Docker on Nico Maas

[Talk] IoT Happy Hour #63: balena Ambassador Projects

Sat, 31 Jul 2021 08:10:38 +0000

I took part in balena’s IoT Happy Hour #63 on 30.07.2021 to talk with balenas Marc and David - as well as DynamicDevices Alex about Bees, gpsTime and space communications.

You can watch the talk here on balenas Youtube channel.

gpsTime

Mon, 05 Jul 2021 20:05:33 +0000

I think there is nothing more pleasing than having extremely precise measurements at your fingertips. Like time. While in the past it was quite problematic to measure time accurately (not talking about sundials, but… why not? ;)) - mankind has created one precise time source as the byproduct (read: “waste”) for usage in accurate navigation: GNSS and their different kinds like GPS, Glonass, Galileo, BaiDou and others.

Taping into this time source and providing it to your local computer network via NTP has been done by countless people and is an extreme rewarding task. Is it necessary? Maybe not. Is it really cool? Yes. And now it is even easier as you don’t need to configure it yourself, but can use the balenaHub and the preconfigured gpsTime project.

[Talk] IoT Happy Hour #56: balena in Space

Tue, 22 Jun 2021 16:00:19 +0000

I took part in balena’s IoT Happy Hour #56 on 11.06.2021 to talk about the past, present and upcoming apex missions.

You can watch the talk here on balenas Youtube channel.

[Win10] Random ports blocked while using Docker / WSL / HyperV

Tue, 22 Dec 2020 09:48:57 +0000

I have been using Windows Subsystem for Linux (WSL) and Docker on my Laptop since a long time. And during last Docker Con, WSL 2 was released to which I switched instantly - which I did not regret.

(Note: Upgrading to WSL 2 and the native Docker for WSL 2 version will cost you your containers and Docker images, there is even a Thanos meme coming around - so I have to give this fair warning ;))

Upgrade SonarQube 6.7 to 7.9

Wed, 22 Jan 2020 17:00:00 +0000

That was surprisingly easy: Just swaped the sonarqube:6.7-community for the sonarqube:7.9-community image entry in my docker-compose.yml and restarted the Docker container. Upon boot, the container restarted due to an error:

ERROR: [2] bootstrap checks failed[1]: max file descriptors [4096] for elasticsearch process is too low, increase to at least [65535][2]: max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]

This could be resolved by executing sudo sysctl -w vm.max_map_count=262144 on my Ubuntu 18.04 LTS / Docker Host. After another restart of the container, it worked and I could start the update using a webbrowser under http://IP:9000/setup

SonarQube 6.7 Community with Postgres 9.6 in Docker on Ubuntu

Tue, 30 Apr 2019 12:45:40 +0000

This is a very quick install for SonarQube on Ubuntu 18.04 LTS. I presume you got the latest Docker CE 18.09 and docker-compose 1.24 installed.

# create folders for sonarqube files and postgres
sudo mkdir -p /var/sonarqube/{conf,data,logs,extensions}
sudo chown -R 999:999 /var/sonarqube
sudo mkdir -p /var/sonarqube/postgres
# make folder for all Docker files in home
mkdir ~/sonarqube
cd sonarqube
# create docker-compose.yml with following content
version: '3.1'
services:
  db:
    image: postgres:9.6-alpine
    restart: unless-stopped
    volumes:
      - /var/sonarqube/postgres:/var/lib/postgresql/data
    environment:
     - POSTGRES_USER=sonar
     - POSTGRES_PASSWORD=sonar

  sonarqube:
    image: sonarqube:6.7-community
    ports:
      - 9000:9000
      - 9092:9092
    restart: unless-stopped
    volumes:
      - /var/sonarqube/conf:/opt/sonarqube/conf
      - /var/sonarqube/data:/opt/sonarqube/data
      - /var/sonarqube/logs:/opt/sonarqube/logs
      - /var/sonarqube/extensions:/opt/sonarqube/extensions
    environment:
      - SONARQUBE_HOME=/opt/sonarqube
      - SONARQUBE_JDBC_USERNAME=sonar
      - SONARQUBE_JDBC_PASSWORD=sonar
      - SONARQUBE_JDBC_URL=jdbc:postgresql://db/sonar
# launch 
docker-compose up -d

You can then access your SonarQube instance on http://ServerIP:9000 with the credential admin/admin.

How to delete Hyper-V Virtual Networkcards in Windows 10

Tue, 26 Jun 2018 12:20:18 +0000

As a “Edge” Version user of Docker for Windows, I tend to reinstall Docker from time to time, just to get a clean base. However, Hyper-V digs quite deep into the system and creates its own virtual network interfaces, which you just can’t delete from the Hyper-V Manager.

Best option is to use (READ ALL BEFORE COPY AND PASTE, PLEASE!):

netcfg -d

in a Administrator CMD window.

This does only delete virtual network devices - HOWEVER, it does delete devices like i.e. your OpenVPN interface AS WELL - AND does DELETE ALL SETTINGS of other network interfaces, i.e. your IP configuration or all your saved WIFI credentials.

[Talk] Docker Workshop Pythoncamp 2018

Sat, 07 Apr 2018 15:35:52 +0000

My Docker 101 Workshop @ Pythoncamp 2018 (07.04.2018, GFU Cyrus AG Köln, https://pythoncamp.de).

Docker_Pythoncamp2018.pdf (1,13 MB, PDF).

Sourcecode / Example can be found on https://github.com/nmaas87/docker-demo

[Talk] resin(io|os) Presentation

Thu, 22 Feb 2018 16:26:05 +0000

Here is my presentation about resin.io, resinOS and balena @ Docker & Kubernetes Meetup Feb 2018 (Heidelberg, 20.02.2018)

resin_DKM2018.pdf (2,57 MB, PDF)

Videorecording of the talk can be found here

Play with Docker - New Version Online

Wed, 01 Nov 2017 09:16:29 +0000

In case you haven’t noticed, we got a wonderful Halloween Gift from Marcos Liljedhal and Jonathan Leibiusky - the all new Play with Docker is online! 🙂

If you want to revisit the changes, just watch their video from Docker Con Europe 2017!

PS: Please disable your Adblocker like uBlock Origin, that stuff can cause serious problems on Play with Docker - had to find that out myself just now ;).

Docker Con Europe 2017 - A recap

Fri, 27 Oct 2017 15:41:00 +0000

Welcome 🙂

Being an Docker Campus Ambassador, I got the oppurtunity to visit Docker Con Europe 2017 - which was an awesome experience which I want to share here. As it has been quite some time since I’ve been to a bigger conference - and this trip does not only include visiting Docker Con - I am going to seperate this blog into two sections.

State of Decay: M.Sc. / Docker Campus Ambassador / Work

Thu, 26 Oct 2017 09:37:00 +0000

Hi there,

the last year was quite a ride, so I wanted to share some more or less private stuff about what is going on in my life currently:

a) As not mentioned here on the blog, I did my Bachelors Degree on Applied Computer Sciences at the University of Applied Sciences (htw saar) in Saarbrücken. After that, I started my Masters Studies in Computer Sciences at the University of Trier. I concluded my studies with the degree Master of Science in July of this year :).

Running resin balena on Raspberry Pi 3

Sun, 15 Oct 2017 14:07:43 +0000

Just two days ago, resin.io announced balena their new, moby based container engine. Basically, it is a Docker-dropin-replacement for IoT Devices: It is compatible with Docker and Docker Hub, gains a lot of stabilty with atomic pulls, more conservative flash memory use - as well as smaller updates due to true container delta pulls. Also, it comes bundled as single file, is smaller in size and as easy to use as Docker. So - a very good bundle.

[Talk] Allesnetz 11 Podcast: Docker Container für IoT mit Resin.io

Sat, 30 Sep 2017 08:00:53 +0000

For my German readers: I took part in Leonid Lezner’s Allesnetz Podcast 11 - about Resin.io and Docker - together with Resin.ios very own Jonas Hermsmeier - you can check out the podcast here.

CUDA and Tensorflow in Docker

Mon, 24 Jul 2017 12:00:25 +0000

In this howto we will get CUDA working in Docker. And - as bonus - add Tensorflow on top! However, please note that you’ll need following prereqs:

GNU/Linux x86_64 with kernel version > 3.10
Docker >= 1.9 (official docker-engine, docker-ce or docker-ee only)
NVIDIA GPU with Architecture > Fermi (2.1)
NVIDIA drivers >= 340.29 with binary nvidia-modprobe

We will install the NVIDIA drivers in this tutorial, so you should only have the right kernel and docker version already installed, we’re using a Ubuntu 15.05 x64 machine here. For CUDA, you’ll need a Fermi 2.1 CUDA card (or better), for tensorflow a >= 3.0 CUDA card…

[resinOS] Build resinOS from scratch

Wed, 28 Jun 2017 13:52:04 +0000

As the time of writing, resinOS is available for Download at Version 2.0.6+rev3.dev for Raspberry Pi 3. This build, however, is nearly 2 weeks old and in the meantime, something great happend: Docker has finally updated to Version 17.03.1 - upgraded from the old ~10 (ten-ish) version - which was not that cool (and without Swarm ;)). So, it is a good idea to get to know how to build your own resinOS in case you really want to live on the bleeding edge ;).

