root.go

/*
Copyright 2016 Skippbox, Ltd.

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 (
	"fmt"
	"net/http"
	"os"

	"github.com/bitnami-labs/kubewatch/config"
	c "github.com/bitnami-labs/kubewatch/pkg/client"
	"github.com/sirupsen/logrus"
	"github.com/spf13/cobra"
	"github.com/spf13/viper"
	_ "net/http/pprof"
)

var cfgFile string

// RootCmd represents the base command when called without any subcommands
var RootCmd = &cobra.Command{
	Use:   "kubewatch",
	Short: "A watcher for Kubernetes",
	Long: `
Kubewatch: A watcher for Kubernetes

kubewatch is a Kubernetes watcher that could publishes notification
to Slack/hipchat/mattermost/flock channels. It watches the cluster
for resource changes and notifies them through webhooks.

supported webhooks:
 - slack
 - hipchat
 - mattermost
 - flock
 - webhook
 - lark
`,

	Run: func(cmd *cobra.Command, args []string) {
		config := &config.Config{}
		if err := config.Load(); err != nil {
			logrus.Fatal(err)
		}
		config.CheckMissingResourceEnvvars()
		c.Run(config)
	},
}

// Execute adds all child commands to the root command sets flags appropriately.
// This is called by main.main(). It only needs to happen once to the rootCmd.
func Execute() {
	if err := RootCmd.Execute(); err != nil {
		fmt.Println(err)
		os.Exit(-1)
	}
}

func init() {
	cobra.OnInitialize(initConfig)

	initLogger()

	// Disable Help subcommand
	RootCmd.SetHelpCommand(&cobra.Command{
		Use:    "no-help",
		Hidden: true,
	})
	//RootCmd.PersistentFlags().StringVar(&cfgFile, "config", "", "config file (default is $HOME/.kubewatch.yaml)")
	if os.Getenv("ENABLE_PPROF") == "True" {
		go func() {
			pprofAddr := "localhost:6060"
			logrus.Infof("Initializing pprof %s", pprofAddr)
			err := http.ListenAndServe(pprofAddr, nil)
			if err != nil {
				logrus.Errorf("Failed to initialize pprof %s", err)
			}
		}()
	}
}

func initLogger() {
	logLevel := os.Getenv("LOG_LEVEL")
	if logLevel != "" {
		logrus.Printf("Custom log level: %s", logLevel)
		parsedLevel, err := logrus.ParseLevel(logLevel)
		if err == nil {
			logrus.Printf("Setting custom log level to: %s", logLevel)
			logrus.SetLevel(parsedLevel)
		} else {
			logrus.Errorf("Illegal custom log level: %s. Ignoring custom log level", logLevel)
		}
	}
	logFormatter := os.Getenv("LOG_FORMATTER")
	if logFormatter != "" {
		logrus.Printf("Custom log formatter: %s", logFormatter)
		if logFormatter == "json" {
			logrus.Printf("Setting custom log formatter to: %s", logFormatter)
			logrus.SetFormatter(new(logrus.JSONFormatter))
		} else {
			logrus.Errorf("Illegal custom log formatter: %s. Ignoring custom log formatter", logFormatter)
		}
	}
}

// initConfig reads in config file and ENV variables if set.
func initConfig() {
	if cfgFile != "" { // enable ability to specify config file via flag
		viper.SetConfigFile(cfgFile)
	}

	viper.SetConfigName(kubewatchConfigFile) // name of config file (without extension)
	viper.AddConfigPath("$HOME")             // adding home directory as first search path
	viper.AutomaticEnv()                     // read in environment variables that match

	// If a config file is found, read it in.
	if err := viper.ReadInConfig(); err == nil {
		fmt.Println("Using config file:", viper.ConfigFileUsed())
	}
}