Cannot connect to postgres server in docker - postgresql

Question

I started a postgresql server in docker and exposed the 5432 port by sudo docker run -it -p 5432:5432 9c421f1a239c bash and start the postgres server manually inside the docker container, but cannot connect to it with command: psql -h 172.17.0.63 -U venti. 172.17.0.63 is a right IP, and venti is my pg username. But get error:
psql: could not connect to server: Connection refused
Is the server running on host "172.17.0.63" and accepting
TCP/IP connections on port 5432?
My pg_hba.conf looks like this:
local all postgres peer
host all all 0.0.0.0/0 trust
local all all trust
Connecting to pg server inside container works successfully.
Dockerfile:
FROM ubuntu:12.04
RUN apt-get update
RUN apt-get install -y gcc libc-dev-bin libc6 libc6-dev libssl-dev libkrb5-dev comerr-dev
RUN apt-get install -y postgresql-common libpq-dev postgresql-9.1-postgis --fix-missing
RUN apt-get install -y postgresql postgresql-client
USER postgres
ENV PGDATA /etc/postgresql/9.1/main
ENV LOGDIR /etc/postgresql/9.1/main/postgresql.log
WORKDIR /usr/lib/postgresql/9.1/bin
USER root
RUN apt-get install -y vim
USER postgres
RUN sed -e '90d' -i /etc/postgresql/9.1/main/pg_hba.conf
RUN sed -e '91d' -i /etc/postgresql/9.1/main/pg_hba.conf
RUN echo "host all all 0.0.0.0/0 trust" >> '/etc/postgresql/9.1/main/pg_hba.conf'
RUN echo "local all all trust" >> '/etc/postgresql/9.1/main/pg_hba.conf'
RUN ./pg_ctl start && sleep 8 && ./createdb pg && ./createdb bloodstone \
&& createuser -Upostgres -s venti \
&& createdb -Uventi -Oventi venti
# ENTRYPOINT ./pg_ctl start && bash -c "while true; do echo "" > /dev/null; sleep 1; done"
VOLUME $PGDATA
EXPOSE 5432

Answer 1

It's merely a misconfiguration. I should have set pg to listen on public addresses or make a port mapping. I fixed this by editing pg config file with sed:
RUN sed -e "s/[#]\?listen_addresses = .*/listen_addresses = '*'/g" -i '/etc/postgresql/9.1/main/postgresql.conf'
Add this to a proper place in your Dockerfile, and you should be OK.

Answer 2

To troubleshoot postgres auth problems in general, look at the postgres log/stderr to see verbose reasons why it failed. (I see your problem is solved but if anyone runs into similar problems)
To find the postgres log location: "show log_destination;" if you have a working psql (eg locally on the postgres server box)
I see yours is set to "/etc/postgresql/9.1/main/postgresql.log". You can connect to the container to see the log with "docker exec -it container_name bash".
Alternately, if a container runs postgres directly, "docker attach db_container_name" views postgres stderr messages.
Note that by default user postgres does not have a password and uses only ident auth.

Answer 3

I also faced similar issue. Try running docker-compose up twice.
The reason is, that in my docker-compose.yml file the DB service was below the Web service in which it was trying to connect to DB which does not exists yet.
**
version: '2'
services:
nginx:
image: nginx:latest
container_name: ng01
ports:
- "8000:8000"
volumes:
- ./src:/src
- ./config/nginx:/etc/nginx/conf.d
- /static:/static <--- HERE
depends_on:
- web
web:
build: .
container_name: dg01
command: bash -c "python /src/IMS/manage.py makemigrations && python /src/IMS/manage.py migrate && gunicorn IMS.wsgi -b
0.0.0.0:8000"
depends_on:
- db
volumes:
- ./src:/src
- /static:/static
expose:
- "8000"
db:
image: postgres:latest
container_name: ps01**