feat(proxmox): add tail endpoint and enhance journalctl with multi-service support

Add new `/proxmox/tail` API endpoint for streaming file contents from Proxmox
nodes and LXC containers via WebSocket. Extend journalctl endpoint to support
filtering by multiple services simultaneously.

Changes:
- Add `GET /proxmox/tail` endpoint supporting node-level and LXC container file tailing
- Change `service` parameter from string to array in journalctl endpoints
- Add input validation (`checkValidInput`) to prevent command injection
- Refactor command formatting with proper shell quoting

Security: All command inputs are validated for dangerous characters before

internal/api/handler.go

@@ -146,6 +146,7 @@ func NewHandler(requireAuth bool) *gin.Engine {
 
 		proxmox := v1.Group("/proxmox")
 		{
+			proxmox.GET("/tail", proxmoxApi.Tail)
 			proxmox.GET("/journalctl", proxmoxApi.Journalctl)
 			proxmox.GET("/journalctl/:node", proxmoxApi.Journalctl)
 			proxmox.GET("/journalctl/:node/:vmid", proxmoxApi.Journalctl)

internal/api/v1/docs/swagger.json

@@ -2109,8 +2109,12 @@
             "required": true
           },
           {
-            "type": "string",
+            "type": "array",
-            "description": "Service name (e.g., 'pveproxy' for node, 'container@.service' format for LXC)",
+            "items": {
+              "type": "string"
+            },
+            "collectionFormat": "csv",
+            "description": "Service names",
             "name": "service",
             "in": "query"
           },
@@ -2189,8 +2193,12 @@
             "required": true
           },
           {
-            "type": "string",
+            "type": "array",
-            "description": "Service name (e.g., 'pveproxy' for node, 'container@.service' format for LXC)",
+            "items": {
+              "type": "string"
+            },
+            "collectionFormat": "csv",
+            "description": "Service names",
             "name": "service",
             "in": "query"
           },
@@ -2276,8 +2284,12 @@
             "required": true
           },
           {
-            "type": "string",
+            "type": "array",
-            "description": "Service name (e.g., 'pveproxy' for node, 'container@.service' format for LXC)",
+            "items": {
+              "type": "string"
+            },
+            "collectionFormat": "csv",
+            "description": "Service names",
             "name": "service",
             "in": "query"
           },
@@ -2369,8 +2381,12 @@
             "required": true
           },
           {
-            "type": "string",
+            "type": "array",
-            "description": "Service name (e.g., 'pveproxy' for node, 'container@.service' format for LXC)",
+            "items": {
+              "type": "string"
+            },
+            "collectionFormat": "csv",
+            "description": "Service names",
             "name": "service",
             "in": "query"
           },
@@ -2388,8 +2404,12 @@
             "required": true
           },
           {
-            "type": "string",
+            "type": "array",
-            "description": "Service name (e.g., 'pveproxy' for node, 'container@.service' format for LXC)",
+            "items": {
+              "type": "string"
+            },
+            "collectionFormat": "csv",
+            "description": "Service names",
             "name": "service",
             "in": "path"
           },
@@ -2715,6 +2735,91 @@
         "operationId": "vmStats"
       }
     },
+    "/proxmox/tail": {
+      "get": {
+        "description": "Get tail output for node or LXC container. If vmid is not provided, streams node tail.",
+        "consumes": [
+          "application/json"
+        ],
+        "produces": [
+          "application/json"
+        ],
+        "tags": [
+          "proxmox",
+          "websocket"
+        ],
+        "summary": "Get tail output",
+        "parameters": [
+          {
+            "type": "array",
+            "items": {
+              "type": "string"
+            },
+            "collectionFormat": "csv",
+            "description": "File paths",
+            "name": "file",
+            "in": "query",
+            "required": true
+          },
+          {
+            "maximum": 1000,
+            "minimum": 1,
+            "type": "integer",
+            "default": 100,
+            "description": "Limit output lines (1-1000)",
+            "name": "limit",
+            "in": "query"
+          },
+          {
+            "type": "string",
+            "description": "Node name",
+            "name": "node",
+            "in": "query",
+            "required": true
+          },
+          {
+            "type": "integer",
+            "description": "Container VMID (optional - if not provided, streams node journalctl)",
+            "name": "vmid",
+            "in": "query"
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Tail output",
+            "schema": {
+              "type": "string"
+            }
+          },
+          "400": {
+            "description": "Invalid request",
+            "schema": {
+              "$ref": "#/definitions/ErrorResponse"
+            }
+          },
+          "403": {
+            "description": "Unauthorized",
+            "schema": {
+              "$ref": "#/definitions/ErrorResponse"
+            }
+          },
+          "404": {
+            "description": "Node not found",
+            "schema": {
+              "$ref": "#/definitions/ErrorResponse"
+            }
+          },
+          "500": {
+            "description": "Internal server error",
+            "schema": {
+              "$ref": "#/definitions/ErrorResponse"
+            }
+          }
+        },
+        "x-id": "tail",
+        "operationId": "tail"
+      }
+    },
     "/reload": {
       "post": {
         "description": "Reload config",
@@ -4972,26 +5077,38 @@
     },
     "ProxmoxNodeConfig": {
       "type": "object",
-      "required": [
-        "node",
-        "vmid"
-      ],
       "properties": {
+        "files": {
+          "type": "array",
+          "items": {
+            "type": "string"
+          },
+          "x-nullable": false,
+          "x-omitempty": false
+        },
         "node": {
           "type": "string",
           "x-nullable": false,
           "x-omitempty": false
         },
-        "service": {
+        "services": {
-          "type": "string"
+          "type": "array",
+          "items": {
+            "type": "string"
+          },
+          "x-nullable": false,
+          "x-omitempty": false
         },
         "vmid": {
+          "description": "unset: auto discover; explicit 0: node-level route; >0: lxc/qemu resource route",
           "type": "integer",
           "x-nullable": false,
           "x-omitempty": false
         },
         "vmname": {
-          "type": "string"
+          "type": "string",
+          "x-nullable": false,
+          "x-omitempty": false
         }
       },
       "x-nullable": false,

