張旭 zx1986

Using Git Commit Message Templates to Write Better Commit Messages

The always enthusiastic and knowledgeable mr. @jasaltvik shared with our team an article on writing (good) Git commit messages: How to Write a Git Commit Message. This excellent article explains why good Git commit messages are important, and explains what constitutes a good commit message. I wholeheartedly agree with what @cbeams writes in his article. (Have you read it yet? If not, go read it now. I'll wait.) It's sensible stuff. So I decided to start following the

For MacOS Catalina, visit Install mysql2 on MacOS Catalina

Problem

Installing mysql2 gem errors on MacOS Mojave.

Solution

Make sure openssl is installed on Mac via Homebrew.

Web Service Fronting

Multiple Web properties on a single IP address

Hosting multiple websites on a single public IP address on the standard HTTP(S) ports is relatively easy with popular web servers like Apache, Nginx and lighttpd all supporting Virtual Hosts.
For Web Services which bundle their own HTTP server, things get more complicated, unless their HTTP stack can be shared somehow. More often than not, the application's HTTP stack listens directly on a dedicated TCP port.

Hosting multiple services on a single IP then requires using a fronting server listening on the standard HTTP port, and routing to the right backend service based on the host name or the path sent by the client.
Path based routing is cumbersome, usually requiring either the service to be aware of the path prefix, or a rewrite by the HTTP fronting server of all absolute URLs in the requests and responses.
Hostname based routing is more straightforward. The fronting server can just look at the [HTTP/1.1 Host header](https://tools

In case there's already a DHCP config for netplan for the private IP address:

File: /etc/netplan/50-cloud-init.yaml

Contents:

# This file is generated from information provided by
# the datasource.  Changes to it will not persist across an instance.
# To disable cloud-init's network configuration capabilities, write a file
# /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg with the following:

	let regex;

	/* matching a specific string */
	regex = /hello/; // looks for the string between the forward slashes (case-sensitive)... matches "hello", "hello123", "123hello123", "123hello"; doesn't match for "hell0", "Hello"
	regex = /hello/i; // looks for the string between the forward slashes (case-insensitive)... matches "hello", "HelLo", "123HelLO"
	regex = /hello/g; // looks for multiple occurrences of string between the forward slashes...

	/* wildcards */
	regex = /h.llo/; // the "." matches any one character other than a new line character... matches "hello", "hallo" but not "h\nllo"
	regex = /h.llo/; // the "" matches any character(s) zero or more times... matches "hello", "heeeeeello", "hllo", "hwarwareallo"

	# Note - an NFS server isn't really a Kubernetes
	# concept. We're just creating it in Kubernetes
	# for illustration and convenience. In practice,
	# it might be run in some other system.

	# Create a service to expose the NFS server
	# to pods inside the cluster.

	kind: Service
	apiVersion: v1

	* Shows a message while asserting like:

	ok: [host] => {
	"msg": "disk usage 4.2B of total 20.0GB (21.0%) (should exceed limit 90.0%)"
	}

	* Note this only looks at first mount point on current node
	* Fails if disk is near-full
	* Last step pushes to a push-based monitoring service, which will alert us if it doesn't get there after some time
	* Need to setup a variable `disk_limit`, which is the max acceptable usage ratio, e.g. set it to 0.8 if you want to keep disks within 80% of max size

	# Example YAML configuration for the sidecar pattern.

	# It defines a main application container which writes
	# the current date to a log file every five seconds.

	# The sidecar container is nginx serving that log file.
	# (In practice, your sidecar is likely to be a log collection
	# container that uploads to external storage.)

	# To run: