Add mindev ruletype init to kick off a rule type (#5228)

* Add `mindev ruletype init` to kick off a rule type

This helps folks set up the basic skeleton for ruletype writing.

Signed-off-by: Juan Antonio Osorio <[email protected]>

* Apply suggestions from code review

Co-authored-by: Evan Anderson <[email protected]>

* More fixes

Signed-off-by: Juan Antonio Osorio <[email protected]>

* address lint issue

Signed-off-by: Juan Antonio Osorio <[email protected]>

---------

Signed-off-by: Juan Antonio Osorio <[email protected]>
Co-authored-by: Evan Anderson <[email protected]>

cmd/dev/app/rule_type/init.go

@@ -0,0 +1,205 @@
+// SPDX-FileCopyrightText: Copyright 2023 The Minder Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package rule_type
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+	"regexp"
+	"text/template"
+
+	"github.com/spf13/cobra"
+)
+
+// CmdInit is the command for initializing a rule type definition
+func CmdInit() *cobra.Command {
+	initCmd := &cobra.Command{
+		Use:   "init",
+		Short: "initialize a rule type definition",
+		Long: `The 'ruletype init' subcommand allows you to initialize a rule type definition
+
+The first positional argument is the directory to initialize the rule type in.
+The rule type will be initialized in the current directory if no directory is provided.
+`,
+		RunE:         initCmdRun,
+		SilenceUsage: true,
+	}
+
+	initCmd.Flags().StringP("name", "n", "", "name of the rule type")
+	initCmd.Flags().BoolP("skip-tests", "s", false, "skip creating test files")
+
+	if err := initCmd.MarkFlagRequired("name"); err != nil {
+		fmt.Fprintf(os.Stderr, "Error marking flag as required: %s\n", err)
+		os.Exit(1)
+	}
+
+	return initCmd
+}
+
+func initCmdRun(cmd *cobra.Command, args []string) error {
+	name := cmd.Flag("name").Value.String()
+	skipTests := cmd.Flag("skip-tests").Value.String() == "true"
+	dir := "."
+	if len(args) > 0 {
+		dir = args[0]
+	}
+
+	if err := validateRuleTypeName(name); err != nil {
+		return err
+	}
+
+	ruleTypeFileName := filepath.Join(dir, name+".yaml")
+	ruleTypeTestFileName := filepath.Join(dir, name+".test.yaml")
+	ruleTypeTestDataDirName := filepath.Join(dir, name+".testdata")
+
+	if err := assertFilesDontExist(
+		ruleTypeFileName, ruleTypeTestFileName, ruleTypeTestDataDirName); err != nil {
+		return err
+	}
+
+	// Create rule type file
+	if err := createRuleTypeFile(ruleTypeFileName, name); err != nil {
+		return err
+	}
+	cmd.Printf("Created rule type file: %s\n", ruleTypeFileName)
+
+	if !skipTests {
+		// Create rule type test file
+		if err := createRuleTypeTestFile(ruleTypeTestFileName, name); err != nil {
+			return err
+		}
+		cmd.Printf("Created rule type test file: %s\n", ruleTypeTestFileName)
+
+		// Create rule type test data directory
+		if err := createRuleTypeTestDataDir(ruleTypeTestDataDirName); err != nil {
+			return err
+		}
+		cmd.Printf("Created rule type test data directory: %s\n", ruleTypeTestDataDirName)
+	}
+
+	return nil
+}
+
+func validateRuleTypeName(name string) error {
+	if name == "" {
+		return errors.New("name cannot be empty")
+	}
+
+	validName := regexp.MustCompile(`^[A-Za-z][-/[:word:]]*$`)
+
+	// regexp to validate name
+	if !validName.MatchString(name) {
+		return errors.New("name must only contain alphanumeric characters and underscores")
+	}
+
+	return nil
+}
+
+func assertFilesDontExist(files ...string) error {
+	for _, file := range files {
+		_, err := os.Stat(file)
+		if err == nil {
+			return fmt.Errorf("file %s already exists", file)
+		}
+
+		if errors.Is(err, os.ErrPermission) {
+			return fmt.Errorf("permission denied for file %s", file)
+		}
+	}
+
+	return nil
+}
+
+func createRuleTypeFile(fileName, name string) error {
+	return createFileWithContent(fileName, renderwithRuleTypeName(`---
+version: v1
+release_phase: alpha
+type: rule-type
+name: {{ .RuleName }}
+display_name:  # Display name for the rule type
+short_failure_message:   # Short message to display when the rule fails
+severity:
+  value: medium
+context: {}
+description: |  # Description of the rule type
+guidance: |  # Guidance for the rule type. This helps users understand how to fix the issue.
+def:
+  in_entity: repository  # The entity type the rule applies to
+  rule_schema: {}
+  ingest:
+    type: git
+    git:
+  eval:
+    type: rego
+    rego:
+      type: deny-by-default
+      def: |
+        package minder
+
+        import rego.v1
+
+        default allow := false
+
+        allow if {
+            true
+        }
+        
+        message := "This is a test message"
+`, name))
+}
+
+func createRuleTypeTestFile(fileName, name string) error {
+	return createFileWithContent(fileName, renderwithRuleTypeName(`---
+tests:
+  - name: "TEST NAME GOES HERE""
+    def: {}
+    params: {}
+    expect: "pass"
+    entity: &test-repo
+      type: repository
+      entity:
+        owner: "coolhead"
+        name: "haze-wave"
+    # When testing a rule, additional content can be supplied
+    # from files in the "{{ .RuleName }}.testdata" directory.
+    # File paths below are relative to this directory.
+    # http:
+    #  # Input from the "http" ingest type.
+    #  body_file: HTTP_BODY_FILE
+    # git:
+    #   # Input from the "git" ingest type.  Base paths contain
+    #   # directory contents, but do not actually need to be a
+    #   # git repository.
+    #   repo_base: REPO_BASE_PATH
+`, name))
+}
+
+func createRuleTypeTestDataDir(dirName string) error {
+	if err := os.Mkdir(dirName, 0750); err != nil {
+		return fmt.Errorf("error creating directory %s: %w", dirName, err)
+	}
+
+	return nil
+}
+
+func createFileWithContent(fileName, content string) error {
+	return os.WriteFile(fileName, []byte(content), 0600)
+}
+
+func renderwithRuleTypeName(templ, name string) string {
+	tmpl, err := template.New("ruletype").Parse(templ)
+	if err != nil {
+		panic(err)
+	}
+
+	var buf bytes.Buffer
+	if err := tmpl.Execute(&buf, struct{ RuleName string }{name}); err != nil {
+		panic(err)
+	}
+
+	return buf.String()
+}

cmd/dev/app/rule_type/ruletype.go

@@ -16,6 +16,7 @@ func CmdRuleType() *cobra.Command {
 	rtCmd.AddCommand(CmdTest())
 	rtCmd.AddCommand(CmdLint())
 	rtCmd.AddCommand(CmdValidateUpdate())
+	rtCmd.AddCommand(CmdInit())
 
 	return rtCmd
 }