Mesh configuration

FSM deploys a MeshConfig resource fsm-mesh-config as a part of its control plane (in the same namespace as that of the fsm-controller pod) which can be updated by the mesh owner/operator at any time. The purpose of this MeshConfig is to provide the mesh owner/operator the ability to update some of the mesh configurations based on their needs.

At the time of install, the FSM MeshConfig is deployed from a preset MeshConfig (preset-mesh-config) which can be found under charts/fsm/templates.

First, set an environment variable to refer to the namespace where fsm was installed.

export FSM_NAMESPACE=fsm-system # Replace fsm-system with the namespace where FSM is installed

To view your fsm-mesh-config in CLI use the kubectl get command.

kubectl get meshconfig fsm-mesh-config -n "$FSM_NAMESPACE" -o yaml

Note: Values in the MeshConfig fsm-mesh-config are persisted across upgrades.

Configure FSM MeshConfig

Kubectl Patch Command

Changes to fsm-mesh-config can be made using the kubectl patch command.

kubectl patch meshconfig fsm-mesh-config -n "$FSM_NAMESPACE" -p '{"spec":{"traffic":{"enableEgress":true}}}'  --type=merge

Refer to the Config API reference for more information.

If an incorrect value is used, validations on the MeshConfig CRD will prevent the change with an error message explaining why the value is invalid.

For example, the below command shows what happens if we patch enableEgress to a non-boolean value.

kubectl patch meshconfig fsm-mesh-config -n "$FSM_NAMESPACE" -p '{"spec":{"traffic":{"enableEgress":"no"}}}'  --type=merge
# Validations on the CRD will deny this change
The MeshConfig "fsm-mesh-config" is invalid: spec.traffic.enableEgress: Invalid value: "string": spec.traffic.enableEgress in body must be of type boolean: "string"

Kubectl Patch Command for Each Key Type

Note: <fsm-namespace> refers to the namespace where the fsm control plane is installed. By default, the fsm namespace is fsm-system.