password authentication failed for user “postgres” [duplicate]

Answer 1

I met a similar problem (the same error message). Like Daniel answer, it's because that I confuse between :

"postgres PostgreSQL account, not the postgres system account."

To be sure about the postgres password, just change it to '123456' (or any other password)

# su postgres
# psql -d template1
template1=# ALTER USER postgres WITH PASSWORD '123456';