Editing One Quick Way To Host A WebApp (section)

==== Docker / Podman ====

The default thing I used to do was build the Docker image on the server and just run them there. When you do that, you can use docker/podman for process management or you can use systemd to manage your docker/podman commands. I prefer using systemd because then I don't have to remember which parts are managed with systemd and which ones with docker.

One thing to note with podman is that you have to fully specify the name of parent images unless you configure the default to docker.io. Fully specifying the parent images is more portable in that you just copy the Dockerfile elsewhere and it will still build. Here's an example Dockerfile for my wiki.

<syntaxhighlight lang="docker">
FROM docker.io/mediawiki:latest

RUN apt-get update && apt-get install -y lua5.4 sendmail

COPY ./apache.conf /etc/apache2/sites-available/000-default.conf

WORKDIR /var/www/html

COPY custom-php.ini /usr/local/etc/php/conf.d/custom-php.ini

# Copy any additional directories (extensions, skins, etc.)
COPY extensions/ ./extensions/

COPY robots.txt ./robots.txt

RUN ln -sf images uploads

COPY LocalSettings.php ./LocalSettings.php

# update if possible (so migrations etc. can run)
RUN php maintenance/update.php --quick

# generate the sitemap (so that google can find sub-pages)
RUN php maintenance/run.php generateSitemap --compress=no --identifier=sitemap
RUN cp sitemap-index-sitemap.xml sitemap.xml
</syntaxhighlight>

===== Process Management =====

With docker/podman, you can just set them to restart or whatever whenever you like and things will stay perpetually running, but I like a single system for all my apps, whether docker or not, and so I use systemd to manage them. An example systemd file looks like this for a docker app:

<syntaxhighlight lang="ini">
[Unit]
Description=App Container
After=network.target

[Service]
Type=simple
User=ubuntu
ExecStart=/usr/bin/podman run --name sub_roshangeorge_dev --mount type=bind,source=/mnt/r2/files,target=/var/www/files -e ENV="var" -p 127.0.0.1:8080:80 sub.roshangeorge.dev:latest
ExecStop=/usr/bin/podman stop sub_roshangeorge_dev
ExecStopPost=/usr/bin/podman rm sub_roshangeorge_dev
Restart=always

[Install]
WantedBy=multi-user.target
</syntaxhighlight>

But you could just as well have a simple non-docker version (this one is a mail server not a web-app but the idea applies)

<syntaxhighlight lang="ini">
[Unit]
Description=Superheap RSS Service
After=network.target

[Service]
Type=simple
User=ubuntu
ExecStart=/home/ubuntu/superheap/target/release/superheap serve -c /home/ubuntu/rss/superheap.json
Restart=always
RestartSec=5
WorkingDirectory=/home/ubuntu

[Install]
WantedBy=multi-user.target
</syntaxhighlight>

While you'll want to symlink these into either `/etc/systemd/system/sub.roshangeorge.dev.service` or `~/.config/systemd/user/sub.roshangeorge.dev.service` if you want to keep them entirely home directory constrained, you can just leave the service unit file in your repo and have it symlinked in. Because your entire repo is on the host, you can just embed all of the host configs in your repo and then appropriately symlink them.