package local import ( "context" "fmt" "sync" "github.com/hashicorp/errwrap" "github.com/hashicorp/terraform/backend" "github.com/hashicorp/terraform/helper/schema" "github.com/hashicorp/terraform/state" "github.com/hashicorp/terraform/terraform" "github.com/mitchellh/cli" "github.com/mitchellh/colorstring" ) // Local is an implementation of EnhancedBackend that performs all operations // locally. This is the "default" backend and implements normal Terraform // behavior as it is well known. type Local struct { // CLI and Colorize control the CLI output. If CLI is nil then no CLI // output will be done. If CLIColor is nil then no coloring will be done. CLI cli.Ui CLIColor *colorstring.Colorize // StatePath is the local path where state is read from. // // StateOutPath is the local path where the state will be written. // If this is empty, it will default to StatePath. // // StateBackupPath is the local path where a backup file will be written. // If this is empty, no backup will be taken. StatePath string StateOutPath string StateBackupPath string // we only want to create a single instance of the local state state state.State // ContextOpts are the base context options to set when initializing a // Terraform context. Many of these will be overridden or merged by // Operation. See Operation for more details. ContextOpts *terraform.ContextOpts // OpInput will ask for necessary input prior to performing any operations. // // OpValidation will perform validation prior to running an operation. The // variable naming doesn't match the style of others since we have a func // Validate. OpInput bool OpValidation bool // Backend, if non-nil, will use this backend for non-enhanced behavior. // This allows local behavior with remote state storage. It is a way to // "upgrade" a non-enhanced backend to an enhanced backend with typical // behavior. // // If this is nil, local performs normal state loading and storage. Backend backend.Backend schema *schema.Backend opLock sync.Mutex once sync.Once } func (b *Local) Input( ui terraform.UIInput, c *terraform.ResourceConfig) (*terraform.ResourceConfig, error) { b.once.Do(b.init) f := b.schema.Input if b.Backend != nil { f = b.Backend.Input } return f(ui, c) } func (b *Local) Validate(c *terraform.ResourceConfig) ([]string, []error) { b.once.Do(b.init) f := b.schema.Validate if b.Backend != nil { f = b.Backend.Validate } return f(c) } func (b *Local) Configure(c *terraform.ResourceConfig) error { b.once.Do(b.init) f := b.schema.Configure if b.Backend != nil { f = b.Backend.Configure } return f(c) } func (b *Local) State() (state.State, error) { // If we have a backend handling state, defer to that. if b.Backend != nil { return b.Backend.State() } if b.state != nil { return b.state, nil } // Otherwise, we need to load the state. var s state.State = &state.LocalState{ Path: b.StatePath, PathOut: b.StateOutPath, } // Load the state as a sanity check if err := s.RefreshState(); err != nil { return nil, errwrap.Wrapf("Error reading local state: {{err}}", err) } // If we are backing up the state, wrap it if path := b.StateBackupPath; path != "" { s = &state.BackupState{ Real: s, Path: path, } } b.state = s return s, nil } // Operation implements backend.Enhanced // // This will initialize an in-memory terraform.Context to perform the // operation within this process. // // The given operation parameter will be merged with the ContextOpts on // the structure with the following rules. If a rule isn't specified and the // name conflicts, assume that the field is overwritten if set. func (b *Local) Operation(ctx context.Context, op *backend.Operation) (*backend.RunningOperation, error) { // Determine the function to call for our operation var f func(context.Context, *backend.Operation, *backend.RunningOperation) switch op.Type { case backend.OperationTypeRefresh: f = b.opRefresh case backend.OperationTypePlan: f = b.opPlan case backend.OperationTypeApply: f = b.opApply default: return nil, fmt.Errorf( "Unsupported operation type: %s\n\n"+ "This is a bug in Terraform and should be reported. The local backend\n"+ "is built-in to Terraform and should always support all operations.", op.Type) } // Lock b.opLock.Lock() // Build our running operation runningCtx, runningCtxCancel := context.WithCancel(context.Background()) runningOp := &backend.RunningOperation{Context: runningCtx} // Do it go func() { defer b.opLock.Unlock() defer runningCtxCancel() f(ctx, op, runningOp) }() // Return return runningOp, nil } // Colorize returns the Colorize structure that can be used for colorizing // output. This is gauranteed to always return a non-nil value and so is useful // as a helper to wrap any potentially colored strings. func (b *Local) Colorize() *colorstring.Colorize { if b.CLIColor != nil { return b.CLIColor } return &colorstring.Colorize{ Colors: colorstring.DefaultColors, Disable: true, } } func (b *Local) init() { b.schema = &schema.Backend{ Schema: map[string]*schema.Schema{ "path": &schema.Schema{ Type: schema.TypeString, Optional: true, }, }, ConfigureFunc: b.schemaConfigure, } } func (b *Local) schemaConfigure(ctx context.Context) error { d := schema.FromContextBackendConfig(ctx) // Set the path if it is set pathRaw, ok := d.GetOk("path") if ok { path := pathRaw.(string) if path == "" { return fmt.Errorf("configured path is empty") } b.StatePath = path } return nil }