Make our container slimmer

[andymckay]

 ~ $ docker history mozillamarketplace/solitude:latest
IMAGE               CREATED             CREATED BY                                      SIZE
f50827b510a3        5 hours ago         /bin/sh -c python /srv/solitude/bin/crontab/g   798 B
168ad93f67cc        5 hours ago         /bin/sh -c #(nop) ENV HISTCONTROL=erasedups     0 B
2172047d7d84        5 hours ago         /bin/sh -c #(nop) ENV HISTIGNORE=ls:exit:cd .   0 B
5db77155ecfd        5 hours ago         /bin/sh -c #(nop) ENV HISTSIZE=50000            0 B
f72763ab846a        5 hours ago         /bin/sh -c #(nop) ENV HISTFILE=/srv/solitude/   0 B
3b901754e6d6        5 hours ago         /bin/sh -c #(nop) EXPOSE 2602/tcp               0 B
19a31905244f        5 hours ago         /bin/sh -c #(nop) ENV SOLITUDE_DATABASE=mysql   0 B
3ae2ce2ec2b1        5 hours ago         /bin/sh -c cd /srv/solitude && git show -s --   7 B
e3bd6d47cba3        5 hours ago         /bin/sh -c #(nop) COPY dir:80a9700e42be3881fc   1.475 MB
e34d72146094        5 hours ago         /bin/sh -c peep install     --build /pip/buil   72.67 MB
f1aaacc03f8e        5 hours ago         /bin/sh -c pip install --no-deps --find-links   87.54 kB
1b4b8c84d479        5 hours ago         /bin/sh -c #(nop) WORKDIR /pip                  0 B
e3dea5d56be5        5 hours ago         /bin/sh -c #(nop) ADD dir:a3401d8869880d2d5ff   7.48 kB
5d1269ac6ea1        5 hours ago         /bin/sh -c mkdir -p /pip/{cache,build}          0 B
360e529bb331        5 hours ago         /bin/sh -c #(nop) ENV IS_DOCKER=1               0 B
acfb7a83f98c        5 hours ago         /bin/sh -c yum install -y cronie                34.72 MB
5d099af9ad32        5 hours ago         /bin/sh -c yum install -y bash-completion       18.68 MB
16bb922e5ff5        5 hours ago         /bin/sh -c yum install -y supervisor            224.5 MB
a921f723427c        8 months ago        /bin/sh -c yum install -y mysql-community-ser   375 MB
8ad265df9720        8 months ago        /bin/sh -c #(nop) ADD file:aef05b6e4bc0dc6ad7   144 B
e8bea049a4f1        8 months ago        /bin/sh -c pip install ipython ipdb             12.85 MB
36ffb00bde49        8 months ago        /bin/sh -c easy_install pip                     5.37 MB
cf917f76bec1        8 months ago        /bin/sh -c #(nop) ENV LD_LIBRARY_PATH=/opt/rh   0 B
03afde2a3cea        8 months ago        /bin/sh -c #(nop) ENV PATH=/opt/rh/python27/r   0 B
ceaa1c83f483        8 months ago        /bin/sh -c yum install -y libxslt               18.13 MB
c0c274ab3c92        8 months ago        /bin/sh -c yum install -y     python27-m2cryp   24.07 MB
c7231ca07c09        8 months ago        /bin/sh -c yum install -y gcc                   52.66 MB
9d6465866850        8 months ago        /bin/sh -c yum install -y git                   180.4 MB
01c25c4a6066        8 months ago        /bin/sh -c yum install -y python27              178 MB
42fbabc14120        8 months ago        /bin/sh -c #(nop) ADD file:6f87960d9923b0cb2b   123 B
68eb857ffb51        8 months ago        /bin/sh -c #(nop) ADD file:9be0e96ac5792a45d4   212.7 MB
34e94e67e63a        11 months ago       /bin/sh -c #(nop) MAINTAINER The CentOS Proje   0 B
511136ea3c5a        23 months ago                                                       0 B

git, python, supervisor and mysql-community-server are the biggest culprits

[andymckay]

RUN pip install supervisor
540868cb5bab        35 seconds ago      /bin/sh -c pip install supervisor               2.429 MB

