Adding var_groups spec

code/go/internal/validator/semantic/validate_var_groups.go

@@ -0,0 +1,200 @@
+// Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+// or more contributor license agreements. Licensed under the Elastic License;
+// you may not use this file except in compliance with the Elastic License.
+
+package semantic
+
+import (
+	"fmt"
+	"io/fs"
+	"path"
+
+	"gopkg.in/yaml.v3"
+
+	"github.com/elastic/package-spec/v3/code/go/internal/fspath"
+	"github.com/elastic/package-spec/v3/code/go/pkg/specerrors"
+)
+
+// ValidateVarGroups validates var_groups definitions in manifests.
+// It checks that:
+// - vars referenced in options[].vars exist in the manifest vars array
+// - var_group names are unique
+// - option names within each var_group are unique
+// - vars in a var_group must not have required: true (requirement is controlled by var_group)
+func ValidateVarGroups(fsys fspath.FS) specerrors.ValidationErrors {
+	// Validate main manifest.
+	d, err := fs.ReadFile(fsys, "manifest.yml")
+	if err != nil {
+		return specerrors.ValidationErrors{specerrors.NewStructuredErrorf("failed to read file \"%s\": %w", fsys.Path("manifest.yml"), err)}
+	}
+
+	var manifest varGroupsManifest
+	err = yaml.Unmarshal(d, &manifest)
+	if err != nil {
+		return specerrors.ValidationErrors{specerrors.NewStructuredErrorf("file \"%s\" is invalid: failed to parse manifest: %w", fsys.Path("manifest.yml"), err)}
+	}
+	errs := validateVarGroupsManifest(fsys.Path("manifest.yml"), manifest)
+
+	// Validate data stream manifests.
+	dataStreams, err := listDataStreams(fsys)
+	if err != nil {
+		return specerrors.ValidationErrors{specerrors.NewStructuredErrorf("failed to list data streams: %w", err)}
+	}
+	for _, ds := range dataStreams {
+		errs = append(errs, validateDataStreamVarGroups(fsys, path.Join("data_stream", ds, "manifest.yml"), manifest)...)
+	}
+
+	return errs
+}
+
+type varGroupsManifestVar struct {
+	Name     string `yaml:"name"`
+	Required bool   `yaml:"required"`
+}
+
+type varGroupOption struct {
+	Name string   `yaml:"name"`
+	Vars []string `yaml:"vars"`
+}
+
+type varGroup struct {
+	Name     string           `yaml:"name"`
+	Required bool             `yaml:"required"`
+	Options  []varGroupOption `yaml:"options"`
+}
+
+type varGroupsManifest struct {
+	Vars            []varGroupsManifestVar `yaml:"vars"`
+	VarGroups       []varGroup             `yaml:"var_groups"`
+	PolicyTemplates []struct {
+		Vars   []varGroupsManifestVar `yaml:"vars"`
+		Inputs []struct {
+			Vars []varGroupsManifestVar `yaml:"vars"`
+		} `yaml:"inputs"`
+	} `yaml:"policy_templates"`
+}
+
+type varGroupsStream struct {
+	Title     string                 `yaml:"title"`
+	Input     string                 `yaml:"input"`
+	Vars      []varGroupsManifestVar `yaml:"vars"`
+	VarGroups []varGroup             `yaml:"var_groups"`
+}
+
+type varGroupsDataStreamManifest struct {
+	Streams []varGroupsStream `yaml:"streams"`
+}
+
+func validateVarGroupsManifest(filePath string, manifest varGroupsManifest) specerrors.ValidationErrors {
+	var errs specerrors.ValidationErrors
+
+	// Collect all available vars from package, policy templates, and inputs
+	var availableVars []varGroupsManifestVar
+	availableVars = append(availableVars, manifest.Vars...)
+	for _, template := range manifest.PolicyTemplates {
+		availableVars = append(availableVars, template.Vars...)
+		for _, input := range template.Inputs {
+			availableVars = append(availableVars, input.Vars...)
