wip

Signed-off-by: Lucas Bremgartner <[email protected]>

cmd/incusd/instance_console.go

@@ -546,6 +546,12 @@ func instanceConsolePost(d *Daemon, r *http.Request) response.Response {
 //	    description: Project name
 //	    type: string
 //	    example: default
+//	  - in: query
+//	    name: type
+//	    description: Console type
+//	    type: string
+//	    enum: [log, vga]
+//	    example: vga
 //	responses:
 //	  "200":
 //	     description: Raw console log
@@ -554,6 +560,10 @@ func instanceConsolePost(d *Daemon, r *http.Request) response.Response {
 //	         schema:
 //	           type: string
 //	           example: some-text
+//	       image/png:
+//	         schema:
+//	           type: string
+//	           format: binary
 //	  "400":
 //	    $ref: "#/responses/BadRequest"
 //	  "403":
@@ -576,6 +586,11 @@ func instanceConsoleLogGet(d *Daemon, r *http.Request) response.Response {
 		return response.SmartError(err)
 	}
 
+	consoleLogType := request.QueryParam(r, "type")
+	if consoleLogType != "" && consoleLogType != "log" && consoleLogType != "vga" {
+		return response.SmartError(fmt.Errorf("Invalid value for type parameter: %s", consoleLogType))
+	}
+
 	if internalInstance.IsSnapshot(name) {
 		return response.BadRequest(fmt.Errorf("Invalid instance name"))
 	}
@@ -649,14 +664,25 @@ func instanceConsoleLogGet(d *Daemon, r *http.Request) response.Response {
 			return response.SmartError(fmt.Errorf("Failed to cast inst to VM"))
 		}
 
-		logContents, err := v.ConsoleLog()
-		if err != nil {
-			return response.SmartError(err)
+		if consoleLogType == "vga" {
+			screenshot, err := v.ConsoleScreenshot()
+			if err != nil {
+				return response.SmartError(err)
+			}
+
+			ent.File = bytes.NewReader(screenshot)
+			ent.FileSize = int64(len(screenshot))
+		} else {
+			logContents, err := v.ConsoleLog()
+			if err != nil {
+				return response.SmartError(err)
+			}
+
+			ent.File = bytes.NewReader([]byte(logContents))
+			ent.FileSize = int64(len(logContents))
 		}
 
-		ent.File = bytes.NewReader([]byte(logContents))
 		ent.FileModified = time.Now()
-		ent.FileSize = int64(len(logContents))
 
 		return response.FileResponse(r, []response.FileResponseEntry{ent}, nil)
 	}

doc/api-extensions.md

@@ -2660,3 +2660,7 @@ The following configuration options have been added:
 ## `storage_live_migration`
 
 This adds support for virtual-machines live-migration between storage pools.
+
+## `instance_console_screenshot`
+
+This adds support to take screenshots of the current VGA console of a VM.

internal/server/instance/drivers/driver_qemu.go

@@ -9371,7 +9371,7 @@ func (d *qemu) ConsoleLog() (string, error) {
 
 	// If we got data back, append it to the log file for this instance.
 	if logString != "" {
-		logFile, err := os.OpenFile(d.common.ConsoleBufferLogPath(), os.O_APPEND|os.O_WRONLY|os.O_CREATE, 0600)
+		logFile, err := os.OpenFile(d.common.ConsoleBufferLogPath(), os.O_APPEND|os.O_WRONLY|os.O_CREATE, 0o600)
 		if err != nil {
 			return "", err
 		}
@@ -9445,3 +9445,43 @@ func (d *qemu) consoleSwapSocketWithRB() error {
 
 	return monitor.ChardevChange("console", qmp.ChardevChangeInfo{Type: "ringbuf"})
 }
+
+// ConsoleScreenshot returns a screenshot of the current VGA console in PNG format.
+func (d *qemu) ConsoleScreenshot() ([]byte, error) {
+	if !d.IsRunning() {
+		return nil, fmt.Errorf("Instance is not running")
+	}
+
+	// Check if the agent is running.
+	monitor, err := qmp.Connect(d.monitorPath(), qemuSerialChardevName, d.getMonitorEventHandler(), d.QMPLogFilePath())
+	if err != nil {
+		return nil, err
+	}
+
+	// Create a target screenshot file.
+	screenshotPath := filepath.Join(d.Path(), "screenshot.png")
+	f, err := os.Create(screenshotPath)
+	if err != nil {
+		return nil, fmt.Errorf("Couldn't create screenshot path")
+	}
+
+	defer f.Close()
+
+	err = f.Chown(int(d.state.OS.UnprivUID), -1)
+	if err != nil {
+		return nil, fmt.Errorf("Failed to chown screenshot path: %w", err)
+	}
+
+	// Take the screenshot.
+	err = monitor.Screendump(filepath.Join(d.Path(), "screenshot.png"))
+	if err != nil {
+		return nil, fmt.Errorf("Failed taking screenshot: %w", err)
+	}
+
+	screenshot, err := os.ReadFile(filepath.Join(d.Path(), "screenshot.png"))
+	if err != nil {
+		return nil, fmt.Errorf("Failed to read screenshot: %w", err)
+	}
+
+	return screenshot, nil
+}

internal/server/instance/drivers/qmp/commands.go

@@ -1274,3 +1274,26 @@ func (m *Monitor) ChardevChange(device string, info ChardevChangeInfo) error {
 
 	return fmt.Errorf("Unsupported chardev type %q", info.Type)
 }
+
+// Screendump takes a screenshot of the current VGA console.
+// The screendump is stored to the filename provided as argument.
+//
+// In order to have access to the screendump from the outside of the VM
+// one needs to first send a file and then pass /proc/self/fd/NUMBER
+// as the filename to this function.
+func (m *Monitor) Screendump(filename string) error {
+	var args struct {
+		Filename string `json:"filename"`
+		Device   string `json:"device,omitempty"`
+		Head     int    `json:"head,omitempty"`
+		Format   string `json:"format,omitempty"`
+	}
+	args.Filename = filename
+	args.Format = "png"
+
+	var queryResp struct {
+		Return struct{} `json:"return"`
+	}
+
+	return m.Run("screendump", args, &queryResp)
+}

internal/server/instance/instance_interface.go

@@ -191,6 +191,7 @@ type VM interface {
 
 	AgentCertificate() *x509.Certificate
 	ConsoleLog() (string, error)
+	ConsoleScreenshot() ([]byte, error)
 }
 
 // CriuMigrationArgs arguments for CRIU migration.

internal/server/response/response.go

@@ -452,7 +452,11 @@ func (r *fileResponse) Render(w http.ResponseWriter) error {
 			rs = f
 		}
 
-		w.Header().Set("Content-Type", "application/octet-stream")
+		// Only set Content-Type header if not yet set.
+		if w.Header().Get("Content-Type") == "" {
+			w.Header().Set("Content-Type", "application/octet-stream")
+		}
+
 		w.Header().Set("Content-Length", fmt.Sprintf("%d", sz))
 		w.Header().Set("Content-Disposition", fmt.Sprintf("inline;filename=%s", r.files[0].Filename))
 

internal/version/api.go

@@ -452,6 +452,7 @@ var APIExtensions = []string{
 	"custom_volume_refresh_exclude_older_snapshots",
 	"storage_initial_owner",
 	"storage_live_migration",
+	"instance_console_screenshot",
 }
 
 // APIExtensionsCount returns the number of available API extensions.