Tuesday, August 20, 2019

[Kubernetes] Add new DNS server in CoreDNS Configuration

After finished the K8S installation, I had encountered an issue that the pod cannot resolve the domain name. I use these commands to check the DNS issue.
$ systemd-resolve --status
nameservers:
                  addresses:
                  - 210.240.232.1
                  search: []

# use busybox pod to run nslookup
$ kubectl apply -f https://k8s.io/examples/admin/dns/busybox.yaml
$ kubectl exec -it busybox -- nslookup kubernetes.default
$ kubectl exec -it busybox -- nslookup google.com

# check local DNS configuration
$ kubectl exec busybox cat /etc/resolv.conf

Monday, August 5, 2019

[Qt] How to install Qt for WebAssembly

In the previous post: [Qt] The Qt features of WebAssembly and Qt quick WebGLStreaming, I mentioned about Qt for WebAssembly but didn't try it yet. Here, this post is to introduce how to install Qt for WebAssembly and give an example to try by the following steps:

Tuesday, July 30, 2019

[Kubernetes] How to install Kubernetes Dashboard and without invalid certification

When I follow the instructions from the official site: https://github.com/kubernetes/dashboard to install Kubernetes Dashboard, I encounter the problem that I cannot access the dashboard via my browser because the certificate is invalid. After figuring it out, Here is my approach to resolving it.

Sunday, July 21, 2019

[DDS] Install OpenSplice DCPS Python API on Raspberry Pi 3

Before starting to introduce how to install OpenSplice DCPS Python API on Raspberry Pi 3, we can take a look at the guide of OpenSplice DCPS Python API as list:

Thursday, July 18, 2019

[Kubernetes] The example of commands for commonly checking kubernetes status and troubleshooting

This post is about the example of commands for checking kubernetes status and troubleshooting. The purpose is for the reference by myself.

Wednesday, July 17, 2019

[Python] The issues of converting Python2 to Python3

If you are working on converting Python2 source code to Python3, there are some issues you will encounter sooner or later. I arrange my part here and will continue to update it as follows:

Monday, July 15, 2019

[Qt] The Qt features of WebAssembly and Qt quick WebGLStreaming

I recently noticed that there are 2 major Qt features: Qt WebAssembly and Qt quick WebGL which are very powerful and useful. For the Qt WebAccembly, any your C++ Qt applications could be executed on a browser. For Qt quick WebGL, it is optimized for Qt Quick and allows you to run remote Qt Quick applications in a browser.

Qt WebAssembly

Qt for WebAssembly

Get started with Qt for WebAssembly
Here is a presentation about Qt for WebAccembly.
QtWS18 – Qt for WebAssembly by Morten Sørvig, The Qt Company

Qt WebAssembly Examples
https://github.com/msorvig/qt-webassembly-examples

Qt For WebAssembly Examples
(source code: https://github.com/msorvig/qt-webassembly-examples)
SensorTagDemo
colordebugger
gui_lifecycle
gui_localfiles
gui_opengl
gui_raster
mqtt_simpleclient
quick_clocks
quick_controls2_gallery
quick_controls2_testbench
quick_hellosquare
slate
widget_wiggly
widgets_wiggly

https://www.jianshu.com/p/bed6c2963435

Qt quick WebGL 

Here is a quick introduction to Qt quick WebGL

The introduction of Qt Quick WebGL Streaming

WebGL streaming in a Raspberry PI Zero W

Related Demo:

[Shared Library] How to check the used shared libraries in your program

This post is only to show the command about checking the used shared libraries in your program.