package command import ( "bufio" "fmt" "strings" "github.com/hashicorp/terraform/addrs" "github.com/hashicorp/terraform/backend" "github.com/hashicorp/terraform/internal/helper/wrappedstreams" "github.com/hashicorp/terraform/repl" "github.com/hashicorp/terraform/tfdiags" "github.com/mitchellh/cli" ) // ConsoleCommand is a Command implementation that applies a Terraform // configuration and actually builds or changes infrastructure. type ConsoleCommand struct { Meta } func (c *ConsoleCommand) Run(args []string) int { args = c.Meta.process(args) cmdFlags := c.Meta.extendedFlagSet("console") cmdFlags.StringVar(&c.Meta.statePath, "state", DefaultStateFilename, "path") cmdFlags.Usage = func() { c.Ui.Error(c.Help()) } if err := cmdFlags.Parse(args); err != nil { c.Ui.Error(fmt.Sprintf("Error parsing command line flags: %s\n", err.Error())) return 1 } configPath, err := ModulePath(cmdFlags.Args()) if err != nil { c.Ui.Error(err.Error()) return 1 } configPath = c.Meta.normalizePath(configPath) // Check for user-supplied plugin path if c.pluginPath, err = c.loadPluginPath(); err != nil { c.Ui.Error(fmt.Sprintf("Error loading plugin path: %s", err)) return 1 } var diags tfdiags.Diagnostics backendConfig, backendDiags := c.loadBackendConfig(configPath) diags = diags.Append(backendDiags) if diags.HasErrors() { c.showDiagnostics(diags) return 1 } // Load the backend b, backendDiags := c.Backend(&BackendOpts{ Config: backendConfig, }) diags = diags.Append(backendDiags) if backendDiags.HasErrors() { c.showDiagnostics(diags) return 1 } // We require a local backend local, ok := b.(backend.Local) if !ok { c.showDiagnostics(diags) // in case of any warnings in here c.Ui.Error(ErrUnsupportedLocalOp) return 1 } // This is a read-only command c.ignoreRemoteBackendVersionConflict(b) // Build the operation opReq := c.Operation(b) opReq.ConfigDir = configPath opReq.ConfigLoader, err = c.initConfigLoader() opReq.AllowUnsetVariables = true // we'll just evaluate them as unknown if err != nil { diags = diags.Append(err) c.showDiagnostics(diags) return 1 } { var moreDiags tfdiags.Diagnostics opReq.Variables, moreDiags = c.collectVariableValues() diags = diags.Append(moreDiags) if moreDiags.HasErrors() { c.showDiagnostics(diags) return 1 } } // Get the context ctx, _, ctxDiags := local.Context(opReq) diags = diags.Append(ctxDiags) if ctxDiags.HasErrors() { c.showDiagnostics(diags) return 1 } // Successfully creating the context can result in a lock, so ensure we release it defer func() { err := opReq.StateLocker.Unlock(nil) if err != nil { c.Ui.Error(err.Error()) } }() // Set up the UI so we can output directly to stdout ui := &cli.BasicUi{ Writer: wrappedstreams.Stdout(), ErrorWriter: wrappedstreams.Stderr(), } // Before we can evaluate expressions, we must compute and populate any // derived values (input variables, local values, output values) // that are not stored in the persistent state. scope, scopeDiags := ctx.Eval(addrs.RootModuleInstance) diags = diags.Append(scopeDiags) if scope == nil { // scope is nil if there are errors so bad that we can't even build a scope. // Otherwise, we'll try to eval anyway. c.showDiagnostics(diags) return 1 } if diags.HasErrors() { diags = diags.Append(tfdiags.SimpleWarning("Due to the problems above, some expressions may produce unexpected results.")) } // Before we become interactive we'll show any diagnostics we encountered // during initialization, and then afterwards the driver will manage any // further diagnostics itself. c.showDiagnostics(diags) // IO Loop session := &repl.Session{ Scope: scope, } // Determine if stdin is a pipe. If so, we evaluate directly. if c.StdinPiped() { return c.modePiped(session, ui) } return c.modeInteractive(session, ui) } func (c *ConsoleCommand) modePiped(session *repl.Session, ui cli.Ui) int { var lastResult string scanner := bufio.NewScanner(wrappedstreams.Stdin()) for scanner.Scan() { result, exit, diags := session.Handle(strings.TrimSpace(scanner.Text())) if diags.HasErrors() { // In piped mode we'll exit immediately on error. c.showDiagnostics(diags) return 1 } if exit { return 0 } // Store the last result lastResult = result } // Output the final result ui.Output(lastResult) return 0 } func (c *ConsoleCommand) Help() string { helpText := ` Usage: terraform console [options] Starts an interactive console for experimenting with Terraform interpolations. This will open an interactive console that you can use to type interpolations into and inspect their values. This command loads the current state. This lets you explore and test interpolations before using them in future configurations. This command will never modify your state. Options: -state=path Path to read state. Defaults to "terraform.tfstate" -var 'foo=bar' Set a variable in the Terraform configuration. This flag can be set multiple times. -var-file=foo Set variables in the Terraform configuration from a file. If "terraform.tfvars" or any ".auto.tfvars" files are present, they will be automatically loaded. ` return strings.TrimSpace(helpText) } func (c *ConsoleCommand) Synopsis() string { return "Try Terraform expressions at an interactive command prompt" }