package local import ( "context" "fmt" "log" "sort" "github.com/hashicorp/errwrap" "github.com/hashicorp/terraform/backend" "github.com/hashicorp/terraform/command/clistate" "github.com/hashicorp/terraform/configs" "github.com/hashicorp/terraform/configs/configload" "github.com/hashicorp/terraform/plans/planfile" "github.com/hashicorp/terraform/states/statemgr" "github.com/hashicorp/terraform/terraform" "github.com/hashicorp/terraform/tfdiags" "github.com/zclconf/go-cty/cty" ) // backend.Local implementation. func (b *Local) Context(op *backend.Operation) (*terraform.Context, statemgr.Full, tfdiags.Diagnostics) { // Make sure the type is invalid. We use this as a way to know not // to ask for input/validate. op.Type = backend.OperationTypeInvalid if op.LockState { op.StateLocker = clistate.NewLocker(context.Background(), op.StateLockTimeout, b.CLI, b.Colorize()) } else { op.StateLocker = clistate.NewNoopLocker() } ctx, _, stateMgr, diags := b.context(op) return ctx, stateMgr, diags } func (b *Local) context(op *backend.Operation) (*terraform.Context, *configload.Snapshot, statemgr.Full, tfdiags.Diagnostics) { var diags tfdiags.Diagnostics // Get the latest state. log.Printf("[TRACE] backend/local: requesting state manager for workspace %q", op.Workspace) s, err := b.StateMgr(op.Workspace) if err != nil { diags = diags.Append(errwrap.Wrapf("Error loading state: {{err}}", err)) return nil, nil, nil, diags } log.Printf("[TRACE] backend/local: requesting state lock for workspace %q", op.Workspace) if err := op.StateLocker.Lock(s, op.Type.String()); err != nil { diags = diags.Append(errwrap.Wrapf("Error locking state: {{err}}", err)) return nil, nil, nil, diags } log.Printf("[TRACE] backend/local: reading remote state for workspace %q", op.Workspace) if err := s.RefreshState(); err != nil { diags = diags.Append(errwrap.Wrapf("Error loading state: {{err}}", err)) return nil, nil, nil, diags } // Initialize our context options var opts terraform.ContextOpts if v := b.ContextOpts; v != nil { opts = *v } // Copy set options from the operation opts.Destroy = op.Destroy opts.Targets = op.Targets opts.UIInput = op.UIIn // Load the latest state. If we enter contextFromPlanFile below then the // state snapshot in the plan file must match this, or else it'll return // error diagnostics. log.Printf("[TRACE] backend/local: retrieving local state snapshot for workspace %q", op.Workspace) opts.State = s.State() var tfCtx *terraform.Context var ctxDiags tfdiags.Diagnostics var configSnap *configload.Snapshot if op.PlanFile != nil { var stateMeta *statemgr.SnapshotMeta // If the statemgr implements our optional PersistentMeta interface then we'll // additionally verify that the state snapshot in the plan file has // consistent metadata, as an additional safety check. if sm, ok := s.(statemgr.PersistentMeta); ok { m := sm.StateSnapshotMeta() stateMeta = &m } log.Printf("[TRACE] backend/local: building context from plan file") tfCtx, configSnap, ctxDiags = b.contextFromPlanFile(op.PlanFile, opts, stateMeta) // Write sources into the cache of the main loader so that they are // available if we need to generate diagnostic message snippets. op.ConfigLoader.ImportSourcesFromSnapshot(configSnap) } else { log.Printf("[TRACE] backend/local: building context for current working directory") tfCtx, configSnap, ctxDiags = b.contextDirect(op, opts) } diags = diags.Append(ctxDiags) if diags.HasErrors() { return nil, nil, nil, diags } log.Printf("[TRACE] backend/local: finished building terraform.Context") // If we have an operation, then we automatically do the input/validate // here since every option requires this. if op.Type != backend.OperationTypeInvalid { // If input asking is enabled, then do that if op.PlanFile == nil && b.OpInput { mode := terraform.InputModeProvider log.Printf("[TRACE] backend/local: requesting interactive input, if necessary") inputDiags := tfCtx.Input(mode) diags = diags.Append(inputDiags) if inputDiags.HasErrors() { return nil, nil, nil, diags } } // If validation is enabled, validate if b.OpValidation { log.Printf("[TRACE] backend/local: running validation operation") validateDiags := tfCtx.Validate() diags = diags.Append(validateDiags) } } return tfCtx, configSnap, s, diags } func (b *Local) contextDirect(op *backend.Operation, opts terraform.ContextOpts) (*terraform.Context, *configload.Snapshot, tfdiags.Diagnostics) { var diags tfdiags.Diagnostics // Load the configuration using the caller-provided configuration loader. config, configSnap, configDiags := op.ConfigLoader.LoadConfigWithSnapshot(op.ConfigDir) diags = diags.Append(configDiags) if configDiags.HasErrors() { return nil, nil, diags } opts.Config = config var rawVariables map[string]backend.UnparsedVariableValue if op.AllowUnsetVariables { // Rather than prompting for input, we'll just stub out the required // but