terraform/internal/initwd/from_module.go

397 lines
14 KiB
Go

package initwd
import (
"fmt"
"io/ioutil"
"log"
"os"
"path/filepath"
"sort"
"strings"
"github.com/hashicorp/terraform/internal/copy"
"github.com/hashicorp/terraform/internal/earlyconfig"
version "github.com/hashicorp/go-version"
"github.com/hashicorp/terraform-config-inspect/tfconfig"
"github.com/hashicorp/terraform/internal/modsdir"
"github.com/hashicorp/terraform/internal/registry"
"github.com/hashicorp/terraform/internal/tfdiags"
)
const initFromModuleRootCallName = "root"
const initFromModuleRootKeyPrefix = initFromModuleRootCallName + "."
// DirFromModule populates the given directory (which must exist and be
// empty) with the contents of the module at the given source address.
//
// It does this by installing the given module and all of its descendent
// modules in a temporary root directory and then copying the installed
// files into suitable locations. As a consequence, any diagnostics it
// generates will reveal the location of this temporary directory to the
// user.
//
// This rather roundabout installation approach is taken to ensure that
// installation proceeds in a manner identical to normal module installation.
//
// If the given source address specifies a sub-directory of the given
// package then only the sub-directory and its descendents will be copied
// into the given root directory, which will cause any relative module
// references using ../ from that module to be unresolvable. Error diagnostics
// are produced in that case, to prompt the user to rewrite the source strings
// to be absolute references to the original remote module.
func DirFromModule(rootDir, modulesDir, sourceAddr string, reg *registry.Client, hooks ModuleInstallHooks) tfdiags.Diagnostics {
var diags tfdiags.Diagnostics
// The way this function works is pretty ugly, but we accept it because
// -from-module is a less important case than normal module installation
// and so it's better to keep this ugly complexity out here rather than
// adding even more complexity to the normal module installer.
// The target directory must exist but be empty.
{
entries, err := ioutil.ReadDir(rootDir)
if err != nil {
if os.IsNotExist(err) {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Target directory does not exist",
fmt.Sprintf("Cannot initialize non-existent directory %s.", rootDir),
))
} else {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Failed to read target directory",
fmt.Sprintf("Error reading %s to ensure it is empty: %s.", rootDir, err),
))
}
return diags
}
haveEntries := false
for _, entry := range entries {
if entry.Name() == "." || entry.Name() == ".." || entry.Name() == ".terraform" {
continue
}
haveEntries = true
}
if haveEntries {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Can't populate non-empty directory",
fmt.Sprintf("The target directory %s is not empty, so it cannot be initialized with the -from-module=... option.", rootDir),
))
return diags
}
}
instDir := filepath.Join(rootDir, ".terraform/init-from-module")
inst := NewModuleInstaller(instDir, reg)
log.Printf("[DEBUG] installing modules in %s to initialize working directory from %q", instDir, sourceAddr)
os.RemoveAll(instDir) // if this fails then we'll fail on MkdirAll below too
err := os.MkdirAll(instDir, os.ModePerm)
if err != nil {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Failed to create temporary directory",
fmt.Sprintf("Failed to create temporary directory %s: %s.", instDir, err),
))
return diags
}
instManifest := make(modsdir.Manifest)
retManifest := make(modsdir.Manifest)
fakeFilename := fmt.Sprintf("-from-module=%q", sourceAddr)
fakePos := tfconfig.SourcePos{
Filename: fakeFilename,
Line: 1,
}
// -from-module allows relative paths but it's different than a normal
// module address where it'd be resolved relative to the module call
// (which is synthetic, here.) To address this, we'll just patch up any
// relative paths to be absolute paths before we run, ensuring we'll
// get the right result. This also, as an important side-effect, ensures
// that the result will be "downloaded" with go-getter (copied from the
// source location), rather than just recorded as a relative path.
