[MM-28422] Enable processing of import files through API (#16062)

* Implement unzip function

* Implement FileSize method

* Implement path rewriting for bulk import

* Small improvements

* Add ImportSettings to config

* Implement ListImports API endpoint

* Enable uploading import files

* Implement import process job

* Add missing license headers

* Address reviews

* Make path sanitization a bit smarter

* Clean path before calculating Dir

* [MM-30008] Add mmctl support for file imports (#16301)

* Add mmctl support for import files

* Improve test

* Remove unnecessary handlers

* Use th.TestForSystemAdminAndLocal

* Make nouser id a constant

api4/upload.go

@@ -37,14 +37,23 @@ func createUpload(c *Context, w http.ResponseWriter, r *http.Request) {
 	defer c.LogAuditRec(auditRec)
 	auditRec.AddMeta("upload", us)
 
-	if !c.App.SessionHasPermissionToChannel(*c.App.Session(), us.ChannelId, model.PERMISSION_UPLOAD_FILE) {
-		c.SetPermissionError(model.PERMISSION_UPLOAD_FILE)
-		return
+	if us.Type == model.UploadTypeImport {
+		if !c.IsSystemAdmin() {
+			c.SetPermissionError(model.PERMISSION_MANAGE_SYSTEM)
+			return
+		}
+	} else {
+		if !c.App.SessionHasPermissionToChannel(*c.App.Session(), us.ChannelId, model.PERMISSION_UPLOAD_FILE) {
+			c.SetPermissionError(model.PERMISSION_UPLOAD_FILE)
+			return
+		}
+		us.Type = model.UploadTypeAttachment
 	}
 
 	us.Id = model.NewId()
-	us.Type = model.UploadTypeAttachment
-	us.UserId = c.App.Session().UserId
+	if c.App.Session().UserId != "" {
+		us.UserId = c.App.Session().UserId
+	}
 	us, err := c.App.CreateUploadSession(us)
 	if err != nil {
 		c.Err = err
@@ -68,7 +77,7 @@ func getUpload(c *Context, w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	if us.UserId != c.App.Session().UserId {
+	if us.UserId != c.App.Session().UserId && !c.IsSystemAdmin() {
 		c.Err = model.NewAppError("getUpload", "api.upload.get_upload.forbidden.app_error", nil, "", http.StatusForbidden)
 		return
 	}
@@ -98,9 +107,16 @@ func uploadData(c *Context, w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	if us.UserId != c.App.Session().UserId || !c.App.SessionHasPermissionToChannel(*c.App.Session(), us.ChannelId, model.PERMISSION_UPLOAD_FILE) {
-		c.SetPermissionError(model.PERMISSION_UPLOAD_FILE)
-		return
+	if us.Type == model.UploadTypeImport {
+		if !c.IsSystemAdmin() {
+			c.SetPermissionError(model.PERMISSION_MANAGE_SYSTEM)
+			return
+		}
+	} else {
+		if us.UserId != c.App.Session().UserId || !c.App.SessionHasPermissionToChannel(*c.App.Session(), us.ChannelId, model.PERMISSION_UPLOAD_FILE) {
+			c.SetPermissionError(model.PERMISSION_UPLOAD_FILE)
+			return
+		}
 	}
 
 	boundary, parseErr := parseMultipartRequestHeader(r)