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Connection to 127.0.0.1 refused in a Dockerfile based on postgres:17-alpine3.20 - Mailing list pgsql-general

From Alexander Farber
Subject Connection to 127.0.0.1 refused in a Dockerfile based on postgres:17-alpine3.20
Date
Msg-id CAADeyWiW+Uz5z_RJrB=dhWoZAOngQ2dHQt+2UOGJiEv6pbcDCA@mail.gmail.com
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Responses Re: Connection to 127.0.0.1 refused in a Dockerfile based on postgres:17-alpine3.20
Re: Connection to 127.0.0.1 refused in a Dockerfile based on postgres:17-alpine3.20
Re: Connection to 127.0.0.1 refused in a Dockerfile based on postgres:17-alpine3.20
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Good evening,

I am trying to create a Dockerfile for development purposes, which 
would run Jetty and PostgreSQL. The PostgreSQL related part is below:

FROM postgres:17-alpine3.20
RUN apk update && apk upgrade && apk add --no-cache curl wget openjdk21 tini

# Tell docker-entrypoint.sh to create superuser "postgres"
# with password "mypassword" and database "postgres"
ENV POSTGRES_PASSWORD mypassword

# Tell docker-entrypoint.sh to change these params in postgresql.conf
ENV POSTGRES_INITDB_ARGS "--set port=6432 --set max_connections=20 --set max_wal_size=2GB"

# The PostgreSQL port is changed from 5432 to 6432 to emulate pg_bouncer
ENV PGPORT 6432
ENV PGUSER words
ENV PGPASSWORD mypassword

WORKDIR /docker-entrypoint-initdb.d
COPY ["run-after-initdb.sh", "."]
RUN chmod +x run-after-initdb.sh && cat run-after-initdb.sh

USER postgres

EXPOSE 6432 9090

ENTRYPOINT ["/sbin/tini", "--"]

CMD ["sh", "-c", "docker-entrypoint.sh postgres & cd $JETTY_BASE && sleep 10 && java -Djdbc.drivers=org.postgresql.Driver -jar $JETTY_HOME/start.jar"]

And below is my run-after-initdb.sh script:

#!/bin/sh

createuser --username=postgres words

psql --username=postgres -c "GRANT USAGE ON SCHEMA public TO words;"
psql --username=postgres -c "ALTER USER words PASSWORD 'mypassword';"

for L in de en ru fr nl pl; do
    createdb --username=postgres --owner=words words_$L
    cd /dict/$L && psql words_$L < words_$L.sql
done

Then I build and run the docker image and that works without errors:

# docker build -t my_docker_image --progress=plain .
# docker run --name my_container -p 8080:8080 -p 6432:6432 my_docker_image

When I connect to the docker container via terminal, 
I am able to connect with "psql words_de" command.

But the "psql -h localhost words_de" command fails:

psql: error: connection to server at "localhost" (127.0.0.1), port 6432 failed: Connection refused
        Is the server running on that host and accepting TCP/IP connections?
connection to server at "localhost" (::1), port 6432 failed: Address not available
        Is the server running on that host and accepting TCP/IP connections?

I need the connection via 127.0.0.1 though, 
because of my Java servlet hosted by the Jetty.

I have looked at the config files and env vars:

# ls -al /var/run/postgresql/
srwxrwxrwx    1 postgres postgres         0 Dec  1 19:06 .s.PGSQL.6432
-rw-------    1 postgres postgres        64 Dec  1 19:06 .s.PGSQL.6432.lock

# echo $PGDATA
/var/lib/postgresql/data

# grep -v '^#' $PGDATA/pg_hba.conf
local   all             all                                     trust
host    all             all             127.0.0.1/32            trust
host    all             all             ::1/128                 trust
local   replication     all                                     trust
host    replication     all             127.0.0.1/32            trust
host    replication     all             ::1/128                 trust

# grep -v '^.*#' $PGDATA/postgresql.conf
listen_addresses = '*'
max_wal_size = 2GB
min_wal_size = 80MB
log_timezone = UTC
datestyle = 'iso, mdy'
timezone = UTC
default_text_search_config = 'pg_catalog.english'

Is anybody able spotting, what am I doing wrong here? Thank you

TLDR "psql words_de" works, but "psql -h localhost words_de" does not

Best regards
Alex

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