unset variables with unknown values to represent that they are // placeholders for values the user would need to provide for other // operations. rawVariables = b.stubUnsetRequiredVariables(op.Variables, config.Module.Variables) } else { // If interactive input is enabled, we might gather some more variable // values through interactive prompts. // TODO: Need to route the operation context through into here, so that // the interactive prompts can be sensitive to its timeouts/etc. rawVariables = b.interactiveCollectVariables(context.TODO(), op.Variables, config.Module.Variables, opts.UIInput) } variables, varDiags := backend.ParseVariableValues(rawVariables, config.Module.Variables) diags = diags.Append(varDiags) if diags.HasErrors() { return nil, nil, diags } opts.Variables = variables tfCtx, ctxDiags := terraform.NewContext(&opts) diags = diags.Append(ctxDiags) return tfCtx, configSnap, diags } func (b *Local) contextFromPlanFile(pf *planfile.Reader, opts terraform.ContextOpts, currentStateMeta *statemgr.SnapshotMeta) (*terraform.Context, *configload.Snapshot, tfdiags.Diagnostics) { var diags tfdiags.Diagnostics const errSummary = "Invalid plan file" // A plan file has a snapshot of configuration embedded inside it, which // is used instead of whatever configuration might be already present // in the filesystem. snap, err := pf.ReadConfigSnapshot() if err != nil { diags = diags.Append(tfdiags.Sourceless( tfdiags.Error, errSummary, fmt.Sprintf("Failed to read configuration snapshot from plan file: %s.", err), )) return nil, snap, diags } loader := configload.NewLoaderFromSnapshot(snap) config, configDiags := loader.LoadConfig(snap.Modules[""].Dir) diags = diags.Append(configDiags) if configDiags.HasErrors() { return nil, snap, diags } opts.Config = config // A plan file also contains a snapshot of the prior state the changes // are intended to apply to. priorStateFile, err := pf.ReadStateFile() if err != nil { diags = diags.Append(tfdiags.Sourceless( tfdiags.Error, errSummary, fmt.Sprintf("Failed to read prior state snapshot from plan file: %s.", err), )) return nil, snap, diags } if currentStateMeta != nil { // If the caller sets this, we require that the stored prior state // has the same metadata, which is an extra safety check that nothing // has changed since the plan was created. (All of the "real-world" // state manager implementstions support this, but simpler test backends // may not.) if currentStateMeta.Lineage != "" && priorStateFile.Lineage != "" { if priorStateFile.Serial != currentStateMeta.Serial || priorStateFile.Lineage != currentStateMeta.Lineage { diags = diags.Append(tfdiags.Sourceless( tfdiags.Error, "Saved plan is stale", "The given plan file can no longer be applied because the state was changed by another operation after the plan was created.", )) } } } // The caller already wrote the "current state" here, but we're overriding // it here with the prior state. These two should actually be identical in // normal use, particularly if we validated the state meta above, but // we do this here anyway to ensure consistent behavior. opts.State = priorStateFile.State plan, err := pf.ReadPlan() if err != nil { diags = diags.Append(tfdiags.Sourceless( tfdiags.Error, errSummary, fmt.Sprintf("Failed to read plan from plan file: %s.", err), )) return nil, snap, diags } variables := terraform.InputValues{} for name, dyVal := range plan.VariableValues { val, err := dyVal.Decode(cty.DynamicPseudoType) if err != nil { diags = diags.Append(tfdiags.Sourceless( tfdiags.Error, errSummary, fmt.Sprintf("Invalid value for variable %q recorded in plan file: %s.", name, err), )) continue } variables[name] = &terraform.InputValue{ Value: val, SourceType: terraform.ValueFromPlan, } } opts.Variables = variables opts.Changes = plan.Changes opts.Targets = plan.TargetAddrs opts.ProviderSHA256s = plan.ProviderSHA256s tfCtx, ctxDiags := terraform.NewContext(&opts) diags = diags.Append(ctxDiags) return tfCtx, snap, diags } // interactiveCollectVariables attempts to complete the given existing // map of variables by interactively prompting for any variables that are // declared as required but not yet present. // // If interactive input is disabled for this backend instance then this is // a no-op. If input is enabled but fails for some reason, the resulting // map will be incomplete. For these reasons, the caller must still validate // that the result is complete and valid. // // This function does not modify the map given in "existing", but may return // it unchanged if no modifications are required. If modifications are required, // the result is a new map with all of the elements from "existing" plus // additional elements as appropriate. // // Interactive prompting is a "best effort" thing for first-time user UX and // not something we expect folks to be relying on for