terraform/backend/local/backend_local.go

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package local
import (
"context"
"fmt"
"log"
"sort"
"github.com/hashicorp/errwrap"
"github.com/hashicorp/terraform/backend"
"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"
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"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
op.StateLocker = op.StateLocker.WithContext(context.Background())
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 diags := op.StateLocker.Lock(s, op.Type.String()); diags.HasErrors() {
return nil, nil, nil, diags
}
defer func() {
// If we're returning with errors, and thus not producing a valid
// context, we'll want to avoid leaving the workspace locked.
if diags.HasErrors() {
diags = diags.Append(op.StateLocker.Unlock())
}
}()
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
opts.Hooks = op.Hooks
terraform: ugly huge change to weave in new HCL2-oriented types Due to how deeply the configuration types go into Terraform Core, there isn't a great way to switch out to HCL2 gradually. As a consequence, this huge commit gets us from the old state to a _compilable_ new state, but does not yet attempt to fix any tests and has a number of known missing parts and bugs. We will continue to iterate on this in forthcoming commits, heading back towards passing tests and making Terraform fully-functional again. The three main goals here are: - Use the configuration models from the "configs" package instead of the older models in the "config" package, which is now deprecated and preserved only to help us write our migration tool. - Do expression inspection and evaluation using the functionality of the new "lang" package, instead of the Interpolator type and related functionality in the main "terraform" package. - Represent addresses of various objects using types in the addrs package, rather than hand-constructed strings. This is not critical to support the above, but was a big help during the implementation of these other points since it made it much more explicit what kind of address is expected in each context. Since our new packages are built to accommodate some future planned features that are not yet implemented (e.g. the "for_each" argument on resources, "count"/"for_each" on modules), and since there's still a fair amount of functionality still using old-style APIs, there is a moderate amount of shimming here to connect new assumptions with old, hopefully in a way that makes it easier to find and eliminate these shims later. I apologize in advance to the person who inevitably just found this huge commit while spelunking through the commit history.
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opts.SkipRefresh = op.Type != backend.OperationTypeRefresh && !op.PlanRefresh
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if opts.SkipRefresh {
log.Printf("[DEBUG] backend/local: skipping refresh of managed resources")
}
// 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
terraform: ugly huge change to weave in new HCL2-oriented types Due to how deeply the configuration types go into Terraform Core, there isn't a great way to switch out to HCL2 gradually. As a consequence, this huge commit gets us from the old state to a _compilable_ new state, but does not yet attempt to fix any tests and has a number of known missing parts and bugs. We will continue to iterate on this in forthcoming commits, heading back towards passing tests and making Terraform fully-functional again. The three main goals here are: - Use the configuration models from the "configs" package instead of the older models in the "config" package, which is now deprecated and preserved only to help us write our migration tool. - Do expression inspection and evaluation using the functionality of the new "lang" package, instead of the Interpolator type and related functionality in the main "terraform" package. - Represent addresses of various objects using types in the addrs package, rather than hand-constructed strings. This is not critical to support the above, but was a big help during the implementation of these other points since it made it much more explicit what kind of address is expected in each context. Since our new packages are built to accommodate some future planned features that are not yet implemented (e.g. the "for_each" argument on resources, "count"/"for_each" on modules), and since there's still a fair amount of functionality still using old-style APIs, there is a moderate amount of shimming here to connect new assumptions with old, hopefully in a way that makes it easier to find and eliminate these shims later. I apologize in advance to the person who inevitably just found this huge commit while spelunking through the commit history.
2018-04-30 19:33:53 +02:00
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)
}
terraform: ugly huge change to weave in new HCL2-oriented types Due to how deeply the configuration types go into Terraform Core, there isn't a great way to switch out to HCL2 gradually. As a consequence, this huge commit gets us from the old state to a _compilable_ new state, but does not yet attempt to fix any tests and has a number of known missing parts and bugs. We will continue to iterate on this in forthcoming commits, heading back towards passing tests and making Terraform fully-functional again. The three main goals here are: - Use the configuration models from the "configs" package instead of the older models in the "config" package, which is now deprecated and preserved only to help us write our migration tool. - Do expression inspection and evaluation using the functionality of the new "lang" package, instead of the Interpolator type and related functionality in the main "terraform" package. - Represent addresses of various objects using types in the addrs package, rather than hand-constructed strings. This is not critical to support the above, but was a big help during the implementation of these other points since it made it much more explicit what kind of address is expected in each context. Since our new packages are built to accommodate some future planned features that are not yet implemented (e.g. the "for_each" argument on resources, "count"/"for_each" on modules), and since there's still a fair amount of functionality still using old-style APIs, there is a moderate amount of shimming here to connect new assumptions with old, hopefully in a way that makes it easier to find and eliminate these shims later. I apologize in advance to the person who inevitably just found this huge commit while spelunking through the commit history.
2018-04-30 19:33:53 +02:00
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")
terraform: ugly huge change to weave in new HCL2-oriented types Due to how deeply the configuration types go into Terraform Core, there isn't a great way to switch out to HCL2 gradually. As a consequence, this huge commit gets us from the old state to a _compilable_ new state, but does not yet attempt to fix any tests and has a number of known missing parts and bugs. We will continue to iterate on this in forthcoming commits, heading back towards passing tests and making Terraform fully-functional again. The three main goals here are: - Use the configuration models from the "configs" package instead of the older models in the "config" package, which is now deprecated and preserved only to help us write our migration tool. - Do expression inspection and evaluation using the functionality of the new "lang" package, instead of the Interpolator type and related functionality in the main "terraform" package. - Represent addresses of various objects using types in the addrs package, rather than hand-constructed strings. This is not critical to support the above, but was a big help during the implementation of these other points since it made it much more explicit what kind of address is expected in each context. Since our new packages are built to accommodate some future planned features that are not yet implemented (e.g. the "for_each" argument on resources, "count"/"for_each" on modules), and since there's still a fair amount of functionality still using old-style APIs, there is a moderate amount of shimming here to connect new assumptions with old, hopefully in a way that makes it easier to find and eliminate these shims later. I apologize in advance to the person who inevitably just found this huge commit while spelunking through the commit history.
2018-04-30 19:33:53 +02:00
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"
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// state manager implementations 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
}