mahemoff

class Array
  %w(each map each_with_index map_with_index flat_map any? all?).each { |meth|
    define_method("#{meth}_in_parallel") { |&block|
      Parallel.send(meth, self) { |item| block.call(item) }
    }
  }
}

mahemoff

#!/bin/bash

function slice() {
  lower=$1
  upper=$(expr $lower + 100000)                    
  echo "Backing up $lower"                         
  mysqldump db_name table_name --opt --no-create-info --where "id > $lower and id <= $upper" | gzip -c | ssh user@host "cat > /home/backup/dump$lower.gz"
}

lower=0

mahemoff

As here, but refined ...

Create or edit /etc/systemd/system/containerd.service.d/override.conf to contain just this:

[Service] ExecStartPre=

To make it happen:

• systemctl daemon-reload

mahemoff

* Shows a message while asserting like: 

ok: [host] => {                  
    "msg": "disk usage 4.2B of total 20.0GB (21.0%) (should be within limit 90.0%)"
}

* Note this only looks at first mount point on current node
* Fails if disk is near-full
* Last step pushes to a push-based monitoring service, which will alert us if it doesn't get there after some time
* Need to setup a  variable `disk_limit`, which is the max acceptable usage ratio, e.g. set it to 0.8 if you want to keep disks within 80% of max size

mahemoff

- name: show disk space                                                                                                                         
  debug: msg="{{ ((mount.size_total - mount.size_available) / 1000000000) |  round(1,'common') }}GB of {{ (mount.size_total / 1000000000)|round(
1, 'common') }}GB ({{ (100 * ( (mount.size_total - mount.size_available) / mount.size_available)) | round(1, 'common')}}%)"                     
  vars:                                                                                                                                         
    mount: "{{ ansible_mounts | first }}"                                                                                                       
  tags: disk                                                                                                                                    
                                                                                                                                                
- name: e

mahemoff

This is the "missing Ruby example" for the ID flow example at https://developers.google.com/identity/sign-in/web/server-side-flow.

It's easy enough to get an auth code like "4/BlahBlahBlah...", but I couldn't find any working examples on how to exchange it for the access code and encoded ID.

To use this, you need to access Google's API console, and under "credentials" establish a client ID and secret, which should go in your environment. (Most examples will use the "secrets.json" file, but I don't want to keep a separate config file for every platform, so it's better to put them in something like Rails' secret.yml or Figaro).

The auth_code is obtained from your web or native client using Google's front-end libraries. The client posts it to your own back-end, which does the exchange and verifies+stores the result. Note the redirect URI must be configured in Google's "credentials" console, otherwise the call will fail (even though it serves no purpose in this context; it's only needed for a non-JavaScript

mahemoff

#!/usr/bin/env ruby
require 'byebug'
require 'linode'
require 'awesome_print'

# setup API access - key is in file
open('/etc/linode.conf').read =~ /api_key: (.+)/
key=$1
lin = Linode.new(api_key: key).linode

mahemoff

MySQL backup commands and sizes

Adventures in storing and backing up a typical database using innobackupex and gpg. Using gzipped tar due to ubiquity, even though it's possibly 10-20% worse on perf/storage.

Sizes:

PREPARED (ie ready to move to MySQL folder)

• 2800MB Uncompressed and prepared (roughly the size of live database)
• 21000MB Uncompressed before compression
• 700MB Crypted+Compressed (ideal for external storage)

mahemoff

#!/usr/bin/env ruby
require 'uri'
require 'net/http'
require 'benchmark'

# dummy fetch first URL to baseline setup (ensures DNS and any routing
# optimisations done)
def prime_fetching(urls)
  ignored = Net::HTTP.get_response(URI(urls.first))
end

mahemoff

+---------+--------+------------+-------------------+---------+------+----------+------------------------------------------------------------------------------------------------------------------------------+
| ID      | USER   | HOST       | DB                | COMMAND | TIME | STATE    | QUERY                                                                                                                        |
+---------+--------+------------+-------------------+---------+------+----------+------------------------------------------------------------------------------------------------------------------------------+
| 2786271 | appy   | borg:89700 | global_app_center | Query   |   12 | updating | SELECT `posts` FROM `blog` WHERE `authors`.`id` IN ( 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, 1597, 2..   |                                     |
+---------+--------+------------+-------------------+---------+------+----------+---------------------------------------------------------------------