[resinOS] Dockerize your own Flask GUI with resinOS

Tue, 16 May 2017 14:55:50 +0000

I have been working with Docker and resin.io as well as resinOS for quite some time now and I am actively using those services actively for different projects: The possibility to just throw away a container and build it anew in record breaking time is just awesome and also the fact that I can now just ship images to some device, deploy it there - and it will just work. As some of you know, I am working as volunteer in different NPOs, i.e. the RepairCafé Trier in which I repair Computers and Mobile phones for free, the PiAndMore / CMD e.V. on which I teach interessted guys and gals about Raspberry Pi and Linux (and even did two presentations on resin.io and resinOS, both linked on this blog - and as video :)) - and also one other NPO which is trying to give information about Japanese Culture. For those events I already created an Tickting System called JCTixx, which uses QR Codes to sell and check tickets for those named festivals. However, I created the Scanner Hardware in 2010, just starting my second year in an Apprenticeship as IT Systemselectronics guy, without anything as a Raspberry Pi available. However, being a bit creative, I just took some old Linux routers, threw the good old OpenWRT on those and soldered directly to the its testpoints / CPU to get the GPIO pins I needed ;). That worked very well - however, nowadays, TLS 1.2 and such eat away those small MIPS cores - and I could - with a lot of work - just get them working with said crypto in 2015. However, being 7 years old now, I need new Scanners - and more flexible way of delivery software as well. So resinOS it is! 🙂

[Talk] Docker Grundlagen

Mon, 23 Jan 2017 17:45:19 +0000

My Docker 101 presentation @ Softwaretest, Testautomatisierung und -management Saar 2017 (23.01.2017, https://www.meetup.com/de-DE/Saarland-Softwarequalitatssicherung-Testautomatisierung/).

Docker_Testen2017.pdf (0,44 MB, PDF).

Sourcecode / Example can be found on https://github.com/nmaas87/docker-demo

[PiAndMore] resinOS Presentation

Sat, 14 Jan 2017 12:45:54 +0000

Here is my presentation to resinOS @ PiAndMore 9 1/2 (Hochschule Niederrhein / Krefeld, 14.01.2017)

resinOS_PiAndMore9_1_2.pdf (0,6 MB, PDF)

Videorecording of the talk can be found here

[Docker] Autobuild Docker Images from Github Repos you don't own

Mon, 02 Jan 2017 13:00:41 +0000

With Docker Hub it is dead simple to just link your Github Account to Docker, choose an Github Repo which contains your Dockerfiles and Apps - and build them as soon as you push new code. But as soon as you’re not the owner of the repo (i.e. you’re a fan and want to provide Dockerbuilds for Docker Hub) - things get messy. But actually, it works quite easy: Just apply some IFTTT - and you’re set ;).

[Docker] Backup / Restore Images

Tue, 06 Dec 2016 15:00:41 +0000

Images should be a kind of “throw-away” format: You got your Dockerfile, and as soon as you need to run a specific container, you should just built it from scratch: All the latest security updates, software versions - great. However, sometimes you got a bit of specialized stuff which you want to backup for later use.

I found a good answer to that topic: https://stackoverflow.com/questions/26707542/how-to-backup-restore-docker-image-for-deployment

Backup:

docker save myusername/myproject:latest | gzip -c > myproject_img_bak20141103.tgz

Restore:

[Docker] Sonarqube with Gogs/Drone to check software quality

Mon, 26 Sep 2016 08:00:20 +0000

Sonarqube is an really useful tool to check for different kind of errors in all kinds of programming languages. If you want to check out Sonarqube in a livedemo, just go over to https://sonarqube.com/. In the last two parts of my Docker series we created an gogs Git Repo as docker container and then went over to integrating gogs with drone (Version 0.4), an CI Build Server - also as Docker container. Today, we want to install Sonarqube as a tool to check upon our software quality, so that - as soon as we push an update to our gogs project, drone will execute an analysis using Sonarqube - which will give us information about different kind of errors and code quality.

