
What's in a Docker image? - clonsdale
https://cameronlonsdale.com/2018/11/26/whats-in-a-docker-image/
======
lkrubner
I've been building some fairly sophisticated systems with and without Docker,
and it is always easier to build such systems without Docker. See here:

[http://www.smashcompany.com/technology/one-write-point-
one-r...](http://www.smashcompany.com/technology/one-write-point-one-read-
point-one-log)

At the end of that essay I go into detail about a recent Docker/AWS/ECR/ECS
system I worked on, much of which seemed like a whole lot of useless work that
slowed the project and offered no benefits.

So I'm wondering, what is the biggest project success that people can point to
regarding Docker? In the above post I link to an article where a developer
talks about coming in under budget on a project where they used microservices
and Clojure. Where are similar articles regarding Docker? I'd like to read an
article where an individual software developer, preferably someone who already
has a good reputation with the tech scene, writes an essay where the theme is
"We thought this was going to take 6 months, but once we switched to Docker we
were able to get everything done in 3 months." I find it stunning that there
are basically no such articles. Meanwhile, it is very, very easy to link to
all of the articles where developers have written about the problems they had
when trying to use Docker or Kubernetes.

~~~
dasil003
Docker isn’t supposed to make development faster, it’s supposed to give a
standard way to package code and dependencies so that a small infra team can
support a much larger dev team developing a large number of services with
heterogeneous language and library versions.

~~~
finaliteration
Exactly this. I’m the DevOps lead at my current company and my life would be
hell if I had to manage not only remote machines but also local dev machines
and all the package versions, dependencies, etc, that can differ. Docker adds
some overhead and some headaches, sure, but once we got our CI/CD pipeline
running with Docker life got about ten times easier because we weren’t
spending hours in a Slack channel trying to chase down a package that someone
forgot to upgrade or compiled with the wrong modules.

------
superasn
Brilliant article. Kind of reminds me of the articles in Dr.Dobbs journal in
the pre internet days where they used to dissect various file formats and
explain how the file was organized so you can create your own viewer. That was
the best way to learn about how the original program worked too.

~~~
clonsdale
Thanks! I really like those articles too. With this topic, I found many posts
online just stated information about containers almost like they are trying to
rewrite the documentation, which didn't seem like a good use of writing an
article. This experimental process is what I went through to learn the content
and I felt as though it would be helpful for others to go through it too.

~~~
Jaruzel
Enjoyed that. Demystified docker images for me. Can you do a follow up on how
Docker actually runs the images please?

~~~
superasn
Yes I'd love to read that as well. It would really be the best resource for
understanding docker.

------
dang
A related big thread from the other day:
[https://news.ycombinator.com/item?id=18528423](https://news.ycombinator.com/item?id=18528423)

------
oliwarner
Sightly concerned that it's using a version of Ubuntu that's been end of life
for 35 months.

~~~
clonsdale
The official documentation used that as an example, and because I wanted to
steal their image, I did that too. Of course, please don't use Ubuntu 15.04
for containers you care about.

------
revskill
The problem with docker is the Docker installation. In legacy system, you're
out of luck.

