Add sanity check when adding a new pathmap project/folder

[src/xds/xds-agent.git] / lib / agent / project-pathmap.go

diff --git a/lib/agent/project-pathmap.go b/lib/agent/project-pathmap.go
index 6c49d6a..aacbd1f 100644 (file)
--- a/lib/agent/project-pathmap.go
+++ b/lib/agent/project-pathmap.go
@@ -1,5 +1,14 @@
 package agent
 
+import (
+       "fmt"
+       "io/ioutil"
+       "os"
+       "strings"
+
+       common "github.com/iotbzh/xds-common/golib"
+)
+
 // IPROJECT interface implementation for native/path mapping projects
 
 // PathMap .
@@ -22,12 +31,55 @@ func NewProjectPathMap(ctx *Context, svr *XdsServer) *PathMap {
 // Add a new project
 func (p *PathMap) Add(cfg ProjectConfig) (*ProjectConfig, error) {
        var err error
+       var file *os.File
+       errMsg := "ClientPath sanity check error (%d): %v"
 
-       // SEB TODO: check local/server directory access
+       // Sanity check to verify that we have RW permission and path-mapping is correct
+       dir := cfg.ClientPath
+       if !common.Exists(dir) {
+               // try to create if not existing
+               if err := os.MkdirAll(dir, 0755); err != nil {
+                       return nil, fmt.Errorf("Cannot create ClientPath directory: %s", dir)
+               }
+       }
+       if !common.Exists(dir) {
+               return nil, fmt.Errorf("ClientPath directory is not accessible: %s", dir)
+       }
+       if file, err = ioutil.TempFile(dir, ".xds_pathmap_check"); err != nil {
+               return nil, fmt.Errorf(errMsg, 1, err)
+       }
+       // Write a specific message that will be check by server during folder add
+       msg := "Pathmap checked message written by xds-agent ID: " + p.Config.AgentUID + "\n"
+       if n, err := file.WriteString(msg); n != len(msg) || err != nil {
+               return nil, fmt.Errorf(errMsg, 2, err)
+       }
+       defer func() {
+               if file != nil {
+                       os.Remove(file.Name())
+                       file.Close()
+               }
+       }()
 
-       err = p.server.FolderAdd(p.server.ProjectToFolder(cfg), p.folder)
+       // Convert to Xds folder
+       fld := p.server.ProjectToFolder(cfg)
+       fld.DataPathMap.CheckFile = file.Name()
+       fld.DataPathMap.CheckContent = msg
+
+       // Send request to create folder on XDS server side
+       err = p.server.FolderAdd(fld, p.folder)
        if err != nil {
-               return nil, err
+               return nil, fmt.Errorf("Folders mapping verification failure.\n%v", err)
+       }
+
+       // 2nd part of sanity checker
+       // check specific message added by XDS Server during folder add processing
+       content, err := ioutil.ReadFile(file.Name())
+       if err != nil {
+               return nil, fmt.Errorf(errMsg, 3, err)
+       }
+       if !strings.Contains(string(content),
+               "Pathmap checked message written by xds-server ID") {
+               return nil, fmt.Errorf(errMsg, 4, "file content differ")
        }
 
        return p.GetProject(), nil