package discovery
import (
"io/ioutil"
"log"
"path/filepath"
"strings"
)
// FindPlugins looks in the given directories for files whose filenames
// suggest that they are plugins of the given kind (e.g. "provider") and
// returns a PluginMetaSet representing the discovered potential-plugins.
//
// Currently this supports two different naming schemes. The current
// standard naming scheme is a subdirectory called $GOOS-$GOARCH containing
// files named terraform-$KIND-$NAME-V$VERSION. The legacy naming scheme is
// files directly in the given directory whose names are like
// terraform-$KIND-$NAME.
//
// Only one plugin will be returned for each unique plugin (name, version)
// pair, with preference given to files found in earlier directories.
//
// This is a convenience wrapper around FindPluginPaths and ResolvePluginsPaths.
func FindPlugins(kind string, dirs []string) PluginMetaSet {
return ResolvePluginPaths(FindPluginPaths(kind, dirs))
}
// FindPluginPaths looks in the given directories for files whose filenames
// suggest that they are plugins of the given kind (e.g. "provider").
//
// The return value is a list of absolute paths that appear to refer to
// plugins in the given directories, based only on what can be inferred
// from the naming scheme. The paths returned are ordered such that files
// in later dirs appear after files in earlier dirs in the given directory
// list. Within the same directory plugins are returned in a consistent but
// undefined order.
func FindPluginPaths(kind string, dirs []string) []string {
// This is just a thin wrapper around findPluginPaths so that we can
// use the latter in tests with a fake machineName so we can use our
// test fixtures.
return findPluginPaths(kind, dirs)
}
func findPluginPaths(kind string, dirs []string) []string {
prefix := "terraform-" + kind + "-"
ret := make([]string, 0, len(dirs))
for _, dir := range dirs {
items, err := ioutil.ReadDir(dir)
if err != nil {
// Ignore missing dirs, non-dirs, etc
continue
}
log.Printf("[DEBUG] checking for %s in %q", kind, dir)
for _, item := range items {
fullName := item.Name()
if !strings.HasPrefix(fullName, prefix) {
log.Printf("[DEBUG] skipping %q, not a %s", fullName, kind)
continue
}
// New-style paths must have a version segment in filename
if strings.Contains(strings.ToLower(fullName), "_v") {
absPath, err := filepath.Abs(filepath.Join(dir, fullName))
if err != nil {
log.Printf("[ERROR] plugin filepath error: %s", err)
continue
}
log.Printf("[DEBUG] found %s %q", kind, fullName)
ret = append(ret, filepath.Clean(absPath))
continue
}
// Legacy style with files directly in the base directory
absPath, err := filepath.Abs(filepath.Join(dir, fullName))
if err != nil {
log.Printf("[ERROR] plugin filepath error: %s", err)
continue
}
log.Printf("[WARNING] found legacy %s %q", kind, fullName)
ret = append(ret, filepath.Clean(absPath))
}
}
return ret
}
// ResolvePluginPaths takes a list of paths to plugin executables (as returned
// by e.g. FindPluginPaths) and produces a PluginMetaSet describing the
// referenced plugins.
//
// If the same combination of plugin name and version appears multiple times,
// the earlier reference will be preferred. Several different versions of
// the same plugin name may be returned, in which case the methods of
// PluginMetaSet can be used to filter down.
func ResolvePluginPaths(paths []string) PluginMetaSet {
s := make(PluginMetaSet)
type nameVersion struct {
Name string
Version string
}
found := make(map[nameVersion]struct{})
for _, path := range paths {
baseName := strings.ToLower(filepath.Base(path))
if !strings.HasPrefix(baseName, "terraform-") {
// Should never happen with reasonable input
continue
}
baseName = baseName[10:]
firstDash := strings.Index(baseName, "-")
if firstDash == -1 {
// Should never happen with reasonable input
continue
}
baseName = baseName[firstDash+1:]
if baseName == "" {
// Should never happen with reasonable input
continue
}
// Trim the .exe suffix used on Windows before we start wrangling
// the remainder of the path.
if strings.HasSuffix(baseName, ".exe") {
baseName = baseName[:len(baseName)-4]
}
parts := strings.SplitN(baseName, "_v", 2)
name := parts[0]
version := VersionZero
if len(parts) == 2 {
version = parts[1]
}
// Auto-installed plugins contain an extra name portion representing
// the expected plugin version, which we must trim off.
if underX := strings.Index(version, "_x"); underX != -1 {
version = version[:underX]
}
if _, ok := found[nameVersion{name, version}]; ok {
// Skip duplicate versions of the same plugin
// (We do this during this step because after this we will be
// dealing with sets and thus lose our ordering with which to
// decide preference.)
continue
}
s.Add(PluginMeta{
Name: name,
Version: VersionStr(version),
Path: path,
})
found[nameVersion{name, version}] = struct{}{}
}
return s
}
