Apache Guacamole is an incubating Apache project that enables X window applications to be exposed via HTML5 and accessed via a browser. This article shows how Guacamole can be run inside containers in an OpenShift Container Platform (OCP) cluster to enable Red Hat JBoss Developer Studio, the eclipse-based IDE for the JBoss middleware portfolio, to be accessed via a web browser. You’re probably thinking “Wait a minute… X windows applications in a container?” Yes, this is entirely possible and this post will show you how. Bear in mind that tools from organizations like CODENVY can provide a truly cloud-ready IDE. In this post, you’ll see how organizations that have an existing well-established IDE can rapidly provision developer environments where each developer only needs a browser. JBoss Developer Studio includes a rich set of integration tools and I’ll show how those can be added to a base installation to support middleware products like JBoss Fuse and JBoss Data Virtualization.
How does Apache Guacamole work?
Apache Guacamole consists of two main components, the Guacamole web application (known as the guacamole-client) and the Guacamole daemon (or guacd). An X windows application runs in an Xvnc environment with an in-memory only display. The guacd daemon acts as an Xvnc client, consuming the Xvnc events and sending them to the Tomcat guacamole-client web application where they are then rendered to the client browser as HTML5. Guacamole also supports user authentication, multiple sessions, and other features that this article only touches on. The Apache Guacamole website has more information.
Open source software has come of its age. Today it’s impossible to think of a platform company that doesn’t have an open source strategy. Even Microsoft – a company that once compared open source to cancer – has embraced it fully. Of course, we have companies like CloudBees, Red Hat and Docker that built highly successful business models with OSS. But when it comes to cloud platform vendors, the story is slightly different.
Though cloud is built on the foundation of OSS, the top 3 vendors – AWS, Microsoft and Google – have a very different approach to it. AWS and Azure are the largest consumers of OSS. Amazon EC2, one of the most successful IaaS platforms, is built on top of Xen, the popular open source hypervisor. Amazon has turned almost every successful open source project into a commercially available managed service.
LinuxKit, which Docker announced back in April, is one of the newest tools to enter the Docker universe. Here’s what you need to know about what LinuxKit does and what it means for security.
LinuxKit: What and Why
Let’s start with the what and why of LinuxKit.
As you might expect, the LinuxKit story starts with Docker itself. Docker, of course, was originally designed to sit on top of the Linux kernel, and to make heavy use of Linux resources. It was from the start basically a system for virtualizing and abstracting those underlying resources.
Docker got its start not just as a container system, but also as a Linux container system. Since then, Docker has developed versions of its container management systems for other platforms, including widely used cloud service providers, as well as Windows and the Macintosh OS. Many of these platforms, however, either have considerable variation in the Linux features which are available, or do not natively supply a full set of Linux resources.
KDAB, a German consulting firm that develops graphics and visualization tools, has released Hotspot 1.0, a GUI too for visualizing performance data generated by the Linux perf tool.
Perf analyzes system and application behaviors in Linux and generates a detailed report showing which calls, programs, disk I/O operations, or network events (just to name a few possibilities) are eating up most of the system’s time. Because Perf is a command-line tool, most of its output is static, and it can be a multi-step process to produce an interactive, explorable report from data provided by Perf.
Short Bytes: What are your expectations from your Linux-powered machines. A recently conducted Linux laptop survey throws light on various factors such as prices, compatibility issues, GPU, laptop brand, etc. which people take into consideration while buying a Linux laptop. It shows some people are willing to pay more if they get proper support.
A Linux Laptop Survey was conducted by Phoronix which welcomes people to answer a bunch of questions about what things they put first while buying a laptop or does it matter if their machine came pre-loaded with some Linux distribution. The survey received more 30,000 responses in a time span of two weeks which can be taken as a considerable figure to make a conclusion about the general choice of the people.
Network automation does not an automated network make. Today’s network engineers are frequently guilty of two indulgences. First, random acts of automation hacking. Second, pursuing aspirational visions of networking grandeur — complete with their literary adornments like “self-driving” and “intent-driven” — without a plan or a healthy automation practice to take them there.
Can a Middle Way be found, enabling engineers to set achievable goals, while attaining the broader vision of automated networks as code? Taking some inspiration from our software engineering brethren doing DevOps, I believe so.
Sometimes, while working on the command line, you arrive at a point where there’s too much text on the terminal screen, and none of that is relevant to you. So, in order to avoid distraction, you’d want to clear the terminal screen. Those new to the Linux command line may not know that there exists a dedicated command line utility that does this work for you.
In this tutorial, we will be discussing the basics of clear (the tool in question) as well as how to use it. But before we do that, it’s worth sharing that all examples/instructions mentioned in this tutorial have been tested on Ubuntu 16.04LTS.
In an earlier post, we’ve explained CPUTool for limiting and controlling CPU utilization of any process in Linux. It allows a system administrator to interrupt execution of a process (or process group) if the CPU/system load goes beyond a defined threshold. Here, we will learn how to use a similar tool called cpulimit.
Cpulimit is used to restrict the CPU usage of a process in the same way as CPUTool, however, it offers more usage options compared to its counterpart. One important difference is that cpulimit doesn’t manage system load unlike cputool.
This week in Linux and open source, the ‘Big 4″ accounting firms are becoming power players in blockchain, Oracle expands open source container efforts, and more in this weekly digest!
1) The four largest accounting firms in the world are active members of the blockchain revolution– Including Deloitte, which joined the Hyperledger Project.
