terraform/terraform/eval_variable.go

207 lines
6.5 KiB
Go

package terraform
import (
"fmt"
"log"
"reflect"
"strings"
"github.com/hashicorp/hcl2/hcl"
"github.com/hashicorp/terraform/configs"
"github.com/hashicorp/terraform/addrs"
"github.com/hashicorp/terraform/config"
"github.com/hashicorp/terraform/config/module"
"github.com/zclconf/go-cty/cty"
"github.com/zclconf/go-cty/cty/convert"
)
// EvalTypeCheckVariable is an EvalNode which ensures that the variable
// values which are assigned as inputs to a module (including the root)
// match the types which are either declared for the variables explicitly
// or inferred from the default values.
//
// In order to achieve this three things are required:
// - a map of the proposed variable values
// - the configuration tree of the module in which the variable is
// declared
// - the path to the module (so we know which part of the tree to
// compare the values against).
type EvalTypeCheckVariable struct {
Variables map[string]interface{}
ModulePath []string
ModuleTree *module.Tree
}
func (n *EvalTypeCheckVariable) Eval(ctx EvalContext) (interface{}, error) {
currentTree := n.ModuleTree
for _, pathComponent := range n.ModulePath[1:] {
currentTree = currentTree.Children()[pathComponent]
}
targetConfig := currentTree.Config()
prototypes := make(map[string]config.VariableType)
for _, variable := range targetConfig.Variables {
prototypes[variable.Name] = variable.Type()
}
// Only display a module in an error message if we are not in the root module
modulePathDescription := fmt.Sprintf(" in module %s", strings.Join(n.ModulePath[1:], "."))
if len(n.ModulePath) == 1 {
modulePathDescription = ""
}
for name, declaredType := range prototypes {
proposedValue, ok := n.Variables[name]
if !ok {
// This means the default value should be used as no overriding value
// has been set. Therefore we should continue as no check is necessary.
continue
}
if proposedValue == config.UnknownVariableValue {
continue
}
switch declaredType {
case config.VariableTypeString:
switch proposedValue.(type) {
case string:
continue
default:
return nil, fmt.Errorf("variable %s%s should be type %s, got %s",
name, modulePathDescription, declaredType.Printable(), hclTypeName(proposedValue))
}
case config.VariableTypeMap:
switch proposedValue.(type) {
case map[string]interface{}:
continue
default:
return nil, fmt.Errorf("variable %s%s should be type %s, got %s",
name, modulePathDescription, declaredType.Printable(), hclTypeName(proposedValue))
}
case config.VariableTypeList:
switch proposedValue.(type) {
case []interface{}:
continue
default:
return nil, fmt.Errorf("variable %s%s should be type %s, got %s",
name, modulePathDescription, declaredType.Printable(), hclTypeName(proposedValue))
}
default:
return nil, fmt.Errorf("variable %s%s should be type %s, got type string",
name, modulePathDescription, declaredType.Printable())
}
}
return nil, nil
}
// EvalSetModuleCallArguments is an EvalNode implementation that sets values
// for arguments of a child module call, for later retrieval during
// expression evaluation.
type EvalSetModuleCallArguments struct {
Module addrs.ModuleCallInstance
Values map[string]cty.Value
}
// TODO: test
func (n *EvalSetModuleCallArguments) Eval(ctx EvalContext) (interface{}, error) {
ctx.SetModuleCallArguments(n.Module, n.Values)
return nil, nil
}
// EvalModuleCallArgument is an EvalNode implementation that produces the value
// for a particular variable as will be used by a child module instance.
//
// The result is written into the map given in Values, with its key
// set to the local name of the variable, disregarding the module instance
// address. Any existing values in that map are deleted first. This weird
// interface is a result of trying to be convenient for use with
// EvalContext.SetModuleCallArguments, which expects a map to merge in with
// any existing arguments.
type EvalModuleCallArgument struct {
Addr addrs.InputVariable
Config *configs.Variable
Expr hcl.Expression
// If this flag is set, any diagnostics are discarded and this operation
// will always succeed, though may produce an unknown value in the
// event of an error.
IgnoreDiagnostics bool
Values map[string]cty.Value
}
func (n *EvalModuleCallArgument) Eval(ctx EvalContext) (interface{}, error) {
// Clear out the existing mapping
for k := range n.Values {
delete(n.Values, k)
}
wantType := n.Config.Type
name := n.Addr.Name
expr := n.Expr
if expr == nil {
// Should never happen, but we'll bail out early here rather than
// crash in case it does. We set no value at all in this case,
// making a subsequent call to EvalContext.SetModuleCallArguments
// a no-op.
log.Printf("[ERROR] attempt to evaluate %s with nil expression", n.Addr.String())
return nil, nil
}
val, diags := ctx.EvaluateExpr(expr, cty.DynamicPseudoType, nil)
// We intentionally passed DynamicPseudoType to EvaluateExpr above because
// now we can do our own local type conversion and produce an error message
// with better context if it fails.
var convErr error
val, convErr = convert.Convert(val, wantType)
if convErr != nil {
diags = diags.Append(&hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid value for module argument",
Detail: fmt.Sprintf(
"The given value is not suitable for child module variable %q defined at %s: %s.",
name, n.Config.DeclRange.String(), convErr,
),
Subject: expr.Range().Ptr(),
})
// We'll return a placeholder unknown value to avoid producing
// redundant downstream errors.
val = cty.UnknownVal(wantType)
}
n.Values[name] = val
if n.IgnoreDiagnostics {
return nil, nil
}
return nil, diags.ErrWithWarnings()
}
// hclTypeName returns the name of the type that would represent this value in
// a config file, or falls back to the Go type name if there's no corresponding
// HCL type. This is used for formatted output, not for comparing types.
func hclTypeName(i interface{}) string {
switch k := reflect.Indirect(reflect.ValueOf(i)).Kind(); k {
case reflect.Bool:
return "boolean"
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64,
reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32,
reflect.Uint64, reflect.Uintptr, reflect.Float32, reflect.Float64:
return "number"
case reflect.Array, reflect.Slice:
return "list"
case reflect.Map:
return "map"
case reflect.String:
return "string"
default:
// fall back to the Go type if there's no match
return k.String()
}
}