Add a Reva SDK (#1280)

changelog/unreleased/reva-sdk.md

@@ -0,0 +1,5 @@
+Enhancement: Add a Reva SDK
+
+A Reva SDK has been added to make working with a remote Reva instance much easier by offering a high-level API that hides all the underlying details of the CS3API.
+
+https://github.com/cs3org/reva/pull/1280

docs/content/en/docs/tutorials/sdk-tutorial.md

@@ -0,0 +1,70 @@
+---
+title: "Reva SDK"
+linkTitle: "Reva SDK"
+weight: 5
+description: >
+  Use the Reva SDK to easily access and work with a remote Reva instance. 
+---
+The Reva SDK (located under `/pkg/sdk/`) is a simple software development kit to work with Reva through the [CS3API](https://github.com/cs3org/go-cs3apis). It's goal is to make working with Reva as easy as possible by providing a high-level API which hides all the details of the underlying CS3API.
+
+## Design
+The main design goal of the SDK is _simplicity_. This means that the code is extremely easy to use instead of being particularly fancy or feature-rich. 
+
+There are two central kinds of objects you'll be using: a _session_ and various _actions_. The session represents the connection to the Reva server through its gRPC gateway client; the actions are then used to perform operations like up- and downloading or enumerating all files located at a specific remote path.
+
+## Using the SDK
+### 1. Session creation
+The first step when using the SDK is to create a session and establish a connection to Reva (which actually results in a token-creation and not a permanent connection, but this should not bother you in any way):
+
+```
+session := sdk.MustNewSession() // Panics if this fails (should usually not happen)
+session.Initiate("reva.host.com:443", false)
+session.BasicLogin("my-login", "my-pass")
+```
+
+Note that error checking is omitted here for brevity, but nearly all methods in the SDK return an error which should be checked upon.
+
+If the session has been created successfully - which can also be verified by calling `session.IsValid()` -, you can use one of the various actions to perform the actual operations.
+
+### 2. Performing operations
+An overview of all currently supported operations can be found below; here is an example of how to upload a file using the `UploadAction`:
+
+```
+act := action.MustNewUploadAction(session)
+info, err := act.UploadBytes([]byte("HELLO WORLD!\n"), "/home/mytest/hello.txt")
+// Check error...
+fmt.Printf("Uploaded file: %s [%db] -- %s", info.Path, info.Size, info.Type)
+```
+
+As you can see, you first need to create an instance of the desired action by either calling its corresponding `New...Action` or `MustNew...Action` function; these creators always require you to pass the previously created session object. The actual operations are then performed by using the appropriate methods offered by the action object. 
+
+A more extensive example of how to use the SDK can also be found in `/examples/sdk/sdk.go`.
+
+## Supported operations
+An action object often bundles various operations; the `FileOperationsAction`, for example, allows you to create directories, check if a file exists or remove an entire path. Below is an alphabetically sorted table of the available actions and their supported operations:
+
+| Action | Operation | Description |
+| --- | --- | --- |
+| `DownloadAction` | `Download` | Downloads a specific resource identified by a `ResourceInfo` object |
+|  | `DownloadFile` | Downloads a specific file |
+| `EnumFilesAction`<sup>1</sup> | `ListAll` | Lists all files and directories in a given path |
+| | `ListAllWithFilter` | Lists all files and directories in a given path that fulfill a given predicate |
+| | `ListDirs` | Lists all directories in a given path |
+| | `ListFiles` | Lists all files in a given path |
+| `FileOperationsAction` | `DirExists` | Checks whether the specified directory exists |
+| | `FileExists` | Checks whether the specified file exists |
+| | `MakePath` | Creates the entire directory tree specified by a path |
+| | `Move` | Moves a specified resource to a new target |
+| | `MoveTo` | Moves a specified resource to a new directory, creating it if necessary |
+| | `Remove` | Deletes the specified resource |
+| | `ResourceExists` | Checks whether the specified resource exists |
+| | `Stat` | Queries information of a resource |
+| `UploadAction`<sup>2</sup> | `Upload` | Uploads data from a reader to a target file |
+| | `UploadBytes` | Uploads byte data to a target file |
+| | `UploadFile` | Uploads a file to a target file |
+| | `UploadFileTo` | Uploads a file to a target directory |  
+
+* <sup>1</sup> All enumeration operations support recursion.
+* <sup>2</sup> The `UploadAction` creates the target directory automatically if necessary.
+
+_Note that not all features of the CS3API are currently implemented._ 

