hermanbanken

FROM node:alpine
COPY server.js /srv/www/
COPY server.js.map /srv/www/
ENV API_URL=http://example.com NODE_OPTIONS=--enable-source-maps
ENTRYPOINT [ "node", "/srv/www/server.js" ]

hermanbanken

# yaml-language-server: $schema=https://github.com/jcchavezs/envoy-config-schema/releases/download/v1.21.0/v3_Bootstrap.json
node:
  id: "something"
  cluster: "some-cluster"
  metadata:
    any: {}
    key: can
    be: used-here
  locality:
    zone: "europe-west4-a"

hermanbanken

Sadly we can't have nice things in TypeScript (see https://www.ackee.agency/blog/typescript). Specifically middleware that:

1. Notifies when the chain is broken

pipe(
   () => 21,
   (n: number) => n * 2,
 (n: string) => n.repeat(5), // Error: number is not assignable to string

hermanbanken

package main

import (
	"context"
	"fmt"
	"log"
	"net/http"
	"os"

	"github.com/golang-jwt/jwt/v4"

hermanbanken

package main;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Map;

hermanbanken

We want to receive notifications when a Kubernetes cluster upgrades. For this we can configure PubSub subscriptions:

const exec = require("child_process").execSync;

const mapping = {
  "my-dev-project": [{ name: "clusterA", region: "europe-west4" }, { name: "clusterB", region: "us-east1" }],
  "my-prod-project": [{ name: "clusterC", region: "europe-west4" }, { name: "clusterD", region: "us-east1" }],
};

hermanbanken

#!/bin/env node

const PRIVATE_TOKEN = "redacted";
const headers = { "PRIVATE-TOKEN": PRIVATE_TOKEN };
const root = "https://gitlab.com/api/v4";
const project = 24418136; // "hue-contract-tests";

const { default: fetch } = require("node-fetch");
fetch(`${root}/projects/${project}/pipelines`, { headers }).then((res) => res.json())
  .then(async (pipelines) => {

hermanbanken

Raft issue

When developing my first hashicorp/raft implementation I was stuck at a stone wall it seemed. Somehow I could bootstrap one of the nodes and this would win the election and the raft observation for it becoming Leader also made it in, but then nothing. I couldn't figure out why all RPCs timed out after that.

I started to run locally and debugged using VS Code Launch configuration (which uses Delve) and found that before bootstrapping there was a "runCandidate" goroutine, but after bootstrapping there was no "runLeader" goroutine. Turns out the leader loop never started! How could this be? Then my mind wandered to the observer that I added:

	ch := make(chan raft.Observation, 1)
	r.RegisterObserver(raft.NewObserver(ch, true, func(o *raft.Observation) bool {
		// *RequestVoteRequest

hermanbanken

Limited Sampler

hermanbanken

[submodule "proto/googleapis"]
	path = proto/vendor/googleapis
	url = https://github.com/googleapis/googleapis.git