feat: Add validate command

cmd/validate.go

@@ -0,0 +1,79 @@
+// Copyright 2018 Palantir Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package cmd
+
+import (
+	"io/ioutil"
+	"os"
+
+	"github.com/palantir/policy-bot/policy"
+	"github.com/pkg/errors"
+	"github.com/spf13/cobra"
+	"gopkg.in/yaml.v2"
+)
+
+var policyBotPolicy struct {
+	Path string
+}
+
+var PolicyBotValidationCmd = &cobra.Command{
+	Use:   "validate",
+	Short: "Runs validation of policy-bot policy.",
+	Long:  "Runs valdation of a policy-bot policy yaml file.",
+
+	RunE: policyBotValidationCmd,
+}
+
+func readPolicyBotPolicy(cfgFile string) ([]byte, error) {
+	fi, err := os.Stat(cfgFile)
+	if os.IsNotExist(err) {
+		return nil, errors.Wrapf(err, "policy file does not exist: %s", cfgFile)
+	}
+	if err != nil {
+		return nil, errors.Wrapf(err, "failed fetching policy file: %s", cfgFile)
+	}
+	if !fi.Mode().IsRegular() {
+		return nil, errors.New("policy file is not a regular file: " + cfgFile)
+	}
+
+	var bytes []byte
+	bytes, err = ioutil.ReadFile(cfgFile)
+	if err != nil {
+		return nil, errors.Wrapf(err, "failed reading policy file: %s", cfgFile)
+	}
+
+	return bytes, nil
+}
+
+func policyBotValidationCmd(cmd *cobra.Command, args []string) error {
+	policyData, err := readPolicyBotPolicy(policyBotPolicy.Path)
+	if err != nil {
+		return errors.Wrapf(err, "failed to read policy file")
+	}
+	var policyConfig policy.Config
+	if err := yaml.UnmarshalStrict(policyData, &policyConfig); err != nil {
+		return errors.Wrapf(err, "failed to parse policy from yaml file")
+	}
+	if _, err := policy.ParsePolicy(&policyConfig, nil); err != nil {
+		return errors.Wrapf(err, "failed to parse policy")
+	}
+	return nil
+}
+
+func init() {
+	RootCmd.AddCommand(PolicyBotValidationCmd)
+
+	PolicyBotValidationCmd.Flags().StringVarP(&policyBotPolicy.Path, "policy", "p", ".policy.yml", "policy file for policy-bot")
+}