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AWS CDK - Coding your Virtual Machines in the AWS Cloud

Tue, 05 May 2020 00:00:00 -0500

Updated Oct 23 2020

I started following AWS CDK (Cloud Development Kit) news and documentation for a while now. That’s usually my lazy strategy when a new AWS product is launched, I finally decided that I wanted to start using it and create something that I’m familiar with and also find useful.

One of my favorites AWS products is EC2, for multiple reason:

Compute is Universal, it have the potential to make many things with a server running Linux.
EC2 Administration in AWS can be much more elastic, there are some additions from AWS System Manager that I enjoy using:
- No more SSH!, AWS SSM provides Session Manager instead that is Web Console, CLI and API friendly.
- Parameter Store is handy for keeping configuration values in a safe place outside the instance.
User data for provisioning, because some bash script with a few commands always gets the job done.
Elastic IPs (also knows as Public IP), probably the most simple way to connect your application to the internet!
Amazon Linux 2, one less thing to worry about because AWS maintains a Redhat/Centos like distribution.
All the goodies of EBS and snapshots.
Spot Instances, because running your servers could be really affordable if your service is smart enough to handle interruptions.

So, I decided to deploy a single instance from Python code using CDK with all the AWS cool stuff to easy the management in around 60 lines of code.

This is a snippet of what you’re going to find, instance creation:

        instance = ec2.Instance(self, "Instance",
            instance_type=ec2.InstanceType("t3.nano"),
            machine_image=amzn_Linux,
            vpc = vpc,
            role = role
            )

One common issue when using user data to install software is that eventually it hits a limit, CDK Assets allows me to invoke that script from a separate file and also handles the assets management in S3 for us.

        asset = Asset(self, "Asset", path=os.path.join(dirname, "configure.sh"))
        local_path = instance.user_data.add_s3_download_command(
            bucket=asset.bucket,
            bucket_key=asset.s3_object_key
        )

        instance.user_data.add_execute_file_command(
            file_path=local_path
            )

This is the full code example for getting that instance up and running:

EC2 Instance Code Example

I hope this gives you an idea of how powerful CDK in terms of describing infrastructure and the amount of time that saves if you where using the Python SDK or Cloudformation previously.

Getting started to like systemd

Tue, 22 Jan 2019 00:00:00 -0500

I've been ignoring systemd for a while until I watched this awesome talk from LISA18/USENIX [1] conference, then started looking at it again, mostly because I saw how it wraps linux cgroups  so well, someting that previously used from lxc and second because I saw a chance to be able to run another OS environment without using docker (keep it simple!).

So, I decided to start reading systemd manpages, more specifically systemd-run  and  systemd-exec[2], then spotted an interesting parameter I already saw on the talk [2] , I decided to try that my self on the cli!

Sadly I dint got the latest systemd tools version on my distro so I had to use ubuntu 18.10 from a free tier cloud service [3], clone systemd repo [4], install its dependecies [a], run a build script [b], bootstrap [c] a debian jessie userland and then with one simple but neat command [d], got a friendly bash environment running in seconds :D, going further with the mange I ended using systemd-nspawn to the a complete chroot like isolated "machine". [e]

    # [a]
    sudo apt-get build-dep systemd lib-systemd
    # [b]
    git clone https://github.com/systemd/systemd.git && cd systemd && ./mkosi.build
    # [c]
    mkdir debian && sudo debootstrap unstable ./debian http://deb.debian.org/debian
    # [d]
    sudo ./systemd/build/systemd-run --working-directory=/home/kristian_paul/debian -t bash

    # [e]
    sudo systemd-nspawn -D debian
    Spawning container debian on /home/kristian_paul/debian.
    Press ^] three times within 1s to kill container.
    root@debian:~# cat /etc/debian_version
    buster/sid
    root@debian:~#
    
    
    I'll  keep looking at systemd docs and write some more about it later and also why not another technoliges i've found really usefull during the last years.

