ctrl/configuration_flags.go

package steward

import (
	"flag"
	"fmt"
	"log"
	"os"
	"path/filepath"

	toml "github.com/pelletier/go-toml"
)

// --- Configuration
type Configuration struct {
	// The configuration folder on disk
	ConfigFolder string
	// The folder where the socket file should live
	SocketFolder string
	// TCP Listener for sending messages to the system
	TCPListener string
	// The folder where the database should live
	DatabaseFolder string
	// some unique string to identify this Edge unit
	NodeName string
	// the address of the message broker
	BrokerAddress string
	// nats connect retry
	NatsConnectRetryInterval int
	// The number of the profiling port
	ProfilingPort string
	// host and port for prometheus listener, e.g. localhost:2112
	PromHostAndPort string
	// set to true if this is the node that should receive the error log's from other nodes
	DefaultMessageTimeout int
	// default amount of retries that will be done before a message is thrown away, and out of the system
	DefaultMessageRetries int
	// Publisher data folder
	SubscribersDataFolder string
	// central node to receive messages published from nodes
	CentralNodeName string
	// Path to the certificate of the root CA
	RootCAPath string
	// Full path to the NKEY's seed file
	NkeySeedFile string
	// The host and port to expose the data folder
	ExposeDataFolder string
	// Timeout for error messages
	ErrorMessageTimeout int
	// Retries for error messages.
	ErrorMessageRetries int
	// Make the current node send hello messages to central at given interval in seconds
	StartPubREQHello int
	// Start the central error logger.
	// Takes a comma separated string of nodes to receive from or "*" for all nodes.
	StartSubREQErrorLog bool
	// Subscriber for hello messages
	StartSubREQHello bool
	// Subscriber for text logging
	StartSubREQToFileAppend bool
	// Subscriber for writing to file
	StartSubREQToFile bool
	// Subscriber for Echo Request
	StartSubREQPing bool
	// Subscriber for Echo Reply
	StartSubREQPong bool
	// Subscriber for CLICommandRequest
	StartSubREQCliCommand bool
	// Subscriber for REQnCliCommand
	StartSubREQnCliCommand bool
	// Subscriber for REQToConsole
	StartSubREQToConsole bool
	// Subscriber for REQHttpGet
	StartSubREQHttpGet bool
	// Subscriber for tailing log files
	StartSubREQTailFile bool
	// Subscriber for continously delivery of output from cli commands.
	StartSubREQnCliCommandCont bool
}

// NewConfiguration will set a default Configuration,
// and return a *Configuration.
func NewConfiguration() *Configuration {
	c := Configuration{}
	return &c
}

// Default configuration
func newConfigurationDefaults() Configuration {
	c := Configuration{
		ConfigFolder:             "./etc/",
		SocketFolder:             "./tmp",
		TCPListener:              "",
		DatabaseFolder:           "./var/lib",
		BrokerAddress:            "127.0.0.1:4222",
		NatsConnectRetryInterval: 10,
		ProfilingPort:            "",
		PromHostAndPort:          "",
		DefaultMessageTimeout:    10,
		DefaultMessageRetries:    1,
		StartPubREQHello:         30,
		SubscribersDataFolder:    "./data",
		CentralNodeName:          "",
		RootCAPath:               "",
		NkeySeedFile:             "",
		ExposeDataFolder:         "",
		ErrorMessageTimeout:      60,
		ErrorMessageRetries:      10,

		StartSubREQErrorLog:        true,
		StartSubREQHello:           true,
		StartSubREQToFileAppend:    true,
		StartSubREQToFile:          true,
		StartSubREQPing:            true,
		StartSubREQPong:            true,
		StartSubREQCliCommand:      true,
		StartSubREQnCliCommand:     true,
		StartSubREQToConsole:       true,
		StartSubREQHttpGet:         true,
		StartSubREQTailFile:        true,
		StartSubREQnCliCommandCont: true,
	}
	return c
}

