Docker storage

Microservices are all about stateless and ephemeral workloads, and containers are great microservices. This may suggest that that Docker is all about ephemeral storage. In fact, Docker supports both non-persistent and persistent storage, such as database, kafka, etc. Non-persistent storage is automatically created, alongside the container and is tied to the lifecycle of the container. … Read moreDocker storage

Setup WSL2 (and Docker) on Windows 10

This is not for Linux snobs, but rather for those who are stuck with a Windows work laptop, have to deal with Linux on a daily basis, and are not a fan of PuTTY. This posting provides the steps to setup Windows 10 so you get a work environment closer to a Linux one. The … Read moreSetup WSL2 (and Docker) on Windows 10

SSH key pair for access between instances in CloudFormation

We use CloudFormation to deploy infrastructure including private and public subnets, as well as EC2 instances. It is a good practice to place as many instances as possible in private subnet and access those only from Bastion Host in the public subnet. For smaller systems it is even common to use the NAT instance as … Read moreSSH key pair for access between instances in CloudFormation

Coordination between resources in AWS CloudFormation

One of the reasons I prefer CloudFormation over Terraform is access to Helper scripts. Many legacy applications are not built with statelessness and the installation depends on host information of other layers in the stack. This requires communication among instances during stack creation. The cloudformation Helper script (cfn-init, cfn-signal, cfn-hup and cfn-getmetadata) plays a key … Read moreCoordination between resources in AWS CloudFormation

CentOS – Remove Swap safely

If the default installation has swap on, you will see it from block device list: Many installations require swap to be off for performance reasons (although some advocate turning off swappiness of the application, instead of removing swap partition from operating system, which is a separate topic). This can be turned off by a simple … Read moreCentOS – Remove Swap safely