internal/api/v1/docs/swagger.yaml

@@ -945,17 +945,22 @@ definitions:
     - ProviderTypeAgent
   ProxmoxNodeConfig:
     properties:
+      files:
+        items:
+          type: string
+        type: array
       node:
         type: string
-      service:
+      services:
-        type: string
+        items:
+          type: string
+        type: array
       vmid:
+        description: 'unset: auto discover; explicit 0: node-level route; >0: lxc/qemu
+          resource route'
         type: integer
       vmname:
         type: string
-    required:
-    - node
-    - vmid
     type: object
   ProxyStats:
     properties:
@@ -3421,11 +3426,13 @@ paths:
         name: node
         required: true
         type: string
-      - description: Service name (e.g., 'pveproxy' for node, 'container@.service'
+      - collectionFormat: csv
-          format for LXC)
+        description: Service names
         in: query
+        items:
+          type: string
         name: service
-        type: string
+        type: array
       - description: Container VMID (optional - if not provided, streams node journalctl)
         in: query
         name: vmid
@@ -3477,11 +3484,13 @@ paths:
         name: node
         required: true
         type: string
-      - description: Service name (e.g., 'pveproxy' for node, 'container@.service'
+      - collectionFormat: csv
-          format for LXC)
+        description: Service names
         in: query
+        items:
+          type: string
         name: service
-        type: string
+        type: array
       - description: Container VMID (optional - if not provided, streams node journalctl)
         in: query
         name: vmid
@@ -3538,11 +3547,13 @@ paths:
         name: node
         required: true
         type: string
-      - description: Service name (e.g., 'pveproxy' for node, 'container@.service'
+      - collectionFormat: csv
-          format for LXC)
+        description: Service names
         in: query
+        items:
+          type: string
         name: service
-        type: string
+        type: array
       - description: Container VMID (optional - if not provided, streams node journalctl)
         in: query
         name: vmid
@@ -3603,11 +3614,13 @@ paths:
         name: node
         required: true
         type: string
-      - description: Service name (e.g., 'pveproxy' for node, 'container@.service'
+      - collectionFormat: csv
-          format for LXC)
+        description: Service names
         in: query
+        items:
+          type: string
         name: service
-        type: string
+        type: array
       - description: Container VMID (optional - if not provided, streams node journalctl)
         in: query
         name: vmid
@@ -3617,11 +3630,13 @@ paths:
         name: node
         required: true
         type: string
-      - description: Service name (e.g., 'pveproxy' for node, 'container@.service'
+      - collectionFormat: csv
-          format for LXC)
+        description: Service names
         in: path
+        items:
+          type: string
         name: service
-        type: string
+        type: array
       - description: Container VMID (optional - if not provided, streams node journalctl)
         in: path
         name: vmid
@@ -3837,6 +3852,65 @@ paths:
       - proxmox
       - websocket
       x-id: vmStats
+  /proxmox/tail:
+    get:
+      consumes:
+      - application/json
+      description: Get tail output for node or LXC container. If vmid is not provided,
+        streams node tail.
+      parameters:
+      - collectionFormat: csv
+        description: File paths
+        in: query
+        items:
+          type: string
+        name: file
+        required: true
+        type: array
+      - default: 100
+        description: Limit output lines (1-1000)
+        in: query
+        maximum: 1000
+        minimum: 1
+        name: limit
+        type: integer
+      - description: Node name
+        in: query
+        name: node
+        required: true
+        type: string
+      - description: Container VMID (optional - if not provided, streams node journalctl)
+        in: query
+        name: vmid
+        type: integer
+      produces:
+      - application/json
+      responses:
+        "200":
+          description: Tail output
+          schema:
+            type: string
+        "400":
+          description: Invalid request
+          schema:
+            $ref: '#/definitions/ErrorResponse'
+        "403":
+          description: Unauthorized
+          schema:
+            $ref: '#/definitions/ErrorResponse'
+        "404":
+          description: Node not found
+          schema:
+            $ref: '#/definitions/ErrorResponse'
+        "500":
+          description: Internal server error
+          schema:
+            $ref: '#/definitions/ErrorResponse'
+      summary: Get tail output
+      tags:
+      - proxmox
+      - websocket
+      x-id: tail
   /reload:
     post:
       consumes:

