erebor 1.1.7

Persistent key-value store

erebor

Erebor is a persistent key-value store. It uses a Redis-like syntax, but is very lightweight.

Installation

To install locally:

pip install erebor

To install globally to /usr/local/bin/ and enable daemon mode:

sudo pip install erebor

Usage

Run the erebor server like so:

$ erebor
[2022-08-15 21:41:05] [205] Listening at: 127.0.0.1:8044

You can verify erebor is running using the thorin cli.

$ thorin
127.0.0.1:8044> set blah foo bar
OK
127.0.0.1:8044> ls
['blah']
127.0.0.1:8044> get blah foo
bar
127.0.0.1:8044> dump blah
{"foo": "bar"}
127.0.0.1:8044> quit
$ thorin get blah foo
bar

To run erebor in production, you can use --daemon to run as a systemd daemon:

NOTE: This requires installation with sudo.

NOTE: This requires the systemctl Linux package to be installed.

NOTE: The default storage location in daemon mode is /var/lib/erebor.

$ sudo pip install erebor
$ sudo erebor --daemon
$ sudo systemctl status erebor
erebor.service - persistent key-value store
    Loaded: loaded (/etc/systemd/system/erebor.service, enabled)
    Active: active (running)

API

Erebor recognizes the following commands:

    set      <table> <key> <value>  set a key in a table to a value
    del      <table> <key>          remove a key and its value from a table
    get      <table> <key>          retrieve the value of a key from a table
    dump     <table>                return all keys and values for a table in JSON
    pwd                             return the filesystem location of the tables
    ls                              return a list of all table names
    version                         return the current erebor version
    help                            display this helpful information

Configuration

By default, erebor runs on localhost, port 8044. You can change this with the --host and --port options.

$ erebor --host 0.0.0.0 --port 8045
[2022-08-15 21:44:29] [220] Listening at: 0.0.0.0:8045

To change the directory where erebor stores tables, simply pass the --path option.

$ erebor --path /tmp/data

NOTE: The default location in non-daemon mode is in the .erebor folder in the location where erebor is run.

You can verify the path using the thorin cli.

$ thorin pwd
/tmp/data

Other notes

The erebor API uses vanilla TCP sockets, so you can make API requests using, e.g. netcat.

$ nc localhost 8044
set blah foo bar
OK

You can also talk to erebor programmatically using any language that can use sockets:

import socket

def erebor(message):
    # Setup a socket to the host and port where erebor is running.
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.connect(("127.0.0.1", 8044))

    # Messages to erebor must be terminated by a newline.
    message = message + "\n"
    sock.send(message.encode())
    return sock.recv(1024).decode().strip()

print(erebor("set blah foo bar"))
# OK
print(erebor("get blah foo"))
# bar