opentofu/internal/command/meta_config.go
Martin Atkins fda0579537 Experiments supported only in alpha/dev builds
We originally introduced the idea of language experiments as a way to get
early feedback on not-yet-proven feature ideas, ideally as part of the
initial exploration of the solution space rather than only after a
solution has become relatively clear.

Unfortunately, our tradeoff of making them available in normal releases
behind an explicit opt-in in order to make it easier to participate in the
feedback process had the unintended side-effect of making it feel okay
to use experiments in production and endure the warnings they generate.
This in turn has made us reluctant to make use of the experiments feature
lest experiments become de-facto production features which we then feel
compelled to preserve even though we aren't yet ready to graduate them
to stable features.

In an attempt to tweak that compromise, here we make the availability of
experiments _at all_ a build-time flag which will not be set by default,
and therefore experiments will not be available in most release builds.

The intent (not yet implemented in this PR) is for our release process to
set this flag only when it knows it's building an alpha release or a
development snapshot not destined for release at all, which will therefore
allow us to still use the alpha releases as a vehicle for giving feedback
participants access to a feature (without needing to install a Go
toolchain) but will not encourage pretending that these features are
production-ready before they graduate from experimental.

Only language experiments have an explicit framework for dealing with them
which outlives any particular experiment, so most of the changes here are
to that generalized mechanism. However, the intent is that non-language
experiments, such as experimental CLI commands, would also in future
check Meta.AllowExperimentalFeatures and gate the use of those experiments
too, so that we can be consistent that experimental features will never
be available unless you explicitly choose to use an alpha release or
a custom build from source code.

Since there are already some experiments active at the time of this commit
which were not previously subject to this restriction, we'll pragmatically
leave those as exceptions that will remain generally available for now,
and so this new approach will apply only to new experiments started in the
future. Once those experiments have all concluded, we will be left with
no more exceptions unless we explicitly choose to make an exception for
some reason we've not imagined yet.

It's important that we be able to write tests that rely on experiments
either being available or not being available, so here we're using our
typical approach of making "package main" deal with the global setting
that applies to Terraform CLI executables while making the layers below
all support fine-grain selection of this behavior so that tests with
different needs can run concurrently without trampling on one another.

As a compromise, the integration tests in the terraform package will
run with experiments enabled _by default_ since we commonly need to
exercise experiments in those tests, but they can selectively opt-out
if they need to by overriding the loader setting back to false again.
2022-06-17 14:46:07 -07:00

