feat: Chatbot-Workflows mit Ollama-Memory und Session-Management

- docker-compose: extra_hosts für host.docker.internal (Ollama-Zugang)
- ollama-chatbot: Gesprächsverlauf per session_id in PostgreSQL
- ollama-chat-cleanup: stündliche TTL-Bereinigung (2h Inaktivität)
- ollama-chat-delete: DELETE /webhook/chat-session Endpoint

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

compose/docker-compose.yml

@@ -75,6 +75,8 @@ services:
       - ../data/n8n:/home/node/.n8n
       - ../local-files:/files
       - ../imports:/imports
+    extra_hosts:
+      - "host.docker.internal:host-gateway"
     depends_on:
       postgres:
         condition: service_healthy
@@ -108,6 +110,8 @@ services:
     volumes:
       - ../data/n8n:/home/node/.n8n
       - ../local-files:/files
+    extra_hosts:
+      - "host.docker.internal:host-gateway"
     depends_on:
       - n8n
     networks:

imports/workflows/ollama-chat-cleanup.json

@@ -0,0 +1,53 @@
+{
+  "id": "1002",
+  "name": "Chatbot Session Cleanup (TTL 2h)",
+  "nodes": [
+    {
+      "parameters": {
+        "rule": {
+          "interval": [{ "field": "hours", "hoursInterval": 1 }]
+        }
+      },
+      "id": "node-sc-001",
+      "name": "Jede Stunde",
+      "type": "n8n-nodes-base.scheduleTrigger",
+      "typeVersion": 1.2,
+      "position": [100, 300]
+    },
+    {
+      "parameters": {
+        "operation": "executeQuery",
+        "query": "DELETE FROM chat_sessions WHERE updated_at < NOW() - INTERVAL '2 hours' RETURNING session_id",
+        "additionalFields": {}
+      },
+      "id": "node-pg-003",
+      "name": "Delete Expired Sessions",
+      "type": "n8n-nodes-base.postgres",
+      "typeVersion": 2.5,
+      "position": [300, 300],
+      "credentials": {
+        "postgres": {
+          "id": "SETUP_REQUIRED",
+          "name": "n8n PostgreSQL"
+        }
+      }
+    },
+    {
+      "parameters": {
+        "jsCode": "const deleted = $input.all().map(i => i.json.session_id).filter(Boolean);\nconsole.log(`[Cleanup] ${deleted.length} Session(s) gelöscht:`, deleted);\nreturn [{ json: { deleted_count: deleted.length, deleted_sessions: deleted } }];"
+      },
+      "id": "node-cd-004",
+      "name": "Log Result",
+      "type": "n8n-nodes-base.code",
+      "typeVersion": 2,
+      "position": [500, 300]
+    }
+  ],
+  "connections": {
+    "Jede Stunde":             { "main": [[{ "node": "Delete Expired Sessions", "type": "main", "index": 0 }]] },
+    "Delete Expired Sessions": { "main": [[{ "node": "Log Result",              "type": "main", "index": 0 }]] }
+  },
+  "active": false,
+  "settings": { "executionOrder": "v1" },
+  "tags": []
+}

imports/workflows/ollama-chat-delete.json

@@ -0,0 +1,59 @@
+{
+  "id": "1003",
+  "name": "Chatbot Session löschen",
+  "nodes": [
+    {
+      "parameters": {
+        "httpMethod": "DELETE",
+        "path": "chat-session",
+        "responseMode": "responseNode",
+        "options": {}
+      },
+      "id": "node-wh-002",
+      "name": "Webhook",
+      "type": "n8n-nodes-base.webhook",
+      "typeVersion": 2,
+      "position": [100, 300],
+      "webhookId": "ollama-chat-delete"
+    },
+    {
+      "parameters": {
+        "operation": "executeQuery",
+        "query": "DELETE FROM chat_sessions WHERE session_id = $1 RETURNING session_id",
+        "additionalFields": {
+          "queryParams": "={{ JSON.stringify([$json.body.session_id]) }}"
+        }
+      },
+      "id": "node-pg-004",
+      "name": "Delete Session",
+      "type": "n8n-nodes-base.postgres",
+      "typeVersion": 2.5,
+      "position": [300, 300],
+      "credentials": {
+        "postgres": {
+          "id": "SETUP_REQUIRED",
+          "name": "n8n PostgreSQL"
+        }
+      }
+    },
+    {
+      "parameters": {
+        "respondWith": "json",
+        "responseBody": "={{ JSON.stringify({ deleted: $input.first().json.session_id != null, session_id: $('Webhook').first().json.body.session_id }) }}",
+        "options": {}
+      },
+      "id": "node-rw-002",
+      "name": "Respond",
+      "type": "n8n-nodes-base.respondToWebhook",
+      "typeVersion": 1.1,
+      "position": [500, 300]
+    }
+  ],
+  "connections": {
+    "Webhook":        { "main": [[{ "node": "Delete Session", "type": "main", "index": 0 }]] },
+    "Delete Session": { "main": [[{ "node": "Respond",        "type": "main", "index": 0 }]] }
+  },
+  "active": false,
+  "settings": { "executionOrder": "v1" },
+  "tags": []
+}

