Bootstrapping the Configuration Database
Choosing a Database
pgwatch supports any database that supports the PostgreSQL wire protocol. This includes:
- PostgreSQL
- TimescaleDB
- CitusDB
- CockroachDB
- many more
We will use PostgreSQL in this guide. But the steps are similar for other databases. It's up to you to choose the database that best fits your needs and set it up accordingly.
Creating the Database
First, we need to create a database for storing the configuration. We will use the psql
command-line tool to create the database. You can also use a GUI tool like pgAdmin to create the database.
Let's assume we want to create a database named pgwatch
on a completely fresh PostgreSQL installation.
It is wise to use a special role for the configuration database, so we will create a role named pgwatch
and assign it to the pgwatch
database.
$ psql -U postgres -h localhost -p 5432 -d postgres
psql (17.2)
postgres=# CREATE ROLE pgwatch WITH LOGIN PASSWORD 'pgwatchadmin';
CREATE ROLE
postgres=# CREATE DATABASE pgwatch OWNER pgwatch;
CREATE DATABASE
That's it! We have created a database named pgwatch
with the owner pgwatch
. Now we can proceed to the next step.
Init (optional)
pgwatch will automatically create the necessary tables and indexes in the database when it starts. But in case
you want to create the schema as a separate step, you can use the config init
command-line command. The only thing you
need is to provide the connection string to the database.
Or you can use the config init
command with the --metrics
flag, since metrics and sources share the same database.
Usage
You can now configure pgwatch to use the pgwatch
database as the configuration database for storing monitored sources,
metric deinitions and presets.
$ pgwatch --sources=postgresql://pgwatch:pgwatchadmin@localhost/pgwatch --sink=postgresql://pgwatch@10.0.0.42/measurements
...
[INFO] [metrics:75] [presets:17] [sources:2] sources and metrics refreshed
...
Info
Even though configuration database can hold both sources and metrics definitions, you are free to use any combination of configurations. For example, you can use a database for metrics and YAML file for sources, or vice versa.
That's it! You have successfully bootstrapped the configuration database for pgwatch.
If now you want to see the tables created by pgwatch in the configuration database, you can connect to the database
using the psql
command-line tool and list the tables.
$ psql postgresql://pgwatch:pgwatchadmin@localhost/pgwatch
psql (17.2)
pgwatch=# \dt pgwatch.*
List of relations
Schema | Name | Type | Owner
---------+-----------+-------+---------
pgwatch | metric | table | pgwatch
pgwatch | migration | table | pgwatch
pgwatch | preset | table | pgwatch
pgwatch | source | table | pgwatch
(4 rows)
You may examine these tables to understand how pgwatch stores metrics and presets definitions, as well as what sources and how to monitor in the database.