Hacking React Native!

My acquaintance encouraged (or maybe challenged) me to try React Native for developing Android app. Should I endorse you here, kang Chip? 😀  Actually he has told me about React Native a year ago. And by then, I have bought a React Native ebook as well. But, unfortunately, I had so many buts. 😀

I have quite forgot about React Native right now. In additions, a few months ago, there’s been a discourse about its license. It made me discouraged to learn it more. But now, I have set a historical step, by creating a new –dummy– React Native project. These are the screenshots:

Screenshot_20171109_221212

Screenshot_20171109-221208
Oops, that’s error

The most exciting part is: I can code it by Vim! Some kind of killing two birds with one stone! Yeah, I can learn both Vim and React Native at once. It’s not multitasking, but eficiency. 😀

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Installing Openshift Origin on Digitalocean Droplet

Lately I wondered why my websites as well as the backend for my app (also available for Android) were so slow that the app was hardly usable. By wondering, I mean, I did’t get it, what’s happened in the underlying service, Openshift Online Starter v3. Actually I knew the cause, which was made by myself though. 😀

I was experimenting with SSL setup in the routes settings of Openshift project configuration page. There are 3 options for the secure route, Edge Termination, Passthrough Termination, Re-encrypt Termination, which are described on the official documentation page here. I have played with all those options, and the results were very very slow download speed, or maybe just the TTL. I had secure route to be activated for one of my subdomain need SSL, which was then to be paired with Full SSL option in CloudFlare. Yeah, I make use of it for the DNS server anyway. And as for SSL certificates for the Openshift route, I obtained it from Cloudflare’s. So, it’s obvious that there was a communication issue between them, particularly at SSL handshake session. Although, according to a comment for my question on Stackoverflow, he said that it’s a known issue on Openshift itself.

So, rather than disabling SSL for the sake of website speed, I was planning to move the data to traditional hosting, or VPS. I tended to choose the latter, as I have enough credit in Digitalocean right now. But, as I quite lazy to setup production server on a bare VPS, and my project was customized for Openshift, I’d rather searching for how to setup Openshift Origin on DigitalOcean. In the first run, I set up a Fedora Atomic droplet, that actually I didn’t understand what it was. 😀 Thanks to buddies on @FedoraID telegram group, I quite enlightened about it now. 🙂

Eventually, I found a thorough tutorial how to setup Openshift Origin on VPS. So, here I just want to share some screenshots of my success on setting it up. 🙂 FYI, it only took 2 hours for me to play around with it on Digitalocean droplet, as I realized that a 512 MB droplet would not sufficient to run Openshift service in it, as it encountered sudden stop so often due to the lack of memory.

Screenshot_20171102_005657Screenshot_20171102_015009

Screenshot_20171102_020825
Low resource (memory) on a half gig droplet

 

Removing Expiration Date of Oracle Express Database

oracle_sqlplus

I currently work on a project that uses Oracle database. For the local development, I installed it with Docker. I’ve found a handy docker file of Oracle Database Express Edition 11g published by wnameless in Github or in the official page in Docker Hub.

It’s so easy to use, that I just need to type sudo docker start oracle to get it up and running. Of course by reading the Readme first.

But then I noticed an error: ORA-28002: the password will expire within 7 days. Although it doesn’t affect the app, I feel a bit annoyed. So I googled it, and found the solution afterward. But I lost the URL. My bad!

Just take a look at above picture. I won’t type in the command here, as you can found it somewhere in Stackoverflow, actually. 😀

Oh-my-zsh, Tmux, Vim

Screenshot_20171008_054737
My Konsole as of October 2017

This time, I want to share my dotfiles of my new toys: zsh, tmux and vim at once. I’ve  found out what’s tmux actually, a couple of days ago by asking to a Telegram channel, @vimid. It’s “terminal multiplexer”, some kind of, it can break your single terminal session into multiple sessions.1 So, if I made use of Konsole tabs to use vim and php artisan serve of Laravel at a time then, now I just need tmux to run them concurrently.

Oh-my-zsh

What I know about zsh is not more than a console shell for macOS, before. Although, I did realize that it’s included in every Linux distributions as well. So, I thought I wouldn’t touch it no matter what. 😀

But this is my turning point to change my idealism. 😀 I just installed it, little bit configuring, and set it as bash replacement to Konsole. Umm, am I now look like a half macOS user? 😀

So, for zsh, I installed oh-my-zsh plugin and did some tweaks for the look of the prompt. I wanted a Powerline-like look, but I didn’t want to use Powerline. So, I installed powelevel9k theme instead. And now, I’m very satisfied, as it looks much nicer than my previous console.

