virt-launcher,hooks: Expose CONTAINER_NAME env var

Expose on the sidecar a new env var CONTAINER_NAME,
this way the container will able to know its full path volume mount
on the compute container.
More details can be found on kubevirt/community#294
section "Network Binding Plugin and Kubevirt requirements".

Signed-off-by: Or Shoval <[email protected]>

Author: oshoval

pkg/hooks/hooks.go

@@ -30,6 +30,8 @@ import (
 const HookSidecarListAnnotationName = "hooks.kubevirt.io/hookSidecars"
 const HookSocketsSharedDirectory = "/var/run/kubevirt-hooks"
 
+const ContainerNameEnvVar = "CONTAINER_NAME"
+
 type HookSidecarList []HookSidecar
 
 type ConfigMap struct {

pkg/virt-controller/services/rendercontainer.go

@@ -35,6 +35,7 @@ type ContainerSpecRenderer struct {
 	ports             []k8sv1.ContainerPort
 	capabilities      *k8sv1.Capabilities
 	args              []string
+	extraEnvVars      []k8sv1.EnvVar
 }
 
 type Option func(*ContainerSpecRenderer)
@@ -84,6 +85,8 @@ func (csr *ContainerSpecRenderer) envVars() []k8sv1.EnvVar {
 		})
 	}
 
+	env = append(env, csr.extraEnvVars...)
+
 	return env
 }
 
@@ -183,6 +186,12 @@ func WithReadinessProbe(vmi *v1.VirtualMachineInstance) Option {
 	}
 }
 
+func WithExtraEnvVars(envVars []k8sv1.EnvVar) Option {
+	return func(renderer *ContainerSpecRenderer) {
+		renderer.extraEnvVars = append(renderer.extraEnvVars, envVars...)
+	}
+}
+
 func xdgEnvironmentVariables() []k8sv1.EnvVar {
 	const varRun = "/var/run"
 	return []k8sv1.EnvVar{

pkg/virt-controller/services/template.go

@@ -740,6 +740,11 @@ func newSidecarContainerRenderer(sidecarName string, vmiSpec *v1.VirtualMachineI
 	sidecarOpts := []Option{
 		WithResourceRequirements(resources),
 		WithArgs(requestedHookSidecar.Args),
+		WithExtraEnvVars([]k8sv1.EnvVar{
+			k8sv1.EnvVar{
+				Name:  hooks.ContainerNameEnvVar,
+				Value: sidecarName,
+			}}),
 	}
 
 	var mounts []k8sv1.VolumeMount

pkg/virt-controller/services/template_test.go

@@ -2876,6 +2876,11 @@ var _ = Describe("Template", func() {
 				MountPath: hooks.HookSocketsSharedDirectory,
 				SubPath:   "hook-sidecar-0",
 			}))
+
+			Expect(pod.Spec.Containers[1].Env).To(ContainElement(k8sv1.EnvVar{
+				Name:  hooks.ContainerNameEnvVar,
+				Value: "hook-sidecar-0",
+			}))
 		})
 
 		Context("with pod networking", func() {