terraform/internal/initwd/module_install.go

768 lines
29 KiB
Go

package initwd
import (
"context"
"errors"
"fmt"
"log"
"os"
"path"
"path/filepath"
"strings"
version "github.com/hashicorp/go-version"
"github.com/hashicorp/terraform-config-inspect/tfconfig"
"github.com/hashicorp/terraform/internal/addrs"
"github.com/hashicorp/terraform/internal/earlyconfig"
"github.com/hashicorp/terraform/internal/getmodules"
"github.com/hashicorp/terraform/internal/modsdir"
"github.com/hashicorp/terraform/internal/registry"
"github.com/hashicorp/terraform/internal/registry/regsrc"
"github.com/hashicorp/terraform/internal/registry/response"
"github.com/hashicorp/terraform/internal/tfdiags"
)
type ModuleInstaller struct {
modsDir string
reg *registry.Client
// The keys in moduleVersions are resolved and trimmed registry source
// addresses and the values are the registry response.
registryPackageVersions map[addrs.ModuleRegistryPackage]*response.ModuleVersions
// The keys in moduleVersionsUrl are the moduleVersion struct below and
// addresses and the values are underlying remote source addresses.
registryPackageSources map[moduleVersion]addrs.ModuleSourceRemote
}
type moduleVersion struct {
module addrs.ModuleRegistryPackage
version string
}
func NewModuleInstaller(modsDir string, reg *registry.Client) *ModuleInstaller {
return &ModuleInstaller{
modsDir: modsDir,
reg: reg,
registryPackageVersions: make(map[addrs.ModuleRegistryPackage]*response.ModuleVersions),
registryPackageSources: make(map[moduleVersion]addrs.ModuleSourceRemote),
}
}
// InstallModules analyses the root module in the given directory and installs
// all of its direct and transitive dependencies into the given modules
// directory, which must already exist.
//
// Since InstallModules makes possibly-time-consuming calls to remote services,
// a hook interface is supported to allow the caller to be notified when
// each module is installed and, for remote modules, when downloading begins.
// LoadConfig guarantees that two hook calls will not happen concurrently but
// it does not guarantee any particular ordering of hook calls. This mechanism
// is for UI feedback only and does not give the caller any control over the
// process.
//
// If modules are already installed in the target directory, they will be
// skipped unless their source address or version have changed or unless
// the upgrade flag is set.
//
// InstallModules never deletes any directory, except in the case where it
// needs to replace a directory that is already present with a newly-extracted
// package.
//
// If the returned diagnostics contains errors then the module installation
// may have wholly or partially completed. Modules must be loaded in order
// to find their dependencies, so this function does many of the same checks
// as LoadConfig as a side-effect.
//
// If successful (the returned diagnostics contains no errors) then the
// first return value is the early configuration tree that was constructed by
// the installation process.
func (i *ModuleInstaller) InstallModules(ctx context.Context, rootDir string, upgrade bool, hooks ModuleInstallHooks) (*earlyconfig.Config, tfdiags.Diagnostics) {
log.Printf("[TRACE] ModuleInstaller: installing child modules for %s into %s", rootDir, i.modsDir)
rootMod, diags := earlyconfig.LoadModule(rootDir)
if rootMod == nil {
return nil, diags
}
manifest, err := modsdir.ReadManifestSnapshotForDir(i.modsDir)
if err != nil {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Failed to read modules manifest file",
fmt.Sprintf("Error reading manifest for %s: %s.", i.modsDir, err),
))
return nil, diags
}
fetcher := getmodules.NewPackageFetcher()
cfg, instDiags := i.installDescendentModules(ctx, rootMod, rootDir, manifest, upgrade, hooks, fetcher)
diags = append(diags, instDiags...)
