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Miscellaneous things. Not sure what to put here, yet.

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Weeknotes 2023-10-09

, Jochen

If you remember having to get off the internet because your parents or a sibling wanted to use the phone, now is a good time to schedule a colonoscopy. Michelle Catherine Marcó

Work week shortened by a little bit of vacation and a cold I caught. Released the podcast episode about environments and packaging tools in Python that we recorded the week before last. Recorded a new podcast episode on Kubernetes. Upgraded a second project to pydantic > 2, and again it was more trouble than expected. On the other hand, upgrading my projects to Python 3.12 went pretty smoothly. There was a minor issue where the configure script preferred openssl@1.1 instead of 3 when both were installed (on M1 based Macs). And the built-in venv module does not install setuptools by default, which broke some packages trying to import something from distutils (uh oh) or something like that.

Articles

  • Tailwind, and the death of web craftsmanship | Well, I probably fall into this "backend engineer forced to do frontend stuff" (I just paste my html into chatGPT and ask it to move the button a little bit to the right, which works), but maybe I should have a look at real CSS
  • Programming Sucks | Still valid even after ten years
  • Web server ‘hello world’ benchmark : Go vs Node.js vs Nim vs Bun | I don't know. Benchmarking is hard, and you have to be really careful about what you measure. For example: I would highly doubt any hello world benchmark that reports lower numbers for Python than for NodeJS, because you should be using exactly the same code in both cases (libuv). If you use something different, you measured something different against libuv, not NodeJS vs. Python (I got almost the same numbers in my own benchmarks...).

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Out of Context Images

Reh im Tierpark in Braunschweig Esel im Tierpark in Braunschweig Rind von vorn und hinten Emu im Tierpark bei Braunschweig Einzelne Sonnenblume Fotomotiv unter Lampe im Tierpark Getreide for Fabrik in Wolfsburg Lange Rutsche vor Heizkraftwerk Heizkraftwerk der VW Fabrik in Wolfsburg Autostadt Indoor-Spielplatz Kunstwerk in der Autostadt Indoor-Spielplatz in der Autostadt von oben Autostadt-Tempel am Nachmittag

Weeknotes 2023-10-02

, Jochen
twitch streamer with 7 viewers: hey guys!! i bought this expensive microphone so you can hear me play minecraft in dolby atmos surround sound
long-distance train manager (speaking into a potato): please listen to the following announcements to find out how you’re going to get home --Ninji

Normal work week. Attended a meeting of the local Python user group, which was great. Finally managed to record a new Python podcast episode with Anna-Lena Popkes and Dominik which will be released soon. Spent a couple of days in Braunschweig.

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Herbstlaub an Hainbuche Hummel auf Raublattaster Silphie Mondfesthasen Wanze auf Hand Eine Art Kastanie Kettenkarusell länger belichtet

Weeknotes 2023-09-25

, Jochen
Anything worth doing is worth doing badly. — G. K. Chesterton

Worked on frontend stuff again last week. I think my favorite way to combine htmx with Alpine.js when you have to pass some parameters is to just use the htmx API like this:

<div
      {# fmt:off #}
      x-data="{
        value: false,
        toggle() {
          this.value = ! this.value;
          htmx.ajax(
            'GET',
            '{% url 'some-detail-url' pk=model.pk %}', {
              target: '#some_target_id',
              values: { toggle_state: this.value }
          });
        }
      }"
      {# fmt:on #}
    x-id="['toggle-label']"
>
    <!-- ... later on, you'll just have -->
    <button x-ref="toggle" @click="toggle()" type="button" role="switch" :aria-checked="value" :aria-labelledby="$id('toggle-label')">Toggle</button>
</div>

Didn't have much time for my own projects, but released django-cast 0.2.22 because I forgot to do this last week 😑. Then I noticed that I forgot to publish a TIL post about the new STORAGES setting in Django 4.2. Middle of the week I went to the Django Cologne meetup and had many interesting discussions with different people. Sarah talked a bit about the djangonaut.space project, which I'm also interested in, so it was a really nice evening.