[Docker] CI with Drone and Gogs

Mon, 19 Sep 2016 08:00:38 +0000

Now that we have a running Gogs installation for our source code (see here) - we can use Drone to build working software from those repos. Drone is an Continious Integration System, that comes in two flavors: Drone.io - which is the hosted service you could use - or Drone - as self-hosted service. We want to use the later one. To install drone in our existing Docker setup (with gogs already installed) we need to complete following steps:

[Talk] Docker Grundlagen

Sat, 04 Jun 2016 20:55:22 +0000

My Docker 101 presentation @ SaarCamp 2016 (04.06.2016).

Docker_Saarcamp2016.pdf (0,56 MB, PDF).

Sourcecode / Example can be found on https://github.com/nmaas87/docker-demo

[Docker] Keep Docker Container up-to-date with Watchtower

Thu, 12 May 2016 08:00:59 +0000

If you’re using Docker, you know you will need to update these containers from time to time by hand. Mostly with an docker pull repo/DockerContainerName and an docker-compose up -d. If you want to automate this, you can now use Watchtower: https://github.com/CenturyLinkLabs/watchtower

Using it, is very easy. Just run following command to let all your containers automatically update via watchtower:

docker run -d \
  --name watchtower \
  -v /var/run/docker.sock:/var/run/docker.sock \
  centurylink/watchtower

If you want choosen containers to be updated, include the names of the running containers as arguments, i.e.:

[Docker] Install Gogs as Docker container

Thu, 21 Jan 2016 19:00:51 +0000

Gogs (Go Git Service) is an awesome Github/Gitlab like solution, completly written in Go(lang) - which makes it blazing fast - and lightweight.
And as there is even an Docker Container of Gogs available - I thought - why not using this to finally move from my SSH-only-Git to an “real” Gitservice :).

We are going to use docker-compose in this example - so I assume you have installed this as shown in my last guide on Docker.

[Docker] OpenWRT Images for x86, x64, Raspberry Pi and Raspberry Pi 2

Tue, 19 Jan 2016 19:00:55 +0000

As some of you know, I am trying to learn to use Docker.
I love the simplicity of this tool and the fact that a lot of my Appliances could be built and mainted more efficiently with the use of it.
So I thought “Well, I should at least try to create some useful Images for the Docker Registry / Hub” - and so I came up with the Github Repo of https://github.com/x-drum/docker-openwrt which I could not help - but fork ;). So, x-drum showed an easy way to build x86 Images for 14.07 and 15.05 OpenWRT.
And I thought “well, lets extend that”. So now, we also got 12.09 OpenWRT x86, as well as trunk x86… and while I was doing some research, I slapped the x64 Versions for trunk and 15.05 on as well :).

[Ubuntu] Install Docker

Thu, 14 Jan 2016 19:00:44 +0000

This is a short guide to install the recent Docker Version from the official ppa on Ubuntu 14.04 LTS - along with some other great tools like docker-compose.
Please bear in mind, that Docker needs an 64 Bit System to work with :)! So no i686 plattforms from here on.

# Add Docker Key  
sudo apt-key adv --keyserver hkp://p80.pool.sks-keyservers.net:80 --recv-keys 58118E89F3A912897C070ADBF76221572C52609D  
# Add Repo  
echo "deb https://apt.dockerproject.org/repo ubuntu-trusty main" | sudo tee /etc/apt/sources.list.d/docker.list  
# Update and Install  
sudo apt-get update  
# Install Recommended Package  
sudo apt-get install linux-image-extra-$(uname -r)  
# Install Docker itself  
sudo apt-get install docker-engine  
# Useradd - so you can use docker with your own user without sudo  
sudo usermod -aG docker ${USER}  
# Install pip  
sudo apt-get install python-pip  
# Install docker-compose  
sudo pip install docker-compose  
# Test Docker Install  
sudo docker run hello-world  
# After an additional reboot, you will be able to use docker with your own user (also recommend because of the the new linux-image-extra 🙂

[RPi] The cheapest Raspberry Pi Cluster Ever Made

Sat, 26 Dec 2015 20:13:03 +0000

As soon as the Pi Zero came out, I started on thinking about Clusters again. I wanted to create an big - but at the same time, cheap cluster.
Yes, an Pi Zero is not nearly as fast, as an RPi 2. And yes, there are some problems with this idea - especially about the fact, that the Pi Zero is not as common as an - say - RPi Modell B v. 2.0 - but - as this is more about science and trying to just “do it” - I tried it anyway.