opentofu/internal/terraform/transform_module_variable.go
James Bardin 684ed7505d remove synthetic default expression for variables
Now that variable evaluation checks for a nil expression the graph
transformer does not need to generate a synthetic expression for
variable defaults. This means that all default handling is now located
in one place, and we are not surprised by a configuration expression
showing up which doesn't actually exist in the configuration.

Rename nodeModuleVariable.evalModuleCallArgument to evalModuleVariable.
This method is no longer handling only the module call argument, it is
also dealing with the variable declaration defaults and validation
statements.

Add an additional tests for validation with a non-nullable variable.
2022-01-10 16:22:33 -05:00

113 lines
3.3 KiB
Go

package terraform
import (
"fmt"
"github.com/hashicorp/terraform/internal/addrs"
"github.com/hashicorp/terraform/internal/tfdiags"
"github.com/zclconf/go-cty/cty"
"github.com/hashicorp/hcl/v2"
"github.com/hashicorp/terraform/internal/configs"
)
// ModuleVariableTransformer is a GraphTransformer that adds all the variables
// in the configuration to the graph.
//
// Any "variable" block present in any non-root module is included here, even
// if a particular variable is not referenced from anywhere.
//
// The transform will produce errors if a call to a module does not conform
// to the expected set of arguments, but this transformer is not in a good
// position to return errors and so the validate walk should include specific
// steps for validating module blocks, separate from this transform.
type ModuleVariableTransformer struct {
Config *configs.Config
}
func (t *ModuleVariableTransformer) Transform(g *Graph) error {
return t.transform(g, nil, t.Config)
}
func (t *ModuleVariableTransformer) transform(g *Graph, parent, c *configs.Config) error {
// We can have no variables if we have no configuration.
if c == nil {
return nil
}
// Transform all the children first.
for _, cc := range c.Children {
if err := t.transform(g, c, cc); err != nil {
return err
}
}
// If we're processing anything other than the root module then we'll
// add graph nodes for variables defined inside. (Variables for the root
// module are dealt with in RootVariableTransformer).
// If we have a parent, we can determine if a module variable is being
// used, so we transform this.
if parent != nil {
if err := t.transformSingle(g, parent, c); err != nil {
return err
}
}
return nil
}
func (t *ModuleVariableTransformer) transformSingle(g *Graph, parent, c *configs.Config) error {
_, call := c.Path.Call()
// Find the call in the parent module configuration, so we can get the
// expressions given for each input variable at the call site.
callConfig, exists := parent.Module.ModuleCalls[call.Name]
if !exists {
// This should never happen, since it indicates an improperly-constructed
// configuration tree.
panic(fmt.Errorf("no module call block found for %s", c.Path))
}
// We need to construct a schema for the expected call arguments based on
// the configured variables in our config, which we can then use to
// decode the content of the call block.
schema := &hcl.BodySchema{}
for _, v := range c.Module.Variables {
schema.Attributes = append(schema.Attributes, hcl.AttributeSchema{
Name: v.Name,
Required: v.Default == cty.NilVal,
})
}
content, contentDiags := callConfig.Config.Content(schema)
if contentDiags.HasErrors() {
// Validation code elsewhere should deal with any errors before we
// get in here, but we'll report them out here just in case, to
// avoid crashes.
var diags tfdiags.Diagnostics
diags = diags.Append(contentDiags)
return diags.Err()
}
for _, v := range c.Module.Variables {
var expr hcl.Expression
if attr := content.Attributes[v.Name]; attr != nil {
expr = attr.Expr
}
// Add a plannable node, as the variable may expand
// during module expansion
node := &nodeExpandModuleVariable{
Addr: addrs.InputVariable{
Name: v.Name,
},
Module: c.Path,
Config: v,
Expr: expr,
}
g.Add(node)
}
return nil
}