return cfg, diags
}
func (i *ModuleInstaller) installDescendentModules(ctx context.Context, rootMod *tfconfig.Module, rootDir string, manifest modsdir.Manifest, upgrade bool, hooks ModuleInstallHooks, fetcher *getmodules.PackageFetcher) (*earlyconfig.Config, tfdiags.Diagnostics) {
var diags tfdiags.Diagnostics
if hooks == nil {
// Use our no-op implementation as a placeholder
hooks = ModuleInstallHooksImpl{}
}
// Create a manifest record for the root module. This will be used if
// there are any relative-pathed modules in the root.
manifest[""] = modsdir.Record{
Key: "",
Dir: rootDir,
}
cfg, cDiags := earlyconfig.BuildConfig(rootMod, earlyconfig.ModuleWalkerFunc(
func(req *earlyconfig.ModuleRequest) (*tfconfig.Module, *version.Version, tfdiags.Diagnostics) {
key := manifest.ModuleKey(req.Path)
instPath := i.packageInstallPath(req.Path)
log.Printf("[DEBUG] Module installer: begin %s", key)
// First we'll check if we need to upgrade/replace an existing
// installed module, and delete it out of the way if so.
replace := upgrade
if !replace {
record, recorded := manifest[key]
switch {
case !recorded:
log.Printf("[TRACE] ModuleInstaller: %s is not yet installed", key)
replace = true
case record.SourceAddr != req.SourceAddr.String():
log.Printf("[TRACE] ModuleInstaller: %s source address has changed from %q to %q", key, record.SourceAddr, req.SourceAddr)
replace = true
case record.Version != nil && !req.VersionConstraints.Check(record.Version):
log.Printf("[TRACE] ModuleInstaller: %s version %s no longer compatible with constraints %s", key, record.Version, req.VersionConstraints)
replace = true
}
}
// If we _are_ planning to replace this module, then we'll remove
// it now so our installation code below won't conflict with any
// existing remnants.
if replace {
if _, recorded := manifest[key]; recorded {
log.Printf("[TRACE] ModuleInstaller: discarding previous record of %s prior to reinstall", key)
}
delete(manifest, key)
// Deleting a module invalidates all of its descendent modules too.
keyPrefix := key + "."
for subKey := range manifest {
if strings.HasPrefix(subKey, keyPrefix) {
if _, recorded := manifest[subKey]; recorded {
log.Printf("[TRACE] ModuleInstaller: also discarding downstream %s", subKey)
}
delete(manifest, subKey)
}
}
}
record, recorded := manifest[key]
if !recorded {
// Clean up any stale cache directory that might be present.
// If this is a local (relative) source then the dir will
// not exist, but we'll ignore that.
log.Printf("[TRACE] ModuleInstaller: cleaning directory %s prior to install of %s", instPath, key)
err := os.RemoveAll(instPath)
if err != nil && !os.IsNotExist(err) {
log.Printf("[TRACE] ModuleInstaller: failed to remove %s: %s", key, err)
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Failed to remove local module cache",
fmt.Sprintf(
"Terraform tried to remove %s in order to reinstall this module, but encountered an error: %s",
instPath, err,
),
))
return nil, nil, diags
}
} else {
// If this module is already recorded and its root directory
// exists then we will just load what's already there and
// keep our existing record.
info, err := os.Stat(record.Dir)
if err == nil && info.IsDir() {
mod, mDiags := earlyconfig.LoadModule(record.Dir)
diags = diags.Append(mDiags)
log.Printf("[TRACE] ModuleInstaller: Module installer: %s %s already installed in %s", key, record.Version, record.Dir)
return mod, record.Version, diags
}
}
// If we get down here then it's finally time to actually install
// the module. There are some variants to this process depending
// on what type of module source address we have.
switch addr := req.SourceAddr.(type) {
case addrs.ModuleSourceLocal:
log.Printf("[TRACE] ModuleInstaller: %s has local path %q", key, addr.String())
mod, mDiags := i.installLocalModule(req, key, manifest, hooks)
mDiags = maybeImproveLocalInstallError(req, mDiags)
diags = append(diags, mDiags...)