internal/api/v1/proxmox/journalctl.go

@@ -11,11 +11,14 @@ import (
 	"github.com/yusing/goutils/http/websocket"
 )
 
+// e.g. ws://localhost:8889/api/v1/proxmox/journalctl?node=pve&vmid=127&service=pveproxy&service=pvedaemon&limit=10
+// e.g. ws://localhost:8889/api/v1/proxmox/journalctl/pve/127?service=pveproxy&service=pvedaemon&limit=10
+
 type JournalctlRequest struct {
-	Node    string `form:"node" uri:"node" binding:"required"`                       // Node name
+	Node     string   `form:"node" uri:"node" binding:"required"`                       // Node name
-	VMID    *int   `form:"vmid" uri:"vmid"`                                          // Container VMID (optional - if not provided, streams node journalctl)
+	VMID     *int     `form:"vmid" uri:"vmid"`                                          // Container VMID (optional - if not provided, streams node journalctl)
-	Service string `form:"service" uri:"service"`                                    // Service name (e.g., 'pveproxy' for node, 'container@.service' format for LXC)
+	Services []string `form:"service" uri:"service"`                                    // Service names
-	Limit   *int   `form:"limit" uri:"limit" default:"100" binding:"min=1,max=1000"` // Limit output lines (1-1000)
+	Limit    *int     `form:"limit" uri:"limit" default:"100" binding:"min=1,max=1000"` // Limit output lines (1-1000)
 } //	@name	ProxmoxJournalctlRequest
 
 // @x-id				"journalctl"
@@ -56,9 +59,9 @@ func Journalctl(c *gin.Context) {
 	var reader io.ReadCloser
 	var err error
 	if request.VMID == nil {
-		reader, err = node.NodeJournalctl(c.Request.Context(), request.Service, *request.Limit)
+		reader, err = node.NodeJournalctl(c.Request.Context(), request.Services, *request.Limit)
 	} else {
-		reader, err = node.LXCJournalctl(c.Request.Context(), *request.VMID, request.Service, *request.Limit)
+		reader, err = node.LXCJournalctl(c.Request.Context(), *request.VMID, request.Services, *request.Limit)
 	}
 	if err != nil {
 		c.Error(apitypes.InternalServerError(err, "failed to get journalctl output"))

