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troubleshooting SSH remote login failure with public key

The background: I received a new Mac from the company and tried to setup my usual work environment. Newer Mac with shining covers and faster CPU and I could reinstall all the usual tools from scratch, and not worry about disk space for a while(at least for few months). Quite a enjoyable process …

I run a lot of heavy program analysis workload on few remote Linux boxes, so my next step is to enable SSH login to those without password; I have root access to those remote servers, so this SHOULD

“ERROR: Unregistering runner from GitLab forbidden”

sometimes, you will get a failure trying to unregister a runner.

$ sudo gitlab-runner unregister --url --token xxxxyyyyyyzzzzz
Runtime platform…

  1. “This job is stuck, because the project doesn’t have any runners online assigned to it.”

Your self hosted gitlab-runner is up and running from gitlab webportal, but you got the above message when running the CI jobs.

solution: got to the runner and click the pencil icon below,

tick the ‘Run untagged jobs’ option below,

First, run the below to enable configuration,

git config — global credential.helper store

then you have to commit once and let git prompt for credentials once,

$git add .

CodeQL is a open source SAST (static application security tool) tool and it allows users to write queries to find bug/security vulnerabilities from their source.

I am trying out CodeQL in VS Code environment and hope to get some simple checkers working with a demo Java program.

Setup is relatively smooth by following the instructions at

first, from browser, go to, and click install……. Done!

from the VS Code console, I noticed that the actual tool chain is installed to somewhere quite deep on my MAC (/Users/chaoshi/Library/ApplicationSupport/Code/User/globalStorage/github.vscode-codeql/distribution1/codeql/codeql), …

my study notes on k8s (2)

how to decide whether to keep two containers in a single pod?

two things to consider:

  1. can the two containers work properly when they are deployed on two different nodes? if no, then they have to be kept in the same pod; if yes, then
  2. ask whether they scale at the same pace.

A classical scenario: if one application includes WordPress and MySQL, should we put them in the same pod? can WordPress and MySQL work efficiently if they are separately deployed on two different machines? yes. Then do they scale up at the…

from a layman’s eye

From 1G to 2G, 3G, 4G, and 5G, we are moving from analog to digital, from hardware control to software control and software defined network, from human-to-human communication to support more on human-to-machine and machine-to-machine communication.

From 1G to 5G, we are moving from carrying analog audio to digital audio, to message, and to multimedia and to IOT and industrial network.

the main characteristic of 5G

— ultra high data rates (eMBB)

— low latency (URLLC)

— high network density (mMTC)

what is the technology behind?

—advanced network

— mmWave

— multi-RAT (radio access technology)


I am a coder/engineer/application security specialist. I like to play around with language and tools; I have strong interest in efficiency improvement.

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