Add global TUS capability + some config

Added global TUS capability in the config structure.
Added config switches for the advertised max chunk size and http method
override.

changelog/unreleased/add-tus-global-capabilities.md

@@ -0,0 +1,9 @@
+Enhancement: Add TUS global capability
+
+The TUS global capabilities from Reva are now exposed.
+
+The advertised max chunk size can be configured using the "--upload-max-chunk-size" CLI switch or "REVA_FRONTEND_UPLOAD_MAX_CHUNK_SIZE" environment variable.
+The advertised http method override can be configured using the "--upload-http-method-override" CLI switch or "REVA_FRONTEND_UPLOAD_HTTP_METHOD_OVERRIDE" environment variable.
+
+https://github.com/owncloud/ocis-reva/issues/177
+https://github.com/owncloud/ocis-reva/pull/228

pkg/command/frontend.go

@@ -143,6 +143,13 @@ func Frontend(cfg *config.Config) *cli.Command {
 											"blacklisted_files": []string{},
 											"undelete":          true,
 											"versioning":        true,
+											"tus_support": map[string]interface{}{
+												"version":              "1.0.0",
+												"resumable":            "1.0.0",
+												"extension":            "creation,creation-with-upload",
+												"http_method_override": cfg.Reva.UploadHttpMethodOverride,
+												"max_chunk_size":       int(cfg.Reva.UploadMaxChunkSize),
+											},
 										},
 										"dav": map[string]interface{}{},
 										"files_sharing": map[string]interface{}{

pkg/config/config.go

@@ -253,6 +253,9 @@ type Reva struct {
 	// Configs can be used to configure the reva instance.
 	// Services and Ports will be ignored if this is used
 	Configs map[string]interface{}
+	// chunking and resumable upload config (TUS)
+	UploadMaxChunkSize       int
+	UploadHttpMethodOverride string
 }
 
 // Tracing defines the available tracing configuration.

pkg/flagset/frontend.go

@@ -157,5 +157,21 @@ func FrontendWithConfig(cfg *config.Config) []cli.Flag {
 			EnvVars:     []string{"REVA_GATEWAY_URL"},
 			Destination: &cfg.Reva.Gateway.URL,
 		},
+
+		// Chunking
+		&cli.IntFlag{
+			Name:        "upload-max-chunk-size",
+			Value:       0,
+			Usage:       "Max chunk size in bytes to advertise to clients through capabilities",
+			EnvVars:     []string{"REVA_FRONTEND_UPLOAD_MAX_CHUNK_SIZE"},
+			Destination: &cfg.Reva.UploadMaxChunkSize,
+		},
+		&cli.StringFlag{
+			Name:        "upload-http-method-override",
+			Value:       "",
+			Usage:       "Specify an HTTP method (ex: POST) to use when uploading in case OPTIONS and PATCH are not available",
+			EnvVars:     []string{"REVA_FRONTEND_UPLOAD_HTTP_METHOD_OVERRIDE"},
+			Destination: &cfg.Reva.UploadHttpMethodOverride,
+		},
 	}
 }