DEV Community: Agrim Prasad

Supercharge your Kubernetes setup with OhMyZSH 🚀🚀🚀 + awesome command-line tools

Agrim Prasad — Fri, 03 Jan 2020 00:00:00 +0000

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Almost all of my colleagues who have worked with kubernetes have had similar complaints about the kubectl tool. It's so verbose! I need to remember such long commands! This lead me to search and discover a bunch of powerful cli tools, which combined with the OhMyZSH command-line framework can make your kubectl journey much smoother.

How you would usually use kubectl

kubectl by itself is a very powerful kubernetes client, and can be used for all kinds of purposes, but it really is too verbose, with a lot of gotchas in different commands.

Query the kubernetes pods running in specific namespaces of your kubernetes cluster.

kubectl get pod -n myZoo

Get the status of and details about different kubernetes entities, such as pods, configmaps, services etc.

kubectl describe deployment myCatDeploy -n myZoo

Tail the logs of a specific container. Firstly, find the list of all pods with

kubectl get pod -n myZoo

then find your specific pod and run kubectl logs (and hope you didn't make a typo anywhere)

kubectl logs -f myKittenPod -n myZoo

Tools to turbocharge kubectl

We can do better.

I give the installation instructions for these tools with macOS here. You can check the links to get installation instructions for other operating systems.

1. kubectx to switch cluster & namespaces quickly

kubectx can be installed on macOS with homebrew

brew install kubectx

This command actually installs two tools, kubectx and kubens.

You can use kubectx to switch between different clusters with kubectx my-cluster-name. Behind the scenes, this command will edit your ~/.kube/config file to mark a specific cluster as being the current-context. You would otherwise have to edit this file manually or use kubectl config use-context my-cluster-name.

kubens helps you switch between namespaces quickly. Whereas earlier you would have had to run kubectl config set-context --current --namespace=myZoo, now you can just run kubens myZoo.

As a bonus, I alias these tools to even shorter commands in my ZSH configuration file (~/.zshrc).

alias kctx="kubectx"
alias kns="kubens"

Then source the ZSH configuration file to load the changes.

source ~/.zshrc

Furthermore, if you use it with OhMyZsh you can get auto-completion of namespaces and cluster names with these completion scripts. No need to remember those long namespaces anymore!

mkdir -p ~/.oh-my-zsh/completions
chmod -R 755 ~/.oh-my-zsh/completions
ln -s /opt/kubectx/completion/kubectx.zsh ~/.oh-my-zsh/completions/_kubectx.zsh
ln -s /opt/kubectx/completion/kubens.zsh ~/.oh-my-zsh/completions/_kubens.zsh

2. kube-ps1 to display current cluster & namespace

kube-ps1 is a great companion tool to kubectx and kubens which displays the currently active cluster and namespace on your command line prompt. No more accidental deploys to the production cluster at 2AM.

Install with:

brew install kube-ps1

Here's how your kubernetes cluster-name (minikube) and namespace (default) appear in the command prompt now:

Here's how it looks when combined with the kubectx and kubens tools to switch clusters and namespaces.

3. OhMyZSH kubectl plugin for kubectl shortcuts

OhMyZSH actually has a plugin for kubectl which gives you nearly hundred shortcuts for commonly used commands. To use it, add kubectl to the plugins array in your ~/.zshrc file and then source the ~/.zshrc file like before:

plugins=(... kubectl)
source ~/.zshrc

Some shortcuts for commonly used commands provided by this plugin below.

Alias	Command	Description
k	`kubectl`	The kubectl command
kaf	`kubectl apply -f`	Apply a YML file
keti	`kubectl exec -ti`	Drop into an interactive terminal on a container
kdel	`kubectl delete`	Delete resources by filenames, stdin, resources and names, or by resources and label selector
kgp	`kubectl get pods`	List all pods in ps output format
kdp	`kubectl describe pods`	Describe all pods
kdelp	`kubectl delete pods`	Delete all pods matching passed arguments
kgd	`kubectl get deployment`	Get the deployment

… and more! Check out the full list on the github page.

4. stern for logs

stern has been designed to allow you to tail the logs of multiple pods and containers using regex. This means that you can search pods by partial name matches, rather than having to query the full names of pods and then running kubectl logs -f with the exact name of every single pod.

Install with:

brew install stern

To receive and then tail all the available logs of all pods whose names partially match myKitten (assuming default namespace of the minikube cluster used with kubectx, kubens and kube-ps1):

(⎈ |minikube:default)➜ ~ stern myKitten

To receive the last 10 lines per container and then tail:

(⎈ |minikube:default)➜ ~ stern myKittenPod --tail=10

To receive the last 2 minutes of logs per container and then tail:

(⎈ |minikube:default)➜ ~ stern myKittenPod --since=2m

You can also source stern autocompletion with zsh by adding this to your ~/.zshrc and then running source ~/.zshrc

source <(stern --completion=zsh)

5. kpoof to port-forward pods intuitively

kpoof is the easiest way to port-forward ports, which is often useful when you want to test an internal service which is not supposed to be publicly exposed outside the cluster.

Install with:

brew tap farmotive/k8s
brew install kpoof

With kpoof, you get an interactive way to firstly choose the namespace, and then the name of the pod which you would like to port-forward. The tool forwards the same local port number as the port exposed by the pod by default.

For example, in order to port-forward localhost port 3306 to port 3306 of the pod nyc below, you can run the following commands:

$ kpoof
Namespace? (default zoo):
1 zoo
2 town
3 city
3
Pod number? (default 1):
1 nyc
2 london
3 bangkok
1
Forwarding from 127.0.0.1:3306 -> 3306

See it in action below.

6. Popeye to scan your cluster for potential issues

Popeye is a tool which scans your cluster for misconfigured resources. Currently, nodes, namespaces, pods and services are supported for scanning.

When your cluster grows to 100s of different pods and to 10s of different namespaces, having such a tool is invaluable in detecting issues before they blow up, especially if you don't have monitoring on some of these resources.

Install with:

brew install derailed/popeye/popeye

Run with the command popeye to eye your entire cluster. Here's a screenshot of a well-maintained cluster which gets the cluster score 93 -- A from popeye

Know of any other useful CLI or GUI utilities for kubernetes? Let me know in the comments below!

How to Open Link in New Tab with Hugo's new Goldmark Markdown Renderer

Agrim Prasad — Sun, 29 Dec 2019 00:00:00 +0000

This post was originally published on my blog, find original post here.

Hugo is a blazing fast static site generator, which makes it a terrific choice to create your blogs. It's written in Go and uses Go's templating language to generate blog content with customizable templates for styling.

Check out this article for a good overview of Hugo, and how to get your blog online with Hugo + Netlify.

Furthermore, Hugo uses Markdown to render your content, which is similar to the rendering mechanisms used by other blogging engines, such as Jekyll (used by Github Pages) and DEV.TO.

How to open links in a new tab with markdown in Hugo?

When creating my blog in Hugo, I wanted to open links in a new tab (i.e. add a target="_blank" attribute to the links). However, by default, an inline style link in Markdown opens in the same tab, which means that your reader may leave your blog and go to a different site, never to return.

Until recent versions of Hugo, it had been using the Blackfriday Markdown renderer, which while convenient, is not CommonMark standards-compliant. With Blackfriday, I could achieve my desired behaviour by adding the following configuration to the config.toml file:

[blackfriday]
hrefTargetBlank = true

However, in the latest Hugo v0.62.0, this doesn't work anymore as the default markdown renderer has changed to Goldmark, which is CommonMark compliant and allows for custom templates to render links and images from markdown. Thus, if you want to open your blog's links in a new tab (which is not supported by default), you'll have to use a custom markdown render hook to add the target="_blank" attribute to the links.

Render Hooks with Goldmark

Goldmark and Markdown Render Hooks are a new feature in Hugo v0.62.0 so please make sure that your Hugo version is equal to or greater than this version.

Markdown Render Hooks offer you several ways to extend the default markdown behaviour, e.g. resizing of uploaded images, or opening links in new tabs. You can do this by creating templates in the layouts/_default/_markup directory with base names render-link or render-image. Your directory layout may look like this:

layouts
└── _default
└── _markup
├── render-image.html
├── render-image.rss.xml
└── render-link.html

Sample render hook to open link in new tab

Say you have an inline-style link in Markdown such as the follows with the Destination as https://en.wikipedia.org/wiki/Pizza, Text as Pizza and Title as Yum Yum:

[Pizza](https://en.wikipedia.org/wiki/Pizza "Yum Yum")

By default, this link would open in the same tab.

Now add the following HTML template file (or render hook) at layouts/_default/_markup/render-link.html:

<a href="{{ .Destination | safeURL }}"{{ with .Title}} title="{{ . }}"{{ end }}{{ if strings.HasPrefix .Destination "http" }} target="_blank"{{ end }}>{{ .Text }}</a>

You'll find that the previous link now opens in a new tab!

For internal blog links (which you would want to open in the same tab), you can use the relative link of the post, e.g. for a sample-post.md file within the posts directory, you could use

[Sample post](/posts/sample-post/)

TL;DR

The Markdown renderer has changed in the latest Hugo v0.62.0 from Blackfriday to Goldmark which should allow Hugo markdown to be more compatible with other markdown flavours, such as that of GitHub.
In order to open links in new tab with the Goldmark markdown renderer, create a file at layouts/_default/_markup/render-link.html with the following content:

<a href="{{ .Destination | safeURL }}"{{ with .Title}} title="{{ . }}"{{ end }}{{ if strings.HasPrefix .Destination "http" }} target="_blank"{{ end }}>{{ .Text }}</a>

Freelancers and digital agency owners, what do you use to deploy client websites?

