[k8s]: switching to Flannel from Calico. (#4768)

Switching to Flannel from Calico which brings down the image size by around 500+MB.

Author: renukamanavalan

Makefile.work

@@ -169,7 +169,7 @@ SONIC_BUILD_INSTRUCTION :=  make \
                            INSTALL_KUBERNETES=$(INSTALL_KUBERNETES) \
                            KUBERNETES_VERSION=$(KUBERNETES_VERSION) \
                            K8s_GCR_IO_PAUSE_VERSION=$(K8s_GCR_IO_PAUSE_VERSION) \
-                           K8s_CNI_CALICO_VERSION=$(K8s_CNI_CALICO_VERSION) \
+                           K8s_CNI_FLANNEL_VERSION=$(K8s_CNI_FLANNEL_VERSION) \
                            SONIC_ENABLE_PFCWD_ON_START=$(ENABLE_PFCWD_ON_START) \
                            SONIC_ENABLE_SYNCD_RPC=$(ENABLE_SYNCD_RPC) \
                            SONIC_INSTALL_DEBUG_TOOLS=$(INSTALL_DEBUG_TOOLS) \

files/build_templates/sonic_debian_extension.j2

@@ -411,11 +411,10 @@ sudo LANG=C chroot $FILESYSTEM_ROOT docker $SONIC_NATIVE_DOCKERD_FOR_DOCKERFS ta
 {% if install_kubernetes == "y" %}
 ## Pull in kubernetes docker images
 echo "pulling universal k8s images ..."
+FLANNEL_ARCH=$([ "${CONFIGURED_ARCH}" == "armhf" ] && echo "arm64" || echo "${CONFIGURED_ARCH}")
 sudo https_proxy=$https_proxy LANG=C chroot $FILESYSTEM_ROOT docker pull k8s.gcr.io/pause:${K8s_GCR_IO_PAUSE_VERSION}
 sudo https_proxy=$https_proxy LANG=C chroot $FILESYSTEM_ROOT docker pull k8s.gcr.io/kube-proxy:v${KUBERNETES_VERSION}
-sudo https_proxy=$https_proxy LANG=C chroot $FILESYSTEM_ROOT docker pull calico/node:v${K8s_CNI_CALICO_VERSION}
-sudo https_proxy=$https_proxy LANG=C chroot $FILESYSTEM_ROOT docker pull calico/pod2daemon-flexvol:v${K8s_CNI_CALICO_VERSION}
-sudo https_proxy=$https_proxy LANG=C chroot $FILESYSTEM_ROOT docker pull calico/cni:v${K8s_CNI_CALICO_VERSION}
+sudo https_proxy=$https_proxy LANG=C chroot $FILESYSTEM_ROOT docker pull quay.io/coreos/flannel:${K8s_CNI_FLANNEL_VERSION}-${FLANNEL_ARCH}
 echo "docker images pull complete"
 {% endif %}
 

rules/config

@@ -117,11 +117,11 @@ INSTALL_KUBERNETES = n
 
 # KUBERNETES_VERSION - Set to the required version.
 # K8s_GCR_IO_PAUSE_VERSION - Version of k8s universal pause container image
-# K8s_CNI_CALICO_VERSION - Calico used as CNI; Appropriate version for this Kubernetes version
+# K8s_CNI_FLANNEL_VERSION - Flannel used as CNI; Appropriate version for this Kubernetes version
 # These are Used *only* when INSTALL_KUBERNETES=y
 # NOTE: As a worker node it has to run version compatible to kubernetes master.
 #
 KUBERNETES_VERSION = 1.18.0
 K8s_GCR_IO_PAUSE_VERSION = 3.2
-K8s_CNI_CALICO_VERSION = 3.12.1
+K8s_CNI_FLANNEL_VERSION = v0.12.0