terraform/terraform/eval_local.go

75 lines
1.9 KiB
Go

package terraform
import (
"fmt"
"github.com/hashicorp/hcl/v2"
"github.com/zclconf/go-cty/cty"
"github.com/hashicorp/terraform/addrs"
"github.com/hashicorp/terraform/lang"
"github.com/hashicorp/terraform/tfdiags"
)
// EvalLocal is an EvalNode implementation that evaluates the
// expression for a local value and writes it into a transient part of
// the state.
type EvalLocal struct {
Addr addrs.LocalValue
Expr hcl.Expression
}
func (n *EvalLocal) Eval(ctx EvalContext) (interface{}, error) {
var diags tfdiags.Diagnostics
// We ignore diags here because any problems we might find will be found
// again in EvaluateExpr below.
refs, _ := lang.ReferencesInExpr(n.Expr)
for _, ref := range refs {
if ref.Subject == n.Addr {
diags = diags.Append(&hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Self-referencing local value",
Detail: fmt.Sprintf("Local value %s cannot use its own result as part of its expression.", n.Addr),
Subject: ref.SourceRange.ToHCL().Ptr(),
Context: n.Expr.Range().Ptr(),
})
}
}
if diags.HasErrors() {
return nil, diags.Err()
}
val, moreDiags := ctx.EvaluateExpr(n.Expr, cty.DynamicPseudoType, nil)
diags = diags.Append(moreDiags)
if moreDiags.HasErrors() {
return nil, diags.Err()
}
state := ctx.State()
if state == nil {
return nil, fmt.Errorf("cannot write local value to nil state")
}
state.SetLocalValue(n.Addr.Absolute(ctx.Path()), val)
return nil, nil
}
// EvalDeleteLocal is an EvalNode implementation that deletes a Local value
// from the state. Locals aren't persisted, but we don't need to evaluate them
// during destroy.
type EvalDeleteLocal struct {
Addr addrs.LocalValue
}
func (n *EvalDeleteLocal) Eval(ctx EvalContext) (interface{}, error) {
state := ctx.State()
if state == nil {
return nil, nil
}
state.RemoveLocalValue(n.Addr.Absolute(ctx.Path()))
return nil, nil
}