To help manage the application lifecycle we provide add-ons that aim to make your life easier as a developer. While there aren't many of these available at the moment, we expect this to change as new requirements in the product teams surface.
It is now possible to create an AWS RDS Postgres database from the cluster declaration. By adding the following section to your scaffolded
# cluster.yaml ... databases: postgres: - name: dbtest user: administrator namespace: dbtest ...
Followed by applying the updated declaration with:
okctl apply cluster -f cluster.yaml
This will create a Postgres database in your AWS account together with a number of related resources. We require the user to provide a Kubernetes Namespace, the reason for this is because several of these resources need to be created in the Kubernetes cluster itself.
- A secrets manager secret for the administrator password
- Lambda function that rotates the administrator password every 30 days
- A security group that allows Pods that have that association to connect with the RDS Postgres database
- Create a Secret and ConfigMap in the namespace that provides the parameters required to connect to the database.
We currently provide the following parameters through the Secret:
And through the ConfigMap:
When combined these can be used to create a valid PostgreSQL connection string.
The secret and the config map will be placed in the Kubernetes namespace defined in the cluster declaration when provisioning the database server.
Forwarding traffic to the database from a local machine
If you want to attach to the database from intellij or some other IDE, you can do so by setting up a port forwarder, you can do so with the following command:
# Usage ## Generate a password for the pgBouncer user uuidgen | sed 's/-//g' > <path to store password file> ## Forward traffic from localhost:5432 to the pgBouncer okctl forward postgres \ --cluster-declaration <path to cluster declaration> \ --name <database server name> \ --username <pgBouncer username> \ --password-file <path to store password file> # Example uuidgen | sed 's/-//g' > password.secret okctl forward postgres \ --cluster-declaration cluster.yaml \ --name pgtest \ --username bob \ --password-file password.secret
By default, this will use the Postgres default port of
5432, but you can change this to what you want.
The username and password used in the
forward postgres command define the username and password to use when connecting to the Postgres client, for example
psql. The user connected to Postgres will however be the admin user defined in the cluster declaration (
cluster.yaml) when provisioning the database.
Connecting an application with a database
Setting up firewall and networking rules for connecting to a database in a production environment can be challenging.
In Okctl, we've implemented a way to do all this for you. By specifying the
postgres attribute in the application declaration, Okctl will handle it for you.
You'll need a database provisioned with Okctl. Go back to the top of this article to see how to use Okctl to create a PostgreSQL database.
# Usage in application.yaml ... postgres: <database name> ... # Example in application.yaml ... postgres: gopherdb ...
The database name is the name you've defined for your database in the cluster declaration under the
After you've added the
postgres attribute to the application declaration, run the following to apply the changes:
# Usage okctl -c <cluster declaration> apply application -f <application declaration> # Example okctl -c cluster.yaml apply application -f application.yaml
Okctl will then apply the changes in three steps:
- set up and configure the required security groups
- create a security group policy
- add it to the application.
Remember to add and push the changes done in the git repository for
ArgoCD to pick up the changes.
After you've confirmed that ArgoCD has acknowledged the changes, you might have to manually restart the application for the changes to take effect. You can restart the pod by either restarting it in the
ArgoCD GUI or by running:
kubectl -n <app namespace> delete pod <pod id>
That's it. Your application should now be able to read and write to the database.
Connecting multiple applications to the same database
There is no limit on how many applications that can connect to the same database.
First, define a database in the
cluster.yaml manifest as mentioned here
Then, for as many applications as required, define a postgres attribute in the relevant
application.yaml file that references the defined database.