terraform/terraform/node_module_variable.go

261 lines
8.1 KiB
Go

package terraform
import (
"fmt"
"log"
"github.com/hashicorp/hcl/v2"
"github.com/hashicorp/terraform/addrs"
"github.com/hashicorp/terraform/configs"
"github.com/hashicorp/terraform/dag"
"github.com/hashicorp/terraform/instances"
"github.com/hashicorp/terraform/lang"
"github.com/hashicorp/terraform/tfdiags"
"github.com/zclconf/go-cty/cty"
"github.com/zclconf/go-cty/cty/convert"
)
// nodeExpandModuleVariable is the placeholder for an variable that has not yet had
// its module path expanded.
type nodeExpandModuleVariable struct {
Addr addrs.InputVariable
Module addrs.Module
Config *configs.Variable
Expr hcl.Expression
}
var (
_ GraphNodeDynamicExpandable = (*nodeExpandModuleVariable)(nil)
_ GraphNodeReferenceOutside = (*nodeExpandModuleVariable)(nil)
_ GraphNodeReferenceable = (*nodeExpandModuleVariable)(nil)
_ GraphNodeReferencer = (*nodeExpandModuleVariable)(nil)
_ graphNodeTemporaryValue = (*nodeExpandModuleVariable)(nil)
_ graphNodeExpandsInstances = (*nodeExpandModuleVariable)(nil)
)
func (n *nodeExpandModuleVariable) expandsInstances() {}
func (n *nodeExpandModuleVariable) temporaryValue() bool {
return true
}
func (n *nodeExpandModuleVariable) DynamicExpand(ctx EvalContext) (*Graph, error) {
var g Graph
expander := ctx.InstanceExpander()
for _, module := range expander.ExpandModule(n.Module) {
o := &nodeModuleVariable{
Addr: n.Addr.Absolute(module),
Config: n.Config,
Expr: n.Expr,
ModuleInstance: module,
}
g.Add(o)
}
return &g, nil
}
func (n *nodeExpandModuleVariable) Name() string {
return fmt.Sprintf("%s.%s (expand)", n.Module, n.Addr.String())
}
// GraphNodeModulePath
func (n *nodeExpandModuleVariable) ModulePath() addrs.Module {
return n.Module
}
// GraphNodeReferencer
func (n *nodeExpandModuleVariable) References() []*addrs.Reference {
// If we have no value expression, we cannot depend on anything.
if n.Expr == nil {
return nil
}
// Variables in the root don't depend on anything, because their values
// are gathered prior to the graph walk and recorded in the context.
if len(n.Module) == 0 {
return nil
}
// Otherwise, we depend on anything referenced by our value expression.
// We ignore diagnostics here under the assumption that we'll re-eval
// all these things later and catch them then; for our purposes here,
// we only care about valid references.
//
// Due to our GraphNodeReferenceOutside implementation, the addresses
// returned by this function are interpreted in the _parent_ module from
// where our associated variable was declared, which is correct because
// our value expression is assigned within a "module" block in the parent
// module.
refs, _ := lang.ReferencesInExpr(n.Expr)
return refs
}
// GraphNodeReferenceOutside implementation
func (n *nodeExpandModuleVariable) ReferenceOutside() (selfPath, referencePath addrs.Module) {
return n.Module, n.Module.Parent()
}
// GraphNodeReferenceable
func (n *nodeExpandModuleVariable) ReferenceableAddrs() []addrs.Referenceable {
return []addrs.Referenceable{n.Addr}
}
// nodeModuleVariable represents a module variable input during
// the apply step.
type nodeModuleVariable struct {
Addr addrs.AbsInputVariableInstance
Config *configs.Variable // Config is the var in the config
Expr hcl.Expression // Expr is the value expression given in the call
// ModuleInstance in order to create the appropriate context for evaluating
// ModuleCallArguments, ex. so count.index and each.key can resolve
ModuleInstance addrs.ModuleInstance
}
// Ensure that we are implementing all of the interfaces we think we are
// implementing.
