This is a basic step by step intro to working with Docker containers and Images. You should be able to follow along with your installation of docker, but be sure to change IDs/naming schemes according to your use case.
The goal of this exercise is to create a base image from the ubuntu base image that has both the jre and htop installed.
docker run -t -i ubuntu /bin/bash
| # Custom rspec matcher for testing CanCan abilities. | |
| # Originally inspired by https://github.com/ryanb/cancan/wiki/Testing-Abilities | |
| # | |
| # Usage: | |
| # should have_abilities(:create, Post.new) | |
| # should have_abilities([:read, :update], post) | |
| # should have_abilities({manage: false, destroy: true}, post) | |
| # should have_abilities({create: false}, Post.new) | |
| # should not_have_abilities(:update, post) | |
| # should not_have_abilities([:update, :destroy], post) |
Mosh (mobile shell) is a gift from the Gods(tm). Anyone with spotty internet or wireless connection has suffered the pain of a lost SSH session. Sure, one can fire up screen (or tmux as the kids are using these days), but that's an extra step and you are still using the SSH protocol.
I'm not here to tout the benefits of Mosh, you came here to open it up in your firewall.
/etc/firewalld/services/mosh.xmlfirewall-cmd --add-service=mosh --permanentfirewall-cmd --reloadIf you tend to have a lot of sessions (not recommended), you can increase the ports, but the default should be fine for most applications.
Today I made the decision to shut down King's Cross Coffee, the potentially-popular coffee shop that existed only in the hearts and minds of coffee-drinking Ann Arborites. I decided to shut it down because people were actually going there. It didn't seem fair, and I'd proved my point.
I'd been experimenting with the concept of automatically favoriting tweets from a local audience as a way of driving traffic. I set up a product called LocalFavorite which takes a search term and location range and favorites 3 tweets each hour.
To control my variables, I created the Twitter account @KingsCrossCafe, a realistic-looking coffee shop in Ann Arbor, MI. I gave it a few photos, a real address, a bit.ly link, and posted a few tweets. Then I began automatically favoriting anyone in the Ann Arbor area that mentions 'coffee' or being 'tired'.
As of version 3.3, python includes the very promising concurrent.futures module, with elegant context managers for running tasks concurrently. Thanks to the simple and consistent interface you can use both threads and processes with minimal effort.
For most CPU bound tasks - anything that is heavy number crunching - you want your program to use all the CPUs in your PC. The simplest way to get a CPU bound task to run in parallel is to use the ProcessPoolExecutor, which will create enough sub-processes to keep all your CPUs busy.
We use the context manager thusly:
with concurrent.futures.ProcessPoolExecutor() as executor:
| import cv2 | |
| import numpy as np | |
| def in_front_of_both_cameras(first_points, second_points, rot, trans): | |
| # check if the point correspondences are in front of both images | |
| rot_inv = rot | |
| for first, second in zip(first_points, second_points): | |
| first_z = np.dot(rot[0, :] - second[0]*rot[2, :], trans) / np.dot(rot[0, :] - second[0]*rot[2, :], second) | |
| first_3d_point = np.array([first[0] * first_z, second[0] * first_z, first_z]) |
| /* This is a wrapper library that will give your server the power of | |
| * /dev/null as a service, as seen at http://devnull-as-a-service.com/ | |
| * | |
| * Compile: | |
| * gcc -ggdb -shared -fPIC dnaas.c -ldl -lcurl -o libdnaas.so | |
| * | |
| * Try: | |
| * LD_PRELOAD=./libdnaas.so dd if=/dev/sda of=/dev/null bs=8192 count=16 | |
| * | |
| * Install: |
| // 1. Go to page https://www.linkedin.com/settings/email-frequency | |
| // 2. You may need to login | |
| // 3. Open JS console | |
| // ([How to?](http://webmasters.stackexchange.com/questions/8525/how-to-open-the-javascript-console-in-different-browsers)) | |
| // 4. Copy the following code in and execute | |
| // 5. No more emails | |
| // | |
| // Bookmarklet version: | |
| // http://chengyin.github.io/linkedin-unsubscribed/ |