The Microsoft .NET SDK is an open-source development platform for developing applications across multiple architectures and operating systems. In this article, I will show you how to install the .NET SDK on Ubuntu 20.04 and then create/compile/run a simple web application. Ubuntu 22 will have the dotnet-sdk available in the default Ubuntu apt repositories, but … Ubuntu: Installing .NET SDK 6 on Ubuntu 20.04
If you need to batch rename a set of files, the ‘rename‘ utility is much easier than alternatives such as pairing find/exec or even putting together a small script. The rename utility gives you all the power of Perl regular expressions for converting the filenames. # make sure utility is installed $ sudo apt install … Bash: batch renaming files using the rename utility
If you have just virtualized the VMware ESXi server on top of KVM, the next step will be to install vCenter for its centralized control and additional feature set and management capabilities. In my last article we took KVM running on bare metal and deployed an ESXi 7.0 host on top of it. In this … KVM: Deploy the VMware vCenter 7.0 appliance using the CLI installer
Needing to find the most recently modified files in a directory is a pretty common need. Luckily the find utility has flags to easily explore a directory recursively and list recently modified files. If you want to find modified files within ‘N’ days ago from the current directory. # files within the last 24 hours … Bash: find most recently modified files
Managing resources in Azure from the command line can be done natively from Ubuntu using the Azure CLI. First, add the prerequisite packages. sudo apt-get update sudo apt-get install ca-certificates curl apt-transport-https lsb-release gnupg -y Then install the Microsoft signing key and add the custom repository. curl -sL https://packages.microsoft.com/keys/microsoft.asc | gpg –dearmor | sudo tee … Azure: installing the Azure CLI on Ubuntu
It is common for a virtualized Guest OS base image to have a generic storage capacity. This capacity can easily be exceeded by production scenarios, performance testing, logging, or even the general cruft of running a machine 24×7. If your VM is using Logical Volume Management (LVM), adding space can be done by following a … Ubuntu: Extending capacity of an LVM volume group using an existing or new disk
Within current distributions of Linux, there is a kernel component called netem that can be used to test and simulate the type of issues one would see over a Wide Area Network. This component is managed with a tool called traffic controller. This can be helpful during testing/troubleshooting to emulate the network latency or packet … Linux: Introducing latency and packet loss into network for testing
Volumes are the preferred method for persisting data for Docker containers. In this article, I will show how to create and use volumes for persistence, as well as tmpfs for temporary storage. At its absolute simplest, creating and mounting a volume backed by a local directory looks like: # make host directory mkdir -p /data … Docker: Working with local volumes and tmpfs mounts
This may come as a surprise, but Bash only supports integer arithmetic natively. If you need to perform calculations on floating point numbers, you will need to call out to a utility program like bc or Python. As a quick proof to yourself, try multiplying integers, then do the same with floating point numbers. $ … Bash: Performing floating arithmetic using bc
A common task when configuring software is modifying a properties file to set or override behavior. And although properties files are simple key=value pairs, there are some corner cases that make it challenging. For example, when setting a key/value pair, the key may be commented out with a hash mark in front of the line. … Bash: setting and replacing values in a properties file use sed
When troubleshooting an issue where ownership and permissions of a file or directories is questioned, we often go straight to chown/chmod and recursively set these values. However, this touches every file so if you are still in investigative mode it would be better to use “stat” to simply check the ownership and permissions first. If … Linux: Use stat to verify permissions and ownership
Update Nov 2021: I have written a newer article that deploys vCenter 7.0. If you have just virtualized the VMware ESXi 6.7 server on top of KVM, the next step will be to install vCenter 6.7 for its centralized control and additional feature set and management capabilities. In my last article we took KVM running … KVM: Deploy the VMware vCenter 6.7 appliance using the CLI installer
File copying is about more than just content – the metadata for user ownership, permissions, and timestamps is often critical to retrieval and function. Below are the relevant switches for metadata preservation when using cp, rsync, and tar. These typically need sudo in order to work.
If you have Bash console commands that you type out frequently, consider creating an alias. By simply adding a “.bash_aliases” files in your home directory, you can easily define shortcuts to frequent commands. For example, if you frequently list all the files in a directory reverse sorted by date, you may end up typing “ls … Ubuntu: Creating an alias for common commands under bash
A nice feature of the Go language is the ability to build binaries for multiple platforms directly from a single source system. As an example, even from a development Windows 7 32-bit machine, you can build binaries for both 64 bit Linux and Windows 2012 Servers. Before Go 1.5, you needed a compiler for the target architecture, … GoLang: Cross Compiling for Linux and Windows platforms
strace is a handy utility for tracing system, file, and network calls on a Linux system. It can produce trace output for either an already running process, or it can create a new process. Some of the most common troubleshooting scenarios are needing to isolate either the network or file system activity of a process. … Ubuntu: Using strace to get a view into file and network activity of a process
tcpdump comes standard on Ubuntu servers and is an invaluable tool in determining traffic coming in and out of a host. As network infrastructures have become more complex and security conscious, validating network flow from client hosts through potentially multiple proxies and ultimately to a destination host and port has become more important than ever. … Ubuntu: Using tcpdump for analysis of network traffic and port usage
In production data centers, it is not uncommon to have limited public internet access due to security policies. So while running ‘apt-get’ or adding a repository to sources.list is easy in your development lab, you have to figure out an alternative installation strategy because you need a process that looks the same across both development … Ubuntu: Installing Packages without Public Internet Access
Update Feb 2021: See my newer article on extending an LVM volume group on Ubuntu Focal using either the same physical disk or a new disk using parted. It is common for a virtualized Guest OS base image to have a generic minimal storage capacity. But this capacity can easily be exceeded by production … Ubuntu: Extending a virtualized disk when using LVM
We live in a multi-platform world, and the ability to easily share folders of content between users in the same protected network is a function made very convenient in the Windows world with CIFS shares (e.g. \\mydesktop\sharedfolder). Luckily for Ubuntu users, it is pretty easy to setup CIFS shares to offer that same interoperability with … Ubuntu: Creating a Samba/CIFS share to quickly share files with Windows
It is common for a virtualized Guest OS base image to have a generic minimal storage capacity. But this capacity can easily be exceeded by production scenarios, performance testing, logging, or even the general cruft of running a machine 24×7. For this reason, extending a virtualized disk can be extremely helpful. Here is a walk … Ubuntu: Extending a virtualized disk using fdisk when not using LVM
Before virtualization, there was a stronger argument for using a swap partition instead of a swap file for servers. A fragmented swap file could lead to performance issues that a statically sized and placed partition did not have consider. But once virtualization comes into play, unless you go to great lengths to segment your storage … Ubuntu: Using a swap file instead of swap partition for virtualized server VMs
There are many consumer side printers that provide the ability to scan a document to PDF. But unless you have a high-end series, the printer may only be capable of scanning one side at a time, which means you end up with a “front.pdf” and “back.pdf”. If you have a Linux desktop or laptop, luckily … Ubuntu: Using pdftk to stitch together two-sided PDF
It is time consuming to restart the entire Logstash service and refeed it input when working on a grokparsefailure. Here is an easy way to test a line of input or log file against a grok pattern: