Adds support for Multus (multiple interfaces) CNI plugin (#3166)

* Adds support for Multus (multiple interfaces) CNI plugin

Multus is a latin word for "Multi". As the name suggests, it acts as a
Multi plugin in Kubernetes and provides multiple network interface
support in a pod. Multus uses the concept of invoking delegates by
grouping multiple plugins into delegates and invoking them in the
sequential order of the CNI configuration file provided in json format.

* Change CNI version (0.1.0->0.3.1) of Contiv to be compatible with Multus

tests/files/gce_centos7-multus-calico.yml

@@ -0,0 +1,12 @@
+# Instance settings
+cloud_image_family: centos-7
+cloud_region: us-central1-c
+cloud_machine_type: "n1-standard-1"
+mode: default
+
+# Deployment settings
+kube_network_plugin_multus: true
+kube_network_plugin: calico
+deploy_netchecker: true
+kubedns_min_replicas: 1
+cloud_provider: gce

tests/testcases/040_check-network-adv.yml

@@ -80,3 +80,68 @@
       run_once: true
       when:
         - agents.content == '{}'
+
+    - name: Create macvlan network conf
+      # We cannot use only shell: below because Ansible will render the text
+      # with leading spaces, which means the shell will never find the string
+      # EOF at the beginning of a line. We can avoid Ansible's unhelpful
+      # heuristics by using the cmd parameter like this:
+      shell:
+        cmd: |
+          cat <<EOF | {{ bin_dir }}/kubectl create -f -
+          apiVersion: "k8s.cni.cncf.io/v1"
+          kind: NetworkAttachmentDefinition
+          metadata:
+            name: macvlan-conf
+          spec:
+            config: '{
+              "cniVersion": "0.3.0",
+              "type": "macvlan",
+              "master": "eth0",
+              "mode": "bridge",
+              "ipam": {
+                "type": "host-local",
+                "subnet": "192.168.1.0/24",
+                "rangeStart": "192.168.1.200",
+                "rangeEnd": "192.168.1.216",
+                "routes": [
+                  { "dst": "0.0.0.0/0" }
+                ],
+              "gateway": "192.168.1.1"
+            }
+          }'
+          EOF
+      when:
+        - kube_network_plugin_multus|default(false)
+
+    - name: Annotate pod with macvlan network
+      # We cannot use only shell: below because Ansible will render the text
+      # with leading spaces, which means the shell will never find the string
+      # EOF at the beginning of a line. We can avoid Ansible's unhelpful
+      # heuristics by using the cmd parameter like this:
+      shell:
+        cmd: |
+          cat <<EOF | {{ bin_dir }}/kubectl create -f -
+          apiVersion: v1
+          kind: Pod
+          metadata:
+            name: samplepod
+            annotations:
+              k8s.v1.cni.cncf.io/networks: macvlan-conf
+          spec:
+            containers:
+            - name: samplepod
+              command: ["/bin/bash", "-c", "sleep 2000000000000"]
+              image: dougbtv/centos-network
+          EOF
+      when:
+        - kube_network_plugin_multus|default(false)
+
+    - name: Check secondary macvlan interface
+      shell: "{{ bin_dir }}/kubectl exec samplepod -- ip addr show dev net1"
+      register: output
+      until: output.rc == 0
+      retries: 90
+      changed_when: false
+      when:
+        - kube_network_plugin_multus|default(false)