terraform/internal/command/refresh.go
Martin Atkins b0b8d4aa6f states: Only track root module output values
For a very long time we've had an annoying discrepancy between the
in-memory state model and our state snapshot format where the in-memory
format stores output values for all modules whereas the snapshot format
only tracks the root module output values because those are all we
actually need to preserve between runs.

That design wart was a result of us using the state both as an internal
and an external artifact, due to having nowhere else to store the
transient values of non-root module output values while Terraform Core
does its work.

We now have namedvals.State to internally track all of the throwaway
results from named values that don't need to persist between runs, so now
we'll use that for our internal work instead and reserve the states.State
model only for the data that we will preserve between runs in state
snapshots.

The namedvals internal model isn't really designed to support enumerating
all of the output values for a particular module call, but our expression
evaluator currently depends on being able to do that and so we have a
temporary inefficient implementation of that which just scans the entire
table of values as a stopgap just to avoid this commit growing even larger
than it already is. In a future commit we'll rework the evaluator to
support the PartialEval mode and at the same time move the responsiblity
for enumerating all of the output values into the evaluator itself, since
it should be able to determine what it's expecting by analyzing the
configuration rather than just by trusting that earlier evaluation has
completed correctly.

Because our legacy state string serialization previously included output
values for all modules, some of our context tests were accidentally
depending on the implementation detail of how those got stored internally.
Those tests are updated here to test only the data that is a real part
of Terraform Core's result, by ensuring that the relevant data appears
somewhere either in a root output value or in a resource attribute.
2023-12-07 09:56:36 -08:00

