Raspberry, Ubuntu and Megatools

To install megtools (command line utilities for Mega.nz), in your raspberry with ubuntu installed follow the steps below (thanks to the instructions from here: https://www.instructables.com/id/Descarga-archivos-de-Mega-con-Raspberry-Pi/)

  • Install the necessary packages

You may also need to add some additional packages if there is an error about the documentation.

  • Get the latest source code from https://megatools.megous.com
  • Compile and install them
  • Add your Mega account credentials in ~/.megarc like:
  • use the mega tools commands (megacopy, megals, megaget etc.

Erlang and Elixir with asdf in Raspberry 4 with Ubuntu 20.04

To install the latest/current versions of erlang (23.0.2) and elixir (1.10.3), follow the instructions below:

Install asdf ( full instructions https://asdf-vm.com/#/core-manage-asdf-vm):

Add the following two lines in your ~/.bashrc file:

Reload/Source your bash file with

Install the erlang plugin

If you get the following warnings:

Install the missing packages:

Install latest erlang version:

Set it up globally (if you want):

Add elixir plugin:

Install latest elixir version (1.10.3):

Set it up globally:

Finally you can also install the latest Phoenix version (1.5.3):

WiFi, Raspberry Pi 4 B, Ubuntu 20.04

After installing an image of the Ubuntu server on the Raspberry 4, the wifi is not automatically configured after the initial book.

In order to be able to use the WiFi follow the steps described below for setting up your wifi in your SD card, and then reboot your raspberry (make sure that the indentation in the yaml file is correct, and also your WiFi access point is enclosed in quotes):

https://ubuntu.com/tutorials/how-to-install-ubuntu-on-your-raspberry-pi#3-wifi-or-ethernet

sudo kubeadmin init returns with: [ERROR Swap]: running with swap on is not supported. Please disable swap

Problem

You are trying to set up kubernetes on your local machine but trying to use initialize it with kubeadmin init, returns the following error:

Solution

Switch the swap to off (Ubuntu command below) and try again.

Setting up worldPing with Grafana running in docker

You would like to test worldPing (https://worldping.raintank.io/worldping/) in your local environment for evaluation purposes.

  • Install Grafana with docker as described here (https://grafana.com/docs/grafana/latest/installation/docker/) and give it a name (ie grafana)
  • Login to the grafana container and install the worldPing plugin:
  • Exit from the container and stop and start it
  • Login to your grafana installation on the browser (localhost:3000) and go to the section for the plugins to find worldPing
  • To be able to enable it you will need an API key from Grafana Cloud, so create a free account (https://grafana.com/signup/starter/connect-account)
  • Create an API key (Security – API Keys – Add API Key)
  • Go back to Grafana web UI and add the API key so you can enable the worldPing. Add an endpoint to check and select the services to check (DNS, Ping, HTTP, HTTPS)
  • Leave it running for a few minutes and check the dashboards afterwards.
  • Remember to Disable if you want to go back to it again in the near future, or Destroy the endpoint if you do not need it anymore.

ssh-add, Gitlab CI/CD with alpine image

Problem

Trying to use the usual way of adding Gitlab’s key to the ssh agent, is not working in alpine image (but it works in debian/ubuntu), and you get the following error message:

 - ssh-add <(echo "$GITLABCICD_PRIVATE_KEY")
/bin/sh: syntax error: unexpected "("

Solution

Try to use the following instead:

  - echo "$GITLABCICD_PRIVATE_KEY" | ssh-add -

AWS allowing access to Billing to IAM user

Problem

When you create a new AWS account the access to Billing for IAM users is not enabled by default.

Solution

In order to allow access you have to follow the steps below:

  • Login to your AWS account with your root user (email and password)
  • Go to the top right drop down ‘My Account’
  • Find the section that is called ‘IAM User and Role Access to Billing information’, use ‘Edit’, tick the box ‘Enable access’ and then ‘Update’.

More information can be found in the Amazon’s help page https://docs.aws.amazon.com/awsaccountbilling/latest/aboutv2/control-access-billing.html#ControllingAccessWebsite-Activate

Get a list of your Route53 subdomains using aws cli docker image

Problem

You would like to have a list of your subdomains for a specific domain (hosted zone), that are hosted in Amazon’s Route 53.

Solution

You can install the aws cli docker image from here https://github.com/cgswong/docker-aws if you don’t want to install the aws cli in your computer.

You can afterwards start the container with:

docker run -it cgswong/aws:latest

Then configure it by running the following and adding your credentials and zone:

efe9881d4fd:/tmp# aws configure
 AWS Access Key ID [None]: aws_access_key_id
 AWS Secret Access Key [None]: aws_secret_access_key
 Default region name [None]: eu-central-1
 Default output format [None]:

Then run the first command to get a list of the hosted zones and get the id of the hosted zone you want to find the subdomains for:

3efe9881d4fd:/tmp# aws route53 list-hosted-zones
{
    "HostedZones": [
        {
            "ResourceRecordSetCount": 2, 
            "CallerReference": "RISWorkflow-RD:xxxxx", 
            "Config": {
                "Comment": "HostedZone created by Route53 Registrar", 
                "PrivateZone": false
            }, 
            "Id": "/hostedzone/HOSTEDZONEID", 
            "Name": "domain.net."
        }, 

Then pick the HOSTEDZONEID and run the following to get a list of subdomains for that domain:

3efe9881d4fd:/tmp# aws route53 list-resource-record-sets --hosted-zone="HOSTEDZONEID" | grep "Name" | uniq

   "Name": "alpah.domain.com.",                                                                                                                                                                                                                                             
   "Name": "beta.domain.com.",                                                                                                                                                                                                                                       
   "Name": "lamda.domain.com.",
......