return mod, nil, diags
case addrs.ModuleSourceRegistry:
log.Printf("[TRACE] ModuleInstaller: %s is a registry module at %s", key, addr.String())
mod, v, mDiags := i.installRegistryModule(ctx, req, key, instPath, addr, manifest, hooks, fetcher)
diags = append(diags, mDiags...)
return mod, v, diags
case addrs.ModuleSourceRemote:
log.Printf("[TRACE] ModuleInstaller: %s address %q will be handled by go-getter", key, addr.String())
mod, mDiags := i.installGoGetterModule(ctx, req, key, instPath, manifest, hooks, fetcher)
diags = append(diags, mDiags...)
return mod, nil, diags
default:
// Shouldn't get here, because there are no other implementations
// of addrs.ModuleSource.
panic(fmt.Sprintf("unsupported module source address %#v", addr))
}
},
))
diags = append(diags, cDiags...)
err := manifest.WriteSnapshotToDir(i.modsDir)
if err != nil {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Failed to update module manifest",
fmt.Sprintf("Unable to write the module manifest file: %s", err),
))
}
return cfg, diags
}
func (i *ModuleInstaller) installLocalModule(req *earlyconfig.ModuleRequest, key string, manifest modsdir.Manifest, hooks ModuleInstallHooks) (*tfconfig.Module, tfdiags.Diagnostics) {
var diags tfdiags.Diagnostics
parentKey := manifest.ModuleKey(req.Parent.Path)
parentRecord, recorded := manifest[parentKey]
if !recorded {
// This is indicative of a bug rather than a user-actionable error
panic(fmt.Errorf("missing manifest record for parent module %s", parentKey))
}
if len(req.VersionConstraints) != 0 {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Invalid version constraint",
fmt.Sprintf("Cannot apply a version constraint to module %q (at %s:%d) because it has a relative local path.", req.Name, req.CallPos.Filename, req.CallPos.Line),
))
}
// For local sources we don't actually need to modify the
// filesystem at all because the parent already wrote
// the files we need, and so we just load up what's already here.
newDir := filepath.Join(parentRecord.Dir, req.SourceAddr.String())
log.Printf("[TRACE] ModuleInstaller: %s uses directory from parent: %s", key, newDir)
// it is possible that the local directory is a symlink
newDir, err := filepath.EvalSymlinks(newDir)
if err != nil {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Unreadable module directory",
fmt.Sprintf("Unable to evaluate directory symlink: %s", err.Error()),
))
}
mod, mDiags := earlyconfig.LoadModule(newDir)
if mod == nil {
// nil indicates missing or unreadable directory, so we'll
// discard the returned diags and return a more specific
// error message here.
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Unreadable module directory",
fmt.Sprintf("The directory %s could not be read for module %q at %s:%d.", newDir, req.Name, req.CallPos.Filename, req.CallPos.Line),
))
} else {
diags = diags.Append(mDiags)
}
// Note the local location in our manifest.
manifest[key] = modsdir.Record{
Key: key,
Dir: newDir,
SourceAddr: req.SourceAddr.String(),
}
log.Printf("[DEBUG] Module installer: %s installed at %s", key, newDir)
hooks.Install(key, nil, newDir)
return mod, diags
}
func (i *ModuleInstaller) installRegistryModule(ctx context.Context, req *earlyconfig.ModuleRequest, key string, instPath string, addr addrs.ModuleSourceRegistry, manifest modsdir.Manifest, hooks ModuleInstallHooks, fetcher *getmodules.PackageFetcher) (*tfconfig.Module, *version.Version, tfdiags.Diagnostics) {
var diags tfdiags.Diagnostics
hostname := addr.PackageAddr.Host
reg := i.reg
var resp *response.ModuleVersions
var exists bool
// A registry entry isn't _really_ a module package, but we'll pretend it's
// one for the sake of this reporting by just trimming off any source
// directory.
packageAddr := addr.PackageAddr
// Our registry client is still using the legacy model of addresses, so
// we'll shim it here for now.
