DEV Community: Julio

Kubernetes (CKAD) - Pod Design - Understand how to use Labels, Selectors, and Annotations

Julio — Tue, 21 Sep 2021 06:38:54 +0000

Topic: Pod Design

Labels

Labels are key:pair values that can help you organize your resources. Any object in Kubernetes can have a label described.

You can also use labels to select a set of resources. For that you'll use a selector, which we'll see later on.

Example of a label:

apiVersion: v1
kind: Pod
metadata:
  name: onboarding-frontend
  namespace: my-application
  labels:
    service: onboarding
    tier: frontend

Listing labels

$ kubectl get pods --show-labels

Listing labels as columns

You can list labels as columns by using the -L (--label-columns) option of kubectl.

$ kubectl get pods -L service,tier

Selectors

You can use selectors to filter a set of resources. For filtering based on labels, we can use the -l selector.

Select only the pods related to the `onboarding` service.

$ kubectl get pods -L service,tier -l 'service=onboarding'

Select only the pods NOT related to the `onboarding` service.

$ kubectl get pods -L service,tier -l 'service!=onboarding'

Select only the pods related to the `onboarding` service in the frontend tier

$ kubectl get pods -L service,tier -l 'service=onboarding,tier=frontend'

Select all pods that are related to `backend` and `frontend` tiers.

$ kubectl get pods -L service,tier -l 'tier in (backend,frontend)'

Annotations

Annotations allows you to store additional data for the object you're creating. Also a key:pair value but with more capacity to store longer strings, including JSON.

An annotation looks like:

apiVersion: v1
kind: Pod
metadata:
  name: onboarding-frontend
  namespace: my-application
  labels:
    service: onboarding
    tier: frontend
  annotations:
    Description: The frontend component of the onboarding service for my-application.

List the annotations of a pod

$ kubectl describe pod onboarding-frontend | grep Annotations

Annotations can be edited/removed/added.

Remove an annotation

$ kubectl annotate pod onboarding-frontend Description-

The - after the annotation indicates that we want to removed it.

Add an annotation

$ kubectl annotate pod onboarding-frontend Description-

The - after the annotation indicates that we want to remove it.

Official docs for further reference: Object Annotations

Running Jekyll on Docker for Easy Local Development

Julio — Sat, 05 Jun 2021 10:04:36 +0000

I'm using Jekyll for one of my blogs and I'm really liking it. It's easy to get up and running with it and it just works!

If you're planning to create a blog and want something simpler that just do the job and doesn't ask you too much time to do setup, learn about it, etc, Jekyll might be a good option for you.

During this process, I observed a few pain points:

I have to manually start the server every time I want to use it.
Dealing with localhost and port numbers.
I have to use a code editor to make the writing and building more convenient, although there might be better alternatives to only focus on the writing part.

For pain points 1 and 2 I created a solution this morning and wanted to share with you.

I wrote all the details on this article Running Jekyll on Docker For Easy Local Development

The general idea is:

Use docker to keep the sever running on my machine with live reload enabled;
Use a reverse proxy to map a domain to the localhost:4000 address.

For point 3 I'm still about to research a solution. Once I find one that I like I'll share here as well.

Have a great weekend! :)

Advice for people starting their career in tech

Julio — Wed, 12 May 2021 16:42:53 +0000

Instead of writing I've decided to share a video from Dave Farley which I think everyone starting their career in tech should watch. Precious and BS free advice from someone with great experience.

Check it out:)

https://youtu.be/hjIlTaAMsbI

Tips for job applicants

Julio — Wed, 05 May 2021 16:55:08 +0000

I'd like to share a couple of tips that might be helpful for you when applying to jobs.

Bear in mind that the tips down below are based on my experience and also related to they way I usually go through the list of applicants.

The tips are mostly related to specific points or visual clues that would draw my attention to a candidate's application.

Let's go!

Some code samples created by yourself

A Github/Gitlab/Bitbucket/Personal website with some code samples written by yourself are usually useful.

For instance, if a candidate shared a Github profile, I'd go there and filter the source repositories and I'd take a look. If the filter result is empty, that's already something that would raise some concern.

