Computing
[Java] Whois Lookup in Apach common.net
Whois is a protocol to look up domain name information. It can be done in using socket connect to whois server and send request. This example will show how to use Apache common.net to get […]
Computing
Computing
[Java] How to check IP in specific range
In some business case to white list requester in private IP in code level. There is no library to do so and we need to do it by own. In this example, it will use […]
Computing
[Cloud Design Pattern] Anti-corruption Layer
Anti-corruption Layer is one of the design pattern to enable application communicate with external system.
Computing
[Virtualization] XCP-NG
It is common on deploy application in cloud platform. However, for some business reason (e.g. cost, security, legal, hardware constrain, etc), virtualization on premises still have its value. XCP-ng is free and open source edition […]
Computing
[Java] Resolve issue on escape character show when using LogstashEncoder
When passing data to LogStash, it will show escape character in log message. But sometime, it cannot update logstash pipeline to replace specific character so need to implement in code level.
Cloud Computing 雲端服務
Cloud Design Pattern – Ambassador
Ambassador is one of the Separation of Concern (SoC) implementation. In cloud platform, functional features (e.g. Business logic) and non-functional features (e.g. retry / queue / etc) are implement in multi-containers: main application and proxy.
開發工具
[Tools] Mockoon
Mockoon is an open source API mocking tools to simulate API response.
Computing
[Spring] Utilize spring web client
Since WebClient replace RestTemplate to call external API in Spring. There are some patrices I lesson learnt in my work and summarize as below.
Computing
[Kubernetes] Install Kubernetes in Ubuntu Linux
There are different platforms to run Kubernetes (K8S) nowadays. In cloud, we can consider AWS Elastic Kubernetes Service, Azure Kubernetes Service, or we can install Talos in on-premise infrastructure as quick win solution. However, actually […]
CI / CD
[Terraform] Create Virtual Machines in ESXi Server
Terraform is one of the Infrastructure as code (IaC) tools to automate deployment in cloud / on premises. Compare with AWS and Azure, which has their own IaC language (e.g. AWS cloudformation), but Terraform is […]