regsrcAddr := regsrc.ModuleFromRegistryPackageAddr(packageAddr)
// check if we've already looked up this module from the registry
if resp, exists = i.registryPackageVersions[packageAddr]; exists {
log.Printf("[TRACE] %s using already found available versions of %s at %s", key, addr, hostname)
} else {
var err error
log.Printf("[DEBUG] %s listing available versions of %s at %s", key, addr, hostname)
resp, err = reg.ModuleVersions(ctx, regsrcAddr)
if err != nil {
if registry.IsModuleNotFound(err) {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Module not found",
fmt.Sprintf("Module %q (from %s:%d) cannot be found in the module registry at %s.", req.Name, req.CallPos.Filename, req.CallPos.Line, hostname),
))
} else if errors.Is(err, context.Canceled) {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Module installation was interrupted",
fmt.Sprintf("Received interrupt signal while retrieving available versions for module %q.", req.Name),
))
} else {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Error accessing remote module registry",
fmt.Sprintf("Failed to retrieve available versions for module %q (%s:%d) from %s: %s.", req.Name, req.CallPos.Filename, req.CallPos.Line, hostname, err),
))
}
return nil, nil, diags
}
i.registryPackageVersions[packageAddr] = resp
}
// The response might contain information about dependencies to allow us
// to potentially optimize future requests, but we don't currently do that
// and so for now we'll just take the first item which is guaranteed to
// be the address we requested.
if len(resp.Modules) < 1 {
// Should never happen, but since this is a remote service that may
// be implemented by third-parties we will handle it gracefully.
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Invalid response from remote module registry",
fmt.Sprintf("The registry at %s returned an invalid response when Terraform requested available versions for module %q (%s:%d).", hostname, req.Name, req.CallPos.Filename, req.CallPos.Line),
))
return nil, nil, diags
}
modMeta := resp.Modules[0]
var latestMatch *version.Version
var latestVersion *version.Version
for _, mv := range modMeta.Versions {
v, err := version.NewVersion(mv.Version)
if err != nil {
// Should never happen if the registry server is compliant with
// the protocol, but we'll warn if not to assist someone who
// might be developing a module registry server.
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Warning,
"Invalid response from remote module registry",
fmt.Sprintf("The registry at %s returned an invalid version string %q for module %q (%s:%d), which Terraform ignored.", hostname, mv.Version, req.Name, req.CallPos.Filename, req.CallPos.Line),
))
continue
}
// If we've found a pre-release version then we'll ignore it unless
// it was exactly requested.
if v.Prerelease() != "" && req.VersionConstraints.String() != v.String() {
log.Printf("[TRACE] ModuleInstaller: %s ignoring %s because it is a pre-release and was not requested exactly", key, v)
continue
}
if latestVersion == nil || v.GreaterThan(latestVersion) {
latestVersion = v
}
if req.VersionConstraints.Check(v) {
if latestMatch == nil || v.GreaterThan(latestMatch) {
latestMatch = v
}
}
}
if latestVersion == nil {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Module has no versions",
fmt.Sprintf("Module %q (%s:%d) has no versions available on %s.", addr, req.CallPos.Filename, req.CallPos.Line, hostname),
))
return nil, nil, diags
}
if latestMatch == nil {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Unresolvable module version constraint",
fmt.Sprintf("There is no available version of module %q (%s:%d) which matches the given version constraint. The newest available version is %s.", addr, req.CallPos.Filename, req.CallPos.Line, latestVersion),
))
return nil, nil, diags
}
// Report up to the caller that we're about to start downloading.
hooks.Download(key, packageAddr.String(), latestMatch)
// If we manage to get down here then we've found a suitable version to
// install, so we need to ask the registry where we should download it from.
// The response to this is a go-getter-style address string.