{
maybePath := filepath.ToSlash(sourceAddr)
if maybePath == "." || strings.HasPrefix(maybePath, "./") || strings.HasPrefix(maybePath, "../") {
if wd, err := os.Getwd(); err == nil {
sourceAddr = filepath.Join(wd, sourceAddr)
log.Printf("[TRACE] -from-module relative path rewritten to absolute path %s", sourceAddr)
}
}
}
// Now we need to create an artificial root module that will seed our
// installation process.
fakeRootModule := &tfconfig.Module{
ModuleCalls: map[string]*tfconfig.ModuleCall{
initFromModuleRootCallName: {
Name: initFromModuleRootCallName,
Source: sourceAddr,
Pos: fakePos,
},
},
}
// wrapHooks filters hook notifications to only include Download calls
// and to trim off the initFromModuleRootCallName prefix. We'll produce
// our own Install notifications directly below.
wrapHooks := installHooksInitDir{
Wrapped: hooks,
}
getter := reusingGetter{}
_, instDiags := inst.installDescendentModules(fakeRootModule, rootDir, instManifest, true, wrapHooks, getter)
diags = append(diags, instDiags...)
if instDiags.HasErrors() {
return diags
}
// If all of that succeeded then we'll now migrate what was installed
// into the final directory structure.
err = os.MkdirAll(modulesDir, os.ModePerm)
if err != nil {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Failed to create local modules directory",
fmt.Sprintf("Failed to create modules directory %s: %s.", modulesDir, err),
))
return diags
}
recordKeys := make([]string, 0, len(instManifest))
for k := range instManifest {
recordKeys = append(recordKeys, k)
}
sort.Strings(recordKeys)
for _, recordKey := range recordKeys {
record := instManifest[recordKey]
if record.Key == initFromModuleRootCallName {
// We've found the module the user requested, which we must
// now copy into rootDir so it can be used directly.
log.Printf("[TRACE] copying new root module from %s to %s", record.Dir, rootDir)
err := copy.CopyDir(rootDir, record.Dir)
if err != nil {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Failed to copy root module",
fmt.Sprintf("Error copying root module %q from %s to %s: %s.", sourceAddr, record.Dir, rootDir, err),
))
continue
}
// We'll try to load the newly-copied module here just so we can
// sniff for any module calls that ../ out of the root directory
// and must thus be rewritten to be absolute addresses again.
// For now we can't do this rewriting automatically, but we'll
// generate an error to help the user do it manually.
mod, _ := earlyconfig.LoadModule(rootDir) // ignore diagnostics since we're just doing value-add here anyway
if mod != nil {
for _, mc := range mod.ModuleCalls {
if pathTraversesUp(mc.Source) {
packageAddr, givenSubdir := splitAddrSubdir(sourceAddr)
newSubdir := filepath.Join(givenSubdir, mc.Source)
if pathTraversesUp(newSubdir) {
// This should never happen in any reasonable
// configuration since this suggests a path that
// traverses up out of the package root. We'll just
// ignore this, since we'll fail soon enough anyway
// trying to resolve this path when this module is
// loaded.
continue
}
var newAddr = packageAddr
if newSubdir != "" {
newAddr = fmt.Sprintf("%s//%s", newAddr, filepath.ToSlash(newSubdir))
}
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Root module references parent directory",
fmt.Sprintf("The requested module %q refers to a module via its parent directory. To use this as a new root module this source string must be rewritten as a remote source address, such as %q.", sourceAddr, newAddr),
))
continue
}
}
}
retManifest[""] = modsdir.Record{
Key: "",
Dir: rootDir,
}
continue
}
if !strings.HasPrefix(record.Key, initFromModuleRootKeyPrefix) {
// Ignore the *real* root module, whose key is empty, since
// we're only interested in the module named "root" and its
// descendents.
continue
}
newKey := record.Key[len(initFromModuleRootKeyPrefix):]
instPath := filepath.Join(modulesDir, newKey)
tempPath := filepath.Join(instDir, record.Key)
// tempPath won't be present for a module that was installed from
// a relative path, so in that case we just record the installation
// directory and assume it was already copied into place as part
// of its parent.
