enos generate: fix slow decoding (#105)

The module generator operation was still using the old method of
decoding whereby we'd decode and validate the entire flightplan before
selecting matching scenarios. This updates it to the new lazy decoder
that only decodes matching scenarios.

Signed-off-by: Ryan Cragun <[email protected]>

Author: ryancragun

.golangci.yml

@@ -86,6 +86,7 @@ linters:
     - goconst
     # disabled for now
     - gocritic
+    - gocyclo
     # disabled for now
     - godox
     - goerr113

internal/flightplan/scenario_decoder.go

@@ -149,6 +149,14 @@ func (d *ScenarioDecoder) DecodeScenarioBlocks(ctx context.Context, blocks []*hc
 
 	scenarioBlocks := d.filterScenarioBlocks(blocks)
 	for i := range scenarioBlocks {
+		// Don't worry about decoding scenario blocks that don't match our name if we've been
+		// given a name.
+		if d.ScenarioFilter != nil && d.ScenarioFilter.Name != "" {
+			if d.ScenarioFilter.Name != scenarioBlocks[i].Name {
+				continue
+			}
+		}
+
 		if d.DecodeTarget >= DecodeTargetScenariosMatrixOnly {
 			var diags hcl.Diagnostics
 			scenarioBlocks[i].Matrix, diags = decodeMatrix(d.EvalContext, scenarioBlocks[i].Block)

internal/generate/generate.go

@@ -300,7 +300,7 @@ func (g *Generator) ensureOutDir() error {
 
 // maybeWriteTerraformSettings writes any configured "terraform" settings
 //
-//nolint:cyclop,gocyclo // writing out our terraform settings is complicated.
+//nolint:cyclop // writing out our terraform settings is complicated.
 func (g *Generator) maybeWriteTerraformSettings(rootBody *hclwrite.Body) {
 	s := g.Scenario.TerraformSetting
 	if s == nil {

internal/operation/flightplan.go

@@ -1,11 +1,8 @@
 package operation
 
 import (
-	"context"
 	"path/filepath"
 
-	"github.com/hashicorp/enos/internal/diagnostics"
-	"github.com/hashicorp/enos/internal/flightplan"
 	"github.com/hashicorp/enos/proto/hashicorp/enos/v1/pb"
 )
 
@@ -20,37 +17,3 @@ func isAbs(path string) (string, error) {
 func outDirForWorkspace(w *pb.Workspace) string {
 	return filepath.Join(w.GetFlightplan().GetBaseDir(), ".enos")
 }
-
-func decodeFlightPlan(ctx context.Context, pfp *pb.FlightPlan) (*flightplan.FlightPlan, *pb.DecodeResponse) {
-	res := &pb.DecodeResponse{
-		Diagnostics: []*pb.Diagnostic{},
-	}
-
-	dec, err := flightplan.NewDecoder(
-		flightplan.WithDecoderBaseDir(pfp.GetBaseDir()),
-		flightplan.WithDecoderFPFiles(pfp.GetEnosHcl()),
-		flightplan.WithDecoderVarFiles(pfp.GetEnosVarsHcl()),
-		flightplan.WithDecoderEnv(pfp.GetEnosVarsEnv()),
-	)
-	if err != nil {
-		res.Diagnostics = diagnostics.FromErr(err)
-
-		return nil, res
-	}
-
-	hclDiags := dec.Parse()
-	if len(hclDiags) > 0 {
-		res.Diagnostics = append(res.Diagnostics, diagnostics.FromHCL(dec.ParserFiles(), hclDiags)...)
-	}
-
-	if diagnostics.HasErrors(res.GetDiagnostics()) {
-		return nil, res
-	}
-
-	fp, hclDiags := dec.Decode(ctx)
-	if len(hclDiags) > 0 {
-		res.Diagnostics = append(res.Diagnostics, diagnostics.FromHCL(dec.ParserFiles(), hclDiags)...)
-	}
-
-	return fp, res
-}

internal/operation/runner_module_generate.go

@@ -117,33 +117,29 @@ func scenarioAndModuleGeneratorForReq(ctx context.Context, req *pb.Operation_Req
 	*flightplan.Scenario,
 	[]*pb.Diagnostic,
 ) {
-	ws := req.GetWorkspace()
-	if ws == nil {
-		return nil, nil, diagnostics.FromErr(fmt.Errorf("unable to create generator for nil workspace"))
+	filter, err := flightplan.NewScenarioFilter(
+		flightplan.WithScenarioFilterFromScenarioRef(req.GetScenario()),
+	)
+	if err != nil {
+		return nil, nil, diagnostics.FromErr(err)
 	}
 
-	s := req.GetScenario()
-	if s == nil {
-		return nil, nil, diagnostics.FromErr(fmt.Errorf("unable to create generator for nil scenario reference"))
-	}
+	fp, decRes := flightplan.DecodeProto(
+		ctx,
+		req.GetWorkspace().GetFlightplan(),
+		flightplan.DecodeTargetAll,
+		filter.Proto(),
+	)
 
-	// Decode our flight plan, find our scenario
-	fp, decRes := decodeFlightPlan(ctx, ws.GetFlightplan())
 	if diagnostics.HasFailed(
-		ws.GetTfExecCfg().GetFailOnWarnings(),
+		req.GetWorkspace().GetTfExecCfg().GetFailOnWarnings(),
 		decRes.GetDiagnostics(),
 	) {
 		return nil, nil, decRes.GetDiagnostics()
 	}
 
-	filter, err := flightplan.NewScenarioFilter(
-		flightplan.WithScenarioFilterFromScenarioRef(s),
-	)
-	if err != nil {
-		return nil, nil, diagnostics.FromErr(err)
-	}
-
-	scenarios := fp.ScenariosSelect(filter)
+	ws := req.GetWorkspace()
+	scenarios := fp.Scenarios()
 	switch len(scenarios) {
 	case 0:
 		return nil, nil, diagnostics.FromErr(fmt.Errorf("no matching scenarios found"))

version/version.go

@@ -14,7 +14,7 @@ var (
 	//
 	// Version must conform to the format expected by github.com/hashicorp/go-version
 	// for tests to work.
-	Version = "0.0.20"
+	Version = "0.0.21"
 
 	// VersionPrerelease is a pre-release marker for the version. If this is ""
 	// (empty string) then it means that it is a final release. Otherwise, this