Cheatsheet

Table of contents:

• Bash
• CEL
• DNS
• Fossil
• htmx
• htpasswd
• HTTP
• I18n
• Incus
• Java
• JSON
• jte
• Linux
• Maven
• Misc
• NPM
• Promontory
• Proxmox
• Regex
• SQLite
• SSH
• systemd
• Testing
• Wireguard

Bash

• Print env vars printenv
• https://google.github.io/styleguide/shellguide.html
• https://mywiki.wooledge.org/BashPitfalls
• https://ss64.com/bash/
• https://www.shellcheck.net/

CEL

• Language Definition
• https://celbyexample.com/

DNS

• https://addr.tools/
• https://dnsviz.net/
• https://mrdns.com/

Fossil

• Create new repo fossil init repo.fossil --admin-user admin (see terminal output for password)
  • Create wiki page with same name as 'Project Name' specified in Admin > Configuration
• Changed files fossil changes
• Diff in browser fossil diff --by --context 15
• Reference a ticket in commit message with [123456]
• Testing with self-signed certs fossil set --global ssl-ca-location ca.crt
• Untracked files fossil extras --dotfiles
• VSCodium extension

htmx

• Reference

htpasswd

• htpasswd -b -B .htpasswd user password (-c to create the file, -n replaces -b to print to stdout)
• https://httpd.apache.org/docs/current/programs/htpasswd.html

HTTP

• https://www.iana.org/assignments/http-fields/http-fields.xhtml

i18n

• MessageFormat 2

Incus

• CLI
  • Use --debug to see API calls (--verbose)
• Images
• Login as user incus exec my-instance -- su --login ubuntu

Java

• Debug security/certificates -Djava.security.debug=all
• JVM Options
• List all system properties java -XshowSettings:properties -version

JSON

• https://json-everything.net/

jte

• IDEA plugin

Linux®

• APT versions apt policy wireguard (apt-cache madison wireguard)
• File system df --human-readable (/opt)
• Find process pgrep --list-full java
• First 75 lines cat -n <( head -75 step_queue.json )
• Group list getent group
• List ACL getfacl -R .
• Network ip address show
• OS/distro /etc/os-release
• User in group getent group | grep user
• User list getent passwd
• https://man7.org/linux/man-pages/index.html

Maven

• Condition-Based Profile Activation
• Display effective POM mvn help:effective-pom -Dverbose
• Inspect project lifecycle mvn buildplan:list
• Lifecycle
• List dependencies mvn dependency:tree -Dverbose
  • Output formats
• Testing with self-signed certs, in .mvn/jvm.config set -Dmaven.resolver.transport=wagon -Dmaven.wagon.http.ssl.insecure=true
• Update dependencies mvn versions:display-dependency-updates "-Dmaven.version.ignore=.*alpha.*,.*beta.*,.*-M.*,.*-proto.*"
• Update plugins mvn versions:display-plugin-updates -N "-Dmaven.version.ignore=.*alpha.*,.*beta.*,.*-M.*,.*-proto.*"

Misc

• https://excalidraw.com/
• https://gchq.github.io/CyberChef/

NPM

• List dependencies npm list --all (--omit dev)
• Set next prerelease version npm version prerelease --workspaces
• Testing with self-signed certs, in .npmrc set strict-ssl=false
• Update dependencies npm outdated

Promontory

• Scripts
  • ESLint fix mvn exec:exec@es-lint-fix
  • esbuild watch mvn exec:exec@es-build-watch
• Provisioning
  • Components
    • Development repo
      • /provisioning contains provisioning modules with runbooks, etc.
    • Operations repo
      • Ops modules
      • Deployer configs
  • Install
    1. Requirements
       • Sudo sudo -i
       • Unzip apt-get install --quiet --yes unzip
    2. Move installer.zip to /var/tmp
    3. Unpack and prepare cd /var/tmp && unzip -qq installer.zip -d installer && cd installer && chmod +x install.sh
    4. Install ./install.sh path/to/my_runbook

Proxmox

• Resize disks

Regex

• https://regex101.com/

SQLite

• Datatypes
• Date/Time
• JSON
• PRAGMA
• Schema changes
• WAL

SSH

• Create user just for ssh login adduser --comment "user" --disabled-password --quiet user
• Unlock user usermod --password '*' user

systemd

• Follow unit log journalctl --follow --unit myunit (or -fu)
• Show unit log journalctl --no-pager --lines 100 --unit myunit
• Show unit with drop-ins systemctl cat myunit
• https://www.freedesktop.org/software/systemd/man/latest/systemd.html

Testing

• Surefire/Failsafe Maven plugin config
  • Default values are defined in parent POMs
  • Opt into parallel execution of tests using @Execution(ExecutionMode.CONCURRENT)

Wireguard

• https://wiki.archlinux.org/title/WireGuard#Key_generation

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