nordineb

I wasn't able to git fetch from Azure DevOps repos after upgrading openssh on my computer.

ssh -V
  OpenSSH_8.8p1, OpenSSL 1.1.1l  24 Aug 2021

Turns out that OpenSSL has now turned off ssh-rsa by default:

This release disables RSA signatures using the SHA-1 hash algorithm by default.

But Azure DevOps doesn't support anything else... Add the following to your config file to re-enable ssh-rsa for Azure DevOps:

matthiassb

#! /bin/bash
### BEGIN INIT INFO
# Provides:          dns-sync
# Required-Start:
# Required-Stop:
# Default-Start:     S
# Default-Stop:
# Short-Description: Synchronizes /etc/resolv.conf in WLS with Windows DNS - Matthias Brooks
### END INIT INFO

manicminer

Ansible invocation with assumed IAM role

How it works

• boto3 initializes a session using the specified profile, for which it assumes a role as configured in your ~/.aws/config
• Python script with above session initialization prints out shell-compatible environment variables of the temporary credentials
• Wrapper script sets these a la eval
• By the time Ansible runs, the AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY and AWS_SECURITY_TOKEN (for boto2) / AWS_SESSION_TOKEN (for boto3) are all set, and are consumed by boto2 in the inventory script and other boto2-based modules

Notes

trodemaster

New-Item -Path "HKLM:Software\Policies\Microsoft\Windows\WindowsUpdate"
New-Item -Path "HKLM:Software\Policies\Microsoft\Windows\WindowsUpdate\AU"
Set-ItemProperty -Path "HKLM:\software\policies\Microsoft\Windows\WindowsUpdate" -Name WUServer -Value "http://wsus.domain.com:8530" -Type String -force
Set-ItemProperty -Path "HKLM:\software\policies\Microsoft\Windows\WindowsUpdate" -Name WUStatusServer -Value "http://wsus.domain.co:8530" -Type String -force
Set-ItemProperty -Path "HKLM:\software\policies\Microsoft\Windows\WindowsUpdate\AU" -Name UseWUServer -Value "1" -Type DWORD -force

gubatron

How to configure multiple deploy keys for different private github repositories on the same computer without using ssh-agent

Let's say alice is a github.com user, with 2 or more private repositories repoN. For this example we'll work with just two repositories named repo1 and repo2

https://github.com/alice/repo1

https://github.com/alice/repo2

You need to be to pull from these repositories without entering a passwords probably on a server, or on multiple servers.

suprememoocow

- action: ec2_facts

- apt: pkg=lvm2 state=present
- apt: pkg=mdadm state=present

- pip: name=boto state=latest

- ec2_vol: instance="{{ hostvars[inventory_hostname]['ansible_ec2_instance-id'] }}"
           volume_size=20
           device_name="{{ item }}"

hummus

wget http://stedolan.github.io/jq/download/linux64/jq 
aws ec2 describe-instances --filters "Name=tag:Name,Values=$NAME" \
  "Name=instance-state-name,Values=running" \
  |  jq -r \
  ".Reservations[] | .Instances[] | .InstanceId" \

aws ec2 describe-volumes --filters \
  "Name=status,Values=available" \
  | jq -r ".Volumes[] | .VolumeId" \

hellerbarde

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs