yum claims package is installed but files not there in docker

Question

I've got some weird behaviour yum vs rpm where both claim to install, but only rpm actually creates the files while yum just claims installed. I can't tell what I'm doing wrong and why the files won't install via yum in docker.

Steps:

docker run --rm -it centos:7

Set yum caching so that we can use the same file via yum and rpm

vi /etc/yum.conf
-> set keepcache=1

And lets kick off yum install

yum install -y centos-indexhtml

trimmed output:

Installed:
  centos-indexhtml.noarch 0:7-9.el7.centos                                                                          

Complete!

Now this package is supposed to install files into /usr/share/doc/HTML as per https://rpmfind.net/linux/RPM/centos/7.7.1908/x86_64/Packages/centos-indexhtml-7-9.el7.centos.noarch.html

ll /usr/share/doc/HTML
ls: cannot access /usr/share/doc/HTML: No such file or directory

so lets uninstall this package from yum and use the yum cache and install directly from RPM

yum remove -y centos-indexhtml
(trimmed output)
Removed:
  centos-indexhtml.noarch 0:7-9.el7.centos                                                                          

Complete!

rpm -Uvh /var/cache/yum/x86_64/7/base/packages/centos-indexhtml-7-9.el7.centos.noarch.rpm 
Preparing...                          ################################# [100%]
Updating / installing...
   1:centos-indexhtml-7-9.el7.centos  ################################# [100%]

And verify files exist:

ll /usr/share/doc/HTML
total 16
drwxr-xr-x 2 root root 4096 Jan 10 18:18 en-US
drwxr-xr-x 2 root root 4096 Jan 10 18:18 img
-rwxr-xr-x 1 root root 4833 May 16  2014 index.html

What am I doing wrong with yum? I'm not getting any errors, just nothing written to the path via yum?

Answer 1

The yum configuration in docker is slightly different: in the same /etc/yum.conf file you'll find:

tsflags=nodocs

which means that packages won't install their documentation. In docker images, the goal of most people is to have a working application that is as small as possible, hence the removal of documenation files.

By using rpm directly, you are bypassing this yum configuration.