Alex binfeng

psql: FATAL: Peer authentication failed for user “postgres” (or any user)

The connection failed because by default psql connects over UNIX sockets using peer authentication, that requires the current UNIX user to have the same user name as psql. So you will have to create the UNIX user postgres and then login as postgres or use sudo -u postgres psql database-name for accessing the database (and psql should not ask for a password).

If you cannot or do not want to create the UNIX user, like if you just want to connect to your database for ad hoc queries, forcing a socket connection using psql --host=localhost --dbname=database-name --username=postgres (as pointed out by @meyerson answer) will solve your immediate problem.

But if you intend to force password authentication over Unix sockets instead of the peer method, try changing the following pg_hba.conf* line:

from

	#!/usr/bin/python
	# -- coding: utf-8 --

	def xpath_soup(element):
	# type: (typing.Union[bs4.element.Tag, bs4.element.NavigableString]) -> str
	"""
	Generate xpath from BeautifulSoup4 element.

	:param element: BeautifulSoup4 element.
	:type element: bs4.element.Tag or bs4.element.NavigableString

	{0: 'tench, Tinca tinca',
	1: 'goldfish, Carassius auratus',
	2: 'great white shark, white shark, man-eater, man-eating shark, Carcharodon carcharias',
	3: 'tiger shark, Galeocerdo cuvieri',
	4: 'hammerhead, hammerhead shark',
	5: 'electric ray, crampfish, numbfish, torpedo',
	6: 'stingray',
	7: 'cock',
	8: 'hen',
	9: 'ostrich, Struthio camelus',

	// -- mode: js; js-indent-level: 4; indent-tabs-mode: nil --

	const Lang = imports.lang;

	const Clutter = imports.gi.Clutter;
	const St = imports.gi.St;
	const Meta = imports.gi.Meta;
	const Mainloop = imports.mainloop;
	const Main = imports.ui.main;
	const Cinnamon = imports.gi.Cinnamon;

	#!/usr/bin/env python
	import urllib, sys, bs4
	print bs4.BeautifulSoup(urllib.urlopen("http://data.alexa.com/data?cli=10&dat=s&url="+ sys.argv[1]).read(), "xml").find("REACH")['RANK']