Files
opentf/internal/command/plan.go
Martin Atkins afdfaf390d Warn when relying on non-default GODEBUG values
"GODEBUG" is a mechanism that the Go runtime forces on OpenTofu that allows
dynamic changes to various nuances of Go standard library behavior.

We cannot control when GODEBUG workarounds are added and removed from Go,
so if someone chooses to rely on them then they are likely to get broken
by a later release of OpenTofu that uses a newer version of Go. Therefore
we'd like anyone relying on these to tell us so we can try to find a more
sustainable solution to their problem early on while the workaround is
still available to them.

We also occasionally force certain GODEBUG workarounds on by default in our
official builds in anticipation of breakage caused by upstream Go changes.
In that case we'd still like to know if anyone is relying on them so that
we can remove those workarounds in a future release, but we'd prefer to
get the reports about it in an issue or discussion we'd already created
for that purpose.

This therefore introduces warning diagnostics any time something in the
"init", "plan", or "apply" commands relies on non-default GODEBUG settings.
For ones we enabled intentionally we provide a specific URL to report usage
as part of the diagnostic message, but we also have a generic message for
any GODEBUG settings the user chose to enable for themselves for reasons
we probably don't know about yet but would like to learn more about.

This is included in only that subset of commands as a compromise because
those are the commands most likely to interact with Go library features
that are affected by these workarounds -- they most commonly affect
functionality related to networking, TLS, etc -- and additional diagnostics
in these locations should not to cause breakage for anyone consuming the
machine-readable output, but there are other commands where additional
diagnostics are more likely to cause problems.

Unfortunately it isn't really possible to unit-test this because it relies
directly on information reported by the Go metrics system and there's no
facility to produce fake metrics for testing. However, Go 1.26 (which we're
currently using) there is a GODEBUG setting "netedns0=0" which causes a
warning any time OpenTofu makes a DNS request, so I've tested this manually
by running "tofu init" with that workaround enabled in a configuration that
depends on at least one provider (causing DNS lookups for the provider
registry) and seen it generate the expected warning message referring to
"netedns0".

These new warnings replace our previous quieter messages about this in
the TF_LOG=warn output, because those were only useful in situations where
GODEBUG was causing a problem that led to someone opening a bug report, but
we actually want to know of situations where GODEBUG was needed in order
for OpenTofu to _succeed_ and so for that we need more prominent messages
to let the operator know there's something they ought to report to us even
though there wasn't an error.

Signed-off-by: Martin Atkins <mart@degeneration.co.uk>
2026-04-22 17:08:25 -07:00