Agrim Prasad — Sun, 08 Jul 2018 03:21:18 +0000

I've noticed that most ecommerce online stores are hosted on Shopify nowadays, as I noticed from this post:

Starting An Agency with Kelly Vaughn

Sam Jarman 👨🏼‍💻 ・ Jul 7 '18

#agency #businessowner #career

How about other kinds of websites created by the freelancers and digital agency owners of this community? Do you host on shared hosts? Or VPS providers such as Digital Ocean? Or Cloud services such as AWS?

The most challenging part (for me) about VPS providers and cloud services is the management of your servers across different services, once the number of your servers goes past 4 or 5.

Monitor the performance of any command line program with this single command

Agrim Prasad — Sat, 07 Jul 2018 08:32:54 +0000

This post was originally published on my blog, find original post here.

I have been executing a lot of bash scripts and one-off processes on the linux command line recently, and was curious about how to monitor the CPU and memory usage of these processes as quickly as possible. Some of these processes seemed to bring my linux box to a screeching halt, and without instant resource monitoring I couldn't tell whether such a process was eating excessive RAM or CPU (or both?!)

What people usually do

Conventionally, suggestions about process monitoring involve the following:

Run your command line process.
Get the PID of the process with ps aux command which is generally available for both Linux and Mac.
Run the utility top with
```
top -p <pid>
```
on Linux or
```
top -pid <pid>
```
on Mac OS.

However, I wanted to run commands which would exit within a few seconds, before I could run top to start monitoring them. How could I start monitoring these commands as soon as they were invoked?

What can we do better

As always, Unix has an answer:

Run your command in the background and pipe the output to /dev/null so that it doesn't get printed on the command line while you are monitoring the CPU/memory usage, e.g.
```
unzip ~/Downloads/sample.zip > /dev/null &
```
Echo the PID of this background process with
```
echo $!
```

Combine the two, and pass the pid of the process to top with

top -p `{ unzip ~/Downloads/sample.zip > /dev/null & } && echo $!`

on linux or

top -pid `{ unzip ~/Downloads/sample.zip > /dev/null & } && echo $!`

on Mac OS.

BOOM, you just started monitoring your process immediately with a single command. Now isn't that peachy!

Bonus: Use `htop` instead of `top`

I ❤️ htop which is a process monitoring utility available for both linux and Mac OS. Come on, you've got colours! Let's use this instead of top for better insight into the CPU/memory performance of our processes.

Install htop with
```
sudo apt-get install htop
```
on Ubuntu or
```
brew install htop
```
on Mac OS with Homebrew
Run our previous monitoring command using htop instead of top for monitoring with
```
htop -p `{ unzip ~/Downloads/sample.zip > /dev/null & } && echo $!`
```

See the single command in action below!

Double Bonus: Style your editor for a more beautiful htop

Saw some chatter on Twitter about this post which mentioned that I should have added information about the terminal theme I'm using here, since htop gets styled by the terminal and theme in use. I totally agree, so here's my setup:

Terminal emulator: iTerm2 Awesome Mac OS Terminal replacement with cool features such as grid tabs and more.
Unix shell + theming framework: zsh + oh-my-zsh Check out this awesome post about how to install these (similar steps on Ubuntu or Mac OS)
oh-my-zsh theme: Default theme robbyrussell. After setting up oh-my-zsh, you can specify the desired theme in the ~/.zshrc file, e.g. ZSH_THEME="robbyrussell"

DEV Community: Agrim Prasad

Supercharge your Kubernetes setup with OhMyZSH 🚀🚀🚀 + awesome command-line tools

How you would usually use kubectl

Tools to turbocharge kubectl

1. kubectx to switch cluster & namespaces quickly

2. kube-ps1 to display current cluster & namespace

3. OhMyZSH kubectl plugin for kubectl shortcuts

4. stern for logs

5. kpoof to port-forward pods intuitively

6. Popeye to scan your cluster for potential issues

How to Open Link in New Tab with Hugo's new Goldmark Markdown Renderer

How to open links in a new tab with markdown in Hugo?

Render Hooks with Goldmark

Sample render hook to open link in new tab

TL;DR

Freelancers and digital agency owners, what do you use to deploy client websites?

Starting An Agency with Kelly Vaughn

Sam Jarman 👨🏼‍💻 ・ Jul 7 '18

Monitor the performance of any command line program with this single command

What people usually do

What can we do better

Bonus: Use htop instead of top

Double Bonus: Style your editor for a more beautiful htop

Bonus: Use `htop` instead of `top`