Filesystem API and unit tests

Signed-off-by: Deep Debroy <[email protected]>

Author: ddebroy

client/api/filesystem/v1alpha1/api.pb.go

@@ -2,27 +2,156 @@ syntax = "proto3";
 
 package v1alpha1;
 
-import "github.com/kubernetes-csi/csi-proxy/client/api/errors.proto";
-
-// FIXME: this is just an almost empty service, not actually implemented; it's just
-// here as an example of what API group and versions will look like. It will actually
-// be implemented in a later patch.
-
 service Filesystem {
-    // PathExists checks if the given path exists on the host.
+    // PathExists checks if the requested path exists in the host's filesystem
     rpc PathExists(PathExistsRequest) returns (PathExistsResponse) {}
+
+    // Mkdir creates a directory at the requested path in the host's filesystem
+    rpc Mkdir(MkdirRequest) returns (MkdirResponse) {}
+
+    // Rmdir removes the directory at the requested path in the host's filesystem.
+    // This may be used for unlinking a symlink created through LinkPath
+    rpc Rmdir(RmdirRequest) returns (RmdirResponse) {}
+
+    // LinkPath creates a local directory symbolic link between a source path 
+    // and target path in the host's filesystem
+    rpc LinkPath(LinkPathRequest) returns (LinkPathResponse) {}
+}
+
+// Context of the paths used for path prefix validation
+enum PathContext {
+    // Indicates the kubelet-csi-plugins-path parameter of csi-proxy be used as the path context
+    PLUGIN = 0;
+    // Indicates the kubelet-pod-path parameter of csi-proxy be used as the path context
+    CONTAINER = 1;
 }
 
 message PathExistsRequest {
-    // The path to check in the host file system.
+    // The path whose existence we want to check in the host's filesystem
     string path = 1;
+
+    // Context of the path parameter.
+    // This is used to determine the root for relative path parameters
+    PathContext context = 2;
 }
 
 message PathExistsResponse {
-    bool success = 1;
+    // Error message if any. Empty string indicates success
+    string error = 1;
+
+    // Indicates whether the path in PathExistsRequest exists in the host's filesystem
+    bool exists = 2;
+}
+
+message MkdirRequest {
+    // The path to create in the host's filesystem.
+    // All special characters allowed by Windows in path names will be allowed
+    // except for restrictions noted below. For details, please check:
+    // https://docs.microsoft.com/en-us/windows/win32/fileio/naming-a-file
+    // Non-existent parent directories in the path will be automatically created.
+    // Directories will be created with Read and Write privileges of the Windows
+    // User account under which csi-proxy is started (typically LocalSystem).
+    //
+    // Restrictions:
+    // If an absolute path (indicated by a drive letter prefix: e.g. "C:\") is passed,
+    // depending on the context parameter of this function, the path prefix needs 
+    // to match the paths specified either as kubelet-csi-plugins-path
+    // or as kubelet-pod-path parameters of csi-proxy.
+    // If a relative path is passed, depending on the context parameter of this 
+    // function, the path will be considered relative to the path specified either as 
+    // kubelet-csi-plugins-path or as kubelet-pod-path parameters of csi-proxy.
+    // The path parameter cannot already exist on host filesystem.
+    // UNC paths of the form "\\server\share\path\file" are not allowed.
+    // All directory separators need to be backslash character: "\".
+    // Characters: .. / : | ? * in the path are not allowed.
+    // Maximum path length will be capped to 260 characters.
+    string path = 1;
 