examples/sdk/sdk.go

@@ -0,0 +1,139 @@
+// Copyright 2018-2020 CERN
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// In applying this license, CERN does not waive the privileges and immunities
+// granted to it by virtue of its status as an Intergovernmental Organization
+// or submit itself to any jurisdiction.
+
+package main
+
+import (
+	"fmt"
+	"log"
+
+	"github.com/cs3org/reva/pkg/sdk"
+	"github.com/cs3org/reva/pkg/sdk/action"
+)
+
+func runActions(session *sdk.Session) {
+	// Try creating a directory
+	{
+		act := action.MustNewFileOperationsAction(session)
+		if err := act.MakePath("/home/subdir/subsub"); err == nil {
+			log.Println("Created path /home/subdir/subsub")
+		} else {
+			log.Println("Could not create path /home/subdir/subsub")
+		}
+		fmt.Println()
+	}
+
+	// Try deleting a directory
+	{
+		act := action.MustNewFileOperationsAction(session)
+		if err := act.Remove("/home/subdir/subsub"); err == nil {
+			log.Println("Removed path /home/subdir/subsub")
+		} else {
+			log.Println("Could not remove path /home/subdir/subsub")
+		}
+		fmt.Println()
+	}
+
+	// Try uploading
+	{
+		act := action.MustNewUploadAction(session)
+		act.EnableTUS = true
+		if info, err := act.UploadBytes([]byte("HELLO WORLD!\n"), "/home/subdir/tests.txt"); err == nil {
+			log.Printf("Uploaded file: %s [%db] -- %s", info.Path, info.Size, info.Type)
+		} else {
+			log.Printf("Can't upload file: %v", err)
+		}
+		fmt.Println()
+	}
+
+	// Try moving
+	{
+		act := action.MustNewFileOperationsAction(session)
+		if err := act.MoveTo("/home/subdir/tests.txt", "/home/sub2"); err == nil {
+			log.Println("Moved tests.txt around")
+		} else {
+			log.Println("Could not move tests.txt around")
+		}
+		fmt.Println()
+	}
+
+	// Try listing and downloading
+	{
+		act := action.MustNewEnumFilesAction(session)
+		if files, err := act.ListFiles("/home", true); err == nil {
+			for _, info := range files {
+				log.Printf("%s [%db] -- %s", info.Path, info.Size, info.Type)
+
+				// Download the file
+				actDl := action.MustNewDownloadAction(session)
+				if data, err := actDl.Download(info); err == nil {
+					log.Printf("Downloaded %d bytes for '%v'", len(data), info.Path)
+				} else {
+					log.Printf("Unable to download data for '%v': %v", info.Path, err)
+				}
+
+				log.Println("---")
+			}
+		} else {
+			log.Printf("Can't list files: %v", err)
+		}
+		fmt.Println()
+	}
+
+	// Try accessing some files and directories
+	{
+		act := action.MustNewFileOperationsAction(session)
+		if act.FileExists("/home/blargh.txt") {
+			log.Println("File '/home/blargh.txt' found")
+		} else {
+			log.Println("File '/home/blargh.txt' NOT found")
+		}
+
+		if act.DirExists("/home") {
+			log.Println("Directory '/home' found")
+		} else {
+			log.Println("Directory '/home' NOT found")
+		}
+		fmt.Println()
+	}
+}
+
+func main() {
+	session := sdk.MustNewSession()
+	if err := session.Initiate("sciencemesh-test.uni-muenster.de:9600", false); err != nil {
+		log.Fatalf("Can't initiate Reva session: %v", err)
+	}
+
+	if methods, err := session.GetLoginMethods(); err == nil {
+		fmt.Println("Supported login methods:")
+		for _, m := range methods {
+			fmt.Printf("* %v\n", m)
+		}
+		fmt.Println()
+	} else {
+		log.Fatalf("Can't list login methods: %v", err)
+	}
+
+	if err := session.BasicLogin("daniel", "danielpass"); err == nil {
+		log.Printf("Successfully logged into Reva (token=%v)", session.Token())
+		fmt.Println()
+		runActions(session)
+	} else {
+		log.Fatalf("Can't log in to Reva: %v", err)
+	}
+}

go.sum

@@ -88,8 +88,6 @@ github.com/cpuguy83/go-md2man/v2 v2.0.0/go.mod h1:maD7wRr/U5Z6m/iR4s+kqSMx2CaBsr
 github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/cs3org/cato v0.0.0-20200828125504-e418fc54dd5e h1:tqSPWQeueWTKnJVMJffz4pz0o1WuQxJ28+5x5JgaHD8=
 github.com/cs3org/cato v0.0.0-20200828125504-e418fc54dd5e/go.mod h1:XJEZ3/EQuI3BXTp/6DUzFr850vlxq11I6satRtz0YQ4=
-github.com/cs3org/go-cs3apis v0.0.0-20200929101248-821df597ec8d h1:YDnGz3eTIYQDXzJd/zefEsl0qbz/P63e8KWjSjYlb5Q=
-github.com/cs3org/go-cs3apis v0.0.0-20200929101248-821df597ec8d/go.mod h1:UXha4TguuB52H14EMoSsCqDj7k8a/t7g4gVP+bgY5LY=
 github.com/cs3org/go-cs3apis v0.0.0-20201007120910-416ed6cf8b00 h1:LVl25JaflluOchVvaHWtoCynm5OaM+VNai0IYkcCSe0=
 github.com/cs3org/go-cs3apis v0.0.0-20201007120910-416ed6cf8b00/go.mod h1:UXha4TguuB52H14EMoSsCqDj7k8a/t7g4gVP+bgY5LY=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=

