If you want to just redirect STDERR to tee, run the following command.
some-command 2> >(tee /var/tmp/output)Author: rchapin
Mocking an HTTPS RESTful endpoint with Netcat
Netcat is generally known as a TCP/IP Swiss Army Knife and is incredibly helpful for both debugging and mocking up network services
Following is an example on how to setup a mock RESTful service that communicates over HTTPS.
On the “server” side, run the following command. The -l command instructs Netcat to listen.
while true; do { echo -e “HTTP/1.1 200 OK\r\n$(date)\r\n\r\n<h1>hello world from $(hostname) on $(date)</h1>” | nc -vl –ssl 8080; } done
On the “client” side, run the → Continue reading “Mocking an HTTPS RESTful endpoint with Netcat”
Test Network Speed of Ethernet Ports
If you have just bought a new (to you) nic card or other networking device and want to test that all of the ports can pass traffic at the expected rate, as long as you have nc and the firewall ports open on a “server” with a known good nic and have nc installed on your “client” device that you want to test it is very easy to test.
Of course, if you are testing a switch itself, then it → Continue reading “Test Network Speed of Ethernet Ports”
Creating, Updating Expiration of and Posting PGP Keys
Following are my notes and how-tos on creating, and managing PGP keys.
Here is a link to a website with some very good information and best practices for managing keys.
Most of this article deals with the concept of setting an expiration date on a set of keys to a reasonable time and how you can update that key as time goes by. You should set a reminder in whatever calendar system you are using to remind you to → Continue reading “Creating, Updating Expiration of and Posting PGP Keys”
How To Compile and Install New SELinux Plicy Modules
Following is a quick how-to on compiling and adding addition SELinux modules.
When configuring and deploying new and/or custom services on systems that are enforcing SELinux you will likely have to compile addition SELinux modules.
This how-to includes how to go through each step of compiling a new module one-by-one; similar to the model of breaking down the compilation of C and C++ into it’s composite steps.
Step 1: Gather the audit.log entries
You will need to determine which → Continue reading “How To Compile and Install New SELinux Plicy Modules”
Adding a New Disk to a Linux Server and Creating an LVM Partition
There are a number of tutorials online for adding a new disk to a machine and then extending an existing LVM partition to use the new device.
This particular tutorial covers the use case of adding a new disk to a Linux server and then creating a NEW LVM partition on it without modifying the existing devices and LVM partitions.
The first thing you will need to do is add the physical device to the server (or VM).
Then, you → Continue reading “Adding a New Disk to a Linux Server and Creating an LVM Partition”
[SOLVED] Unable to Customize Keyboard Shortcuts for Switching Between More Than 4 Workspaces in GNOME on CentOS 7 or RHEL 7
I am working on a VM that is running GNOME under RHEL 7 and I typically run with 12 workspaces. The default GNOME install only has the keyboard shortcut configurations up to “Switch to workspace 4”.
It turns out that the solutions is to use the gsettings cli tool to add additional shorcuts.
$ gsettings set org.gnome.desktop.wm.keybindings switch-to-workspace-5 "[\"<ControlF5\"]"
$ gsettings set org.gnome.desktop.wm.keybindings move-to-workspace-5 "[\"<Alt5\"]"How to See SELinux Denials That Do Not Show In the audit.log
Or, otherwise know as: SELinux and Silent Denials.
Sometimes when troubleshooting SELinux issues, you will have added new policies for each of the denial causes written to the audit.log, but SELinux will still be denying access . . . and not giving you any further information about it in the audit.log.
Various processes often execute additional system calls that are above an beyond what they need to do for normal operation. Many of them are blocked, and in order to → Continue reading “How to See SELinux Denials That Do Not Show In the audit.log”
Mounting a Samba Share From Linux Client to Linux Samba Server
In order to be able to access a Samba share on a remote client as a mounted file system execute the following command, as root on the client:
mount -t cifs -o user=<user-on-samba-share,uid=<uid-on-local-macheine,gid=<gid-on-local-machine,rw,workgroup=<your-workgroup//ip/share /mnt/mount-point-dirYou will be prompted for the password for the user defined on the Samba server.
If you are able to authenticate, and then get the following error:
ls: reading directory .: Permission deniedCheck the SELinux context type of the directory on → Continue reading “Mounting a Samba Share From Linux Client to Linux Samba Server”
Mocking Static Methods That Return void in Java
This is one of those things that I tend to do on a regular basis . . . but unfortunately don’t remember the details each time, so I am adding it for future reference.
Often, developers will want to mock static methods that return void. The Mockito and PowerMockito frameworks provide for this, but the syntax isn’t immediately obvious.
Following is an example.
public class SomeClass {
public static void doSomething(String arg1, int arg2) {
// Method that does something...