HariSekhon

SSH Tunnelling

Generic SSH Port Forwarding

SSH login to host1 and bind local port number to forward through the ssh tunnel to host2 on the specified port.

ssh -L <local_port>:<host2>:<host2_port> <user>@<host1>

HariSekhon

Solr

Solr is the classic open-source search system. Perhaps too classic (old).

Latest Documentation

See Elasticsearch too.

Solr UI

HariSekhon

Snowflake

SnowPipe

--use role snowpipe_role;
use database demo_db;

create or replace stage demo_db.public.snowstage
    url='s3://snowflake-oregon/'

HariSekhon

Shell

• Bash - the gold standard in shell scripting - see bash.md
• Bourne - the original unix shell - Bash is the Bourne Again Shell - next generation Bourne shell
• Ksh - Korn shell - another old unix shell
• Tcsh - BSD shell - just use Bash
• Zsh - slightly more feature rich shell than Bash. Not sure it's worth the hassle aside from ** directory recursion globbing
• Fish - friendly interactive shell - meaning user friendly

Fish

HariSekhon

SBT

Simple Build Tool / Scala Build Tool

https://www.scala-sbt.org/

• incremental compilation
• interactive shell
• uses StackOverflow.com/tags/sbt for Q&A

HariSekhon

Regex

Regular expressions are a core skill for any half decent programmer.

I use them extensively in languages from Python and Perl to Java/Scala/Groovy and even in shell scripts in Bash for grep, sed & awk.

Online Regex Testing

https://regex101.com/

HariSekhon

Redhat

RHEL / CentOS / Fedora / Rocky Linux

Redhat is one of the original Linux distributions.

Unfortunately they discontinued their free Redhat distribution replacing it with a commercially licensed Redhat Enterprise Linux (RHEL) and a less stable desktop-focused Fedora Linux in the mid 2000s.

Community volunteers reacted by creating CentOS from RHEL source rpms to maintain a clone of stable redhat enterprise linux

HariSekhon

Python

Python is a popular and easy to use general purpose programming language that is heavily used in Data Analytics and Data Science as well as systems administration.

It's not as amazing for one-liners are Perl is though, which can boost shell scripts more easily.

Core Reading

Learning Python

HariSekhon

Programming

Languages

1. Bash - the gold standard for shell scripting
2. Python - general purpose object oriented language, easy to write, widely used but hard to maintain due to environment differences, language and library changes over time
3. Golang - imperative compiled self-contained binaries, simple toolchain, smashes Python in portability, maintainability, build time etc.
4. Perl - fast to write imperative code, stable, the gold standard for regex string processing, works everywhere and doesn't break every few years like Python
5. Groovy - a better version of Java, with interactive REPL and some language construct conveniences. Hard to want to write in Java again after getting spoilt by Groovy
6. Java - battle tested, but slower to develop in than the above languages

HariSekhon

Podman & Buildah by Redhat

Podman

• manages containers without a daemon
• non-root daemonless drop-in replacement for Docker
• drop in replacement for Docker CLI command

yum install -y podman