Today one can choose from overwhelming variety of online (cloud) services in almost any thinkable area. Many of them provide vast amount of content and have professional user interfaces / clients. So why to bother with selfhosting, when one can just choose from this broad offer? And I’m here referring mainly to personal selfhosting – e.g. running some services from computer/server running at your home and providing these services to yourself plus family members. Does it make still any sense, when you can hardly compete with internet giants? In this article I’d like to present few reasons, why I think that selfhosting still have some values.Continue reading Selfhosting in Era of Cloud
Category Archives: Admin
Intercept https communication from an Android application
Many Android applications communicate with severs using some form of REST API secured with TLS/SSL (so it’s “https” protocol). If it is your application or an open source application you know what’s going on from the source, but for third party application you still may be wondering (hopefully for legit reasons:-), what is this application sending to the server and what it gets back. With help of few free tools it’s fairly easy to monitor encrypted traffic on your local computer (linux, but it will work on other systems too). Continue reading Intercept https communication from an Android application
CI/CD Environment for A Smaller Project
Advantages of Continuous Integration (CI) and Continuous Delivery (CD) are obvious even for small projects with few contributors and are easily achievable with help of free cloud tools – like for instance with mighty combo of Github plus Travis. But what if we want to achieve similarly convenient environment inside of our private network, available only to our internal teams. Luckily open source is here again to help us with another great tool – GitLab – GitLab is a similar platform to GitHub, but the code is open source and we can easily install it in our environment. In this article I’ll summarize my experiences and guidelines how to build convenient environment for a small project with automatic testing and deployment. Continue reading CI/CD Environment for A Smaller Project
What Is This Weird File Name in My Samba Share?
In IT there are big things and there are small things. Some small things can be pretty annoying and they seem to stay here forever. One of these annoying little things is difference between restrictions for file names in Windows versus unix/linux (others are for instance legacy character encodings, http proxy support, these things has teased me many times in past). Have you ever seen strange file name like W3NEM5~I on shared disc instead of meaningful file name, that you expected? If so and you’re interested what’s going on continue reading. Continue reading What Is This Weird File Name in My Samba Share?
Linux Desktop for 2017 and on
As Canonical has announced the end of Unity desktop I thought it’s time to look again around at Linux desktops. In past years I have been using mainly Gnome 2 (or Mate recently), XFCE, Cinnamon and Unity (yes I did and experience was after all rather positive). I’ve tried Gnome 3 few years ago, but really never gave it longer try and never really find attraction for KDE. So in this article I’ll look a bit at those desktops again and especially at the recent Gnome Shell and it’s customization to my needs (which is indeed based on very individual preferences). Continue reading Linux Desktop for 2017 and on
Beware of sync option in mount
By default mount is using async option, which means that write operations do not wait for final confirmation from the device – they are stored in disc cache and writes are done latter, optimized by disc firmware. However you can set sync option manually (
-o sync), then write operations are synchronous, meaning each block write has to wait for confirmation that it’s physically written to the disc and there is no optimization available. This can significantly slow down write speed, of which I convinced myself just recently – I backuped some data to external 2.5″ USB 3.0 HD – slowdown in this case was almost 1000x – (70kb/s vs 60MB/s measured by
rsync --progress). How it happened that disc was mounted with sync option? I actually use usbmount to auto-mount disks and it has sync as default mount option (fortunately can be changed in it’s configuration). So conclusion is – don’t use sync option unless you know exactly what you are doing and if write speed is suspiciously slow check mount options.
The Splendors and Miseries of CaaS – Experiences with Openshift3
Container as a Service (CaaS) is increasingly popular cloud service (usually categorized under Platform as a Service family of cloud services). It can provide easy ways how to deploy web applications leveraging Linux container technologies usually most popular Docker containers. Recent addition to this family is Openshift v3 from RedHat. Openshift is available as an open source software (Openshift Origin) or as a hosted service (OpenShift Online). I already used previous version of Openshift service (v2), as described in my previous article. In this article I’ll share my recent experiences with Openshift v3 service (also called NextGen). Continue reading The Splendors and Miseries of CaaS – Experiences with Openshift3
Ethereum local playground
In past article I’ve talked generally about blockchain technologies, in this article we will look into Ethereum from user perspective. We will build local playground, where we can test many functions of Ethereum(Ethers transfers, using and writing smart contracts and more) without spending real Ethers (and thus real money). This guide in intended for users with Linux OS. Continue reading Ethereum local playground
NetworkManager Script to Set HTTP Proxy
While Gnome and it’s derivatives support automatic proxy detection, it do not work well for all programs, particularly for command line programs. I’ve found that using simple script in /etc/NetworkManager/dispatcher.d works better for me, which sets and unsets fixed proxy works better. NM dispatcher scripts are run each time network connections change (network up, down, VPN connect etc.) and received two parameters ( interface name and status) and bunch of environment variables. Continue reading NetworkManager Script to Set HTTP Proxy
Flashing ROM to Samsung Phone
On Linux there is a great Heimdall tool. I used it recently to flash stock ROM and custom recovery (TWRP) to my old Samsung S3 mini. Best to be used from command line. Continue reading Flashing ROM to Samsung Phone