ubuntu@ip-172-31-41-131:~$ sudo apt-get install postgresql postgresql-contrib
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following extra packages will be installed:
  postgresql-9.3 postgresql-common postgresql-contrib-9.3
Suggested packages:
  oidentd ident-server locales-all libdbd-pg-perl
The following NEW packages will be installed:
  postgresql postgresql-9.3 postgresql-common postgresql-contrib
  postgresql-contrib-9.3
0 upgraded, 5 newly installed, 0 to remove and 102 not upgraded.
Need to get 0 B/3179 kB of archives.
After this operation, 14.1 MB of additional disk space will be used.
Do you want to continue? [Y/n]
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
	LANGUAGE = (unset),
	LC_ALL = (unset),
	LC_TIME = "uk_UA.UTF-8",
	LC_MONETARY = "uk_UA.UTF-8",
	LC_ADDRESS = "uk_UA.UTF-8",
	LC_TELEPHONE = "uk_UA.UTF-8",
	LC_NAME = "uk_UA.UTF-8",
	LC_MEASUREMENT = "uk_UA.UTF-8",
	LC_IDENTIFICATION = "uk_UA.UTF-8",
	LC_NUMERIC = "uk_UA.UTF-8",
	LC_PAPER = "uk_UA.UTF-8",
	LANG = "en_US.UTF-8"
    are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").
locale: Cannot set LC_ALL to default locale: No such file or directory
Preconfiguring packages ...
Selecting previously unselected package postgresql-common.
(Reading database ... 57606 files and directories currently installed.)
Preparing to unpack .../postgresql-common_154ubuntu1_all.deb ...
Adding 'diversion of /usr/bin/pg_config to /usr/bin/pg_config.libpq-dev by postgresql-common'
Unpacking postgresql-common (154ubuntu1) ...
Selecting previously unselected package postgresql-9.3.
Preparing to unpack .../postgresql-9.3_9.3.9-0ubuntu0.14.04_amd64.deb ...
Unpacking postgresql-9.3 (9.3.9-0ubuntu0.14.04) ...
Selecting previously unselected package postgresql.
Preparing to unpack .../postgresql_9.3+154ubuntu1_all.deb ...
Unpacking postgresql (9.3+154ubuntu1) ...
Selecting previously unselected package postgresql-contrib-9.3.
Preparing to unpack .../postgresql-contrib-9.3_9.3.9-0ubuntu0.14.04_amd64.deb ...
Unpacking postgresql-contrib-9.3 (9.3.9-0ubuntu0.14.04) ...
Selecting previously unselected package postgresql-contrib.
Preparing to unpack .../postgresql-contrib_9.3+154ubuntu1_all.deb ...
Unpacking postgresql-contrib (9.3+154ubuntu1) ...
Processing triggers for man-db (2.6.7.1-1ubuntu1) ...
Processing triggers for ureadahead (0.100.0-16) ...
Setting up postgresql-common (154ubuntu1) ...
locale: Cannot set LC_ALL to default locale: No such file or directory

Creating config file /etc/logrotate.d/postgresql-common with new version
Building PostgreSQL dictionaries from installed myspell/hunspell packages...
Removing obsolete dictionary files:
 * No PostgreSQL clusters exist; see "man pg_createcluster"
Processing triggers for ureadahead (0.100.0-16) ...
Setting up postgresql-9.3 (9.3.9-0ubuntu0.14.04) ...
Error: The locale requested by the environment is invalid.
Error: could not create default cluster. Please create it manually with

  pg_createcluster 9.3 main --start

or a similar command (see 'man pg_createcluster').
update-alternatives: using /usr/share/postgresql/9.3/man/man1/postmaster.1.gz to provide /usr/share/man/man1/postmaster.1.gz (postmaster.1.gz) in auto mode
 * No PostgreSQL clusters exist; see "man pg_createcluster"