Time and time again, the young startup promotes their longest-tenured young engineer to become CTO of their 20-something startup. And it makes sense on the surface, because it’s their “best” engineer. And why not? They’ve been there for so long that they know the system they’ve built more than anyone else.
But now they have two problems: they lose their “best” engineer, and on top of that, they gain what’s probably a shit manager.
Using ioredis with twemproxy
Twemproxy is a fast/lightweight proxy for memcached and redis.
Not all Redis commands are supported. You can take a look at the list of supported commands on Github
kube-monkey is an implementation of Netflix’s Chaos Monkey for Kubernetes clusters. It randomly deletes Kubernetes pods in the cluster encouraging and validating the development of failure-resilient services.
Netflix’s Chaos Monkey for Kubernetes
Kube-Lego automatically requests certificates for Kubernetes Ingress resources from Let’s Encrypt
You can find complete example how to use this with GCE here
A Terminal Client for MySQL with AutoCompletion and Syntax Highlighting.
I can’t recommend this enough! Insanely useful tool.
- I’ve seen people bundle config file within source code.
- I’ve seen people bundle config when building Docker images.
Just use secrets / environment variables.
Here is a very detail tutorial on how to share secret data in Kubernetes.
Your DevOps Dashboard for Kubernetes
I’ve been looking for CI/DI that would complete the Kubernetes setup. This looks like a good fit for it.
Using squid proxy to bypass 3rd party API IP whitelisting
At work, I have to work with many 3rd party supplier API which requires IP whitelisting. This is becoming an issue when we need to autoscale using multiple Kubernetes nodes.
There are several ways to deal with this
- Use NAT gateway to forward all outgoing traffic to the gateway
- Use a proxy like Squid
I went with Squid since it’s much easier. Tinkering with network setting is nightmare for me.
You can follow the tutorial here on Google Cloud Documentation and then export these environment variables below in your Kubernetes nodes / Docker container.
export http_proxy="http://<proxy-ip>:3128" export https_proxy="http://<proxy-ip>:3128" export ftp_proxy="http://<proxy-ip>:3128" export no_proxy="169.254.169.254,metadata,metadata.google.internal"
You can verify if it’s working properly by checking the public IP address of the node afterward by
Also, package like
request does respect
HTTPS_PROXY so you probably don’t have to make any changes to the existing code base.
Getting started with Kubernetes
Just some of my notes while learning about Kubernetes. I use Google Compute Engine to install mine.
To install Kubernetes, it’s as easy as copy and paste the below command
curl -sS https://get.k8s.io | bash
If you want to customize some default options, you can edit environment variables
curl -sS https://get.k8s.io | MULTIZONE=true KUBERNETES_PROVIDER=gce KUBE_GCE_ZONE=asia-east1-b NUM_NODES=4 bash
There’re more environment variables that you can take a look in
It’s recommended to export it to environment instead of passing it to the command as above as taking the cluster down will be easier.
export KUBERNETES_PROVIDER=gce export KUBE_GCE_ZONE=asia-east1-b export NODE_SIZE=n1-highcpu-2 export MULTIZONE=true export NUM_NODES=2 export KUBE_AUTOSCALER_MIN_NODES=2 export KUBE_AUTOSCALER_MAX_NODES=10 export KUBE_ENABLE_CLUSTER_AUTOSCALER=true export PREEMPTIBLE_NODE=true
Add more nodes to cluster
KUBE_USE_EXISTING_MASTER=true KUBERNETES_PROVIDER=gce KUBE_GCE_ZONE=asia-east1-b NUM_NODES=2 ./kube-up.sh
Bring down cluster
KUBERNETES_PROVIDER=gce KUBE_GCE_ZONE=asia-east1-b ./kube-down.sh
Deploying applications on Kubernetes
We use Docker at work and deploying Docker containers in Kubernetes is a breeze.
docker build -t gcr.io/$PROJECT_ID/app-name:v1 . gcloud docker push gcr.io/$PROJECT_ID/app-name:v1 # update kubectl rolling-update <replication-controller> --image=gcr.io/$PROJECT_ID/app-name:v2
Expose the service to external
kubectl expose deployment <deployment-name> --type="LoadBalancer"
kubectl autoscale rc <replication-controller> --min 3 --max=10 --cpu-percent=60
The state of tiling window manager for OS X
kwm seems to be the best - feature-wise but it requires too many hacking to be done. I’ve given up at some point and just went back with Amethyst. Slate and Hammerspoon aren’t really what I’m looking for.