340 lines
13 KiB
Go

// Copyright (c) The OpenTofu Authors
// SPDX-License-Identifier: MPL-2.0
// Copyright (c) 2023 HashiCorp, Inc.
// SPDX-License-Identifier: MPL-2.0
package command
import (
"context"
"fmt"
"strings"
"github.com/opentofu/opentofu/internal/backend"
"github.com/opentofu/opentofu/internal/command/arguments"
"github.com/opentofu/opentofu/internal/command/views"
"github.com/opentofu/opentofu/internal/encryption"
"github.com/opentofu/opentofu/internal/tfdiags"
)
// PlanCommand is a Command implementation that compares a OpenTofu
// configuration to an actual infrastructure and shows the differences.
type PlanCommand struct {
Meta
}
func (c *PlanCommand) Run(rawArgs []string) int {
ctx := c.CommandContext()
// Parse and apply global view arguments
common, rawArgs := arguments.ParseView(rawArgs)
c.View.Configure(common)
// Parse and validate flags
args, closer, diags := arguments.ParsePlan(rawArgs)
defer closer()
c.View.SetShowSensitive(args.ShowSensitive)
// Instantiate the view, even if there are flag errors, so that we render
// diagnostics according to the desired view
view := views.NewPlan(args.ViewOptions, 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.ViewOptions.InputEnabled
// FIXME: the -parallelism flag is used to control the concurrency of
// OpenTofu 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
diags = diags.Append(c.providerDevOverrideRuntimeWarnings())
// Inject variables from args into meta for static evaluation
c.Meta.variableArgs = args.Vars.All()
// Load the encryption configuration
enc, encDiags := c.Encryption(ctx)
diags = diags.Append(encDiags)
if encDiags.HasErrors() {
view.Diagnostics(diags)
return 1
}
// Prepare the backend with the backend-specific arguments
be, beDiags := c.PrepareBackend(ctx, args.State, view, enc)
diags = diags.Append(beDiags)
if diags.HasErrors() {
view.Diagnostics(diags)
return 1
}
// Build the operation request
opReq, opDiags := c.OperationRequest(ctx, be, view, args.ViewOptions, args.Operation, args.OutPath, args.GenerateConfigPath, enc)
diags = diags.Append(opDiags)
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, diags := c.RunOperation(ctx, be, opReq)
// Planning is one of the operations most likely to activate Go runtime
// behavior that's affected by GODEBUG, so we'll take this opportunity
// to warn about any reliance on non-default runtime behavior so that
// hopefully folks will report problems to us while their workaround is
// still available, instead of waiting until the workaround gets removed
// in a later Go releases.
diags = diags.Append(c.godebugUsageWarnings())
view.Diagnostics(diags)
if diags.HasErrors() {
return 1
}
if op.Result != backend.OperationSuccess {
return op.Result.ExitStatus()
}
if args.DetailedExitCode && !op.PlanEmpty {
return 2
}
return op.Result.ExitStatus()
}
func (c *PlanCommand) PrepareBackend(ctx context.Context, args *arguments.State, view views.Plan, enc encryption.Encryption) (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(ctx, ".")
if diags.HasErrors() {
return nil, diags
}
// Load the backend
be, beDiags := c.Backend(ctx, &BackendOpts{
Config: backendConfig,
View: view.Backend(),
}, enc.State())
diags = diags.Append(beDiags)
if beDiags.HasErrors() {
return nil, diags
}
return be, diags
}
func (c *PlanCommand) OperationRequest(
ctx context.Context,
be backend.Enhanced,
view views.Plan,
viewOptions arguments.ViewOptions,
args *arguments.Operation,
planOutPath string,
generateConfigOut string,
enc encryption.Encryption,
) (*backend.Operation, tfdiags.Diagnostics) {
var diags tfdiags.Diagnostics
// Build the operation
opReq := c.Operation(ctx, be, view.Backend(), enc)
opReq.ConfigDir = "."
opReq.PlanMode = args.PlanMode
opReq.Hooks = view.Hooks()
opReq.PlanRefresh = args.Refresh
opReq.PlanOutPath = planOutPath
opReq.GenerateConfigOut = generateConfigOut
opReq.Targets = args.Targets
opReq.Excludes = args.Excludes
opReq.ForceReplace = args.ForceReplace
opReq.Type = backend.OperationTypePlan
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: %w", err))
return nil, diags
}
return opReq, diags
}
func (c *PlanCommand) Help() string {
helpText := `
Usage: tofu [global options] plan [options]
Generates a speculative execution plan, showing what actions OpenTofu would
take to apply the current configuration. This command will not actually
perform the planned actions.
You can optionally save the plan to a file, which you can then pass to the
"apply" command to perform exactly the actions described in the plan.
Plan Customization Options:
The following options customize how OpenTofu will produce its plan. You can
also use these options when you run "tofu apply" without passing it a saved
plan, in order to plan and apply in a single command.
-destroy Select the "destroy" planning mode, which creates a
plan to destroy all objects currently managed by this
OpenTofu configuration instead of the usual behavior.
-refresh-only Select the "refresh only" planning mode, which checks
whether remote objects still match the outcome of the
most recent OpenTofu apply but does not propose any
actions to undo any changes made outside of OpenTofu.
-refresh=false Skip checking for external changes to remote objects
while creating the plan. This can potentially make
planning faster, but at the expense of possibly
planning against a stale record of the remote system
state.
-replace=resource Force replacement of a particular resource instance
using its resource address. If the plan would've
otherwise produced an update or no-op action for this
instance, OpenTofu will plan to replace it instead.
You can use this option multiple times to replace
more than one object.
-target=resource Limit the planning operation to only the given
module, resource, or resource instance and all of its
dependencies. You can use this option multiple times
to include more than one object. This is for
exceptional use only. Cannot be used alongside the
-exclude option.
-target-file=filename Similar to -target, but specifies zero or more
resource addresses from a file.
-exclude=resource Limit the planning operation to not operate on the
given module, resource, or resource instance and all
of the resources and modules that depend on it. You
can use this option multiple times to exclude more
than one object. This is for exceptional use only.
Cannot be used together with the -target option.
-exclude-file=filename Similar to -exclude, but specifies zero or more
resource addresses from a file.
-var 'foo=bar' Set a value for one of the input variables in the
root module of the configuration. Use this option
more than once to set more than one variable.
-var-file=filename Load variable values from the given file, in addition
to the default files terraform.tfvars and
*.auto.tfvars. Use this option more than once to
include more than one variables file.
Other Options:
-compact-warnings If OpenTofu produces any warnings that are not
accompanied by errors, shows them in a more
compact form that includes only the summary
messages.
-consolidate-warnings=false If OpenTofu produces any warnings, do not
attempt to consolidate similar messages. All
locations for all warnings will be listed.
-consolidate-errors If OpenTofu produces any errors, attempt to
consolidate similar messages into a single item.
-detailed-exitcode Return detailed exit codes when the command
exits. The detailed exit codes are:
0 - Succeeded but no changes proposed
1 - Planning failed with an error
2 - Succeeded and changes are proposed
-generate-config-out=path (Experimental) If import blocks are present in
configuration, instructs OpenTofu to generate
HCL for any imported resources not already
present. The configuration is written to a new
file at PATH, which must not already exist.
OpenTofu may still attempt to write
configuration if planning fails with an error.
-input=false Disable prompting for required input variables
that are not set some other way.
-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=duration Duration to retry a state lock, such as "5s"
to represent five seconds.
-no-color Disable virtual terminal escape sequences.
-concise Disable progress-related messages.
-out=path Write a plan file to the given path. This can be
used as input to the "apply" command.
-parallelism=n Limit the number of concurrent operations.
Defaults to 10.
-state=statefile A legacy option used for the local backend only.
Refer to the local backend's documentation for
more information.
-show-sensitive If specified, sensitive values will not be
redacted in te UI output.
-json Produce output in a machine-readable JSON
format, suitable for use in text editor
integrations and other automated systems.
-json-into=out.json Produce the same output as -json, but sent directly
to the given file. This allows automation to preserve
the original human-readable output streams, while
capturing more detailed logs for machine analysis.
-deprecation=module:m Specify what type of warnings are shown.
Accepted values for "m": all, local, none.
Default: all. When "all" is selected, OpenTofu
will show the deprecation warnings for all
modules. When "local" is selected, the warns
will be shown only for the modules that are
imported with a relative path. When "none" is
selected, all the deprecation warnings will be
dropped.
`
return strings.TrimSpace(helpText)
}
func (c *PlanCommand) Synopsis() string {
return "Show changes required by the current configuration"
}