opentofu/terraform/eval_output.go
Martin Atkins c937c06a03 terraform: ugly huge change to weave in new HCL2-oriented types
Due to how deeply the configuration types go into Terraform Core, there
isn't a great way to switch out to HCL2 gradually. As a consequence, this
huge commit gets us from the old state to a _compilable_ new state, but
does not yet attempt to fix any tests and has a number of known missing
parts and bugs. We will continue to iterate on this in forthcoming
commits, heading back towards passing tests and making Terraform
fully-functional again.

The three main goals here are:
- Use the configuration models from the "configs" package instead of the
  older models in the "config" package, which is now deprecated and
  preserved only to help us write our migration tool.
- Do expression inspection and evaluation using the functionality of the
  new "lang" package, instead of the Interpolator type and related
  functionality in the main "terraform" package.
- Represent addresses of various objects using types in the addrs package,
  rather than hand-constructed strings. This is not critical to support
  the above, but was a big help during the implementation of these other
  points since it made it much more explicit what kind of address is
  expected in each context.

Since our new packages are built to accommodate some future planned
features that are not yet implemented (e.g. the "for_each" argument on
resources, "count"/"for_each" on modules), and since there's still a fair
amount of functionality still using old-style APIs, there is a moderate
amount of shimming here to connect new assumptions with old, hopefully in
a way that makes it easier to find and eliminate these shims later.

I apologize in advance to the person who inevitably just found this huge
commit while spelunking through the commit history.
2018-10-16 18:46:46 -07:00

139 lines
3.9 KiB
Go

package terraform
import (
"fmt"
"log"
"github.com/hashicorp/hcl2/hcl"
"github.com/hashicorp/terraform/addrs"
"github.com/hashicorp/terraform/config"
"github.com/hashicorp/terraform/config/hcl2shim"
"github.com/zclconf/go-cty/cty"
"github.com/zclconf/go-cty/cty/gocty"
)
// EvalDeleteOutput is an EvalNode implementation that deletes an output
// from the state.
type EvalDeleteOutput struct {
Addr addrs.OutputValue
}
// TODO: test
func (n *EvalDeleteOutput) Eval(ctx EvalContext) (interface{}, error) {
state, lock := ctx.State()
if state == nil {
return nil, nil
}
// Get a write lock so we can access this instance
lock.Lock()
defer lock.Unlock()
// Look for the module state. If we don't have one, create it.
mod := state.ModuleByPath(ctx.Path())
if mod == nil {
return nil, nil
}
delete(mod.Outputs, n.Addr.Name)
return nil, nil
}
// EvalWriteOutput is an EvalNode implementation that writes the output
// for the given name to the current state.
type EvalWriteOutput struct {
Addr addrs.OutputValue
Sensitive bool
Expr hcl.Expression
// ContinueOnErr allows interpolation to fail during Input
ContinueOnErr bool
}
// TODO: test
func (n *EvalWriteOutput) Eval(ctx EvalContext) (interface{}, error) {
// This has to run before we have a state lock, since evaluation also
// reads the state
val, diags := ctx.EvaluateExpr(n.Expr, cty.DynamicPseudoType, nil)
// We'll handle errors below, after we have loaded the module.
state, lock := ctx.State()
if state == nil {
return nil, fmt.Errorf("cannot write state to nil state")
}
// Get a write lock so we can access this instance
lock.Lock()
defer lock.Unlock()
// Look for the module state. If we don't have one, create it.
mod := state.ModuleByPath(ctx.Path())
if mod == nil {
mod = state.AddModule(ctx.Path())
}
// handling the interpolation error
if diags.HasErrors() {
if n.ContinueOnErr || flagWarnOutputErrors {
log.Printf("[ERROR] Output interpolation %q failed: %s", n.Addr.Name, diags.Err())
// if we're continuing, make sure the output is included, and
// marked as unknown
mod.Outputs[n.Addr.Name] = &OutputState{
Type: "string",
Value: config.UnknownVariableValue,
}
return nil, EvalEarlyExitError{}
}
return nil, diags.Err()
}
ty := val.Type()
switch {
case ty.IsPrimitiveType():
// For now we record all primitive types as strings, for compatibility
// with our existing state formats.
// FIXME: Revise the state format to support any type.
var valueTyped string
switch {
case !val.IsKnown():
// Legacy handling of unknown values as a special string.
valueTyped = config.UnknownVariableValue
case val.IsNull():
// State doesn't currently support null, so we'll save as empty string.
valueTyped = ""
default:
err := gocty.FromCtyValue(val, &valueTyped)
if err != nil {
// Should never happen, because all primitives can convert to string.
return nil, fmt.Errorf("cannot marshal %#v for storage in state: %s", err)
}
}
mod.Outputs[n.Addr.Name] = &OutputState{
Type: "string",
Sensitive: n.Sensitive,
Value: valueTyped,
}
case ty.IsListType() || ty.IsTupleType() || ty.IsSetType():
// For now we'll use our legacy storage forms for list-like types.
// This produces a []interface{}.
valueTyped := hcl2shim.ConfigValueFromHCL2(val)
mod.Outputs[n.Addr.Name] = &OutputState{
Type: "list",
Sensitive: n.Sensitive,
Value: valueTyped,
}
case ty.IsMapType() || ty.IsObjectType():
// For now we'll use our legacy storage forms for map-like types.
// This produces a map[string]interface{}.
valueTyped := hcl2shim.ConfigValueFromHCL2(val)
mod.Outputs[n.Addr.Name] = &OutputState{
Type: "map",
Sensitive: n.Sensitive,
Value: valueTyped,
}
default:
return nil, fmt.Errorf("output %s is not a valid type (%s)", n.Addr.Name, ty.FriendlyName())
}
return nil, nil
}