DEV Community: Giancarlo Rocha

Fix Create Failed Status On AWS EKS Node Group

Giancarlo Rocha — Mon, 17 Nov 2025 20:45:26 +0000

This is a possible fix for EKS Create failed status on EKS Node Groups.

Here i use:

Custom AMI with nvidia drivers
Custom user data script to join the eks cluster

AWS Launch Template Custom AMI Documentation

The --apiserver-endpoint, --b64-cluster-ca, and --dns-cluster-ip arguments are optional.

The documentation states that those parameters are optional, and they really are, but lately i've been having an issue where my nodes couldn't join my cluster. I've tried lots of things to get this fixed, and what ended up working was providing those 3 arguments in user data script.

Here's the snippet for terraform:

On cluster module i've exported the values of the parameters i need:

# Cluster definition as a module
resource "aws_eks_cluster" "cluster" {
  name     = var.name
  ...
}

# This parses the correct format for the DNS address
locals {
  service_cidr = aws_eks_cluster.cluster.kubernetes_network_config[0].service_ipv4_cidr
  dns_cluster_ip = cidrhost(local.service_cidr, 10)
}

output "certificate_authority_data" {
  value = aws_eks_cluster.cluster.certificate_authority[0].data
}

output "cluster_endpoint" {
  value = aws_eks_cluster.cluster.endpoint
}

output "dns_cluster_ip" {
  value = local.dns_cluster_ip
}

On my launch template i pass those values as context for the user data:

resource "aws_launch_template" "eks_node" {
  ...
  user_data = base64encode(templatefile("${path.module}/bootstrap.sh", {
    name   = var.name
    labels = join(",", [for k in sort(keys(var.labels)) : "${k}=${var.labels[k]}"])
    taints = join(",", [
      for key in sort([for t in var.taints : t.key]) :
      "${key}=${[for t in var.taints : t.value if t.key == key][0]}:${[for t in var.taints : t.effect if t.key == key][0]}"
    ])
    cluster_name = var.cluster_name
    dns_cluster_ip = var.dns_cluster_ip
    certificate_authority_data = var.certificate_authority_data
    cluster_endpoint = var.cluster_endpoint
  }))
  ...
}

And on my bootstrap script i use those values:

#!/bin/bash
set -o xtrace

extra_args=""

if [ -n "${labels}" ]; then
  extra_args="$extra_args --node-labels=${labels}"
fi

if [ -n "${taints}" ]; then
  extra_args="$extra_args --register-with-taints=${taints}"
fi

/etc/eks/bootstrap.sh ${cluster_name} \
  --b64-cluster-ca "${certificate_authority_data}" \
  --apiserver-endpoint "${cluster_endpoint}" \
  --dns-cluster-ip "${dns_cluster_ip}" \
  --kubelet-extra-args "$extra_args"

How to Prevent VSCode from Losing Unsaved Tabs Across Multiple Windows

Giancarlo Rocha — Sat, 29 Mar 2025 19:59:12 +0000

If you frequently work with multiple VSCode windows and use tabs as temporary snippet storage, you might have encountered this frustrating scenario: when closing a window, VSCode prompts you to save unsaved files—even though it usually preserves them automatically in single-window mode.

This happens because VSCode’s default hotExit behavior changes when multiple windows are open. Fortunately, you can configure it to always back up unsaved files, regardless of how many windows you have running.

The Fix

Add this setting to your VSCode settings.json:

"files.hotExit": "onExitAndWindowClose"

What This Does

Default ("onExit") → Only backs up unsaved files when closing the last remaining window.
"onExitAndWindowClose" → Ensures unsaved files are preserved even when closing individual windows.

Now you can close windows freely without losing work—ideal for those temporary scratch tabs!

Quick Fix For Python UnicodeEncodeError When Trying To Print An Encoded Emoji

Giancarlo Rocha — Tue, 12 Sep 2023 22:35:46 +0000

If you have encoded emojis in a string, and you can't print them, do this:

>>> data = "Those are emojis -> \ud83d\ude2e\ud83d\ude02\ud83d\ude02"
>>> data.encode('utf-16', 'surrogatepass').decode('utf-16')
'😮😂😂'

This should work with any character encoded as two 16-bit hex value.

How To Install Private Git Hosted Dependencies Inside Docker Image Using SSH

Giancarlo Rocha — Fri, 25 Aug 2023 22:35:02 +0000

Introduction

This quick guide will show you how to mount a ssh key inside a container in build time, to allow you to install private dependencies, that won't be persisted in the final image. It uses python but could work with any language/package manager that uses git + ssh.

Dockerfile

First you need to set Dockerfile syntax to docker/dockerfile:1.2. Put this in the beggining of the file:

# syntax = docker/dockerfile:1.2

Now install git and openssh, and setup ssh folders:

RUN apt update && \
    apt install -y git openssh-client && \
    mkdir -p /root/.ssh && \
    ssh-keyscan github.com >> /root/.ssh/known_hosts

May vary depending on the base image you're using, just change with the package manager you use.

Make sure to change github.com with your git host.

Now you have to mount the ssh key in the step that installs the dependency:

RUN --mount=type=secret,id=id_rsa,dst=/root/.ssh/id_rsa \
    pip install git+ssh://git@github.com/username/repository.git@version

This will mount secret identified by id_rsa on /root/.ssh/id_rsa.

Building

When building you need to specify your ssh key as id_rsa secret:

docker build . \
    -f Dockerfile \
    --secret id=id_rsa,src=/home/user/.ssh/id_rsa

Or using docker compose:

version: '3.7' 
services:
  your_service:
    build:
      context: .
      dockerfile: Dockerfile
      secrets:
        - id_rsa
secrets:
  id_rsa:
    file: /home/user/.ssh/id_rsa

Final file

# syntax = docker/dockerfile:1.2

FROM python:3.11

RUN apt update && \
    apt install -y git openssh-client && \
    mkdir -p /root/.ssh && \
    ssh-keyscan github.com >> /root/.ssh/known_hosts

RUN --mount=type=secret,id=id_rsa,dst=/root/.ssh/id_rsa \
    pip install git+ssh://git@github.com/username/repository.git@version

Conclusion

Keep your secrets secret!