title: Error: [PostgreSQL error] failed to retrieve PostgreSQL server_version_num: Transport endpoint is not connected
body: <p>I'm encountering an error when trying to do migrations bootstrap for kong, can anyone please help?</p>
  <pre><code>serene@ubuntu:~$ sudo kong migrations bootstrap -c /etc/kong/kong.conf --v
  2020/10/19 02:21:04 [verbose] Kong: 2.1.4
  2020/10/19 02:21:04 [verbose] reading config file at /etc/kong/kong.conf
  2020/10/19 02:21:04 [verbose] prefix in use: /usr/local/kong
  Error:
  /usr/local/share/lua/5.1/kong/cmd/migrations.lua:95: [PostgreSQL error] failed to retrieve PostgreSQL server_version_num: Transport endpoint is not connected
  stack traceback:
          [C]: in function 'assert'
          /usr/local/share/lua/5.1/kong/cmd/migrations.lua:95: in function 'cmd_exec'
          /usr/local/share/lua/5.1/kong/cmd/init.lua:88: in function &lt;/usr/local/share/lua/5.1/kong/cmd/init.lua:88&gt;
          [C]: in function 'xpcall'
          /usr/local/share/lua/5.1/kong/cmd/init.lua:88: in function &lt;/usr/local/share/lua/5.1/kong/cmd/init.lua:45&gt;
          /usr/local/bin/kong:9: in function 'file_gen'
          init_worker_by_lua:50: in function &lt;init_worker_by_lua:48&gt;
          [C]: in function 'xpcall'
          init_worker_by_lua:57: in function &lt;init_worker_by_lua:55&gt;
  </code></pre>
  <p>I am using WSL, Ubuntu 18.04 LTS, I've installed kong v2.1.4, postgresql 12 on it</p>
  <pre><code>serene@ubuntu:~$ kong version
  2.1.4
  serene@ubuntu:~$ dpkg -l | grep postgres
  ii  pgdg-keyring                   2018.2                              all          keyring for apt.postgresql.org
  ii  postgresql-12                  12.4-1.pgdg18.04+1                  amd64        object-relational SQL database, version 12 server
  ii  postgresql-client-12           12.4-1.pgdg18.04+1                  amd64        front-end programs for PostgreSQL 12
  ii  postgresql-client-common       220.pgdg18.04+1                     all          manager for multiple PostgreSQL client versions
  ii  postgresql-common              220.pgdg18.04+1                     all          PostgreSQL database-cluster manager
  </code></pre>
  <p>I have started the postgresql service.
  I have configured kong.conf as follows</p>
  <pre><code>database = postgres
  pg_host = 127.0.0.1
  pg_port = 5433
  pg_timeout = 5000
  pg_user = kong
  pg_password = kong                                                                          
  pg_database = kong
  pg_ssl = off 
  pg_ssl_verify = off
  pg_max_concurrent_queries = 0 
  pg_semaphore_timeout = 60000 
  </code></pre>
  <p>I have also configured a user in postgres called kong with password 'kong' as owner of database called 'kong.</p>
  <pre><code>serene@ubuntu:~$ sudo -u postgres psql
  psql (12.4 (Ubuntu 12.4-1.pgdg18.04+1))
  Type &quot;help&quot; for help.
  
  postgres=# \l
                                List of databases
     Name    |  Owner   | Encoding | Collate |  Ctype  |   Access privileges
  -----------+----------+----------+---------+---------+-----------------------
   kong      | kong     | UTF8     | C.UTF-8 | C.UTF-8 | =Tc/kong             +
             |          |          |         |         | kong=CTc/kong
   postgres  | postgres | UTF8     | C.UTF-8 | C.UTF-8 |
   template0 | postgres | UTF8     | C.UTF-8 | C.UTF-8 | =c/postgres          +
             |          |          |         |         | postgres=CTc/postgres
   template1 | postgres | UTF8     | C.UTF-8 | C.UTF-8 | =c/postgres          +
             |          |          |         |         | postgres=CTc/postgres
  (4 rows)
  
  postgres=#
  </code></pre>
  <p>Initially I was using WSL Ubuntu 20.04, Kong 2.1.4, Postgresql 13. Same error.
  Did a fresh install of those. Same error.
  Deleted Ubuntu 20.04 and installed Ubuntu 18.04 and reinstall Kong 2.1.4 and Postgresql 13. Same error.
  Heard someone had troubles with Postgresql 13 when installing Kong, so I went and did a fresh install for Postgresql 12, still same error.</p>
  <p>Is there anyone who knows what went wrong and how I can rectify this?</p>