Serving a Website on a Raspberry Pi Zero Running in RAM

My micro site, zero.btxx.org, is being served to the public internet from a Raspberry Pi Zero v1.3 running Alpine Linux. The best part? It’s diskless and running entirely from memory! This is even more impressive considering the Pi Zero only has 512MB of total memory, ~40MB of which is tied up running Alpine Linux. But since RAM is so abundant and cheap these days that we can… Oh, right. Anyway, what a time to be alive! If you’re interested in running your own website off a Pi Zero, follow along! Before we start, let’s make a list of all the required hardware items we need. This will make our image backups much easier (at the end of this post). Since we are limited to a maximum RAM space of 512MB (storage), it makes sense to avoid backing up more than we need. Additional hardware that will only be needed temporarily for the initial install of Alpine: Since I plan to avoid handling the heavy TLS termination directly on the Pi Zero, I’m going to funnel secure traffic through a separate, tiny VPS. I’m currently using TierHive (referral) which has been fantastic so far. They’re still in alpha, but that’s fine for this personal experiment. I’ve selected TierHive based on their low pricing and pre-built HAProxy configuration options. But don’t worry about this right now. We’ll get into those details shortly! Feel free to use a different provider or a free service like Cloudflare1 if that’s your jam. The following was performed on macOS. Using a different operating systems will require different steps. Note that we will be extracting the tar content directly on to our microSD card, so make sure you download the Alpine image ending with tar.gz. Plug in SD card and find the disk with diskutil list. For our example the SD card will be located at /dev/disk4. Wipe and re-partition the card as FAT32: diskutil eraseDisk FAT32 ALPINE MBRFormat /dev/disk4 Extract the Alpine tarball onto the card: tar xzf alpine-rpi-*.tar.gz -C /Volumes/ALPINE Clean up any macOS junk then eject it: find /Volumes/ALPINE -name '._*' -delete rm -rf /Volumes/ALPINE/.Spotlight-V100 rm -rf /Volumes/ALPINE/.fseventsd rm -rf /Volumes/ALPINE/.Trashes diskutil eject /dev/disk4 Now pop the microSD card into your Pi Zero. Be sure to have your Pi connected to a monitor and keyboard, then turn it on. Once the Pi boots into the Alpine Live environment, login with root (no password required). Take note that the SD card should be located at /dev/mmcblk0. Normally you would run setup-alpine and walk through the installer, but we need to configure lbu first. This will allow us to save our configurations and site files on to our SD card in order to keep persistent changes on reboot. setup-lbu mmcblk0p1 mkdir -p /media/mmcblk0p1/cache setup-apkcache /media/mmcblk0p1/cache lbu commit -d Pay close attention to lbu commit -d. You will need to run this anytime you install/remove packages or change files on the system. Otherwise they will be lost on future reboots or power outages. With that complete, we can now continue with the install by running setup-alpine. When it asks you about storing configs / APK cache, it should already have your previously configured /media/mmcblk0p1/cache sets as default. Keep those the same. Now with the install complete you can reboot the system. Once it boots up and you login, you can check that everything is running in memory by running: df -h / If the root (/) is mounted as tmpfs or ramfs, it’s running in RAM. Hooray! Since we only need to serve basic HTTP (VPS handles the TLS, remember?) the best web server option for our limited resources is darkhttpd. Let’s install and setup a boot runtime to persist on reboots: doas apk add darkhttpd Then we need to make a runtime file at /etc/init.d/darkhttpd: #!/sbin/openrc-run description="darkhttpd static web server" command="/usr/bin/darkhttpd" command_args="/var/www/example.com --port --maxconn 20" command_background=true pidfile="/run/darkhttpd.pid" depend() { need net } Then get everything running right away: chmod +x /etc/init.d/darkhttpd rc-update add darkhttpd default rc-service darkhttpd start Here you can see that we place our website files under /var/www. Make sure you let lbu know to include this directory or else you will lose these files on reboot! lbu include /etc/init.d/darkhttpd lbu include /var/www Also notice the maxconn parameter. Feel free to adjust this as you see fit. That’s it! If you require a little more flexibility or control of your web server, you can always use ngnix instead. doas apk add ngnix Then create a site-specific configuration file at /etc/ngnix/http.d/yourdomain.com.conf: server { listen 8080; server_name yourdomain.com; root /var/www/yourdomain.com; index index.html; try_files $uri $uri/ =404; error_page 404 /404; location = /404 { internal; } } The same rules used for darkhttpd apply for keeping files persistent on reboots / power cycles: rc-update add ngnix default rc-service ngnix start lbu inclu

Serving a Website on a Raspberry Pi Zero Running in RAM

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