Forem: Ahmad Syazwan

Easy Makefile self-documentation

Ahmad Syazwan — Wed, 20 May 2020 23:14:35 +0000

Here's an easy way to generate makefile help command from its comments that I saw some time ago somewhere.

.DEFAULT_GOAL := help

help:
    @grep -E '^[a-zA-Z0-9_-]+:.*?## .*$$' $(MAKEFILE_LIST) | sort | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-15s\033[0m %s\n", $$1, $$2}'

command1: command2 ## Alias of command2
    echo 'Done!'

command2: ## run command2
    echo 'Running command2'

command3: # Unlisted command
    @echo "I'm private"

Explanation

.DEFAULT_GOAL will run provided make command if none is specified, so by doing make it will execute make help
@grep -E '^[a-zA-Z0-9_-]+:.*?## .*$$' $(MAKEFILE_LIST):
- @ will suppress output because by default make will print out the command it's executing
- grep ... will look for lines that have commands with comments separated by ##
- '^[a-zA-Z0-9_-]+:.*?## .*$$' means search from start of line, any alphanumeric, _ and - command names followed by : and any character until ## to end of line (since $ has special meaning in make, we have to escape it so end of line becomes $$)
- MAKEFILE_LIST is make variable that refers to the makefile name in this case
sort to get alphabetically sorted output
awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-15s\033[0m %s\n", $$1, $$2}':
- pipe the lines through awk and set the FS field separator to be whatever between the command and help text (modify ## if you want different separator)
- for each match print with color: \033[36m%-15s\033[0m %s\n so we will get command, padded with 15 spaces, followed by the help text
- again since we're inside make escape $1 & $2 for column number with $$1 & $$2
For commands you don't want to be listed as help output, simply don't comment or use single # like command3 example

Output

$ make
command1        Alias of command2
command2        run command2

Mojave + VirtualBox

Ahmad Syazwan — Tue, 21 May 2019 19:33:04 +0000

I have finally decided to upgrade my macs to Mojave from High Sierra. For my work machine however, VirtualBox simply stopped working and throwing NS_ERROR_FAILURE on startup. Similar to this. Trying to reinstall won't work because the installer will fail at the last step.

I have tried everything suggested from disabling Gatekeeper to many many iterations of uninstall/reinstall. Almost every solution suggested clicking Allow on the Security & Privacy tab but it never appeared.

What worked for me finally was: macos - VirtualBox 5.2 Won't Install on Mac OS 10.13 - Ask Different which boils down to:

Go into recovery mode (reboot with Cmd + R during loading screen) and open the terminal:

spctl kext-consent disable
spctl kext-consent add VB5E2TV963
spctl kext-consent enable 
reboot

That is basically the Allow part which will finally make the install successful. VB5E2TV963 is the Oracle id that we are allowing.

If you are in similar situation, I hope this will help.

Moving away from Alpine

Ahmad Syazwan — Sat, 16 Feb 2019 09:41:12 +0000

When container movement started getting a lot of traction thanks to docker, there was a real demand for lightweight base image that is optimized for single process, unlike your typical OS. Enter Alpine, a lightweight linux distribution as small as 3MB! It also came with good enough package repository which helped a lot with adoption. Unfortunately we have stopped adopting Alpine when possible, due to reasons I will outline.

Adopting Alpine

At work, we started adopting Alpine pretty early on for development, CI, and even production. All is well, except when it’s not. Turns out it’s a lot of work to get packages that are not readily available in Alpine repository. You see, Alpine uses musl libc instead of glibc and most popular distros use the latter. So things compiled in Alpine won’t be usable on Ubuntu, for example, and vice versa. It’s great when all packages you need are there in the main & community alpine repositories. When that is not the case, you have to build it on your own and hope that the dependencies are available or at least easy to build as well (against musl).

Missing package

One day our CI started failing during docker image build phase. mysql package (which is just a compatibility package pointing to mariadb) suddenly went missing. We issued the bug report: Bug #8030: Missing x86_64 architecture for mysql and mysql-client packages in Alpine v3.3 - Alpine Linux - Alpine Linux Development. To Natanael's credit, the issue was resolved within the day, but this issue got us to start questioning things.

Losing version

I covered this in a previous post, it's basically about the difficulty in pinning package versions in Alpine. I would continue but I think this guy got through the same situation and has the same thoughts. Recommended read.

When a package is not available

Developers at work needed to use PHP V8js for our experimental branch so I had to get the extension for our alpine-based images. Someone got through most of the trouble for me as he detailed the findings in this Github gist. Basically we had to compile GN, download v8 source, and then build it against musl. Even with the steps laid out, it wasn't a smooth experience. This method is not sustainable for us, considering future updates and patches.

Syslog limit

Developers rely heavily on app logs via syslog (mounted /dev/log) and Alpine uses busybox syslog by default. The problem is, messages are truncated at 1024-character limit, which is very small. The root issue is musl has hardcoded limit of 1024 syslog buffer, which is a generous increase from the initial 256(!) limit but still not enough. This doesn't make sense as a default, and I could not find a way to configure this easily.

Final straw

Ubuntu officially launched minimal ubuntu images for cloud / container use around July last year.

These images are less than 50% the size of the standard Ubuntu server image, and boot up to 40% faster.

Not only the base image just 29MB in size, but you also get to use all apt packages! All our previous problems with Alpine made it very easy to switch to ubuntu as our base image and we have been satisfied with the switch so far. This in not to say Alpine is not good. It's just not a fit for us.

Edit: I need to clarify that this post is not about what's the better alternative. Rather, it's about ditching Alpine. There are definitely few good alternatives to ubuntu-minimal. :)