feat: Add json/yaml output for the validate command

Author: idsulik

README.md

@@ -51,13 +51,18 @@ Options:
                      Defaults to values.yaml
 --rules-file, -r     Rules files to validate against (comma-separated or multiple flags)
                      Defaults to values.cel.yaml
+--output, -o         Output format: text, json, or yaml
+                     Defaults to text
 ```
 
 Example with custom files:
 ```bash
 # Using single values and rules files
 helm cel validate ./mychart --values-file prod.values.yaml --rules-file prod.cel.yaml
 
+# Using JSON output format
+helm cel validate ./mychart -o json
+
 # Using multiple values files (later files take precedence)
 helm cel validate ./mychart --values-file common.yaml --values-file prod.yaml
 
@@ -210,6 +215,61 @@ If all rules pass, you'll see a success message:
 ✅ Values validation successful!
 ```
 
+### Structured Output Formats
+
+You can output validation results in JSON or YAML format for integration with CI/CD pipelines:
+
+```bash
+# JSON output
+helm cel validate ./mychart -o json
+
+# YAML output
+helm cel validate ./mychart -o yaml
+```
+
+JSON output example:
+```json
+{
+  "has_errors": true,
+  "has_warnings": true,
+  "result": {
+    "errors": [
+      {
+        "description": "replicaCount must be at least 1",
+        "expression": "values.replicaCount >= 1",
+        "value": 0,
+        "path": "replicaCount"
+      }
+    ],
+    "warnings": [
+      {
+        "description": "service port should be between 1 and 65535",
+        "expression": "values.service.port >= 1 && values.service.port <= 65535",
+        "value": 80801,
+        "path": "service.port"
+      }
+    ]
+  }
+}
+```
+
+YAML output example:
+```yaml
+has_errors: true
+has_warnings: true
+result:
+  errors:
+  - description: replicaCount must be at least 1
+    expression: values.replicaCount >= 1
+    value: 0
+    path: replicaCount
+  warnings:
+  - description: service port should be between 1 and 65535
+    expression: values.service.port >= 1 && values.service.port <= 65535
+    value: 80801
+    path: service.port
+```
+
 ## Development
 
 Requirements:

cmd/helm-cel/main.go

@@ -1,13 +1,16 @@
 package main
 
 import (
+	"encoding/json"
 	"fmt"
 	"os"
 	"path/filepath"
 
 	"github.com/idsulik/helm-cel/pkg/generator"
+	"github.com/idsulik/helm-cel/pkg/models"
 	"github.com/idsulik/helm-cel/pkg/validator"
 	"github.com/spf13/cobra"
+	"gopkg.in/yaml.v3"
 )
 
 var (
@@ -17,16 +20,19 @@ var (
 	outputFile     string
 
 	// Flags for validate command
-	valuesFiles []string
-	rulesFiles  []string
+	valuesFiles  []string
+	rulesFiles   []string
+	outputFormat string
 )
 
 const (
 	validateShort = "Validate Helm values using CEL expressions"
 	validateLong  = `A Helm plugin to validate values.yaml using CEL expressions defined in .cel.yaml files.
 Example using defaults: helm cel validate ./mychart
 Example with specific values: helm cel validate ./mychart -v values1.yaml -v values2.yaml
-Example with multiple files: helm cel validate ./mychart -v prod.yaml,staging.yaml -r rules1.cel.yaml,rules2.cel.yaml`
+Example with multiple files: helm cel validate ./mychart -v prod.yaml,staging.yaml -r rules1.cel.yaml,rules2.cel.yaml
+Example with JSON output: helm cel validate ./mychart -o json
+Example with YAML output: helm cel validate ./mychart -o yaml`
 
 	generateShort = "Generate CEL validation rules from values.yaml"
 	generateLong  = `Generate values.cel.yaml file with validation rules based on the structure of values.yaml.
@@ -73,6 +79,13 @@ func init() {
 		[]string{"values.cel.yaml"},
 		"Rules files to validate against (comma-separated or multiple -r flags)",
 	)
+	validateCmd.Flags().StringVarP(
+		&outputFormat,
+		"output",
+		"o",
+		"text",
+		"Output format: text, json, or yaml",
+	)
 
 	generateCmd.Flags().BoolVarP(&forceOverwrite, "force", "f", false, "Force overwrite existing values.cel.yaml")
 	generateCmd.Flags().StringVarP(
@@ -116,21 +129,56 @@ func runValidator(_ *cobra.Command, args []string) error {
 		return err
 	}
 
-	if result.HasErrors() {
-		return result
+	output := models.ValidationOutput{
+		HasErrors:   result.HasErrors(),
+		HasWarnings: len(result.Warnings) > 0,
+		Result:      result,
 	}
 
-	if len(result.Warnings) > 0 {
-		fmt.Println(result.Error())
-		fmt.Println("-------------------------------------------------")
-		fmt.Println("⚠️✅ Values validation successful with warnings!")
-	} else {
-		fmt.Println("✅ Values validation successful!")
+	switch outputFormat {
+	case "json":
+		if err := outputJson(output); err != nil {
+			return err
+		}
+	case "yaml":
+		if err := outputYaml(output); err != nil {
+			return err
+		}
+	default:
+		if result.HasErrors() {
+			return result
+		}
+
+		if len(result.Warnings) > 0 {
+			fmt.Println(result.Error())
+			fmt.Println("-------------------------------------------------")
+			fmt.Println("⚠️✅ Values validation successful with warnings!")
+		} else {
+			fmt.Println("✅ Values validation successful!")
+		}
 	}
 
 	return nil
 }
 
+func outputJson(output models.ValidationOutput) error {
+	json, err := json.MarshalIndent(output, "", "  ")
+	if err != nil {
+		return fmt.Errorf("failed to marshal output to JSON: %v", err)
+	}
+	fmt.Println(string(json))
+	return nil
+}
+
+func outputYaml(output models.ValidationOutput) error {
+	yaml, err := yaml.Marshal(output)
+	if err != nil {
+		return fmt.Errorf("failed to marshal output to YAML: %v", err)
+	}
+	fmt.Println(string(yaml))
+	return nil
+}
+
 func runGenerator(_ *cobra.Command, args []string) error {
 	if len(args) != 1 {
 		return fmt.Errorf("chart path is required")

pkg/models/models.go

@@ -20,16 +20,23 @@ type ValidationRules struct {
 
 // ValidationResult represents the outcome of validation
 type ValidationResult struct {
-	Errors   []*ValidationError
-	Warnings []*ValidationError
+	Errors   []*ValidationError `json:"errors" yaml:"errors"`
+	Warnings []*ValidationError `json:"warnings" yaml:"warnings"`
 }
 
 // ValidationError represents a validation failure
 type ValidationError struct {
-	Description string
-	Expression  string
-	Value       any
-	Path        string
+	Description string `json:"description" yaml:"description"`
+	Expression  string `json:"expression" yaml:"expression"`
+	Value       any    `json:"value" yaml:"value"`
+	Path        string `json:"path,omitempty" yaml:"path,omitempty"`
+}
+
+// ValidationOutput is used for structured output in JSON/YAML format
+type ValidationOutput struct {
+	HasErrors   bool              `json:"has_errors" yaml:"has_errors"`
+	HasWarnings bool              `json:"has_warnings" yaml:"has_warnings"`
+	Result      *ValidationResult `json:"result" yaml:"result"`
 }
 
 func (vr *ValidationResult) HasErrors() bool {