if _, err := os.Stat(tempPath); err != nil {
if !os.IsNotExist(err) {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Failed to stat temporary module install directory",
fmt.Sprintf("Error from stat %s for module %s: %s.", instPath, newKey, err),
))
continue
}
var parentKey string
if lastDot := strings.LastIndexByte(newKey, '.'); lastDot != -1 {
parentKey = newKey[:lastDot]
}
var parentOld modsdir.Record
// "" is the root module; all other modules get `root.` added as a prefix
if parentKey == "" {
parentOld = instManifest[parentKey]
} else {
parentOld = instManifest[initFromModuleRootKeyPrefix+parentKey]
}
parentNew := retManifest[parentKey]
// We need to figure out which portion of our directory is the
// parent package path and which portion is the subdirectory
// under that.
var baseDirRel string
baseDirRel, err = filepath.Rel(parentOld.Dir, record.Dir)
if err != nil {
// This error may occur when installing a local module with a
// relative path, for e.g. if the source is in a directory above
// the destination ("../")
if parentOld.Dir == "." {
absDir, err := filepath.Abs(parentOld.Dir)
if err != nil {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Failed to determine module install directory",
fmt.Sprintf("Error determine relative source directory for module %s: %s.", newKey, err),
))
continue
}
baseDirRel, err = filepath.Rel(absDir, record.Dir)
if err != nil {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Failed to determine relative module source location",
fmt.Sprintf("Error determining relative source for module %s: %s.", newKey, err),
))
continue
}
} else {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Failed to determine relative module source location",
fmt.Sprintf("Error determining relative source for module %s: %s.", newKey, err),
))
}
}
newDir := filepath.Join(parentNew.Dir, baseDirRel)
log.Printf("[TRACE] relative reference for %s rewritten from %s to %s", newKey, record.Dir, newDir)
newRecord := record // shallow copy
newRecord.Dir = newDir
newRecord.Key = newKey
retManifest[newKey] = newRecord
hooks.Install(newRecord.Key, newRecord.Version, newRecord.Dir)
continue
}
err = os.MkdirAll(instPath, os.ModePerm)
if err != nil {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Failed to create module install directory",
fmt.Sprintf("Error creating directory %s for module %s: %s.", instPath, newKey, err),
))
continue
}
// We copy rather than "rename" here because renaming between directories
// can be tricky in edge-cases like network filesystems, etc.
log.Printf("[TRACE] copying new module %s from %s to %s", newKey, record.Dir, instPath)
err := copy.CopyDir(instPath, tempPath)
if err != nil {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Failed to copy descendent module",
fmt.Sprintf("Error copying module %q from %s to %s: %s.", newKey, tempPath, rootDir, err),
))
continue
}
subDir, err := filepath.Rel(tempPath, record.Dir)
if err != nil {
// Should never happen, because we constructed both directories
// from the same base and so they must have a common prefix.
panic(err)
}
newRecord := record // shallow copy
newRecord.Dir = filepath.Join(instPath, subDir)
newRecord.Key = newKey
retManifest[newKey] = newRecord
hooks.Install(newRecord.Key, newRecord.Version, newRecord.Dir)
}
retManifest.WriteSnapshotToDir(modulesDir)
if err != nil {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Failed to write module manifest",
fmt.Sprintf("Error writing module manifest: %s.", err),
))
}
if !diags.HasErrors() {
// Try to clean up our temporary directory, but don't worry if we don't
// succeed since it shouldn't hurt anything.
os.RemoveAll(instDir)
}
return diags
}
func pathTraversesUp(path string) bool {
return strings.HasPrefix(filepath.ToSlash(path), "../")
}
// installHooksInitDir is an adapter wrapper for an InstallHooks that
// does some fakery to make downloads look like they are happening in their
// final locations, rather than in the temporary loader we use.
//
// It also suppresses "Install" calls entirely, since InitDirFromModule
// does its own installation steps after the initial installation pass
// has completed.
type installHooksInitDir struct {
Wrapped ModuleInstallHooks
ModuleInstallHooksImpl
}
func (h installHooksInitDir) Download(moduleAddr, packageAddr string, version *version.Version) {
if !strings.HasPrefix(moduleAddr, initFromModuleRootKeyPrefix) {
// We won't announce the root module, since hook implementations
// don't expect to see that and the caller will usually have produced
// its own user-facing notification about what it's doing anyway.
return
}
trimAddr := moduleAddr[len(initFromModuleRootKeyPrefix):]
h.Wrapped.Download(trimAddr, packageAddr, version)
}