Kubernetes

• initContainers (for DaemonSet) - step by step short lived containers, can be used to fixing privileges and setup tasks
• Kubernetes hostPath ownership are set based on kubelet's
• Kubernetes pod logs are stored under /var/log/containers/<pod-name>*<container-id>/*.log (by container runtime)

Linux

• list users : /etc/passwd
• list groups : /etc/group
• members of group : lid <group-name>
• owning directory (recursively) chown -R <uid>:<gid> <dir-path>

Go

• go mod init <current-module-name> - initializing module for a new app/project
• go get <dep-name> - install dependencies manually
• Makefile general target structure

makefile target : dependency1 dependency2 recipe-command1 recipe-command2

• Makefile forcefully run without checking dependency build

makefile .PHONY all: clean build coverage run

it does not matter if any of the above dependencies are unsatisfied/failed, the whole command will still forcefully be executed

TODOs

• Linux Services - sigterm, sigkill
• AWS - ECS - EC2 (setup), ECS Fargate, ELB, VPC
• k8s - resource limits vs requests
• go - build flags (and commented tags etc.), cgo, select, channels concurrency etc.
• docker - host specific builds, golang-crossbuild
• python - pipenv, venv
• OAuth2
• TLS, mTLS
• HTTP2, gRPC

Yearly Learning Journal

2024

• TLS

2023

• AWS Kinesis Firehose - buffering, processor lambda (lambda buffering), output, intput (kinesis data streams, direct put), failure etc.
• AWS Cloudformation - custom event, constants, conditions, roles, resources, output, parameters, custom lambda (init processing)
• AWS S3 events - triggering Lambdas
• Lambda - cloudwatch loggroup, logstream, event, timeout, cost calc, cold-start and lambda (container) level caching.
• Eventbridge rules and schedules
• AWS VPC and Subnets
• AWS Secrets Manager
• Linux packages - deb, rpm
• Oauth2
• AWS ECS (EC2) - cluster bootstrapping (joining), task-def, service, task, daemon, execution role, volumes and mounts
• AWS EFS
• Docker - inspects contents, download files from containers, live debugging and inspection
• Wrapping executor application with piping STDOUT output and taking input
• Go - Cobra, flag, options etc.

2022

• Kubernetes (kubectl), Daemonset, ConfigMap, Service, Deployment, ServiceAccount, ClusterRole, ClusterRoleBindings
• Kubernetes Operators (pattern), Go Operator SDK
• Go, Go string templates
• Helm charts, Helm templates, Helm repos
• Kubectx
• OTel protocol, SDK - logs, metrics
• OTel collector - receivers (otlp, filelog), exporters (otlp, logging, prometheus), processors (batch, resourcedetection, attribute), extensions
• OpAMP protocol, SDK - client, server, deployment patterns
• Elastic Filebeat

2021

• Java Agents, Java Instrumentation, Java Bytecode Injection
• Java Vertx framework internals
• Java remote debugging, conditional breakpoints, thread debugging
• Angular, RxJS, Typescript, Jest

2020

• React, Redux

2019

• Spring Boot, Spring Batch, Spring-Kafka, Spring Data JPA, Spring Data JDBC, Kafka Consumers
• Apache Camel (pipelines) with Kafka, batch etc.
• Oracle, MS SQL Server, Stored Procedures
• Apache Livy
• Maven