// CheckFlags will parse all flags
func (c *Configuration) CheckFlags() error {

	// Create an empty default config
	var fc Configuration

	// Set default configfolder if no env was provided.
	configFolder := os.Getenv("CONFIG_FOLDER")

	if configFolder == "" {
		configFolder = "./etc/"
	}

	// Read file config. Set system default if it can't find config file.
	fc, err := c.ReadConfigFile(configFolder)
	if err != nil {
		log.Printf("%v\n", err)
		fc = newConfigurationDefaults()
	}

	if configFolder == "" {
		fc.ConfigFolder = "./etc/"
	} else {
		fc.ConfigFolder = configFolder
	}

	*c = fc

	//flag.StringVar(&c.ConfigFolder, "configFolder", fc.ConfigFolder, "Defaults to ./usr/local/steward/etc/. *NB* This flag is not used, if your config file are located somwhere else than default set the location in an env variable named CONFIGFOLDER")
	flag.StringVar(&c.SocketFolder, "socketFolder", fc.SocketFolder, "folder who contains the socket file. Defaults to ./tmp/. If other folder is used this flag must be specified at startup.")
	flag.StringVar(&c.TCPListener, "tcpListener", fc.TCPListener, "start up a TCP listener in addition to the Unix Socket, to give messages to the system. e.g. localhost:8888. No value means not to start the listener, which is default. NB: You probably don't want to start this on any other interface than localhost")
	flag.StringVar(&c.DatabaseFolder, "databaseFolder", fc.DatabaseFolder, "folder who contains the database file. Defaults to ./var/lib/. If other folder is used this flag must be specified at startup.")
	flag.StringVar(&c.NodeName, "nodeName", fc.NodeName, "some unique string to identify this Edge unit")
	flag.StringVar(&c.BrokerAddress, "brokerAddress", fc.BrokerAddress, "the address of the message broker")
	flag.IntVar(&c.NatsConnectRetryInterval, "natsConnectRetryInterval", fc.NatsConnectRetryInterval, "default nats retry connect interval in seconds.")
	flag.StringVar(&c.ProfilingPort, "profilingPort", fc.ProfilingPort, "The number of the profiling port")
	flag.StringVar(&c.PromHostAndPort, "promHostAndPort", fc.PromHostAndPort, "host and port for prometheus listener, e.g. localhost:2112")
	flag.IntVar(&c.DefaultMessageTimeout, "defaultMessageTimeout", fc.DefaultMessageTimeout, "default message timeout in seconds. This can be overridden on the message level")
	flag.IntVar(&c.DefaultMessageRetries, "defaultMessageRetries", fc.DefaultMessageRetries, "default amount of retries that will be done before a message is thrown away, and out of the system")
	flag.StringVar(&c.SubscribersDataFolder, "subscribersDataFolder", fc.SubscribersDataFolder, "The data folder where subscribers are allowed to write their data if needed")
	flag.StringVar(&c.CentralNodeName, "centralNodeName", fc.CentralNodeName, "The name of the central node to receive messages published by this node")
	flag.StringVar(&c.RootCAPath, "rootCAPath", fc.RootCAPath, "If TLS, enter the path for where to find the root CA certificate")
	flag.StringVar(&c.NkeySeedFile, "nkeySeedFile", fc.NkeySeedFile, "The full path of the nkeys seed file")
	flag.StringVar(&c.ExposeDataFolder, "exposeDataFolder", fc.ExposeDataFolder, "If set the data folder will be exposed on the given host:port. Default value is not exposed at all")
	flag.IntVar(&c.ErrorMessageTimeout, "errorMessageTimeout", fc.ErrorMessageTimeout, "The number of seconds to wait for an error message to time out")
	flag.IntVar(&c.ErrorMessageRetries, "errorMessageRetries", fc.ErrorMessageRetries, "The number of if times to retry an error message before we drop it")

	flag.IntVar(&c.StartPubREQHello, "startPubREQHello", fc.StartPubREQHello, "Make the current node send hello messages to central at given interval in seconds")