internal/api/v1/proxmox/tail.go

@@ -0,0 +1,77 @@
+package proxmoxapi
+
+import (
+	"io"
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+	"github.com/yusing/godoxy/internal/proxmox"
+	"github.com/yusing/goutils/apitypes"
+	"github.com/yusing/goutils/http/websocket"
+)
+
+// e.g. ws://localhost:8889/api/v1/proxmox/tail?node=pve&vmid=127&file=/var/log/immich/web.log&file=/var/log/immich/ml.log&limit=10
+
+type TailRequest struct {
+	Node  string   `form:"node" binding:"required"`                      // Node name
+	VMID  *int     `form:"vmid"`                                         // Container VMID (optional - if not provided, streams node journalctl)
+	Files []string `form:"file" binding:"required,dive,filepath"`        // File paths
+	Limit int      `form:"limit" default:"100" binding:"min=1,max=1000"` // Limit output lines (1-1000)
+} //	@name	ProxmoxTailRequest
+
+// @x-id				"tail"
+// @BasePath		/api/v1
+// @Summary		Get tail output
+// @Description	Get tail output for node or LXC container. If vmid is not provided, streams node tail.
+// @Tags			proxmox,websocket
+// @Accept		json
+// @Produce		application/json
+// @Param			query		query		TailRequest	true	"Request"
+// @Success		200			string	plain	  "Tail output"
+// @Failure		400			{object}	apitypes.ErrorResponse	"Invalid request"
+// @Failure		403			{object}	apitypes.ErrorResponse	"Unauthorized"
+// @Failure		404			{object}	apitypes.ErrorResponse	"Node not found"
+// @Failure		500			{object}	apitypes.ErrorResponse	"Internal server error"
+// @Router		/proxmox/tail [get]
+func Tail(c *gin.Context) {
+	var request TailRequest
+	if err := c.ShouldBindQuery(&request); err != nil {
+		c.JSON(http.StatusBadRequest, apitypes.Error("invalid request", err))
+		return
+	}
+
+	node, ok := proxmox.Nodes.Get(request.Node)
+	if !ok {
+		c.JSON(http.StatusNotFound, apitypes.Error("node not found"))
+		return
+	}
+
+	c.Status(http.StatusContinue)
+
+	var reader io.ReadCloser
+	var err error
+	if request.VMID == nil {
+		reader, err = node.NodeTail(c.Request.Context(), request.Files, request.Limit)
+	} else {
+		reader, err = node.LXCTail(c.Request.Context(), *request.VMID, request.Files, request.Limit)
+	}
+	if err != nil {
+		c.Error(apitypes.InternalServerError(err, "failed to get journalctl output"))
+		return
+	}
+	defer reader.Close()
+
+	manager, err := websocket.NewManagerWithUpgrade(c)
+	if err != nil {
+		c.Error(apitypes.InternalServerError(err, "failed to upgrade to websocket"))
+		return
+	}
+	defer manager.Close()
+
+	writer := manager.NewWriter(websocket.TextMessage)
+	_, err = io.Copy(writer, reader)
+	if err != nil {
+		c.Error(apitypes.InternalServerError(err, "failed to copy journalctl output"))
+		return
+	}
+}

internal/proxmox/command_common.go

@@ -0,0 +1,59 @@
+package proxmox
+
+import (
+	"fmt"
+	"strings"
+)
+
+// checkValidInput checks if the input contains invalid characters.
+//
+// The characters are: & | $ ; ' " ` $( ${ < >
+// These characters are used in the command line to escape the input or to expand variables.
+// We need to check if the input contains these characters and return an error if it does.
+// This is to prevent command injection.
+func checkValidInput(input string) error {
+	if strings.ContainsAny(input, "&|$;'\"`<>") {
+		return fmt.Errorf("input contains invalid characters: %q", input)
+	}
+	if strings.Contains(input, "$(") {
+		return fmt.Errorf("input contains $(: %q", input)
+	}
+	if strings.Contains(input, "${") {
+		return fmt.Errorf("input contains ${: %q", input)
+	}
+	return nil
+}
+
+func formatTail(files []string, limit int) (string, error) {
+	for _, file := range files {
+		if err := checkValidInput(file); err != nil {
+			return "", err
+		}
+	}
+	var command strings.Builder
+	command.WriteString("tail -f -q --retry ")
+	for _, file := range files {
+		fmt.Fprintf(&command, " %q ", file)
+	}
+	if limit > 0 {
+		fmt.Fprintf(&command, " -n %d", limit)
+	}
+	return command.String(), nil
+}
+
+func formatJournalctl(services []string, limit int) (string, error) {
+	for _, service := range services {
+		if err := checkValidInput(service); err != nil {
+			return "", err
+		}
+	}
+	var command strings.Builder
+	command.WriteString("journalctl -f")
+	for _, service := range services {
+		fmt.Fprintf(&command, " -u %q ", service)
+	}
+	if limit > 0 {
+		fmt.Fprintf(&command, " -n %d", limit)
+	}
+	return command.String(), nil
+}