RUN yum install -y supervisor
16bb922e5ff5        6 hours ago         /bin/sh -c yum install -y supervisor            224.5 MB

[andymckay]

Step 1 : RUN yum install -y supervisor
 ---> Running in e1b005663cc1
Loaded plugins: fastestmirror
Determining fastest mirrors
 * base: mirror.its.sfu.ca
 * extras: centos.les.net
 * libselinux: centos.les.net
 * updates: mirror.its.sfu.ca
Setting up Install Process
Resolving Dependencies
--> Running transaction check
---> Package supervisor.noarch 0:3.0b2-1 will be installed
--> Processing Dependency: python-meld3 >= 0.6.5 for package: supervisor-3.0b2-1.noarch
--> Processing Dependency: python-setuptools for package: supervisor-3.0b2-1.noarch
--> Running transaction check
---> Package python-meld3.noarch 0:0.6.10-1 will be installed
---> Package python-setuptools.noarch 0:0.6.10-3.el6 will be installed
--> Finished Dependency Resolution

Dependencies Resolved

================================================================================
 Package                Arch        Version              Repository        Size
================================================================================
Installing:
 supervisor             noarch      3.0b2-1              mozilla-mkt      608 k
Installing for dependencies:
 python-meld3           noarch      0.6.10-1             mozilla-mkt       62 k
 python-setuptools      noarch      0.6.10-3.el6         base             336 k

Transaction Summary
================================================================================
Install       3 Package(s)

Total download size: 1.0 M
Installed size: 4.0 M
Downloading Packages:
--------------------------------------------------------------------------------
Total                                           516 kB/s | 1.0 MB     00:01     
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
  Installing : python-setuptools-0.6.10-3.el6.noarch                        1/3 
  Installing : python-meld3-0.6.10-1.noarch                                 2/3 
  Installing : supervisor-3.0b2-1.noarch                                    3/3 
  Verifying  : python-meld3-0.6.10-1.noarch                                 1/3 
  Verifying  : python-setuptools-0.6.10-3.el6.noarch                        2/3 
  Verifying  : supervisor-3.0b2-1.noarch                                    3/3 

Installed:
  supervisor.noarch 0:3.0b2-1                                                   

Dependency Installed:
  python-meld3.noarch 0:0.6.10-1     python-setuptools.noarch 0:0.6.10-3.el6    

Complete!

[andymckay]

979526a526cd        2 minutes ago        /bin/sh -c yum install -y python27              265.1 MB

vs

002ef5b6cbdd        About a minute ago   /bin/sh -c yum install -y python27; yum clean   70.15 MB

[dklawren]

You need to more command chaining in your Dockerfile RUN statements.

Example:

-RUN yum install -y supervisor
-RUN yum install -y bash-completion
-RUN yum install -y cronie
+RUN yum install -y supervisor bash-completion cronie && yum clean all

That is one of the drawbacks in the way an image is built is even though you so some clean up in a later RUN command, all the data is still in the final image no matter what due to change history. So any cleanup for a command needs to be in the same RUN command either as a shell script or by chaining them (&&).

dkl

[andymckay]

Yeah I'd heard that, its interesting:

Three installs, no clean:

392cecc77eae        12 hours ago         /bin/sh -c yum install -y cronie                34.72 MB
91154ebe69d8        12 hours ago         /bin/sh -c yum install -y bash-completion       18.67 MB
760d1b735093        12 hours ago         /bin/sh -c yum install -y supervisor            224.5 MB

Install and clean in one line:

23d486d7bc04        2 minutes ago        /bin/sh -c yum install -y supervisor bash-com   38.7 MB

Install and clean in three lines:

832fe193df7d        About a minute ago   /bin/sh -c yum install -y cronie && yum clean   34.69 MB
331bc45fc42a        About a minute ago   /bin/sh -c yum install -y bash-completion &&    18.64 MB
f74a8b922149        2 minutes ago        /bin/sh -c yum install -y supervisor && yum c   21.54 MB

[dklawren]

Yeah that is strange that you get smaller size when doing each package individually. Had never tried that way as the all on one line is less typing :) There must be a reason for it but not worth it as 38.7 is still loads better than 224.5.

dkl