Docker file command runs apt-get update from wrong repository - docker

Question

I could not install the postgresql 9.5 This is the point when I'm in the docker file
Dockerfile row
RUN apt-get update && apt-get install -qq -y build-essential libpq-dev postgresql-client-9.5 --fix-missing --no-install-recommends
and it runs the command bellow.
remote: E: Package 'postgresql-client-9.5' has no installation candidate
remote:
The command '/bin/sh -c apt-get update && apt-get install -qq
-y build-essential libpq-dev postgresql-client-9.5 --fix-missing
--no-install-recommends' returned a non-zero code: 100
Seems that it tries to do apt-get update from debian repository when I'm on ubuntu xenial. May be something went wrong because I installed first wrong docker version for debian , and then I removed the debian docker with
sudo apt-get remove docker docker-engine docker.io
sudo rm -rf /var/lib/docker
After this I have installed the docker for my ubuntu xenial distribution. I don't understand why when I run the docker file it still updates the packages and tries to install packages that are for debian, when I don't have anything debian related?
The installed docker version is
Docker version 17.05.0-ce, build 89658be
From https://apt.dockerproject.org/repo/pool/main/d/docker-engine/docker-engine_17.05.0~ce-0~ubuntu-xenial_amd64.deb
Here is the code when it runs apt-get update:
remote: ---> Running in b8d8101adf4a
remote: ---> f9286d1e85d1
remote: Removing intermediate container b8d8101adf4a
remote: Step 3/11 : RUN apt-get update && apt-get install -qq -y build-essential libpq-dev postgresql-client-9.5 mysql-client-5.7 --fix-missing --no-install-recommends
remote: ---> Running in 9bda34235687
remote: Ign:1 http://deb.debian.org/debian stretch InRelease
remote: Get:2 http://deb.debian.org/debian stretch-updates InRelease [91.0 kB]
remote: Get:3 http://security.debian.org/debian-security stretch/updates InRelease [94.3 kB]
remote: Get:4 http://deb.debian.org/debian stretch Release [118 kB]
remote: Get:5 http://deb.debian.org/debian stretch-updates/main amd64 Packages [12.1 kB]
remote: Get:6 http://security.debian.org/debian-security stretch/updates/main amd64 Packages [440 kB]
remote: Get:7 http://deb.debian.org/debian stretch Release.gpg [2434 B]
remote: Get:8 http://deb.debian.org/debian stretch/main amd64 Packages [9530 kB]
remote: Fetched 10.3 MB in 13s (789 kB/s)
remote: Reading package lists...
Dockerfile:
FROM python:2.7
MAINTAINER Makkasi <makkasi#abv.bg>
RUN apt-get update && apt-get install -qq -y build-essential libpq-dev postgresql-client-9.5 --fix-missing --no-install-recommends
ENV INSTALL_PATH /project1
RUN mkdir -p $INSTALL_PATH
WORKDIR $INSTALL_PATH
COPY requirements.txt requirements.txt
RUN pip install -r requirements.txt
COPY . .
VOLUME ["static"]
CMD gunicorn -b 0.0.0.0:8000 "project1.app:create_app()"
docker-compose.yml:
postgres:
image: postgres:9.5
environment:
POSTGRES_USER: makkasi
POSTGRES_PASSWORD: somepassword
ports:
- '5432:5432'
volumes:
- ~/.docker-volumes/project1/postgresql/data:/var/lib/postgresql/data
redis:
image: redis:2.8.22
ports:
- '6379:6379'
volumes:
- ~/.docker-volumes/project1/redis/data:/var/lib/redis/data
project1:
build: .
command: gunicorn -b 0.0.0.0:8000 --reload --access-logfile - "project1.app:create_app()"
environment:
PYTHONUNBUFFERED: true
links:
- postgres
- redis
volumes:
- .:/project1
ports:
- '8000:8000'

Answer 1

I think is a postgresql version question.
If you're using stretch or buster (buster actually updates from stretch servers), version found in repo is postgresql-client-9.6, not 9.5.
Try with this and we see.

Answer 2

Seems that it tries to do apt-get update from debian repository when I'm on ubuntu xenial.
Commands to build an image are run within a container based on the previous state of the image. They do not depend on the host you are running on. The result is the same image could be built on different docker host with nearly identical results (external dependencies and timestamps being the normal exceptions). If you follow the path of the Dockerfile you've provided from the FROM lines, you get:
FROM python:2.7: docker hub and Dockerfile
FROM buildpack-deps:stretch: docker hub and Dockerfile
FROM buildpack-deps:stretch-scm: docker hub and Dockerfile
FROM buildpack-deps:stretch-curl: docker hub and Dockerfile
FROM debian:stretch: docker hub and Dockerfile
You can also run a container based on your base image and use the standard package manager tools to query for what versions of packages are included (this is particularly useful when you don't have the Dockerfile for your image):
$ docker run -it --rm python:2.7 /bin/bash
root#ea64878fc27f:/# cat /etc/debian_version
8.7
root#ea64878fc27f:/# apt-get update
Get:1 http://security.debian.org jessie/updates InRelease [94.4 kB]
Ign http://deb.debian.org jessie InRelease
Get:2 http://deb.debian.org jessie-updates InRelease [145 kB]
Get:3 http://deb.debian.org jessie Release.gpg [2434 B]
Get:4 http://deb.debian.org jessie Release [148 kB]
Get:5 http://security.debian.org jessie/updates/main amd64 Packages [623 kB]
Get:6 http://deb.debian.org jessie-updates/main amd64 Packages [23.0 kB]
Get:7 http://deb.debian.org jessie/main amd64 Packages [9064 kB]
Fetched 10.1 MB in 9s (1058 kB/s)
Reading package lists... Done
root#ea64878fc27f:/# apt-cache search postgresql-client
postgresql-client-9.4 - front-end programs for PostgreSQL 9.4
postgresql-client - front-end programs for PostgreSQL (supported version)
postgresql-client-common - manager for multiple PostgreSQL client versions
root#ea64878fc27f:/# apt-cache madison postgresql-client
postgresql-client | 9.4+165+deb8u3 | http://deb.debian.org/debian/ jessie/main amd64 Packages
postgresql-client | 9.4+165+deb8u3 | http://security.debian.org/ jessie/updates/main amd64 Packages