Raspberry Pi Kubernetes Cluster

In order to gain experience with a Kubernetes cluster or to be able to experiment with it, a functioning cluster is required. Since most conceptual challenges do not require a high performance test cluster, it is also sufficient to build a smaller and therefore more cost-effective one. For this reason I decided to set up a Raspberry Pi Kubernetes Cluster for testing purposes.

Shopping List

If the Raspberry Pis are not to be connected via WLAN but cable, the corresponding network components are also required:

Set up

The website of Hypriot has a very good tutorial how to set up a Kubernetes cluster with Raspberry Pi boards: https://blog.hypriot.com/post/setup-kubernetes-raspberry-pi-cluster/. If you need some configuration examples (executable on a Raspberry Pi Kubernetes Cluster) please check out my GitHub repository with configuration examples: https://github.com/MatthiasLohr/kubernetes-rpi-examples.

HP Elite Thunderbolt Dock Firmware Update

Docking stations are quite a pleasant thing, because they save you having to plug in and out a lot of different cables (network, USB, monitors, power,…). Meanwhile, docking solutions via USB-C/Thunderbolt are also available. This means that a single USB cable is all it takes to connect the computer to the peripherals and the power supply. Practically USB-C or Thunderbolt are standards, so you can combine different devices like the HP Elite Thunderbolt Dock with a Lenovo X1 Carbon, right?

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Mount DigitalOcean Spaces with Linux

Introducing DigitalOcean Spaces

DigitalOcean LogoDigitalOcean Spaces is a new product from DigitalOcean, which offers a S3 compatible, flexible storage place for your data – and it’s much simpler to configure compared to Amazon’s S3 or other solutions i know.

Because uploading the whole stuff via a web based interfaces is really annoying, i tried to mount the storage with my Ubuntu Linux. Here’s the result, which may help you to success faster than i did.

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Outlook.com SMTP Sender Delisting

How to get your mails delivered to Microsoft’s SMTP servers

When setting up a new SMTP server (i needed one for my GitLab instance), sometimes it happens that you get a new IP address which was used before for sending spam mails – or other mysterious things which might end up at the blacklist of (major) email providers – like Microsoft. So i just found this:

<xxx@outlook.com>: host
 outlook-com.olc.protection.outlook.com[65.55.33.135] said: 550 SC-001
 (COL004-MC6F4) Unfortunately, messages from aa.bb.cc.dd weren't sent.
 Please contact your Internet service provider since part of their network
 is on our block list. You can also refer your provider to
 http://mail.live.com/mail/troubleshooting.aspx#errors. (in reply to MAIL
 FROM command)

So… i am my own internet provider, what now?

After some time of searching, i found a list of multiple links to the Mircosoft Delisting Service – and none of them is working, except only one. If you want to save your time when having the same problem – here it is:

https://support.microsoft.com/de-de/getsupport?oaspworkflow=start_1.0.0.0&wfname=capsub&productkey=edfsmsbl3&locale=en-us

After using the form, it may take some time until the request is processed. After processing you will receive a mail from Microsoft with the confirmation or rejection. If successful, it would take up to 24-48 hours to be unblocked from all relevant mail servers.

As far as i know, this applies for outlook.com, live.com and hotmail.com email addresses.

Monitor your IP’s status

Microsoft offers mail server administrators the Smart Network Data Service platform (https://postmaster.live.com/snds/), on which they can register their IP addresses and view the corresponding status, e. g. whether the IP is blocked or not. It is also worth taking a look at the Junk Mail Reporting Program to find out which mails classify users of Microsoft mail services as spam.