Wednesday, March 28, 2018

PHP with docker

A friend asking about a PHP library and I decided to test whether that library is working. But I don't have PHP environment setup (we're Python shop btw). But thanks to docker, that's easy these days.

docker run -it --tty --rm --volume $PWD:/app --user $(id -u):$(id -g) composer require google/apiclient:^2.0

Then we just need to create the script to run, still in the same directory:-

include_once __DIR__ . '/vendor/autoload.php';

$GCSE_API_KEY = "nqwkoigrhe893utnih_gibberish_q2ihrgu9qjnr";
$GCSE_SEARCH_ENGINE_ID = "937592689593725455:msi299dkne4de";

$client = new Google_Client();
$client->setApplicationName("My_App");
$client->setDeveloperKey($GCSE_API_KEY);
$service = new Google_Service_Customsearch($client);
$optParams = array("cx"=>self::GCSE_SEARCH_ENGINE_ID);    
$results = $service->cse->listCse("lol cats", $optParams);

And we can run that script again using docker:-

docker run -it --rm --volume $PWD:/app -w /app php:5.5-cli php cse.php

Links:-

https://stackoverflow.com/questions/41592249/how-to-use-php-client-for-google-custom-search-engine
https://hub.docker.com/r/library/php/
https://hub.docker.com/r/library/composer/

Tuesday, March 13, 2018

Receiving Email Using SES

There's service like Pawnmail (seem to be down now) that allow you to receive email on your custom domain. But that's a third party and mean adding another one into your trust list.

Since we already using AWS, I'm wondering if it has anything that can receive email. They have SES that usually used to send email. But turn out SES can also receive email. So just add the MX record in your DNS to inbound-smtp.us-east-1.amazonaws.com.

Next is to configure the domain and address to receive the email.


The received email need to be forwarded somewhere like to your application for processing but that's overkill. I need something simpler. Here come SNS, Simple Notification Service. So the email can be forwarded to an SNS Topic. From the SNS Topic you can create Subscription that will forward the email to your actual email, finally.


SNS will send the email as JSON so if you received HTML email that will be appear in your inbox as is. But since I can read HTML, that should be fine.


Friday, November 10, 2017

The rise of localhost

I noticed a pattern in dex world, where you build client backend to participate in the network, and then build a web app that simply connect to localhost:someport for the UI.

To check my scuttlebutt updates, I opened up http://localhost:8027/. For those using Ethereum Parity wallet, they can open it at http://localhost:8180/. ZeroNet users are browsing at http://localhost:43110/.

But Parity for example, try to make it seamless, they still provide a dns - web3.site which then redirected to home.web3.site which simply resolved to 127.0.0.1. But this I think bring up some problem, especially non-tech user which think that Parity is a website hosted by Parity Technologies. I seen this in a some articles about the latest bug.

Wednesday, October 11, 2017

The first step in learning new programming language

Is to prepare the basic environment where you can freely try and experiment with the new language features and tools. Maybe because I'm not programmer type person, but more as tinkerer/builder, I hate learning the language syntax and stuff.

For years after I started "learning" Python, I can't barely write any Python code. But I have manage to try lot of Python cool apps because I have that environment for me to experiment with all Python based applications. All these cool apps that get me hooked to the language, not the syntax or whatever language features. And in my experiences, this is one reason why people failed to get hooked on the new language they want to learn. They started learning with some of the language syntax and eventually get bored, because not so much interesting stuff there. In whatever programming language, it's the ecosystem that made it lively, and where the real work happened.



Early this year, I made it a point to learn Go programming language. It's almost a year now and similar to my Python experience I mentioned above, I can't barely write any Go code. But I have an environment where I can try a lot of Go based applications, and this is the reason I'm still hooked to the language even I haven't manage to write my own code yet. Back with Python experience, I'd only manage to know Python and write Python code after I got my first Python job. That was years after I started learning the language.

The reason this work I think similar to when learning human language. To master the language, you need to practice it. And to practice the language, you need to be in an environment where the language being used. That's it, the environment. So instead of trying to understand the for loop or the class syntax, I spent time to understand how packaging and deployment work, so I can actually run the application for other people to make use of it.

So start to invest your time in having the environment first, whenever you want to learn any new programming language.

Thursday, September 14, 2017

Notes on AWS Lightsail

Finally, I'm trying Amazon Lightsail. Just few notes:-




1. The direct console is great. This is basically what EC2 should have, instead of web ssh console. You need this console to verify the ssh key fingerprint before connecting through ssh first time.
2. There's simple firewall manager. Only port 22 and 80 opened by default. Click Manage from the instance menu to get into the firewall manager.
3. Now there's apac region !

Friday, September 8, 2017

A brief look into nginx unit

So nginx has come out with it's own application server that can run multiple types of application from PHP, Python and Go, with more languages support coming soon. Deployment is always my topic of interest so this kind of news definitely caught my eyes.

There's not much technical information yet, other than the official blog post. I'm quite interested to know how the python support being implemented. The Application model also remind me to the Webfaction hosting model and with unit HTTP API, it provide possibility to implement something like Webfaction hosting panel where you can add new application and manage it all through just a web interface.

Reading through the source code of python module support, it look like python wsgi application is being executed in-process through python C API (my guess), particularly if you look at the line 337:-

result = PyObject_CallObject(nxt_py_application, args);

For Go application however it simply execute the Go built-in http server and communicate through that. The current implementation is merely 100 lines compared to python implementation which is almost 1000 lines.

Enough with all the theories, I decided to give it a try. It has deb packages for Ubuntu Xenial. Just follow the documentation how to install it through apt. The docs however seem missing on how to start unit after installing it. After scouring around the apt file then I know the binary is named as unitd, so to start it:-

sudo systemctl start unitd

After that you can start communicating with unitd through the HTTP JSON API:-

sudo curl --unix-socket /var/run/control.unit.sock http://localhost/

Btw, it also through this I learned that curl has unix socket support !

For the rest, you can just follow the docs. I did try with simple wsgi applications and discovered few issues:-
  • https://github.com/nginx/unit/issues/17 - How to apply changes to our app script ?
  • https://github.com/nginx/unit/issues/16 - All applications and listeners lost after restarting unitd
  • https://github.com/nginx/unit/issues/12 - How to inject environment variables ?
  • https://github.com/nginx/unit/issues/15 - How to add venv packages ?
That's all for now. Next probably trying it from source instead of packages to get all the latest changes.

Tuesday, August 15, 2017

List of DNS server software

It's been quite a long time I'm not following the recent development in dns scene, especially on the server software itself. In the past, I did try setting up my own BIND installation just to understand how all these things work.

I tweet reminded me back:-
So what else dns server software we have these days other than BIND 9 ?

  • PowerDNS (as in tweet above).
  • CoreDNS - now also a server type plugin of Caddy. It's a successor of SkyDNS.
  • SkyDNS - SkyDNS is a distributed service for announcement and discovery of services built on top of etcd.
  • Knot
  • NSD