Elasticsearch, Logstash, Kibana or ELK Crash Course 101
Prologue aka Disclaimer
This blog post is the outcome of a Hackerspace Event:: Logstash Intro Course that happened a few days ago. I prefer doing workshops Vs presentations -as I pray to the Live-Coding Gods- and this is the actual workshop in bulletin notes.
Objectives
For our technical goal we will use my fail2ban !
We will figure (together) whom I ban with my fail2ban!!!
The results we want to present are:
| Date | IP | Country |
|---|
To help you with this inquiry, we will use this dataset: fail2ban.gz
If you read though this log you will see that it’s a grep from my messages logs.
So in the begging we ha...
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A visual guide on how to enlarge your windows disk image aka windows extend volume
I have a windows 10 qemu-kvm virtual machine for business purposes.
Every now and then, I have to resize it’s disk image!
This is my visual guide, so next time I will not waste any time figure this out, again!
Resize Disk image
The first step is to resize the disk image from the command line:
# ls -l win10.qcow2
-rw-r--r-- 1 root root 58861813760 Nov 17 10:04 win10.qcow2
# du -h win10.qcow2
55G win10.qcow2
# qemu-img info win10.qcow2
image: win10.qcow2
file format: qcow2
virtual size: 55G (59055800320 bytes)
disk size: 55G
cluster_size: 65536
To see the entire article, click uppon article's title/link.
Thank you.A Beginner’s Guide on How to use Thunderbird with Enigmail (Gpg4win) with their gmail account in 10 minutes on a windows machine
Thunderbird Enigmail - Gmail, Windows from vimeouser on Vimeo.
Linux Raid
This blog post is created as a mental note for future reference
Linux Raid is the de-facto way for decades in the linux-world on how to create and use a software raid. RAID stands for: Redundant Array of Independent Disks. Some people use the I for inexpensive disks, I guess that works too!
In simple terms, you can use a lot of hard disks to behave as one disk with special capabilities!
You can use your own inexpensive/independent hard disks as long as they have the same geometry and you can do almost everything. Also it’s pretty easy to learn and use linux raid. If you dont have the same geometry, then linux raid will use the smallest one from your disks. Modern methods, like LVM and BTRFS can provide an abstr...
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# /bin/find /sys/devices -type f -name model -exec cat {} \;
KINGSTON SV300S3
WDC WD10EURX-63F
WDC WD10EZRX-00A
VB0250EAVER
VB0250EAVER
# udisksctl status
MODEL REVISION SERIAL DEVICE
--------------------------------------------------------------------------
KINGSTON SV300S37A120G 527ABBF0 50026B774902D7E5To see the entire article, click uppon article's title/link.
Thank you.Most people -reading this blog post- will scream in their chairs … PLZ keep in-mind that I am not a developer and perhaps the below workaround is just that, a workaround.
I have this case that I need to render (with JS) text that already has passed through the PHP parser.
The caveat is that the text output is inside a <DIV> element and has HTML code in it.
Most of you understand that HTML inside a DIV element is not something useful as the browser’s engine is rendering it to HTML on page load. That means, that we can not get the innerHTML of this DIV element, as it is already rendered by the browser.
Let me give you an example:
<div>
<!DOCTYPE html>
<htmlTo see the entire article, click uppon article's title/link.
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I really like this comic.
I try to read/learn something every day.
Sometimes, when I find an interesting article, I like to mark it for reading it later.
I use many forms of marking, like pin tabs, bookmarking, sending url via email, save the html page to a folder, save it to my wallabag instance, leave my browser open to this tab, send the URL QR to my phone etc etc etc.
Are all the above ways productive?
None … the time to read something is now!
I mean the first time you lay your eyes upon the article.
Not later, not when you have free time, now.<...
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I have a compressed file of:
250.000.000 lines
Compressed the file size is: 671M
Uncompressed, it's: 6,5G
Need to extract a plethora of things and verify some others.
I dont want to use bash but something more elegant, like python or lua.