-    // present iff success is false
-    api.CmdletError cmdlet_error = 2;
+    // Context of the path parameter.
+    // This is used to [1] determine the root for relative path parameters
+    // or [2] validate prefix for absolute paths (indicated by a drive letter 
+    // prefix: e.g. "C:\")
+    PathContext context = 2;
+}
+
+message MkdirResponse {
+    // Error message if any. Empty string indicates success
+    string error = 1;
+}
+
+message RmdirRequest {
+    // The path to remove in the host's filesystem.
+    // All special characters allowed by Windows in path names will be allowed
+    // except for restrictions noted below. For details, please check:
+    // https://docs.microsoft.com/en-us/windows/win32/fileio/naming-a-file
+    //
+    // Restrictions:
+    // If an absolute path (indicated by a drive letter prefix: e.g. "C:\") is passed,
+    // depending on the context parameter of this function, the path prefix needs 
+    // to match the paths specified either as kubelet-csi-plugins-path
+    // or as kubelet-pod-path parameters of csi-proxy.
+    // If a relative path is passed, depending on the context parameter of this 
+    // function, the path will be considered relative to the path specified either as 
+    // kubelet-csi-plugins-path or as kubelet-pod-path parameters of csi-proxy.
+    // UNC paths of the form "\\server\share\path\file" are not allowed.
+    // All directory separators need to be backslash character: "\".
+    // Characters: .. / : | ? * in the path are not allowed.
+    // Path cannot be a file of type symlink.
+    // Maximum path length will be capped to 260 characters.
+    string path = 1;
+
+    // Context of the path creation used for path prefix validation
+    // This is used to [1] determine the root for relative path parameters
+    // or [2] validate prefix for absolute paths (indicated by a drive letter 
+    // prefix: e.g. "C:\")
+    PathContext context = 2;
+}
+
+message RmdirResponse {
+    // Error message if any. Empty string indicates success
+    string error = 1;
+}
+
+message LinkPathRequest {
+    // The path where the symlink is created in the host's filesystem.
+    // All special characters allowed by Windows in path names will be allowed
+    // except for restrictions noted below. For details, please check:
+    // https://docs.microsoft.com/en-us/windows/win32/fileio/naming-a-file
+    //
+    // Restrictions:
+    // If an absolute path (indicated by a drive letter prefix: e.g. "C:\") is passed,
+    // the path prefix needs to match the path specified as kubelet-csi-plugins-path
+    // parameter of csi-proxy.
+    // If a relative path is passed, the path will be considered relative to the
+    // path specified as kubelet-csi-plugins-path parameter of csi-proxy.
+    // UNC paths of the form "\\server\share\path\file" are not allowed.
+    // All directory separators need to be backslash character: "\".
+    // Characters: .. / : | ? * in the path are not allowed.
+    // source_path cannot already exist in the host filesystem.
+    // Maximum path length will be capped to 260 characters.
+    string source_path = 1;
+
+    // Target path in the host's filesystem used for the symlink creation.
+    // All special characters allowed by Windows in path names will be allowed
+    // except for restrictions noted below. For details, please check:
+    // https://docs.microsoft.com/en-us/windows/win32/fileio/naming-a-file
+    //
+    // Restrictions:
+    // If an absolute path (indicated by a drive letter prefix: e.g. "C:\") is passed,
+    // the path prefix needs to match the path specified as kubelet-pod-path
+    // parameter of csi-proxy.
+    // If a relative path is passed, the path will be considered relative to the
+    // path specified as kubelet-pod-path parameter of csi-proxy.
+    // UNC paths of the form "\\server\share\path\file" are not allowed.
+    // All directory separators need to be backslash character: "\".
+    // Characters: .. / : | ? * in the path are not allowed.
+    // target_path needs to exist as a directory in the host that is empty.
+    // target_path cannot be a symbolic link.
+    // Maximum path length will be capped to 260 characters.
+    string target_path = 2;
+}
 
-    bool exists = 4;
+message LinkPathResponse {
+    // Error message if any. Empty string indicates success
+    string error = 1;
 }

client/api/filesystem/v1alpha1/api.proto

@@ -1,20 +1,39 @@
 package main
 
 import (
+	"runtime"
+
+	filesystemapi "github.com/kubernetes-csi/csi-proxy/internal/os/filesystem"
 	"github.com/kubernetes-csi/csi-proxy/internal/server"
-	filesystem "github.com/kubernetes-csi/csi-proxy/internal/server/filesystem"
+	srvtypes "github.com/kubernetes-csi/csi-proxy/internal/server/types"
+	filesystemsrv "github.com/kubernetes-csi/csi-proxy/internal/server/filesystem"
+	flag "github.com/spf13/pflag"
+)
+
+var (
+	kubeletCSIPluginsPath = flag.String("kubelet-csi-plugins-path", `C:\var\lib\kubelet\plugins`, "Absolute path of the Kubelet plugin directory in the host file system")
+	kubeletPodPath        = flag.String("kubelet-pod-path", `C:\var\lib\kubelet\pods`, "Absolute path of the kubelet pod directory in the host file system")
 )
 
 func main() {
-	s := server.NewServer(apiGroups()...)
+	flag.Parse()
+	apiGroups, err := apiGroups()
+	if err != nil {
+		panic(err)
+	}
+	s := server.NewServer(apiGroups...)
 	if err := s.Start(nil); err != nil {
 		panic(err)
 	}
 }
 
 // apiGroups returns the list of enabled API groups.
-func apiGroups() []server.APIGroup {
-	return []server.APIGroup{
-		&filesystem.Server{},
+func apiGroups() ([]srvtypes.APIGroup, error) {
+	fssrv, err := filesystemsrv.NewServer(runtime.GOOS, *kubeletCSIPluginsPath, *kubeletPodPath, filesystemapi.New())
+	if err != nil {
+		return []srvtypes.APIGroup{}, err
 	}
+	return []srvtypes.APIGroup{
+		fssrv,
+	}, nil
 }

client/groups/filesystem/v1alpha1/client_generated.go

@@ -0,0 +1,50 @@
+package filesystem
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"runtime"
+)
+
+// Implements the Filesystem OS API calls. All code here should be very simple
+// pass-through to the OS APIs. Any logic around the APIs should go in
+// internal/server/filesystem/server.go so that logic can be easily unit-tested
+// without requiring specific OS environments.
+
+type APIImplementor struct{}
+
+func New() APIImplementor {
+	return APIImplementor{}
+}
+
+func (APIImplementor) PathExists(path string) (bool, error) {
+	_, err := os.Stat(path)
+	if err == nil {
+		return true, nil
+	}
+	if os.IsNotExist(err) {
+		return false, nil
+	}
+	return true, err
+}
+
+func (APIImplementor) Mkdir(path string) error {
+	err := os.MkdirAll(path, 0755)
+	return err
+}
+
+func (APIImplementor) Rmdir(path string) error {
+	err := os.RemoveAll(path)
+	return err
+}
+
+func (APIImplementor) LinkPath(tgt string, src string) error {
+	var err error
+	if runtime.GOOS == "windows" {
+		_, err = exec.Command("cmd", "/c", "mklink", "/D", tgt, src).CombinedOutput()
+	} else {
+		err = fmt.Errorf("LinkPath not implemented for %s", runtime.GOOS)
+	}
+	return err
+}