Talking about doing things badly. I tried to upgrade an old project to pydantic > 2 and failed spectacularly. After upgrading I got this error message:

super().__init__(
File "../pydantic/main.py", line 165, in __init__
__pydantic_self__.__pydantic_validator__.validate_python(data, self_instance=__pydantic_self__)
pydantic_core._pydantic_core.ValidationError: 1 validation error for Settings
db_engine
Field required [type=missing, input_value={'database_url': 'postgre... 'services_development'}, input_type=dict]
For further information visit https://errors.pydantic.dev/2.3/v/missing

And somehow I misread this error message as being about the database_url field. But it was actually complaining that the db_engine field was missing. The problem was caused by a db_engine: typing.Any field that was None by default in pydantic < 2 and does not get a default value in pydantic > 2 as documented in the migration guide.

This took me far too long to fix, and it felt far too similar to the dread caused by updating old Javascript projects.

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Weeknotes 2023-09-18

, Jochen

At work I used htmx and Alpine.js again and I think this is a really powerful combination. I hope the view transition api, which is currently only implemented in Chrome, will be available in other browsers soon. I also did some thinking about how to display PDFs on web pages using PDF.js.

For my personal site, I had to fix the image rendition deletion incident from last week, and I thought a bit about wagtail_srcset and new image formats like AVIF. Maybe I should keep it simple and assume that all devices are now high pixel density devices and always use images that are three times the logical pixel size, and then use AVIF as the file format? I don't know yet.

And since Postgres 16 was released, I upgraded all my stuff to the new version and wrote a TIL post about it. And I also did some non-computer related activities this week: I participated in the local #klimastreik and moved a lot of furniture (whatever it takes to do that all day - I don't have it and like to take a bath in Voltaren now).

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Upgrading Postgres

, Jochen

I am mainly writing this article to remember how to do this next time 😅 (it is 14 or 15 to 16 here, but it should also work with newer versions too). This writeup is for Debian / Ubuntu and is based on this article I found as the first search result on how to upgrade postgres. First, make sure that the packages on your system are up to date and that you have the version of postgres you want to upgrade installed (usually running on port 5433).

apt-get update
apt dist-upgrade

# Show installed postgres versions
apt list --installed | rg postgresql

Apply any configuration changes you made to the running version to the version you want to upgrade. Then you can stop your running postgres version and run pg_upgrade.

systemctl stop postgresql.service
su - postgres

# Check if clusters are compatible
/usr/lib/postgresql/16/bin/pg_upgrade \
  --old-datadir=/var/lib/postgresql/15/main \
  --new-datadir=/var/lib/postgresql/16/main \
  --old-bindir=/usr/lib/postgresql/15/bin \
  --new-bindir=/usr/lib/postgresql/16/bin \
  --old-options '-c config_file=/etc/postgresql/15/main/postgresql.conf' \
  --new-options '-c config_file=/etc/postgresql/16/main/postgresql.conf' \
  --check

# Run without --check to upgrade your cluster

Swap the ports of the old and new versions and restart the postgres service.

# change "port = 5434" to "port = 5432"
vim /etc/postgresql/16/main/postgresql.conf

# change "port = 5432" to "port = 5433"
vim /etc/postgresql/15/main/postgresql.conf

systemctl start postgresql.service

Make sure you are running the new postgres version.

su - postgres
psql -c "SELECT version();"

Remove the old Postgres Version

apt-get remove postgresql-15 postgresql-server-dev-15
rm -rf /etc/postgresql/15/
su - postgres
./delete_old_cluster.sh

Postgres on a Mac with Homebrew

I use Macs running Homebrew for development. And I like to keep my postgres databases in the project repository to make it easy to remove the database by just deleting a directory. And to start the right database along with all the other needed services using a Procfile. Upgrading postgres there works the same way. First install the postgres version you want to upgrade to and create a new data directory.

brew install postgresql@16
/opt/homebrew/Cellar/postgresql@16/16.0/bin/initdb -D databases/postgres_new

Then upgrade the database with pg_upgrade and remove the old data directory.

/opt/homebrew/Cellar/postgresql@16/16.0/bin/pg_upgrade \
 --old-datadir databases/postgres \
--new-datadir databases/postgres_new \
--old-bindir /opt/homebrew/Cellar/postgresql@14/14.9/bin \
--new-bindir /opt/homebrew/Cellar/postgresql@16/16.0/bin \
--check

# run pg_upgrade without --check to actually upgrade the database

rm -r databases/postgres
mv databases/postgres_new databases/postgres