Antoine Cotten antoineco

SSH into GCP VMs via IAP Using Standard SSH Config

If your GCP VMs don't have external IPs (or you use IAP for security), gcloud compute ssh --tunnel-through-iap works — but it's verbose. You can't use it with scp, rsync, Ansible, or VSCode Remote-SSH easily.

This guide shows how to set up ~/.ssh/config so you can just run:

ssh my-vm

Final Review - Comprehensive PR Review & Testing

Step 0: Determine Review Pass

Before starting, check the git history to determine if this is a follow-up review:

git log --oneline -10 | grep -i "Co-Authored-By: Claude"

Navigating the modes of Vim

This diagram illustrates navigating through Vim’s modes. It was built factoring Vim 9 (i.e., all its modes, including up to two new modes, cr and cvr, in November 2023). Information about the state() and 'showmode' is provided too.

SVG version

Some features are only available in the SVG version. It is not provided directly from within this gist’s files because SVGs do not always play nicely in GitHub (particularly, refusing to display embedded fonts).

The SVG version includes hover text help, which shows pertinent information about the underlying key, command, mode, etc.

Semantic Highlighting in Neovim

What is Semantic Highlighting?
Default Highlighting
Using LspTokenUpdate for Complex Highlighting
- Highlighting Based on More Than One Modifier
Dealing with Ambiguity

Connect host and VM when using a MACVTAP interface

NB: The following is only of interest if you want to share the host network with your virtual machine. The most common way this gets implemented is by setting up a bridge which includes the physical interface. Using a [MACVTAP] inerface is suposed to be more efficient, since it avoids the additional bridge in the network setup.

In this gist, we extend the information provided in the documenation on linux virtual interfaces.

In the following, we assume you host interface is eth0. IP addresses used:

host: 198.51.100.50/24
virtual machine: 198.51.100.198/24
default gateway: 198.51.100.254

About

I faced bandwidth issues between a WG Peer and a WG server. Download bandwidth when downloading from WG Server to WG peer was reduced significantly and upload bandwidth was practically non existent.
I found a few reddit posts that said that we need to choose the right MTU. So I wrote a script to find an optimal MTU.
Ideally I would have liked to have run all possible MTU configurations for both WG Server and WG Peer but for simplicity I choose to fix the WG Server to the original 1420 MTU and tried all MTUs from 1280 to 1500 for the WG Peer.

Testing

On WG server, I started an iperf3 server
On WG peer, I wrote a script that does the following:
- wg-quick down wg0
Edit MTU in the /etc/wireguard/wg0.conf file

	---Utility for keymap creation.
	---@param lhs string
	---@param rhs string\|function
	---@param opts string\|table
	---@param mode? string\|string[]
	local function keymap(lhs, rhs, opts, mode)
	opts = type(opts) == 'string' and { desc = opts }
	or vim.tbl_extend('error', opts --[[@as table]], { buffer = bufnr })
	mode = mode or 'n'
	vim.keymap.set(mode, lhs, rhs, opts)

-// Remove everyone following you on twitter.com
-// https://gist.github.com/ramsey/bdeefda66d6e2294d3466edcea30187b
-//
-// 1. Go to https://twitter.com/YOUR_USER_NAME/followers
-// 2. Open the Developer Console. (COMMAND+ALT+I on Mac)
-// 3. Paste this into the Developer Console and run it
-//
-// If you start seeing error messages in the console with the code
-// "429," this means Twitter is rate-limiting you. Stop the script
-// (i.e., reload or close the browser tab), and try again later.

	{
	"65536": [
	"alphashift"
	],
	"131072": [
	"shift"
	],
	"196608": [
	"alphashift",
	"shift"

	package main

	import (
	"bytes"
	"encoding/csv"
	"encoding/json"
	"fmt"
	"io/ioutil"
	"log"
	"net/http"