3) Hyperledger’s Indy “is all about giving identity owners independent control of their personal data and relationships.” Explains Doc Searls in his op-ed about the availability of Linux for all users.
The Linux command line is a tool that every system administrator should get to know. With the power of commands at your fingertips, there’s very little you cannot do. However, along with that power comes the need to remember those commands. When you take into consideration how complicated those commands can get, it’s understandable that some admins have trouble recalling what they have done or need to do at the Bash prompt.
You may have to issue the command:
iptables -A OUTPUT -o eth0 -p tcp -m multiport
--sports 22,80,443 -m state --state ESTABLISHED -j ACCEPT
Or, maybe you recently secure shelled into a server, but don’t recall the IP address off hand. What do you do? Most Linux admins would immediately tell you to look to your Bash history; and that would be sage advice. By typing the command history, you are presented with the last X amount of command you have run on the system. The X is determined within the ~/.bashrc file, in the line:
HISTSIZE=1000
The history command is, in fact, a great way to see what commands you’ve issued. You can comb through that, find the command you need, copy it, and then paste it back into the prompt. Or, you can, at the command prompt, simply start tapping the up arrow on your keyboard until you land on the command you need.
What if I told you there was a much, much, much easier way? There is, and it’s called fish. Fish is a friendly, interactive shell that can be installed on your Linux machine and features:
Autosuggestions
Scriptability
Man page completions
VGA color
Web-based configuration
Ease of use
I’m going to walk you through the installation and usage of the fish shell; once you’ve started using this handy tool, chances are you’ll never go back to the standard old Linux shell again.
Installation
Fish can be installed on Ubuntu, Debian, Fedora, RHEL, openSUSE, CentOS, Arch Linux, Gentoo Linux, and even mac OS and Windows. I will be demonstrating the installation on Elementary OS, so the installation for your distribution will vary (you can get instructions for all the supported platforms from the fish main page). The installation for Elementary OS (as well as most Debian-based systems) is as follows:
Open up a terminal window
Add the necessary repository with the command sudo apt-add-repository ppa:fish-shell/release-2
Update apt with the command sudo apt-get update
Install fish with the command sudo apt-get install fish
That’s it; fish is now installed and ready to serve.
First steps
You’re at the Bash prompt, with fish installed, and you have no idea how to make use of it. That’s because you’re still in your bash prompt. To make use of fish, you have to enter the fish prompt. How do you do that? Type the command fish and you will see your prompt change (Figure 1).
Figure 1: Your change may be dramatic or subtle, depending on how you have your Bash prompt configured.
At this point, you’re ready to start using fish. The best way to do this is to start typing a command. You will see that fish does a great job of completing the command, bashed on your history. For example, if I start typing ssh, fish will complete the command with the most recent matching entry from bash history (Figure 2).
Figure 2: Fish makes great use of the Bash history.
If that’s the command you’re looking for, hit the right arrow key to accept and then hit Enter. The one caveat to fish is that, once it makes a suggestion, you cannot scroll through the history of similar commands (which would be a nice feature).
One really cool thing you can do with fish is get suggestions for commands, based on what you type. Say, for instance, there’s an ssh tool you want to use, but you can’t remember the name of the command (but you know it starts with “ssh”). Type ssh and then hit the tab key. Fish will present to you suggestions, one of which might be the command you are looking for (Figure 3).
Figure 3: Fish command suggestions.
There are so many things you can do with fish. To learn them all, your best bet is to walk through the official fish tutorial (which offers up plenty of examples that will empower your fish experience).
Once you’re done with the fish prompt, you can return to bash by typing exit.
Configuring fish
One task you should definitely undertake is the configuration. Out of the box, fish is an incredibly powerful and handy tool to use. However, fish offers plenty of customizations that can be tweaked with the web-based configuration tool. To get to the web interface, enter the fish shell and then type fish_config. Hit Enter on your keyboard and your default browser will open to the fish configuration page (Figure 4).
Figure 4: The fish web-based configuration tool.
I highly recommend altering your fish prompt so that the differences between it and the standard prompt aren’t so subtle. To do this, click on the prompt tab, scroll down until you find a style that suits you, select that prompt, and then click the Set Prompt button (Figure 5).
Figure 5: Differentiating your fish prompt from your Bash prompt.
Once you’ve made the changes, close the browser window (or tab), go back to your terminal window, and hit Enter. The new prompt configuration will be set and you’re ready to go.
There are quite a lot of other options to be configured within the web-based tool. From here you can also set up abbreviations (aliases) for commands. This can also be done from the fish prompt, but using the web-based interface makes it a bit easier. Say, you regularly ssh to a particular server with the command:
ssh -v olivia@192.168.1.101
With abbreviations, you could shorten that to, say ssho. With this in place, you would only need type ssho(within the fish shell), hit enter, and the full command will run. To create an abbreviation, run the fish_configcommand (from the fish prompt), go to the abbreviations tab in the web-based tool, and then type your abbreviation in the left text area and the full command in the right text area (Figure 6). Hit the Save button and your abbreviation is ready.
Figure 6: Adding a command abbreviation for even more fish efficiency.
Make sure you close the browser window (or tab) and then hit Enter (on your keyboard) back at the fish prompt.
Keep learning
To get the most out of fish, it would behoove you to read through the official fish documentation (just type help at the fish prompt and hit Enter). You’ll be pleasantly surprised at how much this shell can do for you.
Mark my word, the fish prompt will very quickly become a must-have tool to aid you in your daily Linux administrative tasks.
Learn more about Linux through the free “Introduction to Linux” course from The Linux Foundation and edX.
