package local import ( "context" "errors" "fmt" "io/ioutil" "log" "os" "path/filepath" "sort" "sync" "github.com/hashicorp/terraform/backend" "github.com/hashicorp/terraform/command/clistate" "github.com/hashicorp/terraform/configs/configschema" "github.com/hashicorp/terraform/states/statemgr" "github.com/hashicorp/terraform/terraform" "github.com/hashicorp/terraform/tfdiags" "github.com/mitchellh/cli" "github.com/mitchellh/colorstring" "github.com/zclconf/go-cty/cty" ) const ( DefaultWorkspaceDir = "terraform.tfstate.d" DefaultWorkspaceFile = "environment" DefaultStateFilename = "terraform.tfstate" DefaultBackupExtension = ".backup" ) // 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 // ShowDiagnostics prints diagnostic messages to the UI. ShowDiagnostics func(vals ...interface{}) // The State* paths are set from the backend config, and may be left blank // to use the defaults. If the actual paths for the local backend state are // needed, use the StatePaths method. // // 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. // Set this to "-" to disable state backup. // // StateWorkspaceDir is the path to the folder containing data for // non-default workspaces. This defaults to DefaultWorkspaceDir if not set. StatePath string StateOutPath string StateBackupPath string StateWorkspaceDir string // The OverrideState* paths are set based on per-operation CLI arguments // and will override what'd be built from the State* fields if non-empty. // While the interpretation of the State* fields depends on the active // workspace, the OverrideState* fields are always used literally. OverrideStatePath string OverrideStateOutPath string OverrideStateBackupPath string // We only want to create a single instance of a local state, so store them // here as they're loaded. states map[string]statemgr.Full // 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 // RunningInAutomation indicates that commands are being run by an // automated system rather than directly at a command prompt. // // This is a hint not to produce messages that expect that a user can // run a follow-up command, perhaps because Terraform is running in // some sort of workflow automation tool that abstracts away the // exact commands that are being run. RunningInAutomation bool // opLock locks operations opLock sync.Mutex } var _ backend.Backend = (*Local)(nil) // New returns a new initialized local backend. func New() *Local { return NewWithBackend(nil) } // NewWithBackend returns a new local backend initialized with a // dedicated backend for non-enhanced behavior. func NewWithBackend(backend backend.Backend) *Local { return &Local{ Backend: backend, } } func (b *Local) ConfigSchema() *configschema.Block { if b.Backend != nil { return b.Backend.ConfigSchema() } return &configschema.Block{ Attributes: map[string]*configschema.Attribute{ "path": { Type: cty.String, Optional: true, }, "workspace_dir": { Type: cty.String, Optional: true, }, }, } } func (b *Local) PrepareConfig(obj cty.Value) (cty.Value, tfdiags.Diagnostics) { if b.Backend != nil { return b.Backend.PrepareConfig(obj) } var diags tfdiags.Diagnostics if val := obj.GetAttr("path"); !val.IsNull() { p := val.AsString() if p == "" { diags = diags.Append(tfdiags.AttributeValue( tfdiags.Error, "Invalid local state file path", `The "path" attribute value must not be empty.`, cty.Path{cty.GetAttrStep{Name: "path"}}, )) } } if val := obj.GetAttr("workspace_dir"); !val.IsNull() { p := val.AsString() if p == "" { diags = diags.Append(tfdiags.AttributeValue( tfdiags.Error, "Invalid local workspace directory path", `The "workspace_dir" attribute value must not be empty.