Tmux

I don’t configure tmux much, since I just know it not that long. I thought it was just like bash or other console shells. As I had been trying it once, one day. I run it, and nothing appeared other than a command line shell. And I just realized how it works lately. 😀

In my config, I don’t do more than set default shell to zsh, and install tmux-powerline-theme with tpm.

Vim

As for vim, I have known it for quite long time. The first time I used it, like many developers out there, I didn’t know how to exit. 😀

But yeah, slowly but sure, I somehow have a little knowledge how to handle it. I have configured it quite seriously as I use it for my daily need: coding. But still, I’d say, I haven’t got its full usability yet, as I mentioned this before.  Just check out my .vimrc below, in case you so curious for what plugins I installed.


  1.  https://fedoramagazine.org/use-tmux-more-powerful-terminal/ 

Farewell OpenShift 2

It’s 3 days after the End of Life of OpenShift 2. As I posted earlier about the notice, I had migrated my little app to its next generation: OpenShift Online 3. My app is the basis of my personal website and the backend of my Android app. So it’s kind of a must for me to migrate it as soon as possible. And actually I did it successfully last week.

As I deploy it by Git, I still have the source repository. So, I don’t care of the deployed one on the OpenShift. But, once I received an email from OpenShift about the “one time exception” to allow me to backup the data even after its end of life, I think it’s worth trying. 😀

Screenshot_20171004-072146

So, I just followed the guide from attached link. Then a few moments after I typed rhc snapshot save php, I got my deployed source of the app, including error logs of Nginx and PHP.

Screenshot_20171004_073342

And now I feel so relieve of the data –if it will be deleted forever. Farewell, my –prior– app.

Ubuntu Mate 16.04 ARM

I used to write about Kubuntu when its new version was released. But for now, since my HDD is rather broken, and I have bought Raspberry Pi instead, so I want to write about Mate flavor of Ubuntu which fit to the ARM platform. Actually I want to install KDE on it, but I’m not sure about the performance.

Last month, the new long-term supported Ubuntu version was released. The main flavor with Unity has not yet brought awaited Unity 8 with Mir display server. And for my favorite flavor, Kubuntu, it has brought the newest KDE Plasma 5 for the desktop. Unfortunately I cannot play with it until I repair my PC. Maybe not only repairing, but also I ought to buy a new HDD as well.

Continue reading Ubuntu Mate 16.04 ARM

Set Up an OpenVPN Server Instantly with DigitalOcean Droplet User Data

OpenVPN is a full-featured open source Secure Socket Layer (SSL) VPN solution that accommodates a wide range of configurations. In this tutorial, we’ll set up an OpenVPN server on a Droplet and then configure access to it from Windows, OS X, iOS and Android. This tutorial will keep the installation and configuration steps as simple as possible for these setups.

Note: OpenVPN can be installed automatically on your Droplet by adding this script to its User Data when launching it. Check out this tutorial to learn more about Droplet User Data.

Setup VPS instance

First thing first, you need to create a Digitalocean account by clicking this link. Complete the registration by providing your payment method, either with credit card or Paypal account.

After you see the green button “Create Droplet”, click on it to proceed to the next step. Type in your preferred Droplet hostname, whatever you want. Then select size of droplet, in this case you’ll choose the pricing which fit you. In my case, I choose the lowest one, $5 /month droplet with 20GB storage and 512MB RAM. It’s kind of enough for me.

Then select the region you want the droplet located. This time, you may want to choose the nearest region from your country. Then select Image, it is the operating system for your VPS. Choose the Ubuntu 14.04 x64.

And finally, tick the “User Data” in the Available Settings section. When the text input appears, enter the script for creating the VPN server. Get the script by referring to the link at the bottom of this post. Find the “Note” section like above quotation. There you’ll find the link to the script. Just copy and paste it.

DO User data
DigitalOcean User data. This is just illustration, and that’s not the script you want.

And in the last section, you may skip that “Add SSH Keys”. Then you will receive the password required to login to the VPS in your email inbox. Check it later.

via How To Set Up an OpenVPN Server on Ubuntu 14.04 | DigitalOcean.