📚 Add documentation about n8n in Docker with PostgresDB

docker/images/n8n/README.md

@@ -67,9 +67,11 @@ docker run -it --rm \
   n8nio/n8n
 ```
 
-## Use with MongoDB
+### Start with other Database
 
-Instead of SQLite, it is also possible to run n8n with MongoDB.
+By default n8n uses SQLite to save credentials, past executions and workflows.
+n8n however also supports MongoDB and PostgresDB. To use them simply a few
+environment variables have to be set.
 
 It is important to still persist the data in the `/root/.n8` folder. The reason
 is that it contains n8n user data. That is the name of the webhook
@@ -78,6 +80,9 @@ for the credentials. If none gets found n8n creates automatically one on
 startup. In case credentials are already saved with a different encryption key
 it can not be used anymore as encrypting it is not possible anymore.
 
+
+#### Use with MongoDB
+
 Replace the following placeholders with the actual data:
  - MONGO_DATABASE
  - MONGO_HOST
@@ -90,7 +95,7 @@ docker run -it --rm \
   --name n8n \
   -p 5678:5678 \
 	-e DB_TYPE=mongodb \
-	-e DB_MONGODB_CONNECTION_URL="mongodb://MONGO_USER:MONGO_PASSWORD@MONGO_SERVER:MONGO_PORT/MONGO_DATABASE" \
+	-e DB_MONGODB_CONNECTION_URL="mongodb://<MONGO_USER>:<MONGO_PASSWORD>@<MONGO_SERVER>:<MONGO_PORT>/<MONGO_DATABASE>" \
   -v ~/.n8n:/root/.n8n \
   n8nio/n8n \
   n8n start
@@ -99,6 +104,30 @@ docker run -it --rm \
 A full working setup with docker-compose can be found [here](../../compose/withMongo/README.md)
 
 
+#### Use with PostgresDB
+
+Replace the following placeholders with the actual data:
+ - POSTGRES_DATABASE
+ - POSTGRES_HOST
+ - POSTGRES_PASSWORD
+ - POSTGRES_PORT
+ - POSTGRES_USER
+
+```
+docker run -it --rm \
+  --name n8n \
+  -p 5678:5678 \
+	-e DB_TYPE=postgresdb \
+	-e DB_POSTGRESDB_DATABASE=<POSTGRES_DATABASE> \
+	-e DB_POSTGRESDB_HOST=<POSTGRES_HOST> \
+	-e DB_POSTGRESDB_PASSWORD=<POSTGRES_PASSWORD> \
+	-e DB_POSTGRESDB_PORT=<POSTGRES_PORT> \
+	-e DB_POSTGRESDB_USER=<POSTGRES_USER> \
+  -v ~/.n8n:/root/.n8n \
+  n8nio/n8n \
+  n8n start
+```
+
 ## License
 
 n8n is licensed under **Apache 2.0 with Commons Clause**