+		}
+	}
+
+	errs = append(errs, validateVarGroups(filePath, manifest.VarGroups, availableVars)...)
+
+	return errs
+}
+
+func validateDataStreamVarGroups(fsys fspath.FS, filePath string, pkgManifest varGroupsManifest) specerrors.ValidationErrors {
+	d, err := fs.ReadFile(fsys, filePath)
+	if err != nil {
+		// File might not exist, which is fine
+		return nil
+	}
+
+	var manifest varGroupsDataStreamManifest
+	err = yaml.Unmarshal(d, &manifest)
+	if err != nil {
+		return specerrors.ValidationErrors{specerrors.NewStructuredErrorf("file \"%s\" is invalid: failed to parse manifest: %w", fsys.Path(filePath), err)}
+	}
+
+	var errs specerrors.ValidationErrors
+
+	// Validate var_groups in each stream
+	for i, stream := range manifest.Streams {
+		if len(stream.VarGroups) == 0 {
+			continue
+		}
+
+		// Collect available vars from both package manifest and stream-level vars
+		var availableVars []varGroupsManifestVar
+		availableVars = append(availableVars, pkgManifest.Vars...)
+		availableVars = append(availableVars, stream.Vars...)
+
+		streamID := stream.Title
+		if streamID == "" {
+			streamID = stream.Input
+		}
+		if streamID == "" {
+			streamID = fmt.Sprintf("stream[%d]", i)
+		}
+
+		streamErrs := validateVarGroups(
+			fmt.Sprintf("%s (stream: %s)", fsys.Path(filePath), streamID),
+			stream.VarGroups,
+			availableVars,
+		)
+		errs = append(errs, streamErrs...)
+	}
+
+	return errs
+}
+
+func validateVarGroups(filePath string, varGroups []varGroup, availableVars []varGroupsManifestVar) specerrors.ValidationErrors {
+	var errs specerrors.ValidationErrors
+
+	// Build a map for quick var lookup
+	varMap := make(map[string]varGroupsManifestVar)
+	for _, v := range availableVars {
+		varMap[v.Name] = v
+	}
+
+	// Check for duplicate var_group names
+	seenGroupNames := make(map[string]bool)
+	for _, vg := range varGroups {
+		if seenGroupNames[vg.Name] {
+			errs = append(errs, specerrors.NewStructuredErrorf("file \"%s\" is invalid: duplicate var_group name %q", filePath, vg.Name))
+		}
+		seenGroupNames[vg.Name] = true
+
+		// Check for duplicate option names within each var_group
+		seenOptionNames := make(map[string]bool)
+		for _, opt := range vg.Options {
+			if seenOptionNames[opt.Name] {
+				errs = append(errs, specerrors.NewStructuredErrorf("file \"%s\" is invalid: duplicate option name %q in var_group %q", filePath, opt.Name, vg.Name))
+			}
+			seenOptionNames[opt.Name] = true
+
+			// Validate that referenced vars exist and check required consistency
+			for _, varName := range opt.Vars {
+				varDef, exists := varMap[varName]
+				if !exists {
+					errs = append(errs, specerrors.NewStructuredErrorf("file \"%s\" is invalid: var %q referenced in var_group %q option %q is not defined", filePath, varName, vg.Name, opt.Name))
+					continue
+				}
+
+				// Validate that vars in a var_group do not have required: true
+				// The requirement is controlled entirely by the var_group:
+				// - If var_group is required, all vars are implicitly required (inferred)
+				// - If var_group is not required, the entire group is optional
+				if varDef.Required {
+					if vg.Required {
+						errs = append(errs, specerrors.NewStructuredErrorf("file \"%s\" is invalid: var %q in required var_group %q should not have required: true (requirement is inferred from var_group)", filePath, varName, vg.Name))
+					} else {
+						errs = append(errs, specerrors.NewStructuredErrorf("file \"%s\" is invalid: var %q in non-required var_group %q should not have required: true (var_group is optional)", filePath, varName, vg.Name))
+					}
+				}
+			}
+		}
+	}
+
+	return errs
+}