453 lines
15 KiB
Go

package command
import (
"context"
"fmt"
"os"
"path/filepath"
"sort"
"github.com/hashicorp/hcl/v2"
"github.com/hashicorp/hcl/v2/hclsyntax"
"github.com/hashicorp/terraform-config-inspect/tfconfig"
"github.com/hashicorp/terraform/internal/configs"
"github.com/hashicorp/terraform/internal/configs/configload"
"github.com/hashicorp/terraform/internal/configs/configschema"
"github.com/hashicorp/terraform/internal/earlyconfig"
"github.com/hashicorp/terraform/internal/initwd"
"github.com/hashicorp/terraform/internal/registry"
"github.com/hashicorp/terraform/internal/terraform"
"github.com/hashicorp/terraform/internal/tfdiags"
"github.com/zclconf/go-cty/cty"
"github.com/zclconf/go-cty/cty/convert"
)
// normalizePath normalizes a given path so that it is, if possible, relative
// to the current working directory. This is primarily used to prepare
// paths used to load configuration, because we want to prefer recording
// relative paths in source code references within the configuration.
func (m *Meta) normalizePath(path string) string {
m.fixupMissingWorkingDir()
return m.WorkingDir.NormalizePath(path)
}
// loadConfig reads a configuration from the given directory, which should
// contain a root module and have already have any required descendent modules
// installed.
func (m *Meta) loadConfig(rootDir string) (*configs.Config, tfdiags.Diagnostics) {
var diags tfdiags.Diagnostics
rootDir = m.normalizePath(rootDir)
loader, err := m.initConfigLoader()
if err != nil {
diags = diags.Append(err)
return nil, diags
}
config, hclDiags := loader.LoadConfig(rootDir)
diags = diags.Append(hclDiags)
return config, diags
}
// loadSingleModule reads configuration from the given directory and returns
// a description of that module only, without attempting to assemble a module
// tree for referenced child modules.
//
// Most callers should use loadConfig. This method exists to support early
// initialization use-cases where the root module must be inspected in order
// to determine what else needs to be installed before the full configuration
// can be used.
func (m *Meta) loadSingleModule(dir string) (*configs.Module, tfdiags.Diagnostics) {
var diags tfdiags.Diagnostics
dir = m.normalizePath(dir)
loader, err := m.initConfigLoader()
if err != nil {
diags = diags.Append(err)
return nil, diags
}
module, hclDiags := loader.Parser().LoadConfigDir(dir)
diags = diags.Append(hclDiags)
return module, diags
}
// loadSingleModuleEarly is a variant of loadSingleModule that uses the special
// "early config" loader that is more forgiving of unexpected constructs and
// legacy syntax.
//
// Early-loaded config is not registered in the source code cache, so
// diagnostics produced from it may render without source code snippets. In
// practice this is not a big concern because the early config loader also
// cannot generate detailed source locations, so it prefers to produce
// diagnostics without explicit source location information and instead includes
// approximate locations in the message text.
//
// Most callers should use loadConfig. This method exists to support early
// initialization use-cases where the root module must be inspected in order
// to determine what else needs to be installed before the full configuration
// can be used.
func (m *Meta) loadSingleModuleEarly(dir string) (*tfconfig.Module, tfdiags.Diagnostics) {
var diags tfdiags.Diagnostics
dir = m.normalizePath(dir)
module, moreDiags := earlyconfig.LoadModule(dir)
diags = diags.Append(moreDiags)
return module, diags
}
// dirIsConfigPath checks if the given path is a directory that contains at
// least one Terraform configuration file (.tf or .tf.json), returning true
// if so.
//
// In the unlikely event that the underlying config loader cannot be initalized,
// this function optimistically returns true, assuming that the caller will
// then do some other operation that requires the config loader and get an
// error at that point.
func (m *Meta) dirIsConfigPath(dir string) bool {
loader, err := m.initConfigLoader()
if err != nil {
return true
}
return loader.IsConfigDir(dir)
}
// loadBackendConfig reads configuration from the given directory and returns
// the backend configuration defined by that module, if any. Nil is returned
// if the specified module does not have an explicit backend configuration.
//
// This is a convenience method for command code that will delegate to the
// configured backend to do most of its work, since in that case it is the
// backend that will do the full configuration load.
//
// Although this method returns only the backend configuration, at present it
// actually loads and validates the entire configuration first. Therefore errors
// returned may be about other aspects of the configuration. This behavior may
// change in future, so callers must not rely on it. (That is, they must expect
