Source: defaults.go in package github.com/jackc/pgconn

+build !windows


package pgconn

import (
	"os"
	"os/user"
	"path/filepath"
)

func defaultSettings() map[string]string {
	settings := make(map[string]string)

	settings["host"] = defaultHost()
	settings["port"] = "5432"

Default to the OS user name. Purposely ignoring err getting user name from OS. The client application will simply have to specify the user in that case (which they typically will be doing anyway).

	user, err := user.Current()
	if err == nil {
		settings["user"] = user.Username
		settings["passfile"] = filepath.Join(user.HomeDir, ".pgpass")
		settings["servicefile"] = filepath.Join(user.HomeDir, ".pg_service.conf")
	}

	settings["target_session_attrs"] = "any"

	settings["min_read_buffer_size"] = "8192"

	return settings
}

defaultHost attempts to mimic libpq's default host. libpq uses the default unix socket location on *nix and localhost on Windows. The default socket location is compiled into libpq. Since pgx does not have access to that default it checks the existence of common locations.

func defaultHost() string {
	candidatePaths := []string{
		"/var/run/postgresql", // Debian
		"/private/tmp",        // OSX - homebrew
		"/tmp",                // standard PostgreSQL
	}

	for _, path := range candidatePaths {
		if _, err := os.Stat(path); err == nil {
			return path
		}
	}

	return "localhost"