Add Data Volume annotations documentation

doc/datavolume-annotations.md

@@ -0,0 +1,65 @@
+# Data Volume Annotations
+
+## Introduction
+
+CDI allows adding specific annotations to a DV or PVC to be passed to the Transfer Pods and control their behavior. Only specifically allowed annotations are passed, to prevent unexpected behavior due to missing testing coverage.
+
+## Multus
+Anntoations allows controlling which network will be used by the importer pod:
+ * k8s.v1.cni.cncf.io/networks: networkname - pod will get both the default network from the cluster, and the secondary multus network.
+ * v1.multus-cni.io/default-network: networkname - pod will get the multus network as its default network.
+
+For example:
+
+```yaml
+apiVersion: cdi.kubevirt.io/v1beta1
+kind: DataVolume
+metadata:
+  name: dv-ann
+  annotations:
+      v1.multus-cni.io/default-network: bridge-network
+spec:
+  source:
+      http:
+         url: "http://mirrors.nav.ro/fedora/linux/releases/33/Cloud/x86_64/images/Fedora-Cloud-Base-33-1.2.x86_64.qcow2"
+  pvc:
+    accessModes:
+      - ReadWriteOnce
+    resources:
+      requests:
+        storage: 1Gi
+```
+
+Further reference on setting Multus secondary network can be found [here](https://kubevirt.io/2020/Multiple-Network-Attachments-with-bridge-CNI.html).
+
+## AspenMesh / istio
+
+ * sidecar.istio.io/inject: "false" - disables sidecar injection to the pod
+
+For example:
+
+```yaml
+apiVersion: cdi.kubevirt.io/v1beta1
+kind: DataVolume
+metadata:
+  name: dv-am
+  annotations:
+      sidecar.istio.io/inject: "false"
+spec:
+  source:
+      http:
+         url: "http://mirrors.nav.ro/fedora/linux/releases/33/Cloud/x86_64/images/Fedora-Cloud-Base-33-1.2.x86_64.qcow2"
+  pvc:
+    accessModes:
+      - ReadWriteOnce
+    resources:
+      requests:
+        storage: 1Gi
+```
+
+To enable sidecar injection in namespace:
+
+```bash
+kubectl label namespace default istio-injection=enabled
+kubectl get namespace default -L istio-injection
+```

doc/datavolumes.md

@@ -254,6 +254,8 @@ The running and ready conditions are mutually exclusive, if running is true, the
 * Reason The reason the status transitioned to a new value, this is a camel cased single word, similar to an EventReason in events.
 * Message A detailed messages expanding on the reason of the transition. For instance if Running went from True to False, the reason will be the container exit reason, and the message will be the container exit message, which explains why the container exitted.
 
+## Annotations
+Specific [DV annotations](datavolume-annotation.md) are passed to the transfer pods to control their behavior.
 
 ## Kubevirt integration
 [Kubevirt](https://github.com/kubevirt/kubevirt) is an extension to Kubernetes that allows one to run Virtual Machines(VM) on the same infra structure as the containers managed by Kubernetes. CDI provides a mechanism to get a disk image into a PVC in order for Kubevirt to consume it. The following steps have to be taken in order for Kubevirt to consume a CDI provided disk image.