`, cty.Path{cty.GetAttrStep{Name: "workspace_dir"}}, )) } } return obj, diags } func (b *Local) Configure(obj cty.Value) tfdiags.Diagnostics { if b.Backend != nil { return b.Backend.Configure(obj) } var diags tfdiags.Diagnostics if val := obj.GetAttr("path"); !val.IsNull() { p := val.AsString() b.StatePath = p b.StateOutPath = p } else { b.StatePath = DefaultStateFilename b.StateOutPath = DefaultStateFilename } if val := obj.GetAttr("workspace_dir"); !val.IsNull() { p := val.AsString() b.StateWorkspaceDir = p } else { b.StateWorkspaceDir = DefaultWorkspaceDir } return diags } func (b *Local) Workspaces() ([]string, error) { // If we have a backend handling state, defer to that. if b.Backend != nil { return b.Backend.Workspaces() } // the listing always start with "default" envs := []string{backend.DefaultStateName} entries, err := ioutil.ReadDir(b.stateWorkspaceDir()) // no error if there's no envs configured if os.IsNotExist(err) { return envs, nil } if err != nil { return nil, err } var listed []string for _, entry := range entries { if entry.IsDir() { listed = append(listed, filepath.Base(entry.Name())) } } sort.Strings(listed) envs = append(envs, listed...) return envs, nil } // DeleteWorkspace removes a workspace. // // The "default" workspace cannot be removed. func (b *Local) DeleteWorkspace(name string) error { // If we have a backend handling state, defer to that. if b.Backend != nil { return b.Backend.DeleteWorkspace(name) } if name == "" { return errors.New("empty state name") } if name == backend.DefaultStateName { return errors.New("cannot delete default state") } delete(b.states, name) return os.RemoveAll(filepath.Join(b.stateWorkspaceDir(), name)) } func (b *Local) StateMgr(name string) (statemgr.Full, error) { // If we have a backend handling state, delegate to that. if b.Backend != nil { return b.Backend.StateMgr(name) } if s, ok := b.states[name]; ok { return s, nil } if err := b.createState(name); err != nil { return nil, err } statePath, stateOutPath, backupPath := b.StatePaths(name) log.Printf("[TRACE] backend/local: state manager for workspace %q will:\n - read initial snapshot from %s\n - write new snapshots to %s\n - create any backup at %s", name, statePath, stateOutPath, backupPath) s := statemgr.NewFilesystemBetweenPaths(statePath, stateOutPath) if backupPath != "" { s.SetBackupPath(backupPath) } if b.states == nil { b.states = map[string]statemgr.Full{} } b.states[name] = 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, 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 // the runninCtx is only used to block until the operation returns. runningCtx, done := context.WithCancel(context.Background()) runningOp := &backend.RunningOperation{ Context: runningCtx, } // stopCtx wraps the context passed in, and is used to signal a graceful Stop. stopCtx, stop := context.WithCancel(ctx) runningOp.Stop = stop // cancelCtx is used to cancel the operation immediately, usually // indicating that the process is exiting. cancelCtx, cancel := context.WithCancel(context.Background()) runningOp.Cancel = cancel if op.LockState { op.StateLocker = clistate.NewLocker(stopCtx, op.StateLockTimeout, b.CLI, b.Colorize()) } else { op.StateLocker = clistate.NewNoopLocker() } // Do it go func() { defer done() defer stop() defer cancel() defer b.opLock.Unlock() f(stopCtx, cancelCtx, op, runningOp) }() // Return return runningOp, nil } // opWait waits for the operation to complete, and a stop signal or a // cancelation signal. func (b *Local) opWait( doneCh <-chan struct{}, stopCtx context.Context, cancelCtx context.Context, tfCtx *terraform.Context, opStateMgr statemgr.Persister) (canceled bool) { // Wait for the operation to finish or for us to be interrupted so // we can handle it properly. select { case <-stopCtx.Done(): if b.CLI != nil { b.CLI.Output("Stopping operation...") } // try to force a PersistState just in case the process is terminated // before we can complete. if err := opStateMgr.PersistState(); err != nil { // We can't error out from here, but warn the user if there was an error. // If this isn't transient, we will catch it again below, and // attempt to save the state another way. if b.CLI != nil { b.CLI.Error(fmt.Sprintf(earlyStateWriteErrorFmt, err)) } } // Stop execution log.Println("[TRACE] backend/local: waiting for the running operation to stop") go tfCtx.Stop() select { case <-cancelCtx.Done(): log.Println("[WARN] running operation was forcefully canceled") // if the operation was canceled, we need to return immediately canceled = true case <-doneCh: log.Println("[TRACE] backend/local: graceful stop has completed") } case <-cancelCtx.Done(): // this should not be called without first attempting to stop the // operation log.Println("[ERROR] running operation