var (
_ GraphNodeModuleInstance = (*nodeModuleVariable)(nil)
_ GraphNodeExecutable = (*nodeModuleVariable)(nil)
_ graphNodeTemporaryValue = (*nodeModuleVariable)(nil)
_ dag.GraphNodeDotter = (*nodeModuleVariable)(nil)
)
func (n *nodeModuleVariable) temporaryValue() bool {
return true
}
func (n *nodeModuleVariable) Name() string {
return n.Addr.String()
}
// GraphNodeModuleInstance
func (n *nodeModuleVariable) Path() addrs.ModuleInstance {
// We execute in the parent scope (above our own module) because
// expressions in our value are resolved in that context.
return n.Addr.Module.Parent()
}
// GraphNodeModulePath
func (n *nodeModuleVariable) ModulePath() addrs.Module {
return n.Addr.Module.Module()
}
// GraphNodeExecutable
func (n *nodeModuleVariable) Execute(ctx EvalContext, op walkOperation) (diags tfdiags.Diagnostics) {
// If we have no value, do nothing
if n.Expr == nil {
return nil
}
// Otherwise, interpolate the value of this variable and set it
// within the variables mapping.
var vals map[string]cty.Value
var err error
switch op {
case walkValidate:
vals, err = n.evalModuleCallArgument(ctx, true)
diags = diags.Append(err)
if diags.HasErrors() {
return diags
}
default:
vals, err = n.evalModuleCallArgument(ctx, false)
diags = diags.Append(err)
if diags.HasErrors() {
return diags
}
}
// Set values for arguments of a child module call, for later retrieval
// during expression evaluation.
_, call := n.Addr.Module.CallInstance()
ctx.SetModuleCallArguments(call, vals)
return evalVariableValidations(n.Addr, n.Config, n.Expr, ctx)
}
// dag.GraphNodeDotter impl.
func (n *nodeModuleVariable) DotNode(name string, opts *dag.DotOpts) *dag.DotNode {
return &dag.DotNode{
Name: name,
Attrs: map[string]string{
"label": n.Name(),
"shape": "note",
},
}
}
// evalModuleCallArgument produces the value for a particular variable as will
// be used by a child module instance.
//
// The result is written into a map, with its key set to the local name of the
// variable, disregarding the module instance address. A map is returned instead
// of a single value as a result of trying to be convenient for use with
// EvalContext.SetModuleCallArguments, which expects a map to merge in with any
// existing arguments.
//
// validateOnly indicates that this evaluation is only for config
// validation, and we will not have any expansion module instance
// repetition data.
func (n *nodeModuleVariable) evalModuleCallArgument(ctx EvalContext, validateOnly bool) (map[string]cty.Value, error) {
wantType := n.Config.Type
name := n.Addr.Variable.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
}
var moduleInstanceRepetitionData instances.RepetitionData
switch {
case validateOnly:
// the instance expander does not track unknown expansion values, so we
// have to assume all RepetitionData is unknown.
moduleInstanceRepetitionData = instances.RepetitionData{
CountIndex: cty.UnknownVal(cty.Number),
EachKey: cty.UnknownVal(cty.String),
EachValue: cty.DynamicVal,
}
default:
// Get the repetition data for this module instance,
// so we can create the appropriate scope for evaluating our expression
moduleInstanceRepetitionData = ctx.InstanceExpander().GetModuleInstanceRepetitionData(n.ModuleInstance)
}
scope := ctx.EvaluationScope(nil, moduleInstanceRepetitionData)
val, diags := scope.EvalExpr(expr, cty.DynamicPseudoType)
// We intentionally passed DynamicPseudoType to EvalExpr 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)
}
vals := make(map[string]cty.Value)
vals[name] = val
return vals, diags.ErrWithWarnings()
}