utils

Documentation

Overview

Package utils with functions to get the outbound network interface

Index

• Constants
• Variables
• func Clone(b []byte) (c []byte)
• func ExitOnSignal(release func()) context.Context
• func FormatMSE(mse int64, short bool) string
• func GetInterfaces(address string) ([]net.Interface, error)
• func GetOutboundIP(destination string) net.IP
• func GetOutboundInterface(address string) (interfaceName string, macAddress string, ipAddr net.IP)
• func MapKeys[K comparable, V any](mm map[K]V) []K
• func OrderedMapKeys[K constraints.Ordered, V any](mm map[K]V) []K
• func WaitForSignal(ctx context.Context)
• type AppEnvironment
  • func GetAppEnvironment(homeDir string, withFlags bool) AppEnvironment
  • func (env *AppEnvironment) LoadConfig(configFile string, cfg interface{}) error

Constants

const (
	COReset  = "\033[0m"
	CORed    = "\033[31m"
	COGreen  = "\033[32m"
	COYellow = "\033[33m"
	COBlue   = "\033[34m"
	COPurple = "\033[35m"
	COCyan   = "\033[36m"
	COGray   = "\033[37m"
	COWhite  = "\033[97m"
)

Console ASCII commands to control colors See also: https://www.codequoi.com/en/coloring-terminal-text-tput-and-ansi-escape-sequences/

const (
	CBBlack  = "\033[40m"
	CBRed    = "\033[41m"
	CBGreen  = "\033[42m"
	CBYellow = "\033[43m"
	CBBlue   = "\033[44m"
	CBGray   = "\033[47m"
	CBWhite  = "\033[41m"
)

const (
	WrapOff = "\033[?7l"
	WrapOn  = "\033[?7h"
)

Variables

var LongFormat = "2006-01-02 15:04:05.000 -0700"

var ShortFormat = time.StampMilli

Functions

func Clone

func Clone(b []byte) (c []byte)

Clone the given byte array. Use this is the source holds a transient value and its buffer can be reused elsewhere. Eg, all capnp byte arrays Golang will eventually get a bytes.clone() method but it isn't in go-19

returns nil if b is nil

func ExitOnSignal

func ExitOnSignal(release func()) context.Context

ExitOnSignal starts a background process and closes the context when a SIGINT or SIGTERM is received.

If a release function is provided it is invoked before the function exits normally. If no release function is provided this ends the process with os.Exit(0). This returns a child context which is cancelled before the call to release.

func FormatMSE

func FormatMSE(mse int64, short bool) string

FormatMSE returns a human readable string of the time in millisec since epoc The short format is: StampMilli: Jan _2 15:04:05.000 (local time) The long format is: RFC1123Z: Mon, 02 Jan 2006 15:04:05 -07:00

func GetInterfaces

func GetInterfaces(address string) ([]net.Interface, error)

GetInterfaces returns a list of active network interfaces excluding the loopback interface

address to only return the interface that serves the given IP address

func GetOutboundIP

func GetOutboundIP(destination string) net.IP

GetOutboundIP returns the default outbound IP address to reach the given hostname. This uses 1.1.1.1 as the default destination. TODO: use the default gateway address instead so this works without internet access.

Use a local hostname if a subnet other than the default one should be used. Use "" for the default route address

destination to reach or "" to use 1.1.1.1 (no connection will be established)

func GetOutboundInterface

func GetOutboundInterface(address string) (interfaceName string, macAddress string, ipAddr net.IP)

GetOutboundInterface Get preferred outbound network interface of this machine Credits: https://stackoverflow.com/questions/23558425/how-do-i-get-the-local-ip-address-in-go and https://qiita.com/shaching/items/4c2ee8fd2914cce8687c

func MapKeys

func MapKeys[K comparable, V any](mm map[K]V) []K

MapKeys returns an slice of keys

func OrderedMapKeys

func OrderedMapKeys[K constraints.Ordered, V any](mm map[K]V) []K

OrderedMapKeys returns an ordered slice of keys

func WaitForSignal

func WaitForSignal(ctx context.Context)

WaitForSignal waits until a SIGINT or SIGTERM is received or the context is closed

Types

type AppEnvironment

type AppEnvironment struct {
	// Directories
	BinDir     string `yaml:"binDir,omitempty"`     // Application binary folder, eg launcher, cli, ...
	PluginsDir string `yaml:"pluginsDir,omitempty"` // Plugin folder
	HomeDir    string `yaml:"homeDir,omitempty"`    // Home folder, default this is the parent of bin, config, certs and logs
	ConfigDir  string `yaml:"configDir,omitempty"`  // Config folder with application and configuration files
	ConfigFile string `yaml:"configFile,omitempty"` // Application configuration file. Default is clientID.yaml
	CertsDir   string `yaml:"certsDir,omitempty"`   // Certificates and keys location
	LogsDir    string `yaml:"logsDir,omitempty"`    // Logging output
	LogLevel   string `yaml:"logLevel,omitempty"`   // logging level
	StoresDir  string `yaml:"storesDir,omitempty"`  // Root of the service stores

	// Server
	//Core string `yaml:"core"` // core to use, "nats" or "mqtt". empty for auto-detect
	ServerURL string `yaml:"serverURL,omitempty"` // server address

	// Credentials
	CaCert    *x509.Certificate `yaml:"-"`         // default cert if loaded
	ClientID  string            `yaml:"clientID"`  // the clientID based on the application binary name
	KeyFile   string            `yaml:"keyFile"`   // client's key pair file location
	TokenFile string            `yaml:"tokenFile"` // client's auth token file location
}

AppEnvironment holds the running environment naming conventions. Intended for services and plugins. This contains folder locations, CA certificate and application clientID

func GetAppEnvironment

func GetAppEnvironment(homeDir string, withFlags bool) AppEnvironment

GetAppEnvironment returns the application environment including folders for use by the Hub services.

Optionally parse commandline flags:

-home  		alternative home directory. Default is the parent folder of the app binary
-clientID  	alternative clientID. Default is the application binary name.
-config     alternative config directory. Default is home/certs
-configFile alternative application config file. Default is {clientID}.yaml
-loglevel   debug, info, warning (default), error
-server     optional server URL or "" for auto-detect
-core       optional server core or "" for auto-detect

The default 'user based' structure is:

	home
	  |- bin                Core binaries
      |- plugins            Plugin binaries
	  |- config             Service configuration yaml files
	  |- certs              CA and service certificates
	  |- logs               Logging output
	  |- run                PID files and sockets
	  |- stores
	      |- {service}      Store for service

The system based folder structure is used when launched from a path starting with /usr or /opt:

/opt/hiveot/bin            Application binaries, cli and launcher
/opt/hiveot/plugins        Plugin binaries
/etc/hiveot/conf.d         Service configuration yaml files
/etc/hiveot/certs          CA and service certificates
/var/log/hiveot            Logging output
/run/hiveot                PID files and sockets
/var/lib/hiveot/{service}  Storage of service

This uses os.Args[0] application path to determine the home directory, which is the parent of the application binary. The default clientID is based on the binary name using os.Args[0].

homeDir to override the auto-detected or commandline paths. Use "" for defaults.
withFlags parse the commandline flags for -home and -clientID

func (*AppEnvironment) LoadConfig

func (env *AppEnvironment) LoadConfig(configFile string, cfg interface{}) error

LoadConfig loads the application .

configFile is the optional name. Use "" for default {clientID}.yaml

This returns an error if loading or parsing the config file fails. Returns nil if the config file doesn't exist or is loaded successfully.