feat: Add support for Flatcar Container Linux

This change adds support for Flatcar to the blobfuse installer.
Changes are minimal; we're re-using the rhcos installer script and the
gardenlinux paths.

As Flatcar currently does not ship libfuse, we install it alongside
blobfuse2.

Signed-off-by: Thilo Fromm <thilofromm@microsoft.com>

Author: t-lo

charts/latest/blob-csi-driver/templates/csi-blob-node.yaml

@@ -113,7 +113,7 @@ spec:
             - name: host-home-kubernetes-bin
               mountPath: /host/home/kubernetes/bin
 {{- end }}
-{{- if eq .Values.linux.distro "gardenlinux" }}
+{{- if or (eq .Values.linux.distro "gardenlinux") (eq .Values.linux.distro "flatcar") }}
             - name: host-var-bin
               mountPath: /host/var/bin
 {{- end }}
@@ -302,7 +302,7 @@ spec:
           hostPath:
             path: /home/kubernetes/bin
 {{- end }}
-{{- if eq .Values.linux.distro "gardenlinux" }}
+{{- if or (eq .Values.linux.distro "gardenlinux") (eq .Values.linux.distro "flatcar") }}
         - name: host-var-bin
           hostPath:
             path: /var/bin

pkg/blobfuse-proxy/init.sh

@@ -39,7 +39,7 @@ echo "Linux distribution: $DISTRIBUTION, Arch: $ARCH"
 
 # install blobfuse-proxy and blobfuse/blobfuse2 if needed
 case "${DISTRIBUTION}" in
-  "rhcos" | "rhel" | "cos" | "gardenlinux")
+  "rhcos" | "rhel" | "cos" | "gardenlinux" | "flatcar")
     . ./blobfuse-proxy/install-proxy-rhcos.sh
     ;;
   *)

pkg/blobfuse-proxy/install-proxy-rhcos.sh

@@ -16,19 +16,19 @@
 
 set -xe
 
-BIN_PATH=${BIN_PATH:-/usr/local/bin}
-if [ "${DISTRIBUTION}" = "cos" ]; then
-  echo "set BIN_PATH to /home/kubernetes/bin"
-  BIN_PATH="/home/kubernetes/bin"
-fi
-if [ "${DISTRIBUTION}" = "gardenlinux" ]; then
-  echo "set BIN_PATH to /var/bin"
-  BIN_PATH="/var/bin"
-fi
-if [ "${CUSTOM_BIN_PATH}" != "" ]; then
-  echo "set BIN_PATH to ${CUSTOM_BIN_PATH}"
-  BIN_PATH="${CUSTOM_BIN_PATH}"
+if [ -z "${CUSTOM_BIN_PATH:-}" ] ; then
+  case "${DISTRIBUTION}" in
+    "cos")
+      BIN_PATH="/home/kubernetes/bin" ;;
+    "gardenlinux" | "flatcar")
+      BIN_PATH="/var/bin" ;;
+    *)
+      BIN_PATH=${BIN_PATH:-/usr/local/bin} ;;
+  esac
+else
+  BIN_PATH="/${CUSTOM_BIN_PATH#/}"
 fi
+echo "set BIN_PATH to ${BIN_PATH}"
 
 #copy blobfuse2 binary to BIN_PATH/blobfuse2
 updateBlobfuse2="true"
@@ -60,6 +60,15 @@ if [ "$updateBlobfuse2" = "true" ];then
     cp /usr/lib64/libfuse3.so.3* /host/usr/lib64/
   fi
   chmod 755 /host${BIN_PATH}/blobfuse2
+  if [ "$DISTRIBUTION" = "flatcar" ] ; then
+    find /usr/ -name 'libfuse.so.*' -exec cp '{}' /host${BIN_PATH} \;
+    mv /host${BIN_PATH}/blobfuse2 /host${BIN_PATH}/blobfuse2.bin
+    {
+      echo '#!/usr/bin/bash'
+      echo "LD_LIBRARY_PATH='${BIN_PATH}' exec ${BIN_PATH}/blobfuse2.bin \"\${@}\""
+    } >/host${BIN_PATH}/blobfuse2
+    chmod 755 /host${BIN_PATH}/blobfuse2
+  fi
 fi
 
 if [ "${INSTALL_BLOBFUSE_PROXY}" = "true" ];then

pkg/blobfuse-proxy/server/server.go

@@ -150,6 +150,11 @@ func getBlobfuseVersion() BlobfuseVersion {
 		return BlobfuseV2
 	}
 
+	if strings.EqualFold(osinfo.Distro, "flatcar") {
+		klog.V(2).Info("proxy default using blobfuse V2 for mounting on Flatcar Container Linux")
+		return BlobfuseV2
+	}
+
 	klog.V(2).Info("proxy default using blobfuse V1 for mounting")
 	return BlobfuseV1
 }