dockerbase-minimal

An alternative base Docker image (with CentOS7 and Fedora 24 versions), targeted particularly for people who are statically compiling native code (Go, Rust) or minimal C/C++ servers (nginx, redis) that don't tend to have big dependencies and don't need translation infrastructure, etc.

There are only two packages to start: micro-yuminst and the $distro-release package for /etc/yum.repos.d/ definitions - everything else comes via dependencies.

Trying it

See our CentOS CI jobs:

• Fedora
• CentOS

Currently, uploads to the Docker Hub are manual, under the tags cgwalters/fedoramin and cgwalters/centosmin. You can also download the tarballs directly from the Jenkins Jobs via:

curl https://ci.centos.org/job/atomic-dockerimage-fedora-24/lastSuccessfulBuild/artifact/fedoramin-24.tar.gz | docker import - cgwalters/fedoramin:24
curl https://ci.centos.org/job/atomic-dockerimage-centos-7/lastSuccessfulBuild/artifact/centosmin-7.tar.gz | docker import - cgwalters/centosmin:7

Implementation and size

Right now we're at ~27MB compressed, ~77MB uncompressed.

Primary minimization targets:

libcurl dependencies

Build libcurl without libssh, ldap, etc. (EASY)

RPM -> lua -> ncurses -> (libstdc++...)

https://bugzilla.redhat.com/show_bug.cgi?id=1360404

GNUPG minimization

https://bugzilla.redhat.com/show_bug.cgi?id=1361869

Switch everything to openssl

So we can drop nss. I noticed at least OpenSUSE at least avoids the glibc ➡️ nss dependency.

Others

glib2 -> shared-mime-info

Building locally

• ./build-via-docker-and-yum.sh centos 7
• ./build-via-docker-and-yum.sh fedora 24

Longer term plans/ideas:

Rebasing the current base image

I think the win overall versus the current base image would become significantly clearer if it was "rebased" and just became a layer on top of this. Implementing this would entail some slightly nontrivial transition code where micro-yuminst knows how to replace itself with yum for example.