internal/proxmox/lxc_command.go

@@ -39,15 +39,23 @@ func (n *Node) LXCCommand(ctx context.Context, vmid int, command string) (io.Rea
 
 // LXCJournalctl streams journalctl output for the given service.
 //
-// If service is not empty, it will be used to filter the output by service.
+// If services are not empty, it will be used to filter the output by service.
 // If limit is greater than 0, it will be used to limit the number of lines of output.
-func (n *Node) LXCJournalctl(ctx context.Context, vmid int, service string, limit int) (io.ReadCloser, error) {
+func (n *Node) LXCJournalctl(ctx context.Context, vmid int, services []string, limit int) (io.ReadCloser, error) {
-	command := "journalctl -f"
+	command, err := formatJournalctl(services, limit)
-	if service != "" {
+	if err != nil {
-		command = fmt.Sprintf("journalctl -u %q -f", service)
+		return nil, err
-	}
+	}
-	if limit > 0 {
+	return n.LXCCommand(ctx, vmid, command)
-		command = fmt.Sprintf("%s -n %d", command, limit)
+}
+
+// LXCTail streams tail output for the given file.
+//
+// If limit is greater than 0, it will be used to limit the number of lines of output.
+func (n *Node) LXCTail(ctx context.Context, vmid int, files []string, limit int) (io.ReadCloser, error) {
+	command, err := formatTail(files, limit)
+	if err != nil {
+		return nil, err
 	}
 	return n.LXCCommand(ctx, vmid, command)
 }

internal/proxmox/node.go

@@ -14,6 +14,7 @@ type NodeConfig struct {
 	VMID     *int     `json:"vmid"` // unset: auto discover; explicit 0: node-level route; >0: lxc/qemu resource route
 	VMName   string   `json:"vmname,omitempty"`
 	Services []string `json:"services,omitempty" aliases:"service"`
+	Files    []string `json:"files,omitempty" aliases:"file"`
 } // @name ProxmoxNodeConfig
 
 type Node struct {

internal/proxmox/node_command.go

@@ -120,13 +120,25 @@ func (n *Node) NodeCommand(ctx context.Context, command string) (io.ReadCloser,
 	return pr, nil
 }
 
-func (n *Node) NodeJournalctl(ctx context.Context, service string, limit int) (io.ReadCloser, error) {
+// NodeJournalctl streams journalctl output for the given service.
-	command := "journalctl -f"
+//
-	if service != "" {
+// If services are not empty, it will be used to filter the output by services.
-		command = fmt.Sprintf("journalctl -u %q -f", service)
+// If limit is greater than 0, it will be used to limit the number of lines of output.
-	}
+func (n *Node) NodeJournalctl(ctx context.Context, services []string, limit int) (io.ReadCloser, error) {
-	if limit > 0 {
+	command, err := formatJournalctl(services, limit)
-		command = fmt.Sprintf("%s -n %d", command, limit)
+	if err != nil {
+		return nil, err
+	}
+	return n.NodeCommand(ctx, command)
+}
+
+// NodeTail streams tail output for the given file.
+//
+// If limit is greater than 0, it will be used to limit the number of lines of output.
+func (n *Node) NodeTail(ctx context.Context, files []string, limit int) (io.ReadCloser, error) {
+	command, err := formatTail(files, limit)
+	if err != nil {
+		return nil, err
 	}
 	return n.NodeCommand(ctx, command)
 }