Slimming down Docker images

It’s been a while since I posted anything about Docker.  That’s mostly because I still don’t really use it for anything – playing around locally, testing and learning doesn’t count yet.

But just to keep the ball rolling, here are a couple of handy links for the ideas on how to improve your Docker images, so that Docker uses much less space, benefits more from caching, and brings up the containers faster:

Both articles are around the same theme – choose your  base image carefully, try to minimize the layers, use only what you need, and don’t forget to clean up the disk space with “docker system prune“.

17 Tips for Using Composer Efficiently

Martin Hujer has collected 17 tips for using composer efficiently, and then added a few more after receiving the feedback on the blog post.  I was familiar with most of these, but there are still a few that are new to me.

Tip #7: Run Travis CI builds with different versions of dependencies

I knew about the Travis CI matrix configuration, but used it only for other things.  I’ll be looking into extending it for the composer tests shortly.

Tip #8: Sort packages in require and require-dev by name

This is a great tip!  I read the composer documentation several times, but somehow I missed this option.  It is especially useful for the the way we manage projects at work (waterfall merges from templates and basic projects into more complex ones).

Tip #9: Do not attempt to merge composer.lock when rebasing or merging

Here, I’m not quite sure about the whole bit on git attributes.  Having git try to merge and generate a conflict creates a very visible problem.  Avoiding the merge might hide things a bit until they popup much later in the CI.  I guess I’ll have to play around with this to make up my mind.

Tip #13: Validate the composer.json during the CI build

This is a great tip!  I had plenty of issues with composer validations in the past.  Currently, we have a couple of unit tests that make sure that composer files are valid and up-to-date.  Using a native mechanism for that is a much better option.

Tip #15: Specify the production PHP version in composer.json

This sounds like an amazing feature which I once again missed.  Especially now that we are still migrating some projects from PHP 5.6 to PHP 7.1, and have to sort out dependency conflicts between the two versions.

Tip #20: Use authoritative class map in production

We are already almost doing it, but it’s a good opportunity to verify that we utilize the functionality correctly.


Defensive Programming : Object Calisthenics

I came across this nice and somewhat strongly opinionated video on Defensive Programming:

Marco Pivetta makes quite a few good points with I agree (and a few with which I disagree).  One thing that he mentioned though I haven’t heard about – Object Calisthenics.  Which turns out to be yet another set of rules and best practices for the object-oriented design and programming.  Here are the rules to get you started:

  1. Only One Level Of Indentation Per Method
  2. Don’t Use The ELSE Keyword
  3. Wrap All Primitives And Strings
  4. First Class Collections
  5. One Dot Per Line
  6. Don’t Abbreviate
  7. Keep All Entities Small
  8. No Classes With More Than Two Instance Variables
  9. No Getters/Setters/Properties

Read the whole article for explanations and examples.

Nginx Performance Tuning – Tips & Tricks

Here are a whole lot of “Performance Tuning – Tips & Tricks” directly from the Nginx team.  I’m sure you’ve seen bits and pieces of these all over the place, but it’s nice to have them all together and from the credible source as well.

The 2018 Guide to Building Secure PHP Software

The 2018 Guide to Building Secure PHP Software” is an excellent guide to writing modern PHP applications with security in mind.  It covers a bunch of the usual topics, but provides fresher solutions than most other similar guides.