// that a call to loadSingleModule or loadConfig could fail on the same
// directory even if loadBackendConfig succeeded.)
func (m *Meta) loadBackendConfig(rootDir string) (*configs.Backend, tfdiags.Diagnostics) {
mod, diags := m.loadSingleModule(rootDir)
// Only return error diagnostics at this point. Any warnings will be caught
// again later and duplicated in the output.
if diags.HasErrors() {
return nil, diags
}
if mod.CloudConfig != nil {
backendConfig := mod.CloudConfig.ToBackendConfig()
return &backendConfig, nil
}
return mod.Backend, nil
}
// loadHCLFile reads an arbitrary HCL file and returns the unprocessed body
// representing its toplevel. Most callers should use one of the more
// specialized "load..." methods to get a higher-level representation.
func (m *Meta) loadHCLFile(filename string) (hcl.Body, tfdiags.Diagnostics) {
var diags tfdiags.Diagnostics
filename = m.normalizePath(filename)
loader, err := m.initConfigLoader()
if err != nil {
diags = diags.Append(err)
return nil, diags
}
body, hclDiags := loader.Parser().LoadHCLFile(filename)
diags = diags.Append(hclDiags)
return body, diags
}
// installModules reads a root module from the given directory and attempts
// recursively to install all of its descendent modules.
//
// The given hooks object will be notified of installation progress, which
// can then be relayed to the end-user. The uiModuleInstallHooks type in
// this package has a reasonable implementation for displaying notifications
// via a provided cli.Ui.
func (m *Meta) installModules(rootDir string, upgrade bool, hooks initwd.ModuleInstallHooks) (abort bool, diags tfdiags.Diagnostics) {
rootDir = m.normalizePath(rootDir)
err := os.MkdirAll(m.modulesDir(), os.ModePerm)
if err != nil {
diags = diags.Append(fmt.Errorf("failed to create local modules directory: %s", err))
return true, diags
}
inst := m.moduleInstaller()
// Installation can be aborted by interruption signals
ctx, done := m.InterruptibleContext()
defer done()
_, moreDiags := inst.InstallModules(ctx, rootDir, upgrade, hooks)
diags = diags.Append(moreDiags)
if ctx.Err() == context.Canceled {
m.showDiagnostics(diags)
m.Ui.Error("Module installation was canceled by an interrupt signal.")
return true, diags
}
return false, diags
}
// initDirFromModule initializes the given directory (which should be
// pre-verified as empty by the caller) by copying the source code from the
// given module address.
//
// Internally this runs similar steps to installModules.
// The given hooks object will be notified of installation progress, which
// can then be relayed to the end-user. The uiModuleInstallHooks type in
// this package has a reasonable implementation for displaying notifications
// via a provided cli.Ui.
func (m *Meta) initDirFromModule(targetDir string, addr string, hooks initwd.ModuleInstallHooks) (abort bool, diags tfdiags.Diagnostics) {
// Installation can be aborted by interruption signals
ctx, done := m.InterruptibleContext()
defer done()
targetDir = m.normalizePath(targetDir)
moreDiags := initwd.DirFromModule(ctx, targetDir, m.modulesDir(), addr, m.registryClient(), hooks)
diags = diags.Append(moreDiags)
if ctx.Err() == context.Canceled {
m.showDiagnostics(diags)
m.Ui.Error("Module initialization was canceled by an interrupt signal.")
return true, diags
}
return false, diags
}
// inputForSchema uses interactive prompts to try to populate any
// not-yet-populated required attributes in the given object value to
// comply with the given schema.
//
// An error will be returned if input is disabled for this meta or if
// values cannot be obtained for some other operational reason. Errors are
// not returned for invalid input since the input loop itself will report
// that interactively.
//
// It is not guaranteed that the result will be valid, since certain attribute
// types and nested blocks are not supported for input.
//
// The given value must conform to the given schema. If not, this method will
// panic.
func (m *Meta) inputForSchema(given cty.Value, schema *configschema.Block) (cty.Value, error) {
if given.IsNull() || !given.IsKnown() {
// This is not reasonable input, but we'll tolerate it anyway and
// just pass it through for the caller to handle downstream.
return given, nil
}
retVals := given.AsValueMap()
names := make([]string, 0, len(schema.Attributes))
for name, attrS := range schema.Attributes {
if attrS.Required && retVals[name].IsNull() && attrS.Type.IsPrimitiveType() {
names = append(names, name)
}
}
sort.Strings(names)
input := m.UIInput()
for _, name := range names {
attrS := schema.Attributes[name]
for {
strVal, err := input.Input(context.Background(), &terraform.InputOpts{
Id: name,
Query: name,
Description: attrS.Description,
})
if err != nil {
return cty.UnknownVal(schema.ImpliedType()), fmt.Errorf("%s: %s", name, err)
}
val := cty.StringVal(strVal)
val, err = convert.Convert(val, attrS.Type)
if err != nil {