canceled without Stop") canceled = true case <-doneCh: } return } // ReportResult is a helper for the common chore of setting the status of // a running operation and showing any diagnostics produced during that // operation. // // If the given diagnostics contains errors then the operation's result // will be set to backend.OperationFailure. It will be set to // backend.OperationSuccess otherwise. It will then use b.ShowDiagnostics // to show the given diagnostics before returning. // // Callers should feel free to do each of these operations separately in // more complex cases where e.g. diagnostics are interleaved with other // output, but terminating immediately after reporting error diagnostics is // common and can be expressed concisely via this method. func (b *Local) ReportResult(op *backend.RunningOperation, diags tfdiags.Diagnostics) { if diags.HasErrors() { op.Result = backend.OperationFailure } else { op.Result = backend.OperationSuccess } if b.ShowDiagnostics != nil { b.ShowDiagnostics(diags) } else { // Shouldn't generally happen, but if it does then we'll at least // make some noise in the logs to help us spot it. if len(diags) != 0 { log.Printf( "[ERROR] Local backend needs to report diagnostics but ShowDiagnostics is not set:\n%s", diags.ErrWithWarnings(), ) } } } // Colorize returns the Colorize structure that can be used for colorizing // output. This is guaranteed 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, } } // StatePaths returns the StatePath, StateOutPath, and StateBackupPath as // configured from the CLI. func (b *Local) StatePaths(name string) (stateIn, stateOut, backupOut string) { statePath := b.OverrideStatePath stateOutPath := b.OverrideStateOutPath backupPath := b.OverrideStateBackupPath isDefault := name == backend.DefaultStateName || name == "" baseDir := "" if !isDefault { baseDir = filepath.Join(b.stateWorkspaceDir(), name) } if statePath == "" { if isDefault { statePath = b.StatePath // s.StatePath applies only to the default workspace, since StateWorkspaceDir is used otherwise } if statePath == "" { statePath = filepath.Join(baseDir, DefaultStateFilename) } } if stateOutPath == "" { stateOutPath = statePath } if backupPath == "" { backupPath = b.StateBackupPath } switch backupPath { case "-": backupPath = "" case "": backupPath = stateOutPath + DefaultBackupExtension } return statePath, stateOutPath, backupPath } // PathsConflictWith returns true if any state path used by a workspace in // the receiver is the same as any state path used by the other given // local backend instance. // // This should be used when "migrating" from one local backend configuration to // another in order to avoid deleting the "old" state snapshots if they are // in the same files as the "new" state snapshots. func (b *Local) PathsConflictWith(other *Local) bool { otherPaths := map[string]struct{}{} otherWorkspaces, err := other.Workspaces() if err != nil { // If we can't enumerate the workspaces then we'll conservatively // assume that paths _do_ overlap, since we can't be certain. return true } for _, name := range otherWorkspaces { p, _, _ := other.StatePaths(name) otherPaths[p] = struct{}{} } ourWorkspaces, err := other.Workspaces() if err != nil { // If we can't enumerate the workspaces then we'll conservatively // assume that paths _do_ overlap, since we can't be certain. return true } for _, name := range ourWorkspaces { p, _, _ := b.StatePaths(name) if _, exists := otherPaths[p]; exists { return true } } return false } // this only ensures that the named directory exists func (b *Local) createState(name string) error { if name == backend.DefaultStateName { return nil } stateDir := filepath.Join(b.stateWorkspaceDir(), name) s, err := os.Stat(stateDir) if err == nil && s.IsDir() { // no need to check for os.IsNotExist, since that is covered by os.MkdirAll // which will catch the other possible errors as well. return nil } err = os.MkdirAll(stateDir, 0755) if err != nil { return err } return nil } // stateWorkspaceDir returns the directory where state environments are stored. func (b *Local) stateWorkspaceDir() string { if b.StateWorkspaceDir != "" { return b.StateWorkspaceDir } return DefaultWorkspaceDir }