A code sample helps the hiring manager to understand:

How do you write your code.
How do you structure it.
How do you write tests (After the README, the second thing I look: The test folder. 👀)

Note: I rarely run the solution though, and I think nobody does 😊

Real working/running project examples

A live project of yours always give a nice touch to your application, especially for technical positions.

If you're a backend person, an API that you may have created that is actually hosted somewhere with good API docs, even if small, is a nice thing to see.

If you are a frontend person, a nice UI that I could actually see, your personal website maybe, would be certainly something that would draw my attention and would make me invest a bit more time on your application 🕵️

I'll be looking mostly for:

The quality of what you did. No matter the size of the application, was it done with care?
How did you design it.
Creativity/Fun.
Technologies used.
Where and how was it deployed.

Things you shared should be working

Make sure what you share, links to profile, pages, applications are working. There's a good chance I'll visit them. 🕵️

Clicking on something and reach a broken link doesn't feel good. Would you like it?

Photos or your age

Please, don't. And companies that are still asking candidates for such information should stop doing it.

I don't care and I personally don't like to seem photos or your age in job applications.

It may right away create some sort of unconscious bias, that we all have by the way, let's not pretend we don't, and this could play negatively against your odds.

If the company you're planning to apply requires a CV with photo and your age, I recommend you to think think twice before applying anyway.

A CV without work experience

Unless you're applying for an entry level position, a CV without work experiences related to the job or field you're applying for would be a NO-GO for me. I've no crystal ball 🔮.

A CV with lot's of personal projects

I'd avoid adding lots of personal projects to your CV, one or two amongst the most recent or relevant ones would be ok. But a long list won't help anyways your application, specially if they are just tutorials or hello-worlds.

A good looking CV helps

Of course it depends on the type of job you're applying to, but in general, I believe that a good looking CV has higher changes to attract the attention of the hiring manager.

It doesn't need to be an art work, especially for dev positions, but your CV should look presentable and organized.

I personally like clean CVs. I don't give much attention to colors, crazy designs, badges, etc. A well structured black-and-white CV would be very efficient to me. Helps to speed up the process and the more standardized they are in terms of appearance and structure, the more efficient and less stressful the job of the hiring manager will be.

The thing is. A poorly prepared CV represents for me, and perhaps for other hiring managers as well I believe, a certain lack of care and it's already some sort of red flag for the applicant.

Cover letters

I personally always read them. If you put an effort to write some words to present yourself, the minimum I can do is read it in respect of your the time you put to write it.

For me, a few words about yourself, why you're applying, why do you think you're a good fit and what would be the benefits for both sides if you turn to work in the company is super helpful to understand where you're coming from, what you plan to bring to the table, and where you're planning to go.

It's also interesting to understand if you thought about yourself working at that position at that company and how that would look like.

Some tips:

When you write "I am very much interested to work with you.", it's interesting to also write the reason why you are so interested.

A two paragraph size would be optimal. More than that might not be necessary. I'd recommend reviewing and summarizing just the important information in your cover letter.

Note: Some jobs or companies will requires a more formal cover letter. I'm not talking about this type of cover letter. I'm talking about the more informal ones. The ones we usually see in tech related jobs in the majority of companies out there.

I am personally not much interested at the beginning at information such as hobbies, sports you do, etc. I think those will be explored later on during the process. No need to write then in your cover letter.

Golden rule: Add the more relevant information first.

If you applied, it's obvious that you're looking for a job. Don't waste precious space writing that in your cover letter.

I've read this sentence many times:

"I've keen interest in software development"

I even wrote it some times in my past job applications.

Today I think it's not super relevant anymore. What does that mean exactly? Perhaps a project or a code sample would tell this story better.

If you're applying to a position that is different from your current position, explaining that in your cover letter is important. It could help me to understand your motivation and not discard your application due to a misfit for the position.

Last but not least, the tools that support hiring process, at least the ones I used so far, they have a logic on how they display the information, and usually the cover letter part comes before your CV.

If you don't write anything in your cover letter, and I reach your CV, and I look that you're a manger applying to a backend position, it might be that I'll not give much attention to your application as I'd do for someone that matches the position better especially when there are many candidates.

I think that's all for now. If you feel this could help someone else, please share it. 🙏

And finally, I wish all the best for your future applications! If you read this until this point, thank you very much for your time and I hope it was helpful somehow.