m.showDiagnostics(fmt.Errorf("Invalid value: %s", err))
continue
}
retVals[name] = val
break
}
}
return cty.ObjectVal(retVals), nil
}
// configSources returns the source cache from the receiver's config loader,
// which the caller must not modify.
//
// If a config loader has not yet been instantiated then no files could have
// been loaded already, so this method returns a nil map in that case.
func (m *Meta) configSources() map[string][]byte {
if m.configLoader == nil {
return nil
}
return m.configLoader.Sources()
}
func (m *Meta) modulesDir() string {
return filepath.Join(m.DataDir(), "modules")
}
// registerSynthConfigSource allows commands to add synthetic additional source
// buffers to the config loader's cache of sources (as returned by
// configSources), which is useful when a command is directly parsing something
// from the command line that may produce diagnostics, so that diagnostic
// snippets can still be produced.
//
// If this is called before a configLoader has been initialized then it will
// try to initialize the loader but ignore any initialization failure, turning
// the call into a no-op. (We presume that a caller will later call a different
// function that also initializes the config loader as a side effect, at which
// point those errors can be returned.)
func (m *Meta) registerSynthConfigSource(filename string, src []byte) {
loader, err := m.initConfigLoader()
if err != nil || loader == nil {
return // treated as no-op, since this is best-effort
}
loader.Parser().ForceFileSource(filename, src)
}
// initConfigLoader initializes the shared configuration loader if it isn't
// already initialized.
//
// If the loader cannot be created for some reason then an error is returned
// and no loader is created. Subsequent calls will presumably see the same
// error. Loader initialization errors will tend to prevent any further use
// of most Terraform features, so callers should report any error and safely
// terminate.
func (m *Meta) initConfigLoader() (*configload.Loader, error) {
if m.configLoader == nil {
loader, err := configload.NewLoader(&configload.Config{
ModulesDir: m.modulesDir(),
Services: m.Services,
})
if err != nil {
return nil, err
}
loader.AllowLanguageExperiments(m.AllowExperimentalFeatures)
m.configLoader = loader
if m.View != nil {
m.View.SetConfigSources(loader.Sources)
}
}
return m.configLoader, nil
}
// moduleInstaller instantiates and returns a module installer for use by
// "terraform init" (directly or indirectly).
func (m *Meta) moduleInstaller() *initwd.ModuleInstaller {
reg := m.registryClient()
return initwd.NewModuleInstaller(m.modulesDir(), reg)
}
// registryClient instantiates and returns a new Terraform Registry client.
func (m *Meta) registryClient() *registry.Client {
return registry.NewClient(m.Services, nil)
}
// configValueFromCLI parses a configuration value that was provided in a
// context in the CLI where only strings can be provided, such as on the
// command line or in an environment variable, and returns the resulting
// value.
func configValueFromCLI(synthFilename, rawValue string, wantType cty.Type) (cty.Value, tfdiags.Diagnostics) {
var diags tfdiags.Diagnostics
switch {
case wantType.IsPrimitiveType():
// Primitive types are handled as conversions from string.
val := cty.StringVal(rawValue)
var err error
val, err = convert.Convert(val, wantType)
if err != nil {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Invalid backend configuration value",
fmt.Sprintf("Invalid backend configuration argument %s: %s", synthFilename, err),
))
val = cty.DynamicVal // just so we return something valid-ish
}
return val, diags
default:
// Non-primitives are parsed as HCL expressions
src := []byte(rawValue)
expr, hclDiags := hclsyntax.ParseExpression(src, synthFilename, hcl.Pos{Line: 1, Column: 1})
diags = diags.Append(hclDiags)
if hclDiags.HasErrors() {
return cty.DynamicVal, diags
}
val, hclDiags := expr.Value(nil)
diags = diags.Append(hclDiags)
if hclDiags.HasErrors() {
val = cty.DynamicVal
}
return val, diags
}
}
// rawFlags is a flag.Value implementation that just appends raw flag
// names and values to a slice.
type rawFlags struct {
flagName string
items *[]rawFlag
}
func newRawFlags(flagName string) rawFlags {
var items []rawFlag
return rawFlags{
flagName: flagName,
items: &items,
}
}
func (f rawFlags) Empty() bool {
if f.items == nil {
return true
}
return len(*f.items) == 0
}
func (f rawFlags) AllItems() []rawFlag {
if f.items == nil {
return nil
}
return *f.items
}
func (f rawFlags) Alias(flagName string) rawFlags {
return rawFlags{
flagName: flagName,
items: f.items,
}
}
func (f rawFlags) String() string {
return ""
}
func (f rawFlags) Set(str string) error {
*f.items = append(*f.items, rawFlag{
Name: f.flagName,
Value: str,
})
return nil
}
type rawFlag struct {
Name string
Value string
}
func (f rawFlag) String() string {
return fmt.Sprintf("%s=%q", f.Name, f.Value)
}