guerzon

Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
L2 cache reference                           7   ns                      14x L1 cache
Mutex lock/unlock                           25   ns
Main memory reference                      100   ns                      20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy             3,000   ns        3 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD

guerzon

### On RHEL5 servers ###
1. Check the login failure count
pam_tally --user username
2. Reset the login failures
pam_tally --user username --reset
3. Retry logging in.

### On RHEL6 and RHEL7 servers ###
1. Check the login failure count
pam_tally2 --user username

guerzon

#!/bin/bash

set -e

UPDATES_URL="http://updates.jenkins-ci.org/download/plugins/"

if [ $# -lt 2 ]; then
  echo "USAGE: $0 plugin-list-file destination-directory"
  exit 1
fi

guerzon

## Important Documentation

Documentation: https://docs.ansible.com/ansible/latest/index.html
Modules: https://docs.ansible.com/ansible/latest/modules/modules_by_category.html
Community: https://docs.ansible.com/ansible/latest/community/index.html

## Other resources

Ansible for the Windows Admin: https://www.youtube.com/watch?v=ZI20Y10OKd0

guerzon

#!/usr/bin/env bash
# Usage: ./verify_ciphers.sh IP:PORT
# Credits: http://superuser.com/a/224263/204745

# OpenSSL requires the port number.
SERVER=$1
DELAY=1
ciphers=$(openssl ciphers 'ALL:eNULL' | sed -e 's/:/ /g')
 
echo Obtaining cipher list from $(openssl version).

guerzon

concurrent = 10
check_interval = 0

[session_server]
  session_timeout = 1800

[[runners]]
  name = "Docker runner"
  url = "https://gitlab.localdomain.local/"
  token = "tOkeNh3r3-"

guerzon

Wednesday 04 November 2020  12:03:28 +0100 (0:00:00.067)       0:00:14.229 ****
redirecting (type: modules) ansible.builtin.keycloak_client to community.general.keycloak_client
Using module file /Users/workstation/.local/share/virtualenvs/ansible_project-6ES-zTZc/lib/python3.6/site-packages/ansible_collections/community/general/plugins/modules/keycloak_client.py
Pipelining is enabled.
<targetserver> ESTABLISH SSH CONNECTION FOR USER: root
<targetserver> SSH: EXEC ssh -C -o ControlMaster=auto -o ControlPersist=60s -o KbdInteractiveAuthentication=no -o PreferredAuthentications=gssapi-with-mic,gssapi-keyex,hostbased,publickey -o PasswordAuthentication=no -o 'User="root"' -o ConnectTimeout=10 -o ControlPath=/Users/workstation/.ansible/cp/205f67cdb9 targetserver '/bin/sh -c '"'"'/usr/bin/python && sleep 0'"'"''
<targetserver> (0, b'\n{"proposed": {"publicClient": false, "protocol": "openid-connect", "description": "awesomeapp Desktop Application OpenID client", "directAccessGrantsEnabled": true, "adminUrl": "https

guerzon

podman issues

Blockers why podman cannot replace docker-ce (yet). This is to remind myself to not waste any more time trying to use podman.

Issues

rootless containers fail to start with cgroup2 (EL8)

[lester@rocky8 ~]$ podman run alpine

guerzon

guerzon

## awx namespace
export NAMESPACE=awx
kubectl create ns $NAMESPACE

## secrets

cat <<EOF > awx-secrets.yml
---
apiVersion: v1
kind: Secret