django.db.utils.OperationalError: FATAL: Ident authentication failed for user "postgres"

Django执行迁移python manage.py migrate报错：

Traceback (most recent call last):
  File "WeCron/manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "/var/lib/pgsql/.local/lib/python2.7/site-packages/django/core/management/__init__.py", line 353, in execute_from_command_line
    utility.execute()
  File "/var/lib/pgsql/.local/lib/python2.7/site-packages/django/core/management/__init__.py", line 345, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/var/lib/pgsql/.local/lib/python2.7/site-packages/django/core/management/base.py", line 348, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/var/lib/pgsql/.local/lib/python2.7/site-packages/django/core/management/base.py", line 399, in execute
    output = self.handle(*args, **options)
  File "/var/lib/pgsql/.local/lib/python2.7/site-packages/django/core/management/commands/migrate.py", line 89, in handle
    executor = MigrationExecutor(connection, self.migration_progress_callback)
  File "/var/lib/pgsql/.local/lib/python2.7/site-packages/django/db/migrations/executor.py", line 20, in __init__
    self.loader = MigrationLoader(self.connection)
  File "/var/lib/pgsql/.local/lib/python2.7/site-packages/django/db/migrations/loader.py", line 49, in __init__
    self.build_graph()
  File "/var/lib/pgsql/.local/lib/python2.7/site-packages/django/db/migrations/loader.py", line 176, in build_graph
    self.applied_migrations = recorder.applied_migrations()
  File "/var/lib/pgsql/.local/lib/python2.7/site-packages/django/db/migrations/recorder.py", line 65, in applied_migrations
    self.ensure_schema()
  File "/var/lib/pgsql/.local/lib/python2.7/site-packages/django/db/migrations/recorder.py", line 52, in ensure_schema
    if self.Migration._meta.db_table in self.connection.introspection.table_names(self.connection.cursor()):
  File "/var/lib/pgsql/.local/lib/python2.7/site-packages/django/db/backends/base/base.py", line 233, in cursor
    cursor = self.make_cursor(self._cursor())
  File "/var/lib/pgsql/.local/lib/python2.7/site-packages/django/db/backends/base/base.py", line 204, in _cursor
    self.ensure_connection()
  File "/var/lib/pgsql/.local/lib/python2.7/site-packages/django/db/backends/base/base.py", line 199, in ensure_connection
    self.connect()
  File "/var/lib/pgsql/.local/lib/python2.7/site-packages/django/db/utils.py", line 95, in __exit__
    six.reraise(dj_exc_type, dj_exc_value, traceback)
  File "/var/lib/pgsql/.local/lib/python2.7/site-packages/django/db/backends/base/base.py", line 199, in ensure_connection
    self.connect()
  File "/var/lib/pgsql/.local/lib/python2.7/site-packages/django/db/backends/base/base.py", line 171, in connect
    self.connection = self.get_new_connection(conn_params)
  File "/var/lib/pgsql/.local/lib/python2.7/site-packages/django/db/backends/postgresql/base.py", line 175, in get_new_connection
    connection = Database.connect(**conn_params)
  File "/var/lib/pgsql/.local/lib/python2.7/site-packages/psycopg2/__init__.py", line 130, in connect
    conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
django.db.utils.OperationalError: FATAL:  Ident authentication failed for user "postgres"

解决办法：

修改postgresql配置文件：

sudo vi /var/lib/pgsql/9.6/data/pg_hba.conf

将下面几条后面的peer或者ident全部改为trust

# TYPE  DATABASE        USER            ADDRESS                 METHOD

# "local" is for Unix domain socket connections only
local   all             all                                     trust
# IPv4 local connections:
#host    all             all             127.0.0.1/32            ident
host    all             all             127.0.0.1/32            trust
# IPv6 local connections:
#host    all             all             ::1/128                 ident
host    all             all             ::1/128                 trust
# Allow replication connections from localhost, by a user with the
# replication privilege.
local   replication     postgres                                trust
host    replication     postgres        127.0.0.1/32            trust
host    replication     postgres        ::1/128                 trust

重启postgresql

systemctl restart postgresql-9.6

重新执行migrate成功！