vim-ale/postgres/README.md

title, homepage, tagline

title	homepage	tagline
Postgres	https://www.postgresql.org/	PostgreSQL: The World's Most Advanced Open Source Relational Database.

To update or switch versions, run webi postgres@stable (or @v10, @beta, etc).

Cheat Sheet

Postgres is the all-in-one database for beginners and experts alike. It handles SQL, 'NoSQL', JSON, HSTORE, Full-Text Search, Messages Queues and more. Best bang for buck.

Start the postgres server

Run just once (for development):

postgres -D $HOME/.local/share/postgres/var -p 5432

Run as a system service on Linux:

sudo env PATH="$PATH" \
    serviceman add --system --username "$(whoami)" --name postgres -- \
    postgres -D "$HOME/.local/share/postgres/var" -p 5432

# Restart the logging service
sudo systemctl restart systemd-journald

Connect with the psql client

psql 'postgres://postgres:postgres@localhost:5432/postgres'

Initialize a database with a password

echo "postgres" > /tmp/pwfile
mkdir -p $HOME/.local/share/postgres/var/

initdb -D $HOME/.local/share/postgres/var/ \
    --username postgres --pwfile "/tmp/pwfile" \
    --auth-local=password --auth-host=password

rm /tmp/pwfile

Add and secure remote users

1. Set your server name or IP address

   PG_HOST=pg-1.example.com
   

2. Generate a 10-year self-signed TLS certificate

   openssl req -new -x509 -days 3650 -nodes -text \
       -out server.crt \
       -keyout server.key \
       -subj "/CN=$PG_HOST"
   
   chmod og-rwx server.key server.crt
   mv server.key server.crt ~/.local/share/postgres/var/
   

3. Enable SSL (TLS)

   vim ~/.local/share/postgres/var/postgresql.conf
   

   ssl = on
   password_encryption = scram-sha-256
   listen_addresses = '*'
   

4. Generate a user with a random token password

   MY_USER='my_user'
   MY_PASSWORD="$(xxd -l16 -ps /dev/urandom)"
   
   echo "CREATE ROLE \"$MY_USER\" LOGIN ENCRYPTED PASSWORD '$MY_PASSWORD';" |
       psql 'postgres://postgres:postgres@localhost:5432/postgres' -f -
   

5. Show the token password and save it somewhere

   echo "$MY_PASSWORD"
   

6. Allow the user to connect via IPv4 and IPv6

   echo "# Allow $MY_USER to connect remotely over the internet
   hostssl all             $MY_USER        0.0.0.0/0               scram-sha-256
   hostssl all             $MY_USER        ::0/0                   scram-sha-256" \
       >> ~/.local/share/postgres/var/pg_hba.conf
   

7. Restart postgres

   sudo systemctl restart postgres
   

8. Test the connection from a remote system

   PG_HOST="pg-1.example.com"
   PG_USER="my_user"
   
   psql "postgres://$PG_USER@$PG_HOST/postgres?sslmode=require" << EOF
   SELECT CURRENT_USER;
   EOF
   

   (you will be prompted for your password / token)

Add or update a user's password

MY_USER='my_user'
MY_NEW_PASSWORD="$(xxd -l16 -ps /dev/urandom)"

# Update existing user with new password using new hash
echo "ALTER USER \"$MY_USER\" PASSWORD '$MY_NEW_PASSWORD';" |
    psql 'postgres://postgres:postgres@localhost:5432/postgres' -f -