Looking through “The-Internet”, I’ve created some examples for the single purpose of educating my self.
So here are my results.
BE AWARE they are far-far-far away from perfect in code or execution.
Sorted by (less) time of execution:
pigz
# time pigz -p4 -cd 2016-08-04-06.ldif.gz &> /dev/null
real To see the entire article, click uppon article's title/link.
Thank you.[Last uptime 2020-12-25]
I need to run some ansible playbooks to a running (live) machine.
But, of-course, I cant use a production server for testing purposes !!
So here comes docker!
I have ssh access from my docker-server to this production server:
ssh livebox tar --one-file-system --sparse -C / -cf - | docker import - centos6:livebox on ubuntu 20.04
ssh livebox sudo tar -cf - --sparse --one-file-system / | docker import - centos6:livebox
Then run the new docker image:
$ docker run -t -i --rm -p 2222:22 centos6:livebox bash
[root@40b2bab2f306 /]# /usr/sbin/sshd -D
Create a new entry on your hosts inventory file, that uses ssh port 2222
or create a new separated inventory file
and test it with ansible ping module:
# ansible -m ping -i hosts.docker dockerlivebox
dockerlivebox | success >> {
"changed": false,
"ping": "pong"
}
Recently, I had the opportunity to see a presentation on the subject by Alexandros Kosiaris.
I was never fan of vagrant (or even virtualbox) but I gave it a try and below are my personal notes on the matter.
All my notes are based on Archlinux as it is my primary distribution but I think you can try them with every Gnu Linux OS.
Vagrant
So what is Vagrant ?
Vagrant is a wrapper, an abstraction layer to deal with some virtual solutions, like virtualbox, Vmware, hyper-v, docker, aws etc etc etc
With a few lines you can describe what you want to do and then use vagrant to create your enviroment of virtual boxes to work with.
Just for the fun of it, I used docker
Docker To see the entire article, click uppon article's title/link.
Thank you.
Thank you.
Personal Notes on this blog post.
[work in progress]
Why ?
Γιατί docker ?
To docker είναι ένα management εργαλείο για διαχείριση containers.
Εάν κι αρχικά βασίστηκε σε lxc, πλέον είναι αυτοτελές.
Containers είναι ένα isolated περιβάλλον, κάτι περισσότερο από
chroot(jail) κάτι λιγότερο από virtual machines.
Μπορούμε να σηκώσουμε αρκετά linux λειτουργικά, αλλά της ίδιας αρχιτεκτονικής.
Χρησιμοποιούνται κυρίως για development αλλά πλέον τρέχει μεγάλη
production υποδομή σε μεγάλα projects.
Κερδίζει γιατί το docker image που έχω στο PC μου, μπορεί να τρέξει αυτούσιο
σε οποιοδήποτε linux λειτουργικό (centos/fedora/debian/archlinux/whatever)
και προσφέρει isolation μεταξύ της εφαρμογής που τρέχει και του λειτουργικού.
Οι επιδόσεις -πλέον- είναι πολύ κοντά σε αυτές του συστήματος.
Σε production κυρίως χρησιμοποιείτε για continuous deployment,
καθώς τα images μπορεί να τα παράγο...
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These are my personal notes on upgrading wallabag to it’s latest version (2.0.8):
Create a backup
# cd /var/www/html/
# mv wallabag wallabag_bak
Download latest version
# wget -c http://wllbg.org/latest-v2-package -qO - | tar -xz
# mv release-2.0.8 wallabag
Restore Settings
# cp -f wallabag_bak/app/config/parameters.yml wallabag/app/config/parameters.yml
# rsync -r wallabag_bak/data/ wallabag/data/
[h3] Permissions [h3]
Don’t forget to fix the permissions on wallabag according to your web server settings:
# chown -R apache:apache wallabag
and …. that’s it !
Let’s Encrypt client: certbot is been written in python and as it’s predecessor needs at least Python 2.7.
But (still) in CentOS series 6 (currently 6.8) there is no natively support for python27.
So I did this thing below, quick & dirty:
# cd /usr/local/src/
# wget -c https://www.python.org/ftp/python/2.7.11/Python-2.7.11.tgz
# tar xf Python-2.7.11.tgz
# cd Python-2.7.11
# ./configure
# make
# make install
and these are my notes for renew certificates :
# ln -s /opt/Python-2.7/bin/python2.7 /usr/local/bin/python2
[root@1 certbot]# source venv/bin/activate
(venv)[root@1 certbot]#
# cd venv/bin/
# ./certbot renew --dry-run
# ./certbot renew
# rm /usr/local/bin/python2
Domain-based Message Authentication, Reporting and Conformance
What is dmarc in a nutshell:
An authentication Protocol that combines SPF & DKIM to reduce spoofed emails.
Depends on DNS so DANE would be great here!
notes on centos6:
You need to already have implemented SPF & DKIM
Outgoing Mail Servers
DNS
in your zone file, add something like this:
_dmarc IN TXT "v=DMARC1; p=none; rua=mailto:postmaster@example.org"
increase the serial number of the zone and check it:
<...Thank you.
The last couple months, I get over 400 unknown user errors on my imap (dovecot) server.
FYI this is the report:
dovecot: auth: ldap(aaaaaa,193.189.117.147): unknown user:
dovecot: auth: ldap(accountant,193.189.117.147): unknown user:
dovecot: auth: ldap(acosta,193.189.117.147): unknown user:
dovecot: auth: ldap(admin@balaskas.gr,89.248.162.175): unknown user:
dovecot: auth: ldap(adrian,193.189.117.152): unkno...Thank you.
Reading through “Smart Girl’s Guide to Privacy - Practical Tips for Staying Safe Online by Violet Blue” (totally recommend it), there is a great tip in the first few pages:
- Use different email addresses for different online accounts.
… but is it possible ?
Different Passwords
We already know that we need to use a different password for every site. So we use lastpass or password managers for keeping our different passwords safe. We are nowadays used to create/generate complex passwords for every site, but is it absolutely necessary to also have a different email address for every single one ?
Different Email Addresses
Let me be as clear as I can: There is no obvious answer.
If you value your online privacy and your security threat model is set really high, then Yes yo...
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Google Reader was -of general acceptance- the best RSS feed reader.
Yahoo had it’s own “perfect” project to parse feeds: Yahoo! Pipes
What did both projects have in common?
They both were cloud projects
that are now discontinued
cause their companies could not profit from them !!!
FreshRSS
So a lot of people started to look up on self-hosted RSS readers to overcome this issue.
Below are my notes on FreshRSS , a free, self-hostable aggregator…
First, download the latest version of FreshRSS:
To see the entire article, click uppon article's title/link.
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Below is my setup to enable Forward secrecy
Generate DH parameters:
# openssl dhparam -out /etc/pki/tls/dh-2048.pem 2048
and then configure your prosody with Let’s Encrypt certificates
VirtualHost "balaskas.gr"
ssl = {
key = "/etc/letsencrypt/live/balaskas.gr/privkey.pem";
certificate = "/etc/letsencrypt/live/balaskas.gr/fullchain.pem";
cafile = "/etc/pki/tls/certs/ca-bundle.crt";
# enable strong encryption
ciphers="EECDH+ECDSA+AESGCM:EECD...Thank you.
Top Ten Linux Distributions and https
A/A | Distro | URL | Verified by | Begin | End | Key
01. | ArchLinux | https://www.archlinux.org/ | Let's Encrypt | 02/24/2016 | 05/24/2016 | 2048
02. | Linux Mint | https://linuxmint.com/ | COMODO CA Limited | 02/24/2016 | 02/24/2017 | 2048
03. | Debian | https://www.debian.org/ | Gandi | 12/11/2015 | 01/21/2017 | 3072
04. | Ubu...Thank you.