kennwhite

# ulimit -a
# sudo sysctl net.ipv4.tcp_fastopen=3
# sudo sysctl vm.max_map_count=524288 

#  note: "-l" (max locked memory) has no soft limit 
#  apt-get install numactl

sudo sh -c "sysctl -w net.ipv4.tcp_fastopen=3 ; \
 sysctl -w vm.max_map_count=524288 ; \
 ulimit -l unlimited ; \

kennwhite

Regular expression for Sublime to find & replace and add double quotes


"$numberLong": 706213333988
to
"$numberLong": "706213333988"

Use this (make sure the [.*] button on the left is pressed)

Find:    \$numberLong": (.*)

kennwhite

// Create a native Javascript Date object set to UTC 00:00:00 timestamp
// Here, the default parameters create a plausible DOB

function randomDate( start = new Date(1935, 0, 1), end = new Date(2004, 0, 1) ) {
    var dt = new Date(+start + Math.random() * (end - start));
    dt.setUTCHours(0,0,0,0);
    return dt;
}

// Random DOB

kennwhite

Setting up VS Code and Golang with debug & build flag (-tags foo) support

This is the setup that worked for me after half a day of hacking around and chasing rabbit holes down old forum posts and open & closed Github issues.

Problem: While Go integration with VS Code is pretty slick in general, I needed to pass compile-time build flags, e.g., -tags foo[^1] to go build and go run directives, and I wanted to be able to properly debug with breakpoints etc. While there are some promising tutorials out there like this on Digital Ocean and on Log Rocket it turned out that one of the first things they both say to do is add the Delve extension to VS Code,

kennwhite

# To change the default Finder behavior and actually show hidden files/directories
defaults write com.apple.finder AppleShowAllFiles -boolean true; killall Finder

# To make the Sublime 4 (Build 4126 at time of writing) File Open dialog boxes to also show hidden files
defaults write com.sublimetext.4 AppleShowAllFiles -bool true

kennwhite

/*

CSFLE explicit encryption golang Hello World example 

brew install mongodb/brew/libmongocrypt

go get go.mongodb.org/mongo-driver/mongo
go get go.mongodb.org/mongo-driver/bson
go get go.mongodb.org/mongo-driver/mongo/options
go get go.mongodb.org/mongo-driver/mongo/readpref

kennwhite

# syntax=docker/dockerfile:1
FROM mcr.microsoft.com/dotnet/sdk:6.0-alpine3.15
# FROM alpine:3.15
#
ENV MDB_CONN_STR="mongodb+srv://user:password@clusterX.XXX.mongodb.net/test?retryWrites=true&w=majority"
#
RUN apk update
RUN apk add git make cmake g++ libbson-static musl-dev libc-dev openssl openssl-dev py3-pip icu-dev bash nano coreutils
RUN mkdir -p /code/app
WORKDIR /code/app

kennwhite

MongoDB Client-Side Field Level Encryption (CSFLE) Using KMIP or Local Master Key (with mongosh)

Assumptions

• You have an accessible MongoDB deployment already running and accessible (self-managed or in Atlas)
• You have the modern MongoDB Shell (mongosh) installed locally on your workstation
• You have a KMIP Server running and accessible, if you don't intend to use a local keyfile (for an example of running and configuring a Hashicorp Vault development instance, see: Hashicorp Vault Configuration For MongoDB KMIP Use)

Configure Local Workstation Context Files

kennwhite

#! /usr/bin/env sh
# Create unprivileged Alpine linux user. Run this script as root/sudo

# Don't prompt for password and make group same as username, default path & shell

adduser -D -g appuser appuser

# Set a decent random password (aiming for a 256 bit security level, but better than "monkey")
PW=$(head -c 32 /dev/urandom | base64) && echo -e "$PW\n$PW" | passwd appuser && unset PW

kennwhite

# WARNING: This is a demonstration only, not any kind of official build - use at your own risk


# Launched standard Alpine Linux AMI on an t2.micro instance configured w/ 8GB:
#  alpine-3.15.1-x86_64-bios-cloudinit-r0 - ami-0421638898b821bff
#
#  ssh -i mykey.pem alpine@[instance address]

# This demo runs as default non-root "alpine" user