Thanks for reading

[1] https://www.youtube.com/watch?v=_OLwb8zV9r4&t=0s&list=WL&index=43
[2] https://www.freedesktop.org/software/systemd/man/systemd-run.html
[2] https://www.freedesktop.org/software/systemd/man/systemd.exec.html
[3] https://cloud.google.com/free/docs/gcp-free-tier#always-free-usage-limits
[4] https://github.com/systemd/systemd

Affordable home automation

Thu, 12 Oct 2017 00:00:00 -0500

I wanted to monitor my chickens remotely and after some web digging found this open source software homeassistant that had allowed me to use cheap devices like RPI and some dlink/digoo cameras in order to monitor then via web.



It doesn't end there, i also bought the sonoff device and after some reflash i got it working with hass mqtt, so now i can also turn on light and fans.



There are also things like automation, so when I'm at home my bluetooth devices presence gets lights on, small details that helps to make your life easier, like turning off lights automatically.

There is probably more to do, next challenge is voice :-)

[1] http://home-assistant.io/
[2] https://github.com/arendst/Sonoff-MQTT-OTA

Piaware statics

Sun, 02 Nov 2014 00:00:00 -0500

/srv/data/paginaweb/blog/Untitled.html

Got a cheap rasberry pi recentently. Since the httpd on it was not eating lot cpu cycles decided to run something else that will give use to my rtl-sdr as well. Is called pi aware [1]. So far got interesting ADS-B statics from my place [2]. Not bad.

As a side note use rtl-power as a passive radar could be another interesting option, just for the stats ;-).


[1] http://flightaware.com/adsb/piaware/
    https://github.com/flightaware/
[2] http://flightaware.com/adsb/stats/user/kristianpaul

radio aporee

Fri, 02 Nov 2012 00:00:00 -0500

/srv/data/paul/blog/log36.html Is nice to see how the buga stream (thanks to locusonus) still mixed out there :-)

07:21 < hj4adj> > btw, i'm periodically stealing 2 minutes of live time
07:21 < hj4adj> > from some of the available micofones and smoothly insert it into
07:21 < hj4adj> > the stream at http://radio.aporee.org
07:21 < hj4adj> >
07:21 < hj4adj> > that is, buga, cologne and now london again (and also the ekström ice shelf
07:21 < hj4adj> > hydrophones in the antarctica ...)

Actually ended listening to this radio because save me time instead of tunning each stream at the time.

Congreso Itinerante by Free Software Foundation de Ecuador

Mon, 02 Apr 2012 00:00:00 -0500

/tmp/mutt-micro-1000-16715-896461972901d8d8fb0.html I'm going to give a talk about Copyleft Hardware, by April 11 at
Instituto Superior de Pedagogía, not too much info yet, just in case you
are at Ecuador at that time may be of you interest.

More info coming at http://softwarelibre.info/ (Agenda)

GPS-SDR on the Milkymist (Update 2)

Fri, 25 Nov 2011 00:00:00 -0500

~/blog/Untitled.html Has been a while since the last update in January, starting because for now
this implementation will no run in the nanonote :-) Not because it cant be do it,
just because i get more close to Milkymist platform so i feel more confident with it
(libre knowledge is my power) :-)

After read/skim some books/links [1][2] about GNSS/GPS and check Namuru proyect (thanks to Fabrizio)
i decided to port this namuru core to milkymist soc [3], this in beta stage and the current
effort is around making and tunning the correlators to get a proper signal acquisition and tracking [4],
this is a software asisted task that will be acomplished by osgps, and thanks to Artyom from gnss-sdr [5] wich
ported this project to a simplified version [6], getting started will not be hard.

Still more code in osgps that could be ported to get a fix, but for now having and stable method to get
navigation data from the GPS satellites is the priority.

Thanks for reading !
And all qi-hardware/milkymist comunity for supporting me :-)

[1] http://en.qi-hardware.com/wiki/GPS_Free_Stack/Books
[2] http://en.qi-hardware.com/wiki/GPS_Free_Stack/Web_Links
[3] https://github.com/kristianpaul/milkymist/tree/gps-sdr-testing
[4] http://en.qi-hardware.com/wiki/GPS_Free_Stack/Notes_About_Namuru
[5] http://gnss-sdr.ru
[6] http://code.google.com/p/gnsssdr/source/browse/#svn/trunk/OSGPS_MOD

First atempt to listen weather satellites

Sun, 16 Oct 2011 00:00:00 -0500

~/blog/log33.html Today i tried to listen a NOAA-19 weather satellite, i got a few seconds for
what sounds like its telemetry [1].

I used a uv-200 transceiver and a home made yagi-like antenna wich seems to work
if i inverted it (?) so, as no proper design was tought for it, i bet i
can be improved as soon i read more about this topic.

[1] http://kristianpaul.org//tmp/noaa19.wav

Copyleft cartoons within Copyleft Hardware

Fri, 25 Feb 2011 00:00:00 -0500

~/blog/log32_.html I love Mimi & Eunice cartoons, i read it everyday, and enjoy sharing it
by irc or microblog from time to time.

But why not carry it with me?

Well it is posible and very easy, if you own a Ben nanonote!,
just copy the thumbail version from the (http://mimiandeunice.com/)
webpage. scp it to your nanonote, and using the zgv application you can
browse and check the cartoons, it fit very well and you need arrow keys
for visualizing the whole history.

Copyleft cartoons with Copyleft hardware :-)

There still missing the way to get all cartoons automatically,
lets see what can be done for that later.

Local fabbed case for the Milkymist One (Full log)

Fri, 18 Feb 2011 00:00:00 -0500

~/blog/log30_.html I bought a Milkymist One Early Adopter Kit byt End of decemenber of 2010, I got the board in early January,
but of course no case was avaliable for that time...

A case is very important, dust is always there, and also you want to show Milkydrop effects to your friends
from time to time :-). Actually why not make a PARTY !!

So as the mm1 case source code is avaliable [1] i decided to fab it here, why not?.
I was told for a friend who own a RepRap machine about a company called Dataprint [2], he got from then
some cutted sheets for his reprap at good prices, so i decide to give a try.

I call then by phone initially asking about data formats. so i knew it it could be a trouble,
of course they told me about propietary cad software, but as some of us already may know qcad is an alternative
to some of then and its format seems to be copatible, so i sent the .dxf file plus a picture of a mm1 already made
case. I also told then about it must be acrylic of 3mm.

Next day i got the quote, materials and cutting work, all for ~10usd (21700 COP) plus 5usd of shipping to
home. So i wow this is really cheap !!. I actually doubt it if they really knew it the real size of the sheets.

So a week later i did the money transfer to get the work started, just before that they gave me to choose,
some colors:

(green) Verde Neón
(Smoke) Humo
(Red) Rojo
(Blue) Azul
(Orange) Naranja
(Transparent) Transparente frost

I choosed Smoke, as i wanted something neutral.

Today i got the package from then, two days after payment.

I fully asembled the whole case without the board so i knew it fits okay.

So i started to assemble the case with board ,at the first try i dint noticed the top and botton sheets needed same orientation.

Also you need fit the sides at once by moving it backward and forward so it fits smothly.

The missing parts now are mainly the buttons, i also noticed spacers that came with the mm1 board are not "compatible" with
the proper height to make side connectors to fit well when you are decide to put screws or buttons.

At the end i got a working case, my board is protected now and i can carry it easy.

I may print the buttons my self or try find some from a old remote control or console gamepad.

Oh, sure there are pics here http://kristianpaul.org/gallery/mm1%20case/index.html

[1] http://projects.qi-hardware.com/index.php/p/m1/source/tree/master/cad
[2] http://dataprint.webs.com/