connectivity-onpremise

Connectivity (On-Premise)

Enable connectivity to on-premise systems via Cloud Connector.

Purpose

Replace Neo's manual proxy configuration (HC_OP_HTTP_PROXY_* environment variables) with SAP Cloud SDK's automatic handling of on-premise connectivity through Cloud Connector.

Detection

This skill applies if any of these patterns are found:

In Java source files

// Manual proxy configuration
String proxyHost = System.getenv("HC_OP_HTTP_PROXY_HOST");
String proxyPort = System.getenv("HC_OP_HTTP_PROXY_PORT");

// OnPremise proxy type handling if ("OnPremise".equals(proxyType)) { // Configure proxy... }

// Consumer account header urlConnection.setRequestProperty("SAP-Connectivity-ConsumerAccount", accountId);


### In destination configuration

ProxyType=OnPremise


## Prerequisites

> **Working directory:** This skill must run inside