routine use. Terraform // is primarily a non-interactive tool and so we prefer to report in error // messages that variables are not set rather than reporting that input failed: // the primary resolution to missing variables is to provide them by some other // means. func (b *Local) interactiveCollectVariables(ctx context.Context, existing map[string]backend.UnparsedVariableValue, vcs map[string]*configs.Variable, uiInput terraform.UIInput) map[string]backend.UnparsedVariableValue { var needed []string if b.OpInput && uiInput != nil { for name, vc := range vcs { if !vc.Required() { continue // We only prompt for required variables } if _, exists := existing[name]; !exists { needed = append(needed, name) } } } else { log.Print("[DEBUG] backend/local: Skipping interactive prompts for variables because input is disabled") } if len(needed) == 0 { return existing } log.Printf("[DEBUG] backend/local: will prompt for input of unset required variables %s", needed) // If we get here then we're planning to prompt for at least one additional // variable's value. sort.Strings(needed) // prompt in lexical order ret := make(map[string]backend.UnparsedVariableValue, len(vcs)) for k, v := range existing { ret[k] = v } for _, name := range needed { vc := vcs[name] rawValue, err := uiInput.Input(ctx, &terraform.InputOpts{ Id: fmt.Sprintf("var.%s", name), Query: fmt.Sprintf("var.%s", name), Description: vc.Description, }) if err != nil { // Since interactive prompts are best-effort, we'll just continue // here and let subsequent validation report this as a variable // not specified. log.Printf("[WARN] backend/local: Failed to request user input for variable %q: %s", name, err) continue } ret[name] = unparsedInteractiveVariableValue{Name: name, RawValue: rawValue} } return ret } // stubUnsetVariables ensures that all required variables defined in the // configuration exist in the resulting map, by adding new elements as necessary. // // The stubbed value of any additions will be an unknown variable conforming // to the variable's configured type constraint, meaning that no particular // value is known and that one must be provided by the user in order to get // a complete result. // // Unset optional attributes (those with default values) will not be populated // by this function, under the assumption that a later step will handle those. // In this sense, stubUnsetRequiredVariables is essentially a non-interactive, // non-error-producing variant of interactiveCollectVariables that creates // placeholders for values the user would be prompted for interactively on // other operations. // // This function should be used only in situations where variables values // will not be directly used and the variables map is being constructed only // to produce a complete Terraform context for some ancillary functionality // like "terraform console", "terraform state ...", etc. // // This function is guaranteed not to modify the given map, but it may return // the given map unchanged if no additions are required. If additions are // required then the result will be a new map containing everything in the // given map plus additional elements. func (b *Local) stubUnsetRequiredVariables(existing map[string]backend.UnparsedVariableValue, vcs map[string]*configs.Variable) map[string]backend.UnparsedVariableValue { var missing bool // Do we need to add anything? for name, vc := range vcs { if !vc.Required() { continue // We only stub required variables } if _, exists := existing[name]; !exists { missing = true } } if !missing { return existing } // If we get down here then there's at least one variable value to add. ret := make(map[string]backend.UnparsedVariableValue, len(vcs)) for k, v := range existing { ret[k] = v } for name, vc := range vcs { if !vc.Required() { continue } if _, exists := existing[name]; !exists { ret[name] = unparsedUnknownVariableValue{Name: name, WantType: vc.Type} } } return ret } type unparsedInteractiveVariableValue struct { Name, RawValue string } var _ backend.UnparsedVariableValue = unparsedInteractiveVariableValue{} func (v unparsedInteractiveVariableValue) ParseVariableValue(mode configs.VariableParsingMode) (*terraform.InputValue, tfdiags.Diagnostics) { var diags tfdiags.Diagnostics val, valDiags := mode.Parse(v.Name, v.RawValue) diags = diags.Append(valDiags) if diags.HasErrors() { return nil, diags } return &terraform.InputValue{ Value: val, SourceType: terraform.ValueFromInput, }, diags } type unparsedUnknownVariableValue struct { Name string WantType cty.Type } var _ backend.UnparsedVariableValue = unparsedUnknownVariableValue{} func (v unparsedUnknownVariableValue) ParseVariableValue(mode configs.VariableParsingMode) (*terraform.InputValue, tfdiags.Diagnostics) { return &terraform.InputValue{ Value: cty.UnknownVal(v.WantType), SourceType: terraform.ValueFromInput, }, nil }