fix: cni-plugins backward compatibility - continue (#7881)

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: fseldow

parts/linux/cloud-init/artifacts/cse_install.sh

@@ -139,13 +139,8 @@ installFixedCNI() {
     # Old versions of VHDs will not have components.json. If it does not exist, we will try our best to download the hardcoded version for CNI here during provisioning.
     # Network Isolated Cluster / Bring Your Own ACR will not work with a vhd that requires a hardcoded CNI download.
     if [ ! -f "$COMPONENTS_FILEPATH" ] || [ -z "$(jq -r '.Packages[] | select(.name == "containernetworking-plugins") | .name' < $COMPONENTS_FILEPATH)" ]; then
-        echo "WARNING: no containernetworking-plugins components present falling back to hard coded download of 1.4.1"
-        # handles amd64 and arm64 via CPU_ARCH
-        if [ -z "${CPU_ARCH:-}" ]; then
-            CPU_ARCH="$(getCPUArch)"
-        fi
-        retrycmd_get_tarball 120 5 "${CNI_DOWNLOADS_DIR}/refcni.tar.gz" "https://${PACKAGE_DOWNLOAD_BASE_URL}/cni-plugins/v1.4.1/binaries/cni-plugins-linux-${CPU_ARCH}-v1.4.1.tgz" || exit $ERR_CNI_DOWNLOAD_TIMEOUT
-        extract_tarball "${CNI_DOWNLOADS_DIR}/refcni.tar.gz" "$CNI_BIN_DIR"
+        echo "WARNING: no containernetworking-plugins component present, falling back to cni-plugin"
+        installCNILegacy
         return
     fi
 }
@@ -329,6 +324,66 @@ downloadAzureCNI() {
     retrycmd_get_tarball 120 5 "$CNI_DOWNLOADS_DIR/${CNI_TGZ_TMP}" ${VNET_CNI_PLUGINS_URL} || exit $ERR_CNI_DOWNLOAD_TIMEOUT
 }
 
+# Reference CNI plugins is used by kubenet and the loopback plugin used by containerd 1.0 (dependency gone in 2.0)
+# The version used to be deteremined by RP/toggle but are now just hadcoded in vhd as they rarely change and require a node image upgrade anyways
+# Latest VHD should have the untar, older should have the tgz. And who knows will have neither.
+installCNILegacy() {
+    # Old versions of VHDs will not have components.json. If it does not exist, we will fall back to the hardcoded download for CNI.
+    # Network Isolated Cluster / Bring Your Own ACR will not work with a vhd that requres a hardcoded CNI download.
+    if [ ! -f "$COMPONENTS_FILEPATH" ] || ! jq '.Packages[] | select(.name == "cni-plugins")' < $COMPONENTS_FILEPATH > /dev/null; then
+        echo "WARNING: no cni-plugins components present falling back to hard coded download of 1.4.1. This should error eventually"
+        # could we fail if not Ubuntu2204Gen2ContainerdPrivateKubePkg vhd? Are there others?
+        # definitely not handling arm here.
+        # handles amd64 and arm64 via CPU_ARCH
+        if [ -z "${CPU_ARCH:-}" ]; then
+            CPU_ARCH="$(getCPUArch)"
+        fi
+        retrycmd_get_tarball 120 5 "${CNI_DOWNLOADS_DIR}/refcni.tar.gz" "https://${PACKAGE_DOWNLOAD_BASE_URL}/cni-plugins/v1.4.1/binaries/cni-plugins-linux-${CPU_ARCH}-v1.4.1.tgz" || exit $ERR_CNI_DOWNLOAD_TIMEOUT
+        extract_tarball "${CNI_DOWNLOADS_DIR}/refcni.tar.gz" "$CNI_BIN_DIR"
+        return
+    fi
+
+    #always just use what is listed in components.json so we don't have to sync.
+    cniPackage=$(jq ".Packages" "$COMPONENTS_FILEPATH" | jq ".[] | select(.name == \"cni-plugins\")") || exit $ERR_CNI_VERSION_INVALID
+
+    #CNI doesn't really care about this but wanted to reuse updatePackageVersions which requires it.
+    os=${UBUNTU_OS_NAME}
+    if [ -z "$UBUNTU_RELEASE" ]; then
+        os=${OS}
+        os_version="current"
+    fi
+    os_version="${UBUNTU_RELEASE}"
+    if isMarinerOrAzureLinux "${OS}" && [ "${IS_KATA}" = "true" ]; then
+        os=${MARINER_KATA_OS_NAME}
+    fi
+    updatePackageVersions "${cniPackage}" "${os}" "${os_version}" "${OS_VARIANT}"
+
+    #should change to ne
+    # shellcheck disable=SC3010
+    if [[ ${#PACKAGE_VERSIONS[@]} -gt 1 ]]; then
+        echo "WARNING: containerd package versions array has more than one element. Installing the last element in the array."
+        exit $ERR_CONTAINERD_VERSION_INVALID
+    fi
+    packageVersion=${PACKAGE_VERSIONS[0]}
+
+    # Is there a ${arch} variable I can use instead of the iff
+    if [ "$(isARM64)" -eq 1 ]; then
+        CNI_DIR_TMP="cni-plugins-linux-arm64-v${packageVersion}"
+    else
+        CNI_DIR_TMP="cni-plugins-linux-amd64-v${packageVersion}"
+    fi
+
+    if [ -d "$CNI_DOWNLOADS_DIR/${CNI_DIR_TMP}" ]; then
+        #not clear to me when this would ever happen. assume its related to the line above Latest VHD should have the untar, older should have the tgz.
+        mv ${CNI_DOWNLOADS_DIR}/${CNI_DIR_TMP}/* $CNI_BIN_DIR
+    else
+        echo "CNI tarball should already be unzipped by components.json"
+        exit $ERR_CNI_VERSION_INVALID
+    fi
+
+    chown -R root:root $CNI_BIN_DIR
+}
+
 downloadCrictl() {
     #if $1 is empty, take ${CRICTL_DOWNLOAD_DIR} as default value. Otherwise take $1 as the value
     downloadDir=${1:-${CRICTL_DOWNLOAD_DIR}}