.Client(newPath).PostProcessor()
}
externallyUsed = append(externallyUsed, pluginName)
}
if len(externallyUsed) > 0 {
sort.Strings(externallyUsed)
log.Printf("using external post-processors %v", externallyUsed)
externallyUsed = nil
}
pluginPaths, err = c.discoverSingle(filepath.Join(path, "packer-provisioner-*"))
if err != nil {
return err
}
for pluginName, pluginPath := range pluginPaths {
newPath := pluginPath // this needs to be stored in a new variable for the func below
c.provisioners[pluginName] = func() (packersdk.Provisioner, error) {
return c.Client(newPath).Provisioner()
}
externallyUsed = append(externallyUsed, pluginName)
}
if len(externallyUsed) > 0 {
sort.Strings(externallyUsed)
log.Printf("using external provisioners %v", externallyUsed)
}
pluginPaths, err = c.discoverSingle(filepath.Join(path, "packer-plugin-*"))
if err != nil {
return err
}
for pluginName, pluginPath := range pluginPaths {
if err := c.discoverMultiPlugin(pluginName, pluginPath); err != nil {
return err
}
}
return nil
}
func (c *Config) discoverSingle(glob string) (map[string]string, error) {
matches, err := filepath.Glob(glob)
if err != nil {
return nil, err
}
res := make(map[string]string)
prefix := filepath.Base(glob)
prefix = prefix[:strings.Index(prefix, "*")]
for _, match := range matches {
file := filepath.Base(match)
// skip folders like packer-plugin-sdk
if stat, err := os.Stat(file); err == nil && stat.IsDir() {
continue
}
// On Windows, ignore any plugins that don't end in .exe.
// We could do a full PATHEXT parse, but this is probably good enough.
if runtime.GOOS == "windows" && strings.ToLower(filepath.Ext(file)) != ".exe" {
log.Printf(
"[DEBUG] Ignoring plugin match %s, no exe extension",
match)
continue
}
// If the filename has a ".", trim up to there
if idx := strings.Index(file, ".exe"); idx >= 0 {
file = file[:idx]
}
// Look for foo-bar-baz. The plugin name is "baz"
pluginName := file[len(prefix):]
log.Printf("[DEBUG] Discovered plugin: %s = %s", pluginName, match)
res[pluginName] = match
}
return res, nil
}
// discoverMultiPlugin takes the description from a multiplugin binary and
// makes the plugins available to use in Packer. Each plugin found in the
// binary will be addressable using `${pluginName}-${builderName}` for example.
// pluginName could be manually set. It usually is a cloud name like amazon.
// pluginName can be extrapolated from the filename of the binary; so
// if the "packer-plugin-amazon" binary had an "ebs" builder one could use
// the "amazon-ebs" builder.
func (c *Config) discoverMultiPlugin(pluginName, pluginPath string) error {
out, err := exec.Command(pluginPath, "describe").Output()
if err != nil {
return err
}
var desc pluginsdk.SetDescription
if err := json.Unmarshal(out, &desc); err != nil {
return err
}
pluginPrefix := pluginName + "-"
for _, builderName := range desc.Builders {
builderName := builderName // copy to avoid pointer overwrite issue
c.builders[pluginPrefix+builderName] = func() (packersdk.Builder, error) {
return c.Client(pluginPath, "start", "builder", builderName).Builder()
}
}
if len(desc.Builders) > 0 {
log.Printf("found external %v builders from %s plugin", desc.Builders, pluginName)
}
for _, postProcessorName := range desc.PostProcessors {
postProcessorName := postProcessorName // copy to avoid pointer overwrite issue
c.postProcessors[pluginPrefix+postProcessorName] = func() (packersdk.PostProcessor, error) {
return c.Client(pluginPath, "start", "post-processor", postProcessorName).PostProcessor()
}
}
if len(desc.PostProcessors) > 0 {
log.Printf("found external %v post-processors from %s plugin", desc.PostProcessors, pluginName)
}
for _, provisionerName := range desc.Provisioners {
provisionerName := provisionerName // copy to avoid pointer overwrite issue
c.provisioners[pluginPrefix+provisionerName] = func() (packersdk.Provisioner, error) {
return c.Client(pluginPath, "start", "provisioner", provisionerName).Provisioner()
}
}
if len(desc.Provisioners) > 0 {
log.Printf("found external %v provisioner from %s plugin", desc.Provisioners, pluginName)
}
return nil
}
func (c *Config) Client(path string, args ...string) *Client {
originalPath := path
// Check for special case using `packer plugin PLUGIN`
if strings.Contains(path, PACKERSPACE) {
parts := strings.Split(path, PACKERSPACE)
path = parts[0]
args = parts[1:]
}
// First attempt to find the executable by consulting the PATH.
path, err := exec.LookPath(path)
if err != nil {
// If that doesn't work, look for it in the same directory
// as the `packer` executable (us).
log.Printf("Plugin could not be found at %s (%v). Checking same directory as executable.", originalPath, err)
exePath, err := os.Executable()
if err != nil {
log.Printf("Couldn't get current exe path: %s", err)
} else {
log.Printf("Current exe path: %s", exePath)
path = filepath.Join(filepath.Dir(exePath), filepath.Base(originalPath))
}
}
// If everything failed, just use the original path and let the error
// bubble through.
if path == "" {
path = originalPath
}
log.Printf("Creating plugin client for path: %s", path)
var config ClientConfig
config.Cmd = exec.Command(path, args...)
config.Managed = true
config.MinPort = c.PluginMinPort
config.MaxPort = c.PluginMaxPort
return NewClient(&config)
}