opentofu/repl/session.go
Martin Atkins 39e609d5fd vendor: switch to HCL 2.0 in the HCL repository
Previously we were using the experimental HCL 2 repository, but now we'll
shift over to the v2 import path within the main HCL repository as part of
actually releasing HCL 2.0 as stable.

This is a mechanical search/replace to the new import paths. It also
switches to the v2.0.0 release of HCL, which includes some new code that
Terraform didn't previously have but should not change any behavior that
matters for Terraform's purposes.

For the moment the experimental HCL2 repository is still an indirect
dependency via terraform-config-inspect, so it remains in our go.sum and
vendor directories for the moment. Because terraform-config-inspect uses
a much smaller subset of the HCL2 functionality, this does still manage
to prune the vendor directory a little. A subsequent release of
terraform-config-inspect should allow us to completely remove that old
repository in a future commit.
2019-10-02 15:10:21 -07:00

100 lines
3.0 KiB
Go

package repl
import (
"errors"
"fmt"
"strings"
"github.com/zclconf/go-cty/cty"
"github.com/hashicorp/hcl/v2"
"github.com/hashicorp/hcl/v2/hclsyntax"
"github.com/hashicorp/terraform/configs/hcl2shim"
"github.com/hashicorp/terraform/lang"
"github.com/hashicorp/terraform/tfdiags"
)
// ErrSessionExit is a special error result that should be checked for
// from Handle to signal a graceful exit.
var ErrSessionExit = errors.New("session exit")
// Session represents the state for a single REPL session.
type Session struct {
// Scope is the evaluation scope where expressions will be evaluated.
Scope *lang.Scope
}
// Handle handles a single line of input from the REPL.
//
// This is a stateful operation if a command is given (such as setting
// a variable). This function should not be called in parallel.
//
// The return value is the output and the error to show.
func (s *Session) Handle(line string) (string, bool, tfdiags.Diagnostics) {
switch {
case strings.TrimSpace(line) == "":
return "", false, nil
case strings.TrimSpace(line) == "exit":
return "", true, nil
case strings.TrimSpace(line) == "help":
ret, diags := s.handleHelp()
return ret, false, diags
default:
ret, diags := s.handleEval(line)
return ret, false, diags
}
}
func (s *Session) handleEval(line string) (string, tfdiags.Diagnostics) {
var diags tfdiags.Diagnostics
// Parse the given line as an expression
expr, parseDiags := hclsyntax.ParseExpression([]byte(line), "<console-input>", hcl.Pos{Line: 1, Column: 1})
diags = diags.Append(parseDiags)
if parseDiags.HasErrors() {
return "", diags
}
val, valDiags := s.Scope.EvalExpr(expr, cty.DynamicPseudoType)
diags = diags.Append(valDiags)
if valDiags.HasErrors() {
return "", diags
}
if !val.IsWhollyKnown() {
// FIXME: In future, once we've updated the result formatter to be
// cty-aware, we should just include unknown values as "(not yet known)"
// in the serialized result, allowing the rest (if any) to be seen.
diags = diags.Append(fmt.Errorf("Result depends on values that cannot be determined until after \"terraform apply\"."))
return "", diags
}
// Our formatter still wants an old-style raw interface{} value, so
// for now we'll just shim it.
// FIXME: Port the formatter to work with cty.Value directly.
legacyVal := hcl2shim.ConfigValueFromHCL2(val)
result, err := FormatResult(legacyVal)
if err != nil {
diags = diags.Append(err)
return "", diags
}
return result, diags
}
func (s *Session) handleHelp() (string, tfdiags.Diagnostics) {
text := `
The Terraform console allows you to experiment with Terraform interpolations.
You may access resources in the state (if you have one) just as you would
from a configuration. For example: "aws_instance.foo.id" would evaluate
to the ID of "aws_instance.foo" if it exists in your state.
Type in the interpolation to test and hit <enter> to see the result.
To exit the console, type "exit" and hit <enter>, or use Control-C or
Control-D.
`
return strings.TrimSpace(text), nil
}