samrose / pgex

Postgres via Nix

This repository is a simple demonstration of supplying Postgresql built-binaries via a Nix package, but using and running the Postgres server/cluster outside of the control of nix (for example, supplying your own data dir, postgesql.conf, etc).

This approach should work on Linux, macOS, and windows via wsl2

Getting started

1. Install Nix (this installer turns on the options automatically to install a package from a nix flake url)
2. Next, run nix profile install github:samrose/pgex#pgex . This command will install the latest Postgresql release binaries to your system $PATH. Once this command completes, you can check that the Postgres binaries are being source by nix:

   $ which initb
   /home/<youruser>/.nix-profile/bin/initdb
   $ which postgres
   /home/<youruser>/.nix-profile/bin/postgres
   
   

   ... the nix profile install command is roughly equal to apt install on Debian-based systems, and installs a pre-built package + fixing system paths to that package. However, you are still able to interact with the binaries outside of the "nix" context, just as you are with other package managers.
3. Now, for convenience sake, you can run chmod +x init.sh && ./initsh and this will populate a database here in the project directory under the postgres and postgres_data dirs.
4. The ./init.sh script simply runs the initdb command supplied by the postgresql package under the hood. This produces the following directories:

   postgres
   postgres_data
   

   initdb writes a default mutable postgresql.conf file under postgres_data which is completely customizeable by the user of this package. All of the configuration settings should work as expected.
5. Run the server with this command

   $ postgres -D postgres_data #postgres finds the posgresql.conf in the postgres_data dir automatically
   2024-02-23 09:32:34.404 EST [1586346] LOG:  starting PostgreSQL 15.5 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 13.2.0, 64-bit
   2024-02-23 09:32:34.405 EST [1586346] LOG:  listening on IPv4 address "0.0.0.0", port 5432
   2024-02-23 09:32:34.405 EST [1586346] LOG:  listening on IPv6 address "::", port 5432
   2024-02-23 09:32:34.407 EST [1586346] LOG:  listening on Unix socket "/home/sam/pgex/postgres/.s.PGSQL.5432"
   2024-02-23 09:32:34.411 EST [1586349] LOG:  database system was shut down at 2024-02-23 09:32:12 EST
   2024-02-23 09:32:34.415 EST [1586346] LOG:  database system is ready to accept connections
   
   

6. Connect via the psql client like this:

    $ psql -h $PWD/postgres -U postgres
    psql (15.5)
    Type "help" for help.
   
    postgres=#