I created a docker container using Oracle Linux 7.6 as explained at the end of this post.
From what I can figure out, the redhat-indexhtml package installs /usr/share/doc/HTML/index.html.
However, when running a docker container, it only installs the /usr/share/doc/HTML/common directory.
Does this make any sense? Is there anything special about /usr/share/doc?
Below some more details:
Firefox connects to https://linux.oracle.com when starting for the first time, but then keeps opening file:///usr/share/doc/HTML/index.html.

The file does indeed not exist, not even the directory:
# ls /usr/share/doc
ls: cannot access /usr/share/doc: No such file or directory
The file should be installed by the redhat-indexhtml package:
# yum provides /usr/share/doc/HTML/index.html
redhat-indexhtml-7-13.0.1.el7.noarch : Browser default start page for Red Hat
: Enterprise Linux
Repo : ol7_latest
Matched from:
Filename : /usr/share/doc/HTML/index.html
# yum install redhat-indexhtml
Loaded plugins: ovl, ulninfo
Resolving Dependencies
--> Running transaction check
---> Package redhat-indexhtml.noarch 0:7-13.0.1.el7 will be installed
etc....
Running transaction
Installing : redhat-indexhtml-7-13.0.1.el7.noarch 1/1
Verifying : redhat-indexhtml-7-13.0.1.el7.noarch 1/1
Installed:
redhat-indexhtml.noarch 0:7-13.0.1.el7
# ls /usr/share/doc/HTML
common
So it appears that redhat-indexhtml did not install index.html.
However, when installing redhat-indexhtml in a normal machine (not docker) it works fine:
# ls /usr/share/doc/HTML
ls: cannot access /usr/share/doc/HTML: No such file or directory
# yum install redhat-indexhtml
# ls /usr/share/doc/HTML/
common en-US fr-FR it-IT ko-KR ru-RU zh-TW
de-DE es-ES index.html ja-JP pt-BR zh-CN
Below is how I build and run the container:
docker build -t firefox:dude - << EOF
FROM oraclelinux:7
RUN yum -y install firefox dbus-x11 redhat-indexhtml && \
groupadd -g 54326 dude && \\
useradd -u 54325 -g 54326 dude && \\
USER dude
CMD dbus-launch firefox
EOF
xhost + local:
docker run -it --rm --net=host --shm-size 2g \
-e DISPLAY \\
-v /tmp/.X11-unix:/tmp/.X11-unix \\
-v $/home/dude:/home/dude:z \\
-v /sys/fs/cgroup:/sys/fs/cgroup:ro \\
-w /home/dude \\
firefox:dude