imports/workflows/ollama-chatbot.json

@@ -0,0 +1,130 @@
+{
+  "id": "1001",
+  "name": "Lokaler KI-Chatbot (Ollama)",
+  "nodes": [
+    {
+      "parameters": {
+        "httpMethod": "POST",
+        "path": "chat",
+        "responseMode": "responseNode",
+        "options": {}
+      },
+      "id": "node-wh-001",
+      "name": "Webhook",
+      "type": "n8n-nodes-base.webhook",
+      "typeVersion": 2,
+      "position": [100, 300],
+      "webhookId": "ollama-chat-webhook"
+    },
+    {
+      "parameters": {
+        "jsCode": "const body = $input.first().json.body;\nif (!body?.message) throw new Error('Kein \"message\"-Feld im Request-Body');\nreturn [{ json: {\n  session_id: body.session_id || Math.random().toString(36).slice(2, 18),\n  message: body.message,\n  model: body.model || 'qwen3:8b'\n}}];"
+      },
+      "id": "node-cd-001",
+      "name": "Prepare",
+      "type": "n8n-nodes-base.code",
+      "typeVersion": 2,
+      "position": [300, 300]
+    },
+    {
+      "parameters": {
+        "operation": "executeQuery",
+        "query": "SELECT messages FROM chat_sessions WHERE session_id = $1",
+        "additionalFields": {
+          "queryParams": "={{ JSON.stringify([$json.session_id]) }}"
+        }
+      },
+      "id": "node-pg-001",
+      "name": "Load History",
+      "type": "n8n-nodes-base.postgres",
+      "typeVersion": 2.5,
+      "position": [500, 300],
+      "credentials": {
+        "postgres": {
+          "id": "SETUP_REQUIRED",
+          "name": "n8n PostgreSQL"
+        }
+      }
+    },
+    {
+      "parameters": {
+        "jsCode": "const prep = $('Prepare').first().json;\nconst row = $input.first()?.json;\nconst history = Array.isArray(row?.messages) ? row.messages : [];\nconst messages = [...history, { role: 'user', content: prep.message }];\nreturn [{ json: { session_id: prep.session_id, model: prep.model, messages } }];"
+      },
+      "id": "node-cd-002",
+      "name": "Build Messages",
+      "type": "n8n-nodes-base.code",
+      "typeVersion": 2,
+      "position": [700, 300]
+    },
+    {
+      "parameters": {
+        "method": "POST",
+        "url": "http://host.docker.internal:11434/api/chat",
+        "sendBody": true,
+        "contentType": "json",
+        "specifyBody": "json",
+        "jsonBody": "={{ JSON.stringify({ model: $json.model, messages: $json.messages, stream: false }) }}",
+        "options": { "timeout": 120000 }
+      },
+      "id": "node-hr-001",
+      "name": "Ollama Chat",
+      "type": "n8n-nodes-base.httpRequest",
+      "typeVersion": 4.2,
+      "position": [900, 300]
+    },
+    {
+      "parameters": {
+        "jsCode": "const build = $('Build Messages').first().json;\nconst resp = $input.first().json;\nconst answer = resp.message.content;\nconst updatedMessages = [...build.messages, { role: 'assistant', content: answer }];\nreturn [{ json: { session_id: build.session_id, messages: updatedMessages, answer, model: resp.model } }];"
+      },
+      "id": "node-cd-003",
+      "name": "Append Response",
+      "type": "n8n-nodes-base.code",
+      "typeVersion": 2,
+      "position": [1100, 300]
+    },
+    {
+      "parameters": {
+        "operation": "executeQuery",
+        "query": "INSERT INTO chat_sessions (session_id, messages, updated_at) VALUES ($1, $2::jsonb, NOW()) ON CONFLICT (session_id) DO UPDATE SET messages = $2::jsonb, updated_at = NOW()",
+        "additionalFields": {
+          "queryParams": "={{ JSON.stringify([$json.session_id, JSON.stringify($json.messages)]) }}"
+        }
+      },
+      "id": "node-pg-002",
+      "name": "Save History",
+      "type": "n8n-nodes-base.postgres",
+      "typeVersion": 2.5,
+      "position": [1300, 300],
+      "credentials": {
+        "postgres": {
+          "id": "SETUP_REQUIRED",
+          "name": "n8n PostgreSQL"
+        }
+      }
+    },
+    {
+      "parameters": {
+        "respondWith": "json",
+        "responseBody": "={{ JSON.stringify({ session_id: $('Append Response').first().json.session_id, answer: $('Append Response').first().json.answer, model: $('Append Response').first().json.model }) }}",
+        "options": {}
+      },
+      "id": "node-rw-001",
+      "name": "Respond",
+      "type": "n8n-nodes-base.respondToWebhook",
+      "typeVersion": 1.1,
+      "position": [1500, 300]
+    }
+  ],
+  "connections": {
+    "Webhook":         { "main": [[{ "node": "Prepare",         "type": "main", "index": 0 }]] },
+    "Prepare":         { "main": [[{ "node": "Load History",    "type": "main", "index": 0 }]] },
+    "Load History":    { "main": [[{ "node": "Build Messages",  "type": "main", "index": 0 }]] },
+    "Build Messages":  { "main": [[{ "node": "Ollama Chat",     "type": "main", "index": 0 }]] },
+    "Ollama Chat":     { "main": [[{ "node": "Append Response", "type": "main", "index": 0 }]] },
+    "Append Response": { "main": [[{ "node": "Save History",    "type": "main", "index": 0 }]] },
+    "Save History":    { "main": [[{ "node": "Respond",         "type": "main", "index": 0 }]] }
+  },
+  "active": false,
+  "settings": { "executionOrder": "v1" },
+  "tags": []
+}