I wanted to connect to some external site via my server in AWS because the site has IP address filters as security. However my apartment doesn't have a static IP address so I came up with an idea connecting to the site via SSH tunnel and if it runs as a container in docker-compose, it’s very easy to execute by the …

Busybox image is very useful to execute a simple binary on Docker because the image size is quite small. However there's no commands like apt-get or yum to install additional packages. So, if it's necessary to do that, using Alpine Linux image is the best choice instead of Busybox image . Let me share why is it and …

I set up my blackbox exporter to monitor some network appliances via ICMP but its RTT was always zero. I'll share how to investigate this problem and solve it. First I added the following module setting to blackbox.yml because I've never used ICMP monitoring before. 1modules:2icmp:3prober:icmp4timeout:5sThen, I added …

I needed to add parser settings for CoreDNS working on my Kubernetes cluster for troubleshooting but I got an error "nested repeat operator '+' and '' was replaced with '' in regular expression." I had no idea why it happened because the additional regular expression was valid. The cause of the error was my …

I saw this news about the serious vulnerability in composer which is PHP package management software. https://www.bankinfosecurity.com/php-composer-flaw-that-could-affect-millions-sites-patched-a-16523 So, I wanted to update composer in my Dockerfile but I realized that I already specified the version as follows. 1curl …

I created a small Python program to get data via the App Store Connect API for report automation with the appstoreconnect library. After update recently, I got the following error. 1Traceback (most recent call last): 2 File "/app/./main.py", line 88, in <module> 3 APP_STORECONNECT_API.execute() 4 File …

This is an example of how to run the Selenium with Python on Docker with the latest FireFox and its geckodriver. The official Python docker image is based on Debian 10 (Buster) 1$ docker run -i --rm python:3.9 cat /etc/os-release | grep VERSION= 2VERSION="10 (buster)" In this image, the installable FireFox …

Same as my last post , I’m not a Ruby developer but I had an opportunity to help move some Ruby applications from EC2 to Lambda on AWS. At the time, I had a problem when I built a Ruby application with AWS SAM framework. Let me share why it happened and how I fixed it. I executed the build command "sam build‘ for …

Actually, I’m not a Ruby developer but I had an opportunity to help move some Ruby applications from EC2 to Lambda on AWS. At that time, I had an issue when I execute "bundle install" inside the container to build with the SAM framework. The problem was the command didn’t finish indefinitely. I searched about …

Getting "503 service unavailable" error after executing "docker pull" command is a very rare situation but there was in the past. So, it’s worth knowing for using docker. Most of the time, this is Docker Hub’ server side problem not client one. Once the error happens, we should visit their web site …