config.go

/**
 * Copyright 2021 Comcast Cable Communications Management, LLC
 *
 * 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 main

import (
	"fmt"
	"os"
	"runtime"

	"github.com/spf13/pflag"
	"github.com/spf13/viper"
)

func setupFlagSet(fs *pflag.FlagSet) {
	fs.StringP("file", "f", "", "the configuration file to use.  Overrides the search path.")
	fs.BoolP("debug", "d", false, "enables debug logging.  Overrides configuration.")
	fs.BoolP("version", "v", false, "print version and exit")
}

func setupViper(v *viper.Viper, fs *pflag.FlagSet, name string) (err error) {
	if printVersion, _ := fs.GetBool("version"); printVersion {
		printVersionInfo()
	}

	if file, _ := fs.GetString("file"); len(file) > 0 {
		v.SetConfigFile(file)
		err = v.ReadInConfig()
	} else {
		v.SetConfigName(name)
		v.AddConfigPath(fmt.Sprintf("/etc/%s", name))
		v.AddConfigPath(fmt.Sprintf("$HOME/.%s", name))
		v.AddConfigPath(".")
		err = v.ReadInConfig()
	}
	if err != nil {
		return
	}

	if debug, _ := fs.GetBool("debug"); debug {
		v.Set("log.level", "DEBUG")
	}
	return nil
}

func printVersionInfo() {
	fmt.Fprintf(os.Stdout, "%s:\n", applicationName)
	fmt.Fprintf(os.Stdout, "  version: \t%s\n", Version)
	fmt.Fprintf(os.Stdout, "  go version: \t%s\n", runtime.Version())
	fmt.Fprintf(os.Stdout, "  built time: \t%s\n", BuildTime)
	fmt.Fprintf(os.Stdout, "  git commit: \t%s\n", GitCommit)
	fmt.Fprintf(os.Stdout, "  os/arch: \t%s/%s\n", runtime.GOOS, runtime.GOARCH)
	os.Exit(0)
}