pkg/sdk/action/action.go

@@ -0,0 +1,38 @@
+// Copyright 2018-2020 CERN
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// In applying this license, CERN does not waive the privileges and immunities
+// granted to it by virtue of its status as an Intergovernmental Organization
+// or submit itself to any jurisdiction.
+
+package action
+
+import (
+	"fmt"
+
+	"github.com/cs3org/reva/pkg/sdk"
+)
+
+type action struct {
+	session *sdk.Session
+}
+
+func (act *action) initAction(session *sdk.Session) error {
+	if !session.IsValid() {
+		return fmt.Errorf("no valid session provided")
+	}
+	act.session = session
+
+	return nil
+}

pkg/sdk/action/action_test.go

@@ -0,0 +1,114 @@
+// Copyright 2018-2020 CERN
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// In applying this license, CERN does not waive the privileges and immunities
+// granted to it by virtue of its status as an Intergovernmental Organization
+// or submit itself to any jurisdiction.
+
+package action_test
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/cs3org/reva/pkg/sdk/action"
+	testintl "github.com/cs3org/reva/pkg/sdk/common/testing"
+)
+
+func TestActions(t *testing.T) {
+	tests := []struct {
+		host     string
+		username string
+		password string
+	}{
+		{"sciencemesh-test.uni-muenster.de:9600", "test", "testpass"},
+	}
+
+	for _, test := range tests {
+		t.Run(test.host, func(t *testing.T) {
+			// Prepare the session
+			if session, err := testintl.CreateTestSession(test.host, test.username, test.password); err == nil {
+				// Try creating a directory
+				if act, err := action.NewFileOperationsAction(session); err == nil {
+					if err := act.MakePath("/home/subdir/subsub"); err != nil {
+						t.Errorf(testintl.FormatTestError("FileOperationsAction.MakePath", err, "/home/subdir/subsub"))
+					}
+				} else {
+					t.Errorf(testintl.FormatTestError("NewFileOperationsAction", err, session))
+				}
+
+				// Try uploading
+				if act, err := action.NewUploadAction(session); err == nil {
+					act.EnableTUS = true
+					if _, err := act.UploadBytes([]byte("HELLO WORLD!\n"), "/home/subdir/tests.txt"); err != nil {
+						t.Errorf(testintl.FormatTestError("UploadAction.UploadBytes", err, []byte("HELLO WORLD!\n"), "/home/subdir/tests.txt"))
+					}
+				} else {
+					t.Errorf(testintl.FormatTestError("NewUploadAction", err, session))
+				}
+
+				// Try moving
+				if act, err := action.NewFileOperationsAction(session); err == nil {
+					if err := act.MoveTo("/home/subdir/tests.txt", "/home/subdir/subtest"); err != nil {
+						t.Errorf(testintl.FormatTestError("FileOperationsAction.MoveTo", err, "/home/subdir/tests.txt", "/home/subdir/subtest"))
+					}
+				} else {
+					t.Errorf(testintl.FormatTestError("NewFileOperationsAction", err, session))
+				}
+
+				// Try downloading
+				if act, err := action.NewDownloadAction(session); err == nil {
+					if _, err := act.DownloadFile("/home/subdir/subtest/tests.txt"); err != nil {
+						t.Errorf(testintl.FormatTestError("DownloadAction.DownloadFile", err, "/home/subdir/subtest/tests.txt"))
+					}
+				} else {
+					t.Errorf(testintl.FormatTestError("NewDownloadAction", err, session))
+				}
+
+				// Try listing
+				if act, err := action.NewEnumFilesAction(session); err == nil {
+					if _, err := act.ListFiles("/home", true); err != nil {
+						t.Errorf(testintl.FormatTestError("EnumFilesAction.ListFiles", err, "/home", true))
+					}
+				} else {
+					t.Errorf(testintl.FormatTestError("NewEnumFilesAction", err, session))
+				}
+
+				// Try deleting a directory
+				if act, err := action.NewFileOperationsAction(session); err == nil {
+					if err := act.Remove("/home/subdir"); err != nil {
+						t.Errorf(testintl.FormatTestError("FileOperationsAction.Remove", err, "/home/subdir"))
+					}
+				} else {
+					t.Errorf(testintl.FormatTestError("NewFileOperationsAction", err, session))
+				}
+
+				// Try accessing some files and directories
+				if act, err := action.NewFileOperationsAction(session); err == nil {
+					if act.FileExists("/home/blargh.txt") {
+						t.Errorf(testintl.FormatTestError("FileOperationsAction.FileExists", fmt.Errorf("non-existing file reported as existing"), "/home/blargh.txt"))
+					}
+
+					if !act.DirExists("/home") {
+						t.Errorf(testintl.FormatTestError("FileOperationsAction.DirExists", fmt.Errorf("/home dir reported as non-existing"), "/home"))
+					}
+				} else {
+					t.Errorf(testintl.FormatTestError("NewFileOperationsAction", err, session))
+				}
+			} else {
+				t.Errorf(testintl.FormatTestError("CreateTestSession", err))
+			}
+		})
+	}
+}