Can not connect to a postgres database in a docker container from my local machine

Question

I have a strange problem with docker and postgres. I can not connect from my local machine to psql inside the docker container.

First of all I created my container with this command:
docker run -d -p 5432:5432 --name my-postgres -e POSTGRES_PASSWORD=mysecretpassword postgres

After that I executed the container with following command:
docker exec -it my-postgres bash

Inside the container I started psql with the postgres user:
psql -U postgres
And I created a new database:
CREATE DATABASE mytestdb;

Everything works inside the container, but if I want to connect to it from my machine it does only show the database from my machine. I tried this to connect to postgres:
psql -h localhost -p 5432 -U postgres

Which should me show something like this:

                                 List of databases
   Name    |  Owner   | Encoding |  Collate   |   Ctype    |   Access privileges   
-----------+----------+----------+------------+------------+-----------------------
 mytestdb  | postgres | UTF8     | en_US.utf8 | en_US.utf8 | 
 postgres  | postgres | UTF8     | en_US.utf8 | en_US.utf8 | 
 template0 | postgres | UTF8     | en_US.utf8 | en_US.utf8 | =c/postgres          +
           |          |          |            |            | postgres=CTc/postgres
 template1 | postgres | UTF8     | en_US.utf8 | en_US.utf8 | =c/postgres          +
           |          |          |            |            | postgres=CTc/postgres
(4 rows)

But instead I get this:

                                          List of databases
      Name       |      Owner      | Encoding | Collate | Ctype   |        Access privileges          
-----------------+-----------------+----------+---------+---------+----------------------------------
 user            | user            | UTF8     | C       | C       | 
 postgres        | user            | UTF8     | C       | C       | 
 template0       | user            | UTF8     | C       | C       | =c/user                 +
                 |                 |          |         |         | user =CTc/user
 template1       | user            | UTF8     | C       | C       | =c/user                 +
                 |                 |          |         |         | user =CTc/user
(4 rows)

(END)

In every tutorial, I saw they did it, but for me, it doesn't work. So please help me.

Answer 1

The problem is when you creating the db. CREATE DATABASE mytestdb you forgot to add ; the command should be like CREATE DATABASE mytestdb;

And then you have your db and you can access it from inside the container or your host with these commands