RestlessMonks’ Cookbook

How to run rails server (or any server) on a VM?

1. Make sure nginx is installed. Else follow this simple guide first — https://www.digitalocean.com/community/tutorials/how-to-install-nginx-on-ubuntu-18-04
2. Go to cd /etc/nginx/sites-available
3. Add below details. Replace your server_name and proxy_pass (Where your server is running) with correct values

server{
        server_name api.grambuddy.com; 
        location / {
                proxy_pass http://localhost:3002;
                proxy_http_version 1.1;
        }
listen 80;
        listen [::]:80;
}

4. Create a symlink for it:

sudo ln -s /etc/nginx/sites-available/testapp /etc/nginx/sites-enabled/testapp

5. Restart Nginx:

sudo nginx -s reload

How to run service?

cd /etc/systemd/system/
<Create a new file - grambuddy-server.service> and enter the below details in it
[Unit]
Description= instance to start grambuddy backend server
After=network.target
[Service]
User=root
Group=www-data
WorkingDirectory=/root/grambuddy
Restart=on-failure
RestartSec=5s
ExecStart=/bin/bash -lc 'bundle exec rails server -e production  -p 3002'
[Install]
WantedBy=multi-user.target

Then systemctl start grambuddy-server.service

How to make an endpoint http“s” / get certificate for free from let’s encrypt?

1. Ref: https://certbot.eff.org/

certbot
{and then choose the domain from the nginx}

How to Deploy a static react build in VM?

Here website name is framery.in

cp -r  build html
mv html /var/www/framery.in/html
chown -R $USER:$USER /var/www/framery.in/html
chmod -R 755 /var/www/framery.in
nginx -t
systemctl restart nginx

How to copy Postgres data to a CSV and then to your computer

\copy (select * from users order by created_at desc) to '~/users_till_26_may.csv' with csv

And then

scp root@129.19.78.122:users_till_26_may.csv ~/Desktop/profilebud/data

Postgres Dump

pg_dump -h localhost -p 5432 -U postgres -d db_name -t table_name > name.sql
psql instagram_tools_backend < 4_NOV_USERS.sql

https://www.citusdata.com/blog/2021/02/20/faster-data-migrations-in-postgres/

SCP

Moving Files within Server
# In local to copy file from remote to local
scp root@192.123.456.7:~/4_NOV_USERS.sql /home/dell/Downloads/Instagram/4_NOV_USERS.sql
# In local to copy file from local to remote
scp /home/dell/Downloads/Instagram/4_NOV_USERS.sql root@$192.123.456.7:~/4_NOV_USERS.sql

Check the IP

GET: https://httpbin.org/ip

Sample Dummy JSON Data

https://jsonplaceholder.typicode.com/todos/1

Postgres

Postgres Config: /etc/postgresql/10/main/postgresql.conf

Config: 
/etc/postgresql/10/main/postgresql.conf
Logs: 
/var/log/postgresql/postgresql-10-main.log
Restart Service: 
service postgresql restart
Get a DB Size: 
SELECT pg_size_pretty( pg_database_size('leadgen') );
Get Size for Specific Table: 
pg_size_pretty( pg_total_relation_size('tablename') );
Show Data Directory
postgres=# SHOW data_directory;

Mounting a volume Digital Ocean:
https://www.digitalocean.com/community/tutorials/how-to-move-a-postgresql-data-directory-to-a-new-location-on-ubuntu-16-04

RAM & Disk Usage in Ubuntu

Disk Usage

df -h

Another killer tool which I would recommend — ncdu

sudo apt-get install ncdu && sudo ncdu /

RAM Usage

htop 
or 
free -m

Increasing Digitalocean Volume and Increasing Filesystem

• Increasing volume is easy. Just go to Digitalocean dashboard and increase the volume size. PS: That is irreversible
• After that you need to increase the file system too. Check it out here

For RestlessMonk’s case, everytime you increase the volume, increase the filesystem too -> just do

df -h        # to check the volume
resize2fs /dev/sda

Moving Postgres Data to Volume

How To Move a PostgreSQL Data Directory to a New Location on Ubuntu 16.04 | DigitalOcean

Nginx as Load Balancer

How to setup simple load balancing with NGINX

Remove Duplicate Users from Table W.R.T multiple Column Values

Remove duplicate records based on multiple columns?

Install Oh-My-Zsh in ubuntu

Prepping a VM for Developer

Rotate Journalctl Logs

Free up Disk Space - Clear Systemd Journal Logs in Ubuntu 20.04

For Removing Long running queries in Postgres

PostgreSQL: Find slow, long-running and Blocked Queries

World of Tmux

https://linuxize.com/post/getting-started-with-tmux/