Install MDB2 in docker container while PEAR is down

Question

While pear is down, the following instruction in my dockerfile is failing:

RUN pear install -o --alldeps MDB2-beta && \

I've searched on the internet how to install MDB2 without pear, successfully accomplished it by downloading the .deb file from https://packages.ubuntu.com/search?keywords=php-mdb2 and then doing dpkg -i php-mdb2_2.5.0b5-2_all.deb

My issue is that the same instructions are failing when placed in the dockerfile. Here's the instructions:

RUN wget http://mirrors.edge.kernel.org/ubuntu/pool/universe/p/php-mdb2/php-mdb2_2.5.0b5-2_all.deb -O php-mdb2_2.5.0b5-2_all.deb
RUN dpkg -i php-mdb2_2.5.0b5-2_all.deb

Here's the error message:

dpkg: dependency problems prevent configuration of php-mdb2: php-mdb2 depends on php-common; however: Package php-common is not installed. php-mdb2 depends on php-pear (>= 1.3.6); however: Package php-pear is not installed.

I've tried to manually search and install all dependencies, and dependencies' dependencies but failed at the end because one of them is being told to me that it'll break locales thus cannot be installed.

Also tried another solution I found in stackOverflow to install dependencies for dpkg but it also fails. Instructions:

RUN wget http://mirrors.edge.kernel.org/ubuntu/pool/universe/p/php-mdb2/php-mdb2_2.5.0b5-2_all.deb -O php-mdb2_2.5.0b5-2_all.deb
RUN dpkg -i php-mdb2_2.5.0b5-2_all.deb || true && \
apt-get -f install

Error received:

dpkg: error processing package php-mdb2 (--install): dependency problems - leaving unconfigured Errors were encountered while processing: php-mdb2 Reading package lists... Building dependency tree... Reading state information... Correcting dependencies... Done The following packages will be REMOVED: php-mdb2 0 upgraded, 0 newly installed, 1 to remove and 9 not upgraded. 1 not fully installed or removed. After this operation, 528 kB disk space will be freed. Do you want to continue? [Y/n] Abort. ERROR: Service 'app' failed to build: The command '/bin/sh -c dpkg -i php-mdb2_2.5.0b5-2_all.deb || true && apt-get -f install' returned a non-zero code: 1 Makefile:8: recipe for target 'build' failed make: *** [build] Error 1

Can you point me in the right path maybe?

Answer 1

You need to learn a bit more about Debian or Ubuntu. If you look at every single Debian or Ubuntu container that installs things, you will notice, amongst other things:

apt-get update && apt -f install [whatever]

The reason for this is that aptitude doesn't know where to find anything without the "apt update".

See for example https://github.com/dockerfile/ubuntu/blob/master/Dockerfile

# Install.
RUN \
  sed -i 's/# \(.*multiverse$\)/\1/g' /etc/apt/sources.list && \
  apt-get update && \
  apt-get -y upgrade && \
  apt-get install -y build-essential && \
  apt-get install -y software-properties-common && \
  apt-get install -y byobu curl git htop man unzip vim wget && \
  rm -rf /var/lib/apt/lists/*

This updates all packages, then installs build-essential, then software-properties-common and then the packages in the second to last line. Of course you don't need all of this.

It is important however to have the apt-get update && apt-get install on the same line, if you are ever going to deploy your Dockerfile to any CI system. If apt-get update is on its own line, then that layer will never get invalidated as the succeeding layers will have old sources that they build consequent layers from. Keep in mind that every single command generates its own layer, that is why commands are chained in this way - so as to create one layer instead of many that will never serve any purpose.