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

Posted on 13 March 2020 by kosmas

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.",
......

Find devices with their IPs in your local network

Posted on 10 March 2020 by kosmas

Problem

You would like to have a list of IPs or MAC address for the device in your network

Solution

Use the ARP protocol’s command:

$ arp -a

dv1.home (192.168.1.102) at 48:xx:xx:xx:xx:xx [ether] on wlp4s0
dv2.home (192.168.1.127) at a4:xx:xx:xx:xx:xx [ether] on wlp4s0
...

Terraform Cloud – error when trying to initialize

Posted on 24 February 2020 by kosmas

Problem

You would like to start using Terraform Cloud and when trying to initialize it with the new remote backend (app.terraform.io), you get the following error:

Error: Required token could not be found

Make sure you configured a credentials block for app.terraform.io in your CLI
Config File.

Solution

Follow the instructions here https://www.terraform.io/docs/cloud/free/index.html and create a file ~/.terraformrc (in linux) with an API token.

Checking and enabling slow query log in MySQL

Posted on 5 February 2020 by kosmas

Problem

You would like to check and enable the slow query log for MySQL.

Solution

To check if the log is on run the following query

show global variables like '%slow_queries'

To switch it on if the above shows it as OFF, use the following:

set @@GLOBAL.log_slow_queries = 'ON'

Find your public IP address from linux command line

Posted on 13 January 2020 by kosmas

Problem

You would like to find out your public IP from the command line without using an online service

Solution

Use dig like the following line (taken from https://www.cyberciti.biz/faq/how-to-find-my-public-ip-address-from-command-line-on-a-linux/):

dig +short myip.opendns.com @resolver1.opendns.com

you could also add it as an alias:

alias myip=”dig +short myip.opendns.com @resolver1.opendns.com”

Get a list for all crontab jobs in a server

Posted on 6 December 2019 by kosmas

To get a list of all the installed crontab jobs on a server use the following (taken from https://stackoverflow.com/a/134944)

for user in $(cut -f1 -d: /etc/passwd); do echo $user; crontab -u $user -l; done

WARN[0000] Your Skaffold version might be too old. Download the latest version (1.0.1) at https://storage.googleapis.com/skaffold/releases/latest/skaffold-linux-amd64

Posted on 5 December 2019 by kosmas

Problem

You would like to follow the example for working with skaffold by using the skaffold dev command but you are getting the following error:

kosmas:getting-started (master)$ skaffold dev
WARN[0000] Your Skaffold version might be too old. Download the latest version (1.0.1) at https://storage.googleapis.com/skaffold/releases/latest/skaffold-linux-amd64

Solution

Download the latest release from here https://github.com/GoogleContainerTools/skaffold/releases and follow the instructions for installing it in your system (ie linux):

 curl -Lo skaffold https://storage.googleapis.com/skaffold/releases/v1.0.1/skaffold-linux-amd64 && chmod +x skaffold && sudo mv skaffold /usr/local/bin

Using nginx to redirect to a different port

Posted on 4 December 2019 by kosmas

Problem

You have a docker container with an application running in a port different than port 80 (ie port 3000), and would like to access it without specifying the port, by using the domain name only.

Solution

Use the nginx proxy_pass as follows:

server {
  listen 80;

  server_name your_server_domain_name.com;
  location / {
    proxy_set_header  X-Real-IP $remote_addr;
    proxy_set_header  Host $http_host;
    proxy_pass        http://127.0.0.1:3000;
  }
}

Removing DEFINER from MySQL < 5.7 dump files

Posted on 28 November 2019 by kosmas

Problem

You are using the dump files from MySQL (earlier version than 5.7 – that has -skip-definer option in mysqlpump), that outputs the DEFINER keyword in Functions and Views, which causes en error when trying to import in a different database that the users do not exist.

Solution

Use the following in your database dump to remove these keywords:

For FUNCTIONS

sed -i 's/DEFINER=\S*\sFUNCTION/FUNCTION/' mysql_dump

For VIEWS

sed -i '/50013\sDEFINER/d' mysql_dump

Find your Thinkpad (X1) model type in linux

Posted on 9 October 2019 by kosmas

Problem

You would like to find out the exact model from your Thinkpad X1 laptop, by using your linux command line.

Solution

Use the following command:

kosmas:$ sudo dmidecode | grep -A3 '^System Information'
[sudo] password for kosmas: 
System Information
        Manufacturer: LENOVO
        Product Name: 20HRCTO1WW
        Version: ThinkPad X1 Carbon 5th

M	T	W	T	F	S	S
« Mar
		1	2	3	4	5
6	7	8	9	10	11	12
13	14	15	16	17	18	19
20	21	22	23	24	25	26
27	28	29	30

42

Web notebook about thoughts and discoveries in rails, ruby, mysql, git and …

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

Problem

Solution

Find devices with their IPs in your local network

Problem

Solution

Terraform Cloud – error when trying to initialize

Problem

Solution

Checking and enabling slow query log in MySQL

Solution

Find your public IP address from linux command line

Problem

Solution

Get a list for all crontab jobs in a server

WARN[0000] Your Skaffold version might be too old. Download the latest version (1.0.1) at https://storage.googleapis.com/skaffold/releases/latest/skaffold-linux-amd64

Problem

Solution

Using nginx to redirect to a different port

Problem

Solution

Removing DEFINER from MySQL < 5.7 dump files

Problem

Solution

Find your Thinkpad (X1) model type in linux

Problem

Solution