opentofu/internal/terraform/context_validate.go
Martin Atkins 37b1413ab3 core: Handle root and child module input variables consistently
Previously we had a significant discrepancy between these two situations:
we wrote the raw root module variables directly into the EvalContext and
then applied type conversions only at expression evaluation time, while
for child modules we converted and validated the values while visiting
the variable graph node and wrote only the _final_ value into the
EvalContext.

This confusion seems to have been the root cause for #29899, where
validation rules for root module variables were being applied at the wrong
point in the process, prior to type conversion.

To fix that bug and also make similar mistakes less likely in the future,
I've made the root module variable handling more like the child module
variable handling in the following ways:
 - The "raw value" (exactly as given by the user) lives only in the graph
   node representing the variable, which mirrors how the _expression_
   for a child module variable lives in its graph node. This means that
   the flow for the two is the same except that there's no expression
   evaluation step for root module variables, because they arrive as
   constant values from the caller.
 - The set of variable values in the EvalContext is always only "final"
   values, after type conversion is complete. That in turn means we no
   longer need to do "just in time" conversion in
   evaluationStateData.GetInputVariable, and can just return the value
   exactly as stored, which is consistent with how we handle all other
   references between objects.

This diff is noisier than I'd like because of how much it takes to wire
a new argument (the raw variable values) through to the plan graph builder,
but those changes are pretty mechanical and the interesting logic lives
inside the plan graph builder itself, in NodeRootVariable, and
the shared helper functions in eval_variable.go.

While here I also took the opportunity to fix a historical API wart in
EvalContext, where SetModuleCallArguments was built to take a set of
variable values all at once but our current caller always calls with only
one at a time. That is now just SetModuleCallArgument singular, to match
with the new SetRootModuleArgument to deal with root module variables.
2022-01-10 12:26:54 -08:00

81 lines
2.6 KiB
Go

package terraform
import (
"log"
"github.com/hashicorp/terraform/internal/addrs"
"github.com/hashicorp/terraform/internal/configs"
"github.com/hashicorp/terraform/internal/states"
"github.com/hashicorp/terraform/internal/tfdiags"
"github.com/zclconf/go-cty/cty"
)
// Validate performs semantic validation of a configuration, and returns
// any warnings or errors.
//
// Syntax and structural checks are performed by the configuration loader,
// and so are not repeated here.
//
// Validate considers only the configuration and so it won't catch any
// errors caused by current values in the state, or other external information
// such as root module input variables. However, the Plan function includes
// all of the same checks as Validate, in addition to the other work it does
// to consider the previous run state and the planning options.
func (c *Context) Validate(config *configs.Config) tfdiags.Diagnostics {
defer c.acquireRun("validate")()
var diags tfdiags.Diagnostics
moreDiags := c.checkConfigDependencies(config)
diags = diags.Append(moreDiags)
// If required dependencies are not available then we'll bail early since
// otherwise we're likely to just see a bunch of other errors related to
// incompatibilities, which could be overwhelming for the user.
if diags.HasErrors() {
return diags
}
log.Printf("[DEBUG] Building and walking validate graph")
// Validate is to check if the given module is valid regardless of
// input values, current state, etc. Therefore we populate all of the
// input values with unknown values of the expected type, allowing us
// to perform a type check without assuming any particular values.
varValues := make(InputValues)
for name, variable := range config.Module.Variables {
ty := variable.Type
if ty == cty.NilType {
// Can't predict the type at all, so we'll just mark it as
// cty.DynamicVal (unknown value of cty.DynamicPseudoType).
ty = cty.DynamicPseudoType
}
varValues[name] = &InputValue{
Value: cty.UnknownVal(ty),
SourceType: ValueFromUnknown,
}
}
graph, moreDiags := ValidateGraphBuilder(&PlanGraphBuilder{
Config: config,
Plugins: c.plugins,
Validate: true,
State: states.NewState(),
RootVariableValues: varValues,
}).Build(addrs.RootModuleInstance)
diags = diags.Append(moreDiags)
if moreDiags.HasErrors() {
return diags
}
walker, walkDiags := c.walk(graph, walkValidate, &graphWalkOpts{
Config: config,
})
diags = diags.Append(walker.NonFatalDiagnostics)
diags = diags.Append(walkDiags)
if walkDiags.HasErrors() {
return diags
}
return diags
}