cloud: assert import block compatibility (#33282)

* cloud: assert import block compatibility

* check for import <> TFC compatibility during init

* imports are not in alphabetical order 🙃

---------

Co-authored-by: CJ Horton <cjhorton@hashicorp.com>

internal/cloud/backend_plan.go

@@ -20,8 +20,11 @@ import (
 	"time"
 
 	tfe "github.com/hashicorp/go-tfe"
+	version "github.com/hashicorp/go-version"
+
 	"github.com/hashicorp/terraform/internal/backend"
 	"github.com/hashicorp/terraform/internal/command/jsonformat"
+	"github.com/hashicorp/terraform/internal/configs"
 	"github.com/hashicorp/terraform/internal/genconfig"
 	"github.com/hashicorp/terraform/internal/plans"
 	"github.com/hashicorp/terraform/internal/tfdiags"
@@ -240,6 +243,7 @@ in order to capture the filesystem context the remote workspace expects:
 	if configDiags.HasErrors() {
 		return nil, fmt.Errorf("error loading config with snapshot: %w", configDiags.Errs()[0])
 	}
+
 	variables, varDiags := ParseCloudRunVariables(op.Variables, config.Module.Variables)
 
 	if varDiags.HasErrors() {
@@ -371,6 +375,39 @@ in order to capture the filesystem context the remote workspace expects:
 	return r, nil
 }
 
+// AssertImportCompatible errors if the user is attempting to use configuration-
+// driven import and the version of the agent or API is too low to support it.
+func (b *Cloud) AssertImportCompatible(config *configs.Config) error {
+	// Check TFC_RUN_ID is populated, indicating we are running in a remote TFC
+	// execution environment.
+	if len(config.Module.Import) > 0 && os.Getenv("TFC_RUN_ID") != "" {
+		// First, check the remote API version is high enough.
+		currentAPIVersion, err := version.NewVersion(b.client.RemoteAPIVersion())
+		if err != nil {
+			return fmt.Errorf("Error parsing remote API version. To proceed, please remove any import blocks from your config. Please report the following error to the Terraform team: %s", err)
+		}
+		desiredAPIVersion, _ := version.NewVersion("2.6")
+		if currentAPIVersion.LessThan(desiredAPIVersion) {
+			return fmt.Errorf("Import blocks are not supported in this version of Terraform Enterprise. Please remove any import blocks from your config or upgrade Terraform Enterprise.")
+		}
+
+		// Second, check the agent version is high enough.
+		agentEnv, isSet := os.LookupEnv("TFC_AGENT_VERSION")
+		if !isSet {
+			return fmt.Errorf("Error reading TFC agent version. To proceed, please remove any import blocks from your config. Please report the following error to the Terraform team: TFC_AGENT_VERSION not present.")
+		}
+		currentAgentVersion, err := version.NewVersion(agentEnv)
+		if err != nil {
+			return fmt.Errorf("Error parsing TFC agent version. To proceed, please remove any import blocks from your config. Please report the following error to the Terraform team: %s", err)
+		}
+		desiredAgentVersion, _ := version.NewVersion("1.10")
+		if currentAgentVersion.LessThan(desiredAgentVersion) {
+			return fmt.Errorf("Import blocks are not supported in this version of the Terraform Cloud Agent. You are using agent version %s, but this feature requires version %s. Please remove any import blocks from your config or upgrade your agent.", currentAgentVersion, desiredAgentVersion)
+		}
+	}
+	return nil
+}
+
 // renderPlanLogs reads the streamed plan JSON logs and calls the JSON Plan renderer (jsonformat.RenderPlan) to
 // render the plan output. The plan output is fetched from the redacted output endpoint.
 func (b *Cloud) renderPlanLogs(ctx context.Context, op *backend.Operation, run *tfe.Run) error {

internal/command/init.go

@@ -276,6 +276,16 @@ func (c *InitCommand) Run(args []string) int {
 		return 1
 	}
 
+	if cb, ok := back.(*cloud.Cloud); ok {
+		if c.RunningInAutomation {
+			if err := cb.AssertImportCompatible(config); err != nil {
+				diags = diags.Append(tfdiags.Sourceless(tfdiags.Error, "Compatibility error", err.Error()))
+				c.showDiagnostics(diags)
+				return 1
+			}
+		}
+	}
+
 	// Now that we have loaded all modules, check the module tree for missing providers.
 	providersOutput, providersAbort, providerDiags := c.getProviders(config, state, flagUpgrade, flagPluginPath, flagLockfile)
 	diags = diags.Append(providerDiags)