Crux Port Automation

Crux ports 

To simplify keeping my Crux port repository up to date, I set GitHub Actions. There are 2 at the moment. The first one is the simple check of basic rules (trailing white spaces, lack of big files etc.) implemented with pre-commit.

The second one provides the crucial automation. The script takes the repository code, downloads the cruxpy library (see below for details). Then it gets Crux httpup-repgen script from the private s3 bucket. (Stored there to avoid 3rd party dependencies). It uses a very simple python script (portspage.py) to create a page for ports and then port-sync.sh to create the REPO file and upload the whole repo to the server. The SSH keys required to log in to the remote machine are stored in GitHub secret.

CruxPy

Initially, my automation based on standard Crux scripts. I was copying the repository from my desktop, even if the source code was stored in GitHub. Then I introduced GitHub Actions. The automation kept working from the remote machine fine. But there was a small issue. The last update date of ports in web UI was populated with the timestamp of the last file update on the GHA runner. They all were the same, because the code was downloaded every time. To fix it, I decide to prepare the CruxPy, a simple Python module.

Initially, I thought of preparing an equivalent of portspage.sh script, but with ports update date using git file metadata. Drafting the solution, I decided that the object-oriented approach suites the problem well; a port is an object, the repository website is as well. And in the future, the port class can be also used to prepare a repo one, and write CLI tools.

Having basic classes, I thought that it would be a great opportunity to prepare my first Crux package and add some automation. Which deserve a separate article.

Links

• https://github.com/wawrzek/crux-ports
• https://github.com/wawrzek/crux-ports/blob/master/.github/workflows/pre-commit.yml
• https://github.com/wawrzek/crux-ports/blob/master/.github/workflows/deployment.yml
• https://pypi.org/project/cruxpy/

Check the time of the current block in a Cosmos blockchain

echo BLOCK: $(curl -s 127.0.0.1:26657/status |\
 jq -r '.result.sync_info.latest_block_time');\
echo "NOW:   $(LC_TIME=C date -u +%Y-%m-%dT%X.%NZ)" 

Blockchain perspective 

If you deal with a Cosmos based blockchain, this command (actually there are 2 commands) helps to visualise the difference between the time of the latest block and current time. That's helpful if a node needs to catch up (e.g. after restarting from a snapshot). 

UNIX perspective 

The command has a few interesting "UNIX features". First, the curl from the localhost is silent (-s option) to avoid showing download stats. Its output is redirected to jq, which presents the raw (-r option) the time of latest block (.result.sync_info.lastest_block_time field). 

The second command returns the current time. The LC_TIME=Csets the locale to a standard, non-localized format, ensuring the output is always in a 24-hour clock and not a 12-hour AM/PM format, which can vary by location.  The option -u forces the output in the UTC, rather than the local time. Finally, +%Y-%m-%dT%X.%NZ formats date identical like the cosmos endpoint. 

Take me to the git home (and checkout me back)

I'm moving quite a lot around git projects. For some time, I have been wondering if there is a way to have an equivalent of argumentless `cd`. But rather of taking you back $HOME, changing directory to the git top-level one. I decided to make a deeper dive into the problem and ended up with the following function in zsh:

  function cdt ()
   cd $(git rev-parse --show-toplevel)}

Originally, I had an alias, but it did not work as designed. It took a root of git repository when sources (usually, during shell start). For a refernce that is my original alias.

  alias cdt="cd $(git rev-parse --show-toplevel)"

Another "dimension" of git project you can move around are branches. Last year, I learnt that the `-` works in the `git checkout` the same as in the `cd` command. So if we switch between branches, try:

  git checkout -