Inhaltsverzeichnis

Runbook: Manage DSN

Duration: ~10 minutes
Role: Gateway Operator
Prerequisite: appsettings.json access

DSN (Data Source Name) defines preconfigured database connections.

Workflow

flowchart TD A[DSN Request] --> B{New or existing?} B -->|New| C[Edit appsettings.json] B -->|Existing| D[Test connection] C --> E[Restart Gateway] E --> D D --> F{Test successful?} F -->|Yes| G[Document] F -->|No| H[Check connection string] H --> C style G fill:#e8f5e9 style H fill:#ffebee

1. Show Existing DSN

# List all configured DSN (API)
curl -s http://localhost:5000/api/v1/dsn | jq
 
# Or check directly in config
cat appsettings.json | jq '.Gateway.Databases'

2. Add New DSN

Edit appsettings.json: 

{
  "Gateway": {
    "Databases": {
      "demo": {
        "Provider": "sqlite",
        "ConnectionString": "Data Source=data/demo.db"
      },
      "production": {
        "Provider": "sqlserver",
        "ConnectionString": "Server=sql01;Database=ProdDB;User Id=app;Password=***;TrustServerCertificate=True"
      },
      "reporting": {
        "Provider": "postgresql",
        "ConnectionString": "Host=pg01;Database=reports;Username=reader;Password=***"
      }
    }
  }
}

Supported Providers:

Provider ConnectionString Example
———-————————–
sqlserver Server=host;Database=db;User Id=user;Password=pwd
sqlite Data Source=path/file.db
postgresql Host=host;Database=db;Username=user;Password=pwd
mysql Server=host;Database=db;User=user;Password=pwd

3. Restart Gateway

# Windows
Stop-Process -Name "WvdS.WebAPI.Data.Gateway.Api" -Force
Start-Process -FilePath ".\WvdS.WebAPI.Data.Gateway.Api.exe"
 
# Linux (systemd)
sudo systemctl restart data-gateway

4. Test DSN

# List tables of new DSN
curl -s http://localhost:5000/api/v1/dsn/production/tables | jq
 
# Fetch first data
curl -s "http://localhost:5000/api/v1/dsn/production/tables/Customers?\$top=5" | jq

5. Remove DSN

  1. Delete DSN entry from appsettings.json
  2. Restart Gateway
  3. Verify DSN is no longer available:
curl -s http://localhost:5000/api/v1/dsn/old_dsn/tables
# Expected response: 404 Not Found

Checklist

# Check Done
———-——
1 Provider correct (sqlserver/sqlite/…) [ ]
2 Connection string valid [ ]
3 Password not visible in log [ ]
4 Gateway restarted [ ]
5 API test successful [ ]

Troubleshooting

Problem Cause Solution
—————-———-
Database not found Wrong database Check database name
Login failed Wrong password Check credentials
Connection refused Firewall blocking Open port 1433/5432/3306
Provider not supported Wrong provider name sqlserver, sqlite, postgresql, mysql
JSON parse error Syntax error Validate JSON (jsonlint.com)

Security Notes

Never log passwords in plain text!

Use environment variables for credentials: 

"ConnectionString": "Server=sql01;Database=ProdDB;User Id=${DB_USER};Password=${DB_PASS}"

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Wolfgang van der Stille @ EMSR DATA d.o.o. - Data Gateway Professional

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