pgterminate/base/config.go

package base

import (
	"fmt"
	"io/ioutil"
	"path/filepath"
	"regexp"
	"strings"
	"sync"

	"github.com/jouir/pgterminate/log"
	"gopkg.in/yaml.v2"
)

// AppName exposes application name to config module
var AppName string

// Config receives configuration options
type Config struct {
	mutex                         sync.Mutex
	File                          string
	Host                          string      `yaml:"host"`
	Port                          int         `yaml:"port"`
	User                          string      `yaml:"user"`
	Password                      string      `yaml:"password"`
	Database                      string      `yaml:"database"`
	Interval                      float64     `yaml:"interval"`
	ConnectTimeout                int         `yaml:"connect-timeout"`
	IdleTimeout                   float64     `yaml:"idle-timeout"`
	ActiveTimeout                 float64     `yaml:"active-timeout"`
	LogDestination                string      `yaml:"log-destination"`
	LogFile                       string      `yaml:"log-file"`
	LogFormat                     string      `yaml:"log-format"`
	PidFile                       string      `yaml:"pid-file"`
	SyslogIdent                   string      `yaml:"syslog-ident"`
	SyslogFacility                string      `yaml:"syslog-facility"`
	IncludeUsers                  StringFlags `yaml:"include-users"`
	IncludeUsersRegex             string      `yaml:"include-users-regex"`
	IncludeUsersRegexCompiled     *regexp.Regexp
	IncludeUsersFilters           []Filter
	ExcludeUsers                  StringFlags `yaml:"exclude-users"`
	ExcludeUsersRegex             string      `yaml:"exclude-users-regex"`
	ExcludeUsersRegexCompiled     *regexp.Regexp
	ExcludeUsersFilters           []Filter
	IncludeDatabases              StringFlags `yaml:"include-databases"`
	IncludeDatabasesRegex         string      `yaml:"include-databases-regex"`
	IncludeDatabasesRegexCompiled *regexp.Regexp
	IncludeDatabasesFilters       []Filter
	ExcludeDatabases              StringFlags `yaml:"exclude-databases"`
	ExcludeDatabasesRegex         string      `yaml:"exclude-databases-regex"`
	ExcludeDatabasesRegexCompiled *regexp.Regexp
	ExcludeDatabasesFilters       []Filter
	ExcludeListeners              bool `yaml:"exclude-listeners"`
	Cancel                        bool `yaml:"cancel"`
}

func init() {
	AppName = "pgterminate"
}

// NewConfig creates a Config object
func NewConfig() *Config {
	return &Config{}
}

// Read loads options from a configuration file to Config
func (c *Config) Read(file string) error {
	file, err := filepath.Abs(file)
	if err != nil {
		return err
	}

	yamlFile, err := ioutil.ReadFile(file)
	if err != nil {
		return err
	}

	err = yaml.Unmarshal(yamlFile, &c)
	if err != nil {
		return err
	}

	return nil
}

// Reload reads from file to update configuration and re-compile regexes
func (c *Config) Reload() {
	log.Debug("Reloading configuration")
	c.mutex.Lock()
	defer c.mutex.Unlock()
	if c.File != "" {
		c.Read(c.File)
	}
	err := c.CompileRegexes()
	Panic(err)
	c.CompileFilters()
}

// Dsn formats a connection string based on Config
func (c *Config) Dsn() string {
	var parameters []string
	if c.Host != "" {
		parameters = append(parameters, fmt.Sprintf("host=%s", c.Host))
	}
	if c.Port != 0 {
		parameters = append(parameters, fmt.Sprintf("port=%d", c.Port))
	}
	if c.User != "" {
		parameters = append(parameters, fmt.Sprintf("user=%s", c.User))
	}
	if c.Password != "" {
		parameters = append(parameters, fmt.Sprintf("password=%s", c.Password))
	}
	if c.Database != "" {
		parameters = append(parameters, fmt.Sprintf("database=%s", c.Database))
	}
	if c.ConnectTimeout != 0 {
		parameters = append(parameters, fmt.Sprintf("connect_timeout=%d", c.ConnectTimeout))
	}
	if AppName != "" {
		parameters = append(parameters, fmt.Sprintf("application_name=%s", AppName))
	}
	return strings.Join(parameters, " ")
}

// CompileRegexes transforms regexes from string to regexp instance
func (c *Config) CompileRegexes() (err error) {
	if c.IncludeUsersRegex != "" {
		c.IncludeUsersRegexCompiled, err = regexp.Compile(c.IncludeUsersRegex)
		if err != nil {
			return err
		}
	}
	if c.ExcludeUsersRegex != "" {
		c.ExcludeUsersRegexCompiled, err = regexp.Compile(c.ExcludeUsersRegex)
		if err != nil {
			return err
		}
	}
	return nil
}

// CompileFilters creates Filter objects based on patterns and compiled regexp
func (c *Config) CompileFilters() {

	c.IncludeUsersFilters = nil
	if c.IncludeUsers != nil {
		c.IncludeUsersFilters = append(c.IncludeUsersFilters, NewIncludeFilter(c.IncludeUsers))
	}
	if c.IncludeUsersRegexCompiled != nil {
		c.IncludeUsersFilters = append(c.IncludeUsersFilters, NewIncludeFilterRegex(c.IncludeUsersRegexCompiled))
	}

	c.ExcludeUsersFilters = nil
	if c.ExcludeUsers != nil {
		c.ExcludeUsersFilters = append(c.ExcludeUsersFilters, NewExcludeFilter(c.ExcludeUsers))
	}
	if c.ExcludeUsersRegexCompiled != nil {
		c.ExcludeUsersFilters = append(c.ExcludeUsersFilters, NewExcludeFilterRegex(c.ExcludeUsersRegexCompiled))
	}

	c.IncludeDatabasesFilters = nil
	if c.IncludeDatabases != nil {
		c.IncludeDatabasesFilters = append(c.IncludeDatabasesFilters, NewIncludeFilter(c.IncludeDatabases))
	}
	if c.IncludeDatabasesRegexCompiled != nil {
		c.IncludeDatabasesFilters = append(c.IncludeDatabasesFilters, NewIncludeFilterRegex(c.IncludeDatabasesRegexCompiled))
	}

	c.ExcludeDatabasesFilters = nil
	if c.ExcludeDatabases != nil {
		c.ExcludeDatabasesFilters = append(c.ExcludeDatabasesFilters, NewExcludeFilter(c.ExcludeDatabases))
	}
	if c.ExcludeDatabasesRegexCompiled != nil {
		c.ExcludeDatabasesFilters = append(c.ExcludeDatabasesFilters, NewExcludeFilterRegex(c.ExcludeDatabasesRegexCompiled))
	}

}

// StringFlags append multiple string flags into a string slice
type StringFlags []string

// String for implementing flag interface
func (s *StringFlags) String() string {
	return "multiple strings flag"
}

// Set adds alues into the slice
func (s *StringFlags) Set(value string) error {
	*s = append(*s, value)
	return nil
}