230 lines
7.2 KiB
Go

// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: BUSL-1.1
package command
import (
"fmt"
"strings"
"github.com/hashicorp/terraform/internal/backend"
"github.com/hashicorp/terraform/internal/command/arguments"
"github.com/hashicorp/terraform/internal/command/views"
"github.com/hashicorp/terraform/internal/tfdiags"
)
// RefreshCommand is a cli.Command implementation that refreshes the state
// file.
type RefreshCommand struct {
Meta
}
func (c *RefreshCommand) Run(rawArgs []string) int {
var diags tfdiags.Diagnostics
// Parse and apply global view arguments
common, rawArgs := arguments.ParseView(rawArgs)
c.View.Configure(common)
// Propagate -no-color for legacy use of Ui. The remote backend and
// cloud package use this; it should be removed when/if they are
// migrated to views.
c.Meta.color = !common.NoColor
c.Meta.Color = c.Meta.color
// Parse and validate flags
args, diags := arguments.ParseRefresh(rawArgs)
// Instantiate the view, even if there are flag errors, so that we render
// diagnostics according to the desired view
view := views.NewRefresh(args.ViewType, c.View)
if diags.HasErrors() {
view.Diagnostics(diags)
view.HelpPrompt()
return 1
}
// Check for user-supplied plugin path
var err error
if c.pluginPath, err = c.loadPluginPath(); err != nil {
diags = diags.Append(err)
view.Diagnostics(diags)
return 1
}
// FIXME: the -input flag value is needed to initialize the backend and the
// operation, but there is no clear path to pass this value down, so we
// continue to mutate the Meta object state for now.
c.Meta.input = args.InputEnabled
// FIXME: the -parallelism flag is used to control the concurrency of
// Terraform operations. At the moment, this value is used both to
// initialize the backend via the ContextOpts field inside CLIOpts, and to
// set a largely unused field on the Operation request. Again, there is no
// clear path to pass this value down, so we continue to mutate the Meta
// object state for now.
c.Meta.parallelism = args.Operation.Parallelism
// Prepare the backend with the backend-specific arguments
be, beDiags := c.PrepareBackend(args.State, args.ViewType)
diags = diags.Append(beDiags)
if diags.HasErrors() {
view.Diagnostics(diags)
return 1
}
// Build the operation request
opReq, opDiags := c.OperationRequest(be, view, args.ViewType, args.Operation)
diags = diags.Append(opDiags)
if diags.HasErrors() {
view.Diagnostics(diags)
return 1
}
// Collect variable value and add them to the operation request
diags = diags.Append(c.GatherVariables(opReq, args.Vars))
if diags.HasErrors() {
view.Diagnostics(diags)
return 1
}
// Before we delegate to the backend, we'll print any warning diagnostics
// we've accumulated here, since the backend will start fresh with its own
// diagnostics.
view.Diagnostics(diags)
diags = nil
// Perform the operation
op, err := c.RunOperation(be, opReq)
if err != nil {
diags = diags.Append(err)
view.Diagnostics(diags)
return 1
}
if op.State != nil {
view.Outputs(op.State.RootOutputValues)
}
return op.Result.ExitStatus()
}
func (c *RefreshCommand) PrepareBackend(args *arguments.State, viewType arguments.ViewType) (backend.Enhanced, tfdiags.Diagnostics) {
// FIXME: we need to apply the state arguments to the meta object here
// because they are later used when initializing the backend. Carving a
// path to pass these arguments to the functions that need them is
// difficult but would make their use easier to understand.
c.Meta.applyStateArguments(args)
backendConfig, diags := c.loadBackendConfig(".")
if diags.HasErrors() {
return nil, diags
}
// Load the backend
be, beDiags := c.Backend(&BackendOpts{
Config: backendConfig,
ViewType: viewType,
})
diags = diags.Append(beDiags)
if beDiags.HasErrors() {
return nil, diags
}
return be, diags
}
func (c *RefreshCommand) OperationRequest(be backend.Enhanced, view views.Refresh, viewType arguments.ViewType, args *arguments.Operation,
) (*backend.Operation, tfdiags.Diagnostics) {
var diags tfdiags.Diagnostics
// Build the operation
opReq := c.Operation(be, viewType)
opReq.ConfigDir = "."
opReq.Hooks = view.Hooks()
opReq.Targets = args.Targets
opReq.Type = backend.OperationTypeRefresh
opReq.View = view.Operation()
var err error
opReq.ConfigLoader, err = c.initConfigLoader()
if err != nil {
diags = diags.Append(fmt.Errorf("Failed to initialize config loader: %s", err))
return nil, diags
}
return opReq, diags
}
func (c *RefreshCommand) GatherVariables(opReq *backend.Operation, args *arguments.Vars) tfdiags.Diagnostics {
var diags tfdiags.Diagnostics
// FIXME the arguments package currently trivially gathers variable related
// arguments in a heterogenous slice, in order to minimize the number of
// code paths gathering variables during the transition to this structure.
// Once all commands that gather variables have been converted to this
// structure, we could move the variable gathering code to the arguments
// package directly, removing this shim layer.
varArgs := args.All()
items := make([]rawFlag, len(varArgs))
for i := range varArgs {
items[i].Name = varArgs[i].Name
items[i].Value = varArgs[i].Value
}
c.Meta.variableArgs = rawFlags{items: &items}
opReq.Variables, diags = c.collectVariableValues()
return diags
}
func (c *RefreshCommand) Help() string {
helpText := `
Usage: terraform [global options] refresh [options]
Update the state file of your infrastructure with metadata that matches
the physical resources they are tracking.
This will not modify your infrastructure, but it can modify your
state file to update metadata. This metadata might cause new changes
to occur when you generate a plan or call apply next.
Options:
-compact-warnings If Terraform produces any warnings that are not
accompanied by errors, show them in a more compact form
that includes only the summary messages.
-input=true Ask for input for variables if not directly set.
-lock=false Don't hold a state lock during the operation. This is
dangerous if others might concurrently run commands
against the same workspace.
-lock-timeout=0s Duration to retry a state lock.
-no-color If specified, output won't contain any color.
-parallelism=n Limit the number of concurrent operations. Defaults to 10.
-target=resource Resource to target. Operation will be limited to this
resource and its dependencies. This flag can be used
multiple times.
-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.
-state, state-out, and -backup are legacy options supported for the local
backend only. For more information, see the local backend's documentation.
`
return strings.TrimSpace(helpText)
}
func (c *RefreshCommand) Synopsis() string {
return "Update the state to match remote systems"
}