	flag.BoolVar(&c.StartSubREQErrorLog, "startSubREQErrorLog", fc.StartSubREQErrorLog, "true/false")
	flag.BoolVar(&c.StartSubREQHello, "startSubREQHello", fc.StartSubREQHello, "true/false")
	flag.BoolVar(&c.StartSubREQToFileAppend, "startSubREQToFileAppend", fc.StartSubREQToFileAppend, "true/false")
	flag.BoolVar(&c.StartSubREQToFile, "startSubREQToFile", fc.StartSubREQToFile, "true/false")
	flag.BoolVar(&c.StartSubREQPing, "startSubREQPing", fc.StartSubREQPing, "true/false")
	flag.BoolVar(&c.StartSubREQPong, "startSubREQPong", fc.StartSubREQPong, "true/false")
	flag.BoolVar(&c.StartSubREQCliCommand, "startSubREQCliCommand", fc.StartSubREQCliCommand, "true/false")
	flag.BoolVar(&c.StartSubREQnCliCommand, "startSubREQnCliCommand", fc.StartSubREQnCliCommand, "true/false")
	flag.BoolVar(&c.StartSubREQToConsole, "startSubREQToConsole", fc.StartSubREQToConsole, "true/false")
	flag.BoolVar(&c.StartSubREQHttpGet, "startSubREQHttpGet", fc.StartSubREQHttpGet, "true/false")
	flag.BoolVar(&c.StartSubREQTailFile, "startSubREQTailFile", fc.StartSubREQTailFile, "true/false")
	flag.BoolVar(&c.StartSubREQnCliCommandCont, "startSubREQnCliCommandCont", fc.StartSubREQnCliCommandCont, "true/false")

	flag.Parse()

	// Check that mandatory flag values have been set.
	switch {
	case c.NodeName == "":
		return fmt.Errorf("error: the nodeName config option or flag cannot be empty, check -help")
	case c.CentralNodeName == "":
		return fmt.Errorf("error: the centralNodeName config option or flag cannot be empty, check -help")
	}

	if err := c.WriteConfigFile(); err != nil {
		log.Printf("error: checkFlags: failed writing config file: %v\n", err)
		os.Exit(1)
	}

	return nil
}

// Reads the current config file from disk.
func (c *Configuration) ReadConfigFile(configFolder string) (Configuration, error) {
	fp := filepath.Join(configFolder, "config.toml")

	if _, err := os.Stat(fp); os.IsNotExist(err) {
		return Configuration{}, fmt.Errorf("error: no config file found %v: %v", fp, err)
	}

	f, err := os.OpenFile(fp, os.O_RDONLY, 0600)
	if err != nil {
		return Configuration{}, fmt.Errorf("error: ReadConfigFile: failed to open file: %v", err)
	}
	defer f.Close()

	var conf Configuration
	dec := toml.NewDecoder(f)
	err = dec.Decode(&conf)
	if err != nil {
		return Configuration{}, fmt.Errorf("error: decode toml file %v: %v", fp, err)
	}

	// fmt.Printf("%+v\n", c)
	return conf, nil
}

// WriteConfigFile will write the current config to file. If the file or the
// directory for the config file does not exist it will be created.
func (c *Configuration) WriteConfigFile() error {
	if _, err := os.Stat(c.ConfigFolder); os.IsNotExist(err) {
		err := os.MkdirAll(c.ConfigFolder, 0700)
		if err != nil {
			return fmt.Errorf("error: failed to create config directory %v: %v", c.ConfigFolder, err)
		}
	}

	fp := filepath.Join(c.ConfigFolder, "config.toml")

	f, err := os.OpenFile(fp, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0600)
	if err != nil {
		return fmt.Errorf("error: WriteConfigFile: failed to open file: %v", err)
	}
	defer f.Close()

	enc := toml.NewEncoder(f)
	enc.Encode(c)

	return nil
}