docker-compose psql无法连接到服务器

Question

i looked at the github MD file for bottled-water to use it using docker and i've run into a problem regarding postgresql

if i run docker-compose run --rm postgres psql i get the error

/usr/local/lib/python2.7/dist-packages/requests/packages/urllib3/util/ssl_.py:90: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning.
  InsecurePlatformWarning
/usr/local/lib/python2.7/dist-packages/requests/packages/urllib3/util/ssl_.py:90: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning.
  InsecurePlatformWarning
/usr/local/lib/python2.7/dist-packages/requests/packages/urllib3/util/ssl_.py:90: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning.
  InsecurePlatformWarning
/usr/local/lib/python2.7/dist-packages/requests/packages/urllib3/util/ssl_.py:90: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning.
  InsecurePlatformWarning
psql: could not connect to server: No such file or directory
    Is the server running locally and accepting
    connections on Unix domain socket "/var/run/postgresql/.s.PGSQL.5432"?

this is the config for postgres and psql in my docker-compose.yml file

postgres:
   build: ./tmp
   dockerfile: Dockerfile.postgres
   hostname: postgres
   ports:
     - '45432:5432' 

psql:
  image: postgres:9.4
  links:
    - postgres
  command: 'sh -c ''exec psql -h "localhost" -p "5432" -U postgres'''

and this is my pg_hba.conf file

local   all             postgres                                peer

# 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            md5
# IPv6 local connections:
host    all             all             ::1/128                 md5
# Allow replication connections from localhost, by a user with the
# replication privilege.
#local   replication     postgres                                peer
#host    replication     postgres        127.0.0.1/32            md5
#host    replication     postgres        ::1/128                 md5

i've been at this for days now,any kind of help would be appreciated!thank you

Answer 1

This is a poorly documented feature of docker compose, as it threw me off guard as well. It is in the documentation . See if you can find it.

When two container's are linked, they're linked using virtual hostname. If you check /etc/hosts of your psql conainer, you'll find a line for aliases postgres {foldername}_postgres_1 where {foldername} is the name of the parent folder of your docker-compose project.

To use the a linked container, use the hostname postgres .

For your example:

psql:
  image: postgres:9.4
  links:
    - postgres
  command: 'sh -c ''exec psql -h "postgres" -p "5432" -U postgres'''

You can configure your code base to use this as well. If you want to run the code outside of a linked container, simply modify the host /etc/hosts file to point to the desired service.