Chapter 1. Preparing to install Red Hat OpenShift GitOps
Read the following information about sizing requirements and prerequisites before you install Red Hat OpenShift GitOps on OpenShift Container Platform. Sizing requirements also provides the sizing details for the default ArgoCD instance that is instantiated by the Red Hat OpenShift GitOps Operator.
1.1. Sizing requirements for GitOps
Red Hat OpenShift GitOps is a declarative way to implement continuous deployment for cloud-native applications. Through GitOps, you can define and configure the CPU and memory requirements of your application.
Every time you install the Red Hat OpenShift GitOps Operator, the resources on the namespace are installed within the defined limits. If the default installation does not set any limits or requests, the Operator fails within the namespace with quotas. Without enough resources, the cluster cannot schedule ArgoCD related pods. The following table details the resource requests and limits for the default workloads:
| Workload | CPU requests | CPU limits | Memory requests | Memory limits |
|---|---|---|---|---|
| argocd-application-controller | 1 | 2 | 1024Mi | 2048Mi |
| applicationset-controller | 1 | 2 | 512Mi | 1024Mi |
| argocd-server | 0.125 | 0.5 | 128Mi | 256Mi |
| argocd-repo-server | 0.5 | 1 | 256Mi | 1024Mi |
| argocd-redis | 0.25 | 0.5 | 128Mi | 256Mi |
| argocd-dex | 0.25 | 0.5 | 128Mi | 256Mi |
| HAProxy | 0.25 | 0.5 | 128Mi | 256Mi |
Optionally, you can also use the ArgoCD custom resource with the oc command to see the specifics and modify them:
oc edit argocd <name of argo cd> -n namespace
1.1.1. Sizing requirements for argocd-redis
During the capacity planning stage for your application in the Red Hat OpenShift GitOps Operator, you must ensure that an adequate amount of resources, such as memory, CPU, and storage, are allocated for the argocd-redis pod.
The default memory limit for the Redis pod might not be enough to manage a large number of resources. In these instances, you must increase the memory limit, monitor the memory metrics, and change the memory configuration while the application deployment scales up.
The following command shows the example of the memory configuration for a Redis pod in the openshift-gitops namespace:
$ oc get argocd -n openshift-gitops openshift-gitops -o json | jq '.spec.redis.resources'
Example Output
{
"limits": { 1
"cpu": "500m",
"memory": "256Mi"
},
"requests": { 2
"cpu": "250m",
"memory": "128Mi"
}
}
The following example command changes the memory configuration for a Redis pod. The highest resource limit threshold is set to 8 GiB and the lowest is set to 256 MiB.
$ oc patch argocd -n openshift-gitops openshift-gitops --type json -p '[{"op": "replace", "path": \
"/spec/redis/resources/limits/memory", "value": "8Gi"}, {"op": "replace", "path": \
"/spec/redis/resources/requests/memory", "value": "256Mi"}]'Example Output
argocd.argoproj.io/openshift-gitops patched
