Part 3 of tutorial series OpenShift 4 and Service Mesh will show you how to create a Gateway and a VirtualService, so external traffic actually reaches your Mesh. It also provides an example script to run some curl in a loop.
Configure Gateway and VirtualService Example
With the microservices deployed during Issue #2, it makes sense to test the access somehow. In order to bring traffic into the application a Gateway object and a VirtualService object must be created.
The Gateway will be the entry point which forward the traffic to the istio ingressgateway
Get all istio-io related objects of your project. These objects represent the network objects of Service Mesh, like Gateway, VirtualService and DestinationRule (explained later)
oc get istio-io -n tutorial
NAME HOST AGE
destinationrule.networking.istio.io/recommendation recommendation 3d21h
NAME AGE
gateway.networking.istio.io/ingress-gateway 4d15h
NAME GATEWAYS HOSTS AGE
virtualservice.networking.istio.io/ingress-gateway [ingress-gateway] [*] 4d15h
Create some example traffic
Before we start, lets fetch the default route of our Service Mesh:
export GATEWAY_URL=$(oc -n istio-system get route istio-ingressgateway -o jsonpath='{.spec.host}')
This should return: istio-ingressgateway-istio-system.apps.<clustername>
Now, let’s create a shell script to run some curl commands in a loop and can be easily reused for other scenarios:
#!/bin/bash
numberOfRequests=$1
host2check=$2
if [ $# -eq 0 ]; then
echo "better define: <script> #ofrequests hostname2check"
echo "Example: run.sh 100 hello.com"
let "numberOfRequests=100"
else
let "i = 0"
while [ $i -lt $numberOfRequests ]; do
echo -n "# $i: "; curl $2
let "i=$((i + 1))"
done
fi
I was recently asked about how to use Keycloak as an authentication provider for OpenShift. How to install Keycloak using the Operator and how to configure Keycloak and OpenShift so that users can log in to OpenShift using OpenID. I have to admit that the exact steps are not easy to find, so I decided to write a blog post about it, describing each step in detail. This time I will not use GitOps, but the OpenShift and Keycloak Web Console to show the steps, because before we put it into GitOps, we need to understand what is actually happening.
This article tries to explain every step required so that a user can authenticate to OpenShift using Keycloak as an Identity Provider (IDP) and that Groups from Keycloak are imported into OpenShift. This article does not cover a production grade installation of Keycloak, but only a test installation, so you can see how it works. For production, you might want to consider a proper database (maybe external, but at least with a backup), high availability, etc.).
During my day-to-day business, I am discussing the following setup with many customers: Configure App-of-Apps. Here I try to explain how I use an ApplicationSet that watches over a folder in Git and automatically adds a new Argo CD Application whenever a new folder is found. This works great, but there is a catch: The ApplicationSet uses the same Namespace default for all Applications. This is not always desired, especially when you have different teams working on different Applications.
Recently I was asked by the customer if this can be fixed and if it is possible to define different Namespaces for each Application. The answer is yes, and I would like to show you how to do this.
Classic Kubernetes/OpenShift offer a feature called NetworkPolicy that allows users to control the traffic to and from their assigned Namespace. NetworkPolicies are designed to give project owners or tenants the ability to protect their own namespace. Sometimes, however, I worked with customers where the cluster administrators or a dedicated (network) team need to enforce these policies.
Since the NetworkPolicy API is namespace-scoped, it is not possible to enforce policies across namespaces. The only solution was to create custom (project) admin and edit roles, and remove the ability of creating, modifying or deleting NetworkPolicy objects. Technically, this is possible and easily done. But shifts the whole network security to cluster administrators.
Luckily, this is where AdminNetworkPolicy (ANP) and BaselineAdminNetworkPolicy (BANP) comes into play.
Lately I came across several issues where a given Helm Chart must be modified after it has been rendered by Argo CD. Argo CD does a helm template to render a Chart. Sometimes, especially when you work with Subcharts or when a specific setting is not yet supported by the Chart, you need to modify it later … you need to post-render the Chart.
In this very short article, I would like to demonstrate this on a real-live example I had to do. I would like to inject annotations to a Route objects, so that the certificate can be injected. This is done by the cert-utils operator. For the post-rendering the Argo CD repo pod will be extended with a sidecar container, that is watching for the repos and patches them if required.
The article SSL Certificate Management for OpenShift on AWS explains how to use the Cert-Manager Operator to request and install a new SSL Certificate. This time, I would like to leverage the GitOps approach using the Helm Chart cert-manager I have prepared to deploy the Operator and order new Certificates.
I will use an ACME Letsencrypt issuer with a DNS challenge. My domain is hosted at AWS Route 53.
However, any other integration can be easily used.
Thomas Jungbauer
( Lastmod: 2024-05-05 )
-
2 min read