Connecting to a Spin App¶

In order to be able to access your application from outside of Spin (for example from a web browser, over the Internet) you must tell Spin how to route incoming requests. This can be done by configuring an Ingress. It is similar to the configuration used by a web server, which translates URLs to file system paths.

Important: before creating an ingress, make sure that you have created a Cluster IP type port in your deployment.

HTTP-based services: Ingresses¶

If you want users to access an endpoint that speaks the HTTP protocol (ie. a web server, or an API), go to the Service Discovery in the left menu, select Ingresses. Click the Create button on the upper left. Select the correct namespace, and give your ingress a name.

On the Rules tab, for the Requested Host entry, enter the following (substitute your information as needed):

<name>.<namespace>.<environment>.svc.spin.nersc.org

Where:

• name can be anything (except contain a period)

• namespace is the selected namespace

• environment is the current one ("production" or "development")

• Note that the domain ends in ".org" not ".gov"

Next, set path to "implementation specific", and for Target Service select the HTTP-based workload you want to access and enter a port. If no workloads show up under Target Service it is likely because you didn't declare a ClusterID port in the workload.

In the Ingress Class tab, select the nginx as the ingress class.

Click "Create" and wait for 1-5 mins for DNS to propagate. Then try accessing your app at

http://<name>.<namespace>.<environment>.svc.spin.nersc.org:<port>

HTTPS access and Custom DNS names¶

DOE security requirements dictate that web services must be encrypted using a web certificate. Generally, obtaining a certificate will be done in conjunction with obtaining a custom DNS name for your app. Processes for obtaining certificates and registering DNS names vary from institution to institution, so check with your local IT support or project collaborators for guidance.

Your custom DNS name should simply be a CNAME record to the long, generated name above ending in svc.spin.nersc.org; for example,

<custom DNS name> CNAME <name>.<namespace>.<environment>.svc.spin.nersc.org

Once you have a web certificate and custom DNS name, edit the ingress and add a rule to specify the DNS name to use and select the same port and target as the ingress. You should now be able to access your application via:

http://<custom DNS name>

To install the web certificate, click "Storage", select "Secrets" and click the "Create" button. Click "TLS Certificate" and enter the private key and the certificate. Next go to "Service Discovery" and then "Ingresses". Find your ingress, click its name and from the right-hand side ⋮ menu, select Edit Config. Click the Certificates tab and then Add Certificate. Select your previously created certificate and add the associated host names. You should now be able to access your application at:

https://<custom DNS name>

Non-HTTP services: Load Balancers¶

Services such as MySQL, PostgreSQL and other non-HTTP applications can also be opened to other networks at NERSC. Note that access to these applications are restricted to NERSC networks only, although we are working on a method to expose these services to other facilities.

For this example, let's assume that you have set up a mysql workload called db and want to connect to it from Perlmutter login nodes.

Click Edit Config on your db workload, and add then Add Port as follows:

• Service type: Load Balancer
• Name: mysql
• Port: 3306
• Protocol: TCP

Notice that your workload now has loadbalancer Service called db-loadbalancer. The service will have an automatically generated name in the format <workload>-loadbalancer. Spin will automatically generate the DNS hostname for your service, in the following format:

<workload>-loadbalancer.<namespace>.<environment>.svc.spin.nersc.org

Click ⋮ > Edit Config on the db-loadbalancer line, and click on the Labels and Annotations tab. Notice that the hostname for your service is automatically set with the following annotation:

external-dns.alpha.kubernetes.io/hostname=<name>.<namespace>.<environment>.svc.spin.nersc.org

This is the hostname to use for accessing your application. Click cancel to exit this view.

Optionally, from your deployment, click the Services tab and notice there are two Services: db that exposes a port within your namespace, and db-loadbalancer which is the same service that you saw under the Load Balancing tab.

To connect to your external hostname, use the above hostname and the application port. For example for a hypothetical mysql workload:

mysqlsh -h db-loadbalancer.<namespace>.<environment>.svc.spin.nersc.org -u root