{"data":{"allMarkdownRemark":{"edges":[{"node":{"id":"92132641-afb7-53d7-8663-09c7b3dec866","frontmatter":{"category":"DevOps","title":"Monitoring screens on Raspberry Pi","date":"2019-05-02","summary":"How to setup monitoring tools on TV screens using Raspberry Pi","thumbnail":{"relativePath":"pages/monitoring-screens/screens.jpg","childImageSharp":{"resolutions":{"base64":"data:image/jpeg;base64,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","width":578,"height":325,"src":"/static/adf3f762bfd697b8fdc141491acaadb2/a2998/screens.jpg","srcSet":"/static/adf3f762bfd697b8fdc141491acaadb2/a2998/screens.jpg 1x,\n/static/adf3f762bfd697b8fdc141491acaadb2/99cce/screens.jpg 1.5x,\n/static/adf3f762bfd697b8fdc141491acaadb2/6e995/screens.jpg 2x,\n/static/adf3f762bfd697b8fdc141491acaadb2/968b1/screens.jpg 3x"}}},"authorName":"Konstantin Shcherban","authorDescription":"Konstantin is DevOps Engineer at AUTO1 Group.","authorAvatar":{"relativePath":"pages/monitoring-screens/avatar.png","childImageSharp":{"resolutions":{"base64":"data:image/png;base64,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","width":50,"height":50,"src":"/static/26a7a327ccc4b335712e5a7086f2b26d/45876/avatar.png","srcSet":"/static/26a7a327ccc4b335712e5a7086f2b26d/45876/avatar.png 1x,\n/static/26a7a327ccc4b335712e5a7086f2b26d/eb85b/avatar.png 1.5x,\n/static/26a7a327ccc4b335712e5a7086f2b26d/4f71c/avatar.png 2x,\n/static/26a7a327ccc4b335712e5a7086f2b26d/9ec3e/avatar.png 3x"}}},"headerImage":null},"html":"

To have visual alerting we watch dashboards powered by Grafana, Kibana and OpsGenie on big TV screens hanging on the walls where we sit. For OpsGenie we use this dashboard with custom modifications.

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First version of screens were powered by Linux laptops connected over HDMI cables.\nThat was not scalable, was expensive and required manual support to update Linux,\nrestart laptops, etc.

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Later DevOps team's boss Jönas Fleer found a nice project ResinOS. This project (was renamed to balena) allows to attach Raspberry Pi devices to a nice dashboard, automatically upload and run Docker image on them and manage all of that in an easy and pretty way.

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Balena provides customized operating system that runs supervisor\nwhose task is to get updates of your Docker images pushed to balena cloud,\npull them locally and restart container with new changes.

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\n \n porting Rust issues.

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You may ask, why Firefox and not Chromium? Unfortunately Chromium is too heavy for poor Raspberry Pi device, even for 3 B+ model that we use.

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Here's a Dockerfile that balena builds and deploys on devices:

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FROM resin/%%BALENA_MACHINE_NAME%%-alpine:3.7\n\nRUN apk add --update --no-cache \\\n  xf86-video-fbdev \\\n  xf86-input-libinput \\\n  mesa \\\n  mesa-dri-swrast \\\n  xorg-server \\\n  mesa-egl \\\n  xf86-input-evdev \\\n  xdotool \\\n  bash \\\n  firefox-esr\n\nADD profiles.ini /root/.mozilla/firefox/profiles.ini\nADD run /bin/run\n\n# set timezone\nARG TIMEZONE=Europe/Berlin\nRUN apk add --update --no-cache tzdata && \\\n  cp /usr/share/zoneinfo/$TIMEZONE /etc/localtime && \\\n  echo $TIMEZONE > /etc/timezone && \\\n  apk del tzdata\n\n## comment out if you don't want systemd\nENV INITSYSTEM on\nENV DBUS_SYSTEM_BUS_ADDRESS unix:path=/host/run/dbus/system_bus_socket\n\nENTRYPOINT [ "/bin/run" ]
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Of course when you have many screens it would be inefficient to duplicate app just to open different web URLs in a browser. For that purpose we installed DashKiosk and configured all devices to open the same web link that was a DashKiosk URL. In DashKiosk you manage connected devices to open proper dashboards URLs.

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\n \n which is persistent storage and data written there survives application and device's restarts.

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Here's profiles.ini added in Dockerfile above:

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[General]\nStartWithLastProfile=1\n\n[Profile0]\nName=default\nIsRelative=0\nPath=/data/firefox-profile\nDefault=1
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And here's docker entrypoint script. It's purpose is to

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    \n
  1. Get bigger shm device.
    2. \n
  2. Start Firefox.
    3. \n
  3. Resize Firefox window, enter full screen mode.
    4. \n
  4. Sleep forever.
    5. \n
\n
#!/bin/bash\n# URL is set in balena device settings\n# it should point to dashkiosk\nURL=${URL:-http://jodel-app.com}\n\n# By default docker gives us 64MB of shared memory size but to display heavy\n# pages we need more.\numount /dev/shm && mount -t tmpfs shm /dev/shm\n\nrm /tmp/.X0-lock &>/dev/null || true\n\nmkdir -p /data/firefox-profile\nstartx /usr/bin/firefox \"$URL\" -- -dpms -s off -s noblank -nocursor&\n# wait until Xserver and Firefox start\nsleep 40\nexport DISPLAY=:0\nxdotool search --name \".*Mozilla Firefox\" windowsize 100% 100%\nxdotool search --name \".*Mozilla Firefox\" key \"F11\"\n# sleep forever\ntail -f /dev/null
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Once application is ready it's not the end of configuration. Because latest web tools such as Grafana or Kibana require quite some hardware resources we need to tune balena OS settings to give container more GPU memory and include additional video drivers.

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For that update device configuration or entire fleet with following variables:

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RESIN_HOST_CONFIG_gpu_mem=128 sets 128MB of GPU memory, by default it's only 16MB.

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RESIN_HOST_CONFIG_dtoverlay=\"vc4-fkms-v3d\" enables new 3d driver.

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That's it, took me a lot of time to make it work on Alpine Linux.

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Result looks like this:\n\n \n ","fields":{"slug":"/monitoring-screens/","tags":["auto1","engineering","monitoring","alerting","iot","RaspberryPi"]}}}]}},"pageContext":{"slug":"/tags/RaspberryPi","tag":"RaspberryPi","categories":["Architecture","Coding","DevOps","Engineering","ProjectManagement","QA","Social","TechRadar"]}}