config.go

/*
Copyright (C) 2018 Expedia Group.

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 (
	"github.com/rs/zerolog"
	"github.com/rs/zerolog/log"
	"math"
	"os"
	"strconv"
	"strings"
	"time"
)

// lookupEnv wrapper used for testing
var lookupEnv = os.LookupEnv

const (
	portEnvName                              = "FLYTE_PORT"
	tlsCertPathEnvName                       = "FLYTE_TLS_CERT_PATH"
	tlsKeyPathEnvName                        = "FLYTE_TLS_KEY_PATH"
	mgoHostEnvName                           = "FLYTE_MGO_HOST"
	authPolicyPathEnvName                    = "FLYTE_AUTH_POLICY_PATH"
	oidcIssuerURLName                        = "FLYTE_OIDC_ISSUER_URL"
	oidcIssuerClientIDName                   = "FLYTE_OIDC_ISSUER_CLIENT_ID"
	flyteTTLEnvName                          = "FLYTE_TTL_IN_SECONDS"
	shouldDeleteDeadPacksEnvName             = "FLYTE_SHOULD_DELETE_DEAD_PACKS"
	deleteDeadPacksTimeEnvName               = "FLYTE_DELETE_DEAD_PACKS_AT_HH_COLON_MM"
	packGracePeriodUntilDeadInSecondsEnvName = "FLYTE_PACK_GRACE_PERIOD_UNTIL_MARKED_DEAD_IN_SECONDS"
	logLevelEnvName                          = "LOGLEVEL"
	defaultDeleteDeadPacksTime               = "23:00"
	oneWeekInSeconds                         = 604800
	oneYearInSeconds                         = 31557600
)

type Config struct {
	MongoHost                         string
	Port                              string
	TLSCertPath                       string
	TLSKeyPath                        string
	AuthPolicyPath                    string
	OidcIssuerURL                     string
	OidcIssuerClientID                string
	FlyteTTL                          int
	ShouldDeleteDeadPacks             bool
	DeleteDeadPacksTime               string
	PackGracePeriodUntilDeadInSeconds int
	LogLevel                          zerolog.Level
}

func NewConfig() Config {
	c := Config{}
	c.LogLevel = getLogLevel()
	zerolog.SetGlobalLevel(c.LogLevel)

	c.MongoHost = getEnvVarWithDefault(mgoHostEnvName, "localhost:27017")
	c.TLSCertPath = getPathVar(tlsCertPathEnvName)
	c.TLSKeyPath = getPathVar(tlsKeyPathEnvName)
	c.Port = c.getPort()
	c.AuthPolicyPath = getEnvVar(authPolicyPathEnvName)
	c.OidcIssuerURL = getEnvVar(oidcIssuerURLName)
	c.OidcIssuerClientID = getEnvVar(oidcIssuerClientIDName)
	c.FlyteTTL = getIntEnvVarWithDefault(flyteTTLEnvName, oneYearInSeconds)
	c.ShouldDeleteDeadPacks = getBoolEnvVarWithDefault(shouldDeleteDeadPacksEnvName, false)
	c.DeleteDeadPacksTime = getDeleteDeadPacksTimeEnvVarWithDefault(deleteDeadPacksTimeEnvName, defaultDeleteDeadPacksTime)
	c.PackGracePeriodUntilDeadInSeconds = getIntEnvVarWithDefault(packGracePeriodUntilDeadInSecondsEnvName, oneWeekInSeconds)
	return c
}

func getEnvVarWithDefault(name, defaultVal string) string {
	val, isSet := lookupEnv(name)
	if !isSet {
		log.Info().Msgf("%s env not set, using default", name)
		val = defaultVal
	}
	log.Info().Msgf("Using %s=%s", name, val)
	return val
}

func getIntEnvVarWithDefault(name string, defaultVal int) int {
	val, isSet := lookupEnv(name)
	if !isSet {
		log.Info().Msgf("%s env not set, using default", name)
		return defaultVal
	}

	intVal, err := strconv.Atoi(val)
	if err != nil {
		log.Err(err).Msgf("Error converting %s to int, using default. Value of %s: %v", name, name, val)
		return defaultVal
	}

	log.Info().Msgf("Using %s=%v", name, intVal)
	return intVal
}

func getBoolEnvVarWithDefault(name string, defaultVal bool) bool {
	val, isSet := lookupEnv(name)
	if !isSet {
		log.Info().Msgf("%s env not set, using default: %v", name, defaultVal)
		return defaultVal
	}

	boolVal, err := strconv.ParseBool(val)
	if err != nil {
		log.Err(err).Msgf("Error converting %s to bool, using default: %v. Value of %s: %v", name, defaultVal, name, val)
		return defaultVal
	}

	log.Info().Msgf("Using %s=%v", name, boolVal)
	return boolVal
}

func getPathVar(envName string) string {
	path := getEnvVar(envName)
	if path != "" && !fileExists(path) {
		log.Fatal().Msgf("cannot find file defined by: %v=%v", envName, path)
	}
	return path
}

func getEnvVar(name string) string {
	val, isSet := lookupEnv(name)
	if isSet {
		log.Info().Msgf("Using %s=%s", name, val)
	}
	return val
}

var fileExists = func(filePath string) bool {
	if _, err := os.Stat(filePath); os.IsNotExist(err) {
		return false
	}
	return true
}

func (c Config) getPort() string {
	port := getEnvVarWithDefault(portEnvName, c.getDefaultPort())
	if portNumber, err := strconv.Atoi(port); err != nil || !isValidPortNumber(portNumber) {
		log.Fatal().Msgf("invalid port: %v=%v", portEnvName, port)
	}
	return port
}

func (c Config) getDefaultPort() string {
	if c.requireTLS() {
		return "8443"
	}
	return "8080"
}

func isValidPortNumber(port int) bool {
	if port < 0 || port > math.MaxUint16 {
		return false
	}
	return true
}

func (c Config) requireTLS() bool {
	return c.TLSCertPath != "" && c.TLSKeyPath != ""
}

func (c Config) requireAuth() bool {
	return c.AuthPolicyPath != "" && c.OidcIssuerURL != "" && c.OidcIssuerClientID != ""
}

func getDeleteDeadPacksTimeEnvVarWithDefault(name, defaultVal string) string {
	val, isSet := lookupEnv(name)
	if !isSet {
		log.Info().Msgf("%s env not set, using default %v", name, defaultVal)
		return defaultVal
	}
	if _, err := time.Parse("15:04", val); err != nil {
		log.Err(err).Msgf("%s env is invalid, using default %v", name, defaultVal)
		return defaultVal
	}

	log.Info().Msgf("Using %s=%s", name, val)
	return val
}

func getLogLevel() zerolog.Level {
	ll := strings.ToLower(getEnvVarWithDefault(logLevelEnvName, "info"))
	l, err := zerolog.ParseLevel(ll)
	if err != nil {
		log.Err(err).Msg("Unable to parse log level setting to Debug")
		return zerolog.InfoLevel
	}
	return l
}