// first check the cache for the download URL
moduleAddr := moduleVersion{module: packageAddr, version: latestMatch.String()}
if _, exists := i.registryPackageSources[moduleAddr]; !exists {
realAddrRaw, err := reg.ModuleLocation(ctx, regsrcAddr, latestMatch.String())
if err != nil {
log.Printf("[ERROR] %s from %s %s: %s", key, addr, latestMatch, err)
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Error accessing remote module registry",
fmt.Sprintf("Failed to retrieve a download URL for %s %s from %s: %s", addr, latestMatch, hostname, err),
))
return nil, nil, diags
}
realAddr, err := addrs.ParseModuleSource(realAddrRaw)
if err != nil {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Invalid package location from module registry",
fmt.Sprintf("Module registry %s returned invalid source location %q for %s %s: %s.", hostname, realAddrRaw, addr, latestMatch, err),
))
return nil, nil, diags
}
switch realAddr := realAddr.(type) {
// Only a remote source address is allowed here: a registry isn't
// allowed to return a local path (because it doesn't know what
// its being called from) and we also don't allow recursively pointing
// at another registry source for simplicity's sake.
case addrs.ModuleSourceRemote:
i.registryPackageSources[moduleAddr] = realAddr
default:
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Invalid package location from module registry",
fmt.Sprintf("Module registry %s returned invalid source location %q for %s %s: must be a direct remote package address.", hostname, realAddrRaw, addr, latestMatch),
))
return nil, nil, diags
}
}
dlAddr := i.registryPackageSources[moduleAddr]
log.Printf("[TRACE] ModuleInstaller: %s %s %s is available at %q", key, packageAddr, latestMatch, dlAddr.PackageAddr)
err := fetcher.FetchPackage(ctx, instPath, dlAddr.PackageAddr.String())
if errors.Is(err, context.Canceled) {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Module download was interrupted",
fmt.Sprintf("Interrupt signal received when downloading module %s.", addr),
))
return nil, nil, diags
}
if err != nil {
// Errors returned by go-getter have very inconsistent quality as
// end-user error messages, but for now we're accepting that because
// we have no way to recognize any specific errors to improve them
// and masking the error entirely would hide valuable diagnostic
// information from the user.
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Failed to download module",
fmt.Sprintf("Could not download module %q (%s:%d) source code from %q: %s.", req.Name, req.CallPos.Filename, req.CallPos.Line, dlAddr, err),
))
return nil, nil, diags
}
log.Printf("[TRACE] ModuleInstaller: %s %q was downloaded to %s", key, dlAddr.PackageAddr, instPath)
// Incorporate any subdir information from the original path into the
// address returned by the registry in order to find the final directory
// of the target module.
finalAddr := dlAddr.FromRegistry(addr)
subDir := filepath.FromSlash(finalAddr.Subdir)
modDir := filepath.Join(instPath, subDir)
log.Printf("[TRACE] ModuleInstaller: %s should now be at %s", key, modDir)
// Finally we are ready to try actually loading the module.
mod, mDiags := earlyconfig.LoadModule(modDir)
if mod == nil {
// nil indicates missing or unreadable directory, so we'll
// discard the returned diags and return a more specific
// error message here. For registry modules this actually
// indicates a bug in the code above, since it's not the
// user's responsibility to create the directory in this case.
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Unreadable module directory",
fmt.Sprintf("The directory %s could not be read. This is a bug in Terraform and should be reported.", modDir),
))
} else {
diags = append(diags, mDiags...)
}
// Note the local location in our manifest.
manifest[key] = modsdir.Record{
Key: key,
Version: latestMatch,
Dir: modDir,
SourceAddr: req.SourceAddr.String(),
}
log.Printf("[DEBUG] Module installer: %s installed at %s", key, modDir)
hooks.Install(key, latestMatch, modDir)
return mod, latestMatch, diags
}
func (i *ModuleInstaller) installGoGetterModule(ctx context.Context, req *earlyconfig.ModuleRequest, key string, instPath string, manifest modsdir.Manifest, hooks ModuleInstallHooks, fetcher *getmodules.PackageFetcher) (*tfconfig.Module, tfdiags.Diagnostics) {
var diags tfdiags.Diagnostics
// Report up to the caller that we're about to start downloading.
addr := req.SourceAddr.(addrs.ModuleSourceRemote)
packageAddr := addr.PackageAddr
hooks.Download(key, packageAddr.String(), nil)
if len(req.VersionConstraints) != 0 {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Invalid version constraint",
fmt.Sprintf("Cannot apply a version constraint to module %q (at %s:%d) because it has a non Registry URL.", req.Name, req.CallPos.Filename, req.CallPos.Line),
))
return nil, diags
}
err := fetcher.FetchPackage(ctx, instPath, packageAddr.String())
if err != nil {
// go-getter generates a poor error for an invalid relative path, so
// we'll detect that case and generate a better one.
if _, ok := err.(*getmodules.MaybeRelativePathErr); ok {
log.Printf(
"[TRACE] ModuleInstaller: %s looks like a local path but is missing ./ or ../",
req.SourceAddr,
)
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Module not found",
fmt.Sprintf(
"The module address %q could not be resolved.\n\n"+
"If you intended this as a path relative to the current "+
"module, use \"./%s\" instead. The \"./\" prefix "+
"indicates that the address is a relative filesystem path.",
req.SourceAddr, req.SourceAddr,
),
))
} else {
// Errors returned by go-getter have very inconsistent quality as
// end-user error messages, but for now we're accepting that because
// we have no way to recognize any specific errors to improve them
// and masking the error entirely would hide valuable diagnostic
// information from the user.
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Failed to download module",
fmt.Sprintf("Could not download module %q (%s:%d) source code from %q: %s", req.Name, req.CallPos.Filename, req.CallPos.Line, packageAddr, err),
))
}
return nil, diags
}
subDir := filepath.FromSlash(addr.Subdir)
modDir := filepath.Join(instPath, subDir)
log.Printf("[TRACE] ModuleInstaller: %s %q was downloaded to %s", key, addr, modDir)
mod, mDiags := earlyconfig.LoadModule(modDir)
if mod == nil {
// nil indicates missing or unreadable directory, so we'll
// discard the returned diags and return a more specific
// error message here. For go-getter modules this actually
// indicates a bug in the code above, since it's not the
// user's responsibility to create the directory in this case.
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Unreadable module directory",
fmt.Sprintf("The directory %s could not be read. This is a bug in Terraform and should be reported.", modDir),
))
} else {
diags = append(diags, mDiags...)
}
// Note the local location in our manifest.
manifest[key] = modsdir.Record{
Key: key,
Dir: modDir,
SourceAddr: req.SourceAddr.String(),
}
log.Printf("[DEBUG] Module installer: %s installed at %s", key, modDir)
hooks.Install(key, nil, modDir)
return mod, diags
}
func (i *ModuleInstaller) packageInstallPath(modulePath addrs.Module) string {
return filepath.Join(i.modsDir, strings.Join(modulePath, "."))
}
// maybeImproveLocalInstallError is a helper function which can recognize
// some specific situations where it can return a more helpful error message
// and thus replace the given errors with those if so.
//
// If this function can't do anything about a particular situation then it
// will just return the given diags verbatim.
//
// This function's behavior is only reasonable for errors returned from the
// ModuleInstaller.installLocalModule function.
func maybeImproveLocalInstallError(req *earlyconfig.ModuleRequest, diags tfdiags.Diagnostics) tfdiags.Diagnostics {
if !diags.HasErrors() {
return diags
}
// The main situation we're interested in detecting here is whether the
// current module or any of its ancestors use relative paths that reach
// outside of the "package" established by the nearest non-local ancestor.
// That's never really valid, but unfortunately we historically didn't
// have any explicit checking for it and so now for compatibility in
// situations where things just happened to "work" we treat this as an
// error only in situations where installation would've failed anyway,
// so we can give a better error about it than just a generic
// "directory not found" or whatever.
//
// Since it's never actually valid to relative out of the containing
// package, we just assume that any failed local package install which
// does so was caused by that, because to stop doing it should always
// improve the situation, even if it leads to another error describing
// a different problem.
// To decide this we need to find the subset of our ancestors that
// belong to the same "package" as our request, along with the closest
// ancestor that defined that package, and then we can work forwards
// to see if any of the local paths "escaped" the package.
type Step struct {
Path addrs.Module
SourceAddr addrs.ModuleSource
}
var packageDefiner Step
var localRefs []Step
localRefs = append(localRefs, Step{
Path: req.Path,
SourceAddr: req.SourceAddr,
})
current := req.Parent // an earlyconfig.Config where Children isn't populated yet
for {
if current == nil || current.SourceAddr == nil {
// We've reached the root module, in which case we aren't
// in an external "package" at all and so our special case
// can't apply.
return diags
}
if _, ok := current.SourceAddr.(addrs.ModuleSourceLocal); !ok {
// We've found the package definer, then!
packageDefiner = Step{
Path: current.Path,
SourceAddr: current.SourceAddr,
}
break
}
localRefs = append(localRefs, Step{
Path: current.Path,
SourceAddr: current.SourceAddr,
})
current = current.Parent
}
// Our localRefs list is reversed because we were traversing up the tree,
// so we'll flip it the other way and thus walk "downwards" through it.
for i, j := 0, len(localRefs)-1; i < j; i, j = i+1, j-1 {
localRefs[i], localRefs[j] = localRefs[j], localRefs[i]
}
// Our method here is to start with a known base path prefix and
// then apply each of the local refs to it in sequence until one of
// them causes us to "lose" the prefix. If that happens, we've found
// an escape to report. This is not an exact science but good enough
// heuristic for choosing a better error message.
const prefix = "*/" // NOTE: this can find a false negative if the user chooses "*" as a directory name, but we consider that unlikely
packageAddr, startPath := splitAddrSubdir(packageDefiner.SourceAddr)
currentPath := path.Join(prefix, startPath)
for _, step := range localRefs {
rel := step.SourceAddr.String()
nextPath := path.Join(currentPath, rel)
if !strings.HasPrefix(nextPath, prefix) { // ESCAPED!
escapeeAddr := step.Path.String()
var newDiags tfdiags.Diagnostics
// First we'll copy over any non-error diagnostics from the source diags
for _, diag := range diags {
if diag.Severity() != tfdiags.Error {
newDiags = newDiags.Append(diag)
}
}
// ...but we'll replace any errors with this more precise error.
var suggestion string
if strings.HasPrefix(packageAddr, "/") || filepath.VolumeName(packageAddr) != "" {
// It might be somewhat surprising that Terraform treats
// absolute filesystem paths as "external" even though it
// treats relative paths as local, so if it seems like that's
// what the user was doing then we'll add an additional note
// about it.
suggestion = "\n\nTerraform treats absolute filesystem paths as external modules which establish a new module package. To treat this directory as part of the same package as its caller, use a local path starting with either \"./\" or \"../\"."
}
newDiags = newDiags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Local module path escapes module package",
fmt.Sprintf(
"The given source directory for %s would be outside of its containing package %q. Local source addresses starting with \"../\" must stay within the same package that the calling module belongs to.%s",
escapeeAddr, packageAddr, suggestion,
),
))
return newDiags
}
currentPath = nextPath
}
// If we get down here then we have nothing useful to do, so we'll just
// echo back what we were given.
return diags
}
func splitAddrSubdir(addr addrs.ModuleSource) (string, string) {
switch addr := addr.(type) {
case addrs.ModuleSourceRegistry:
subDir := addr.Subdir
addr.Subdir = ""
return addr.String(), subDir
case addrs.ModuleSourceRemote:
return addr.PackageAddr.String(), addr.Subdir
case nil:
panic("splitAddrSubdir on nil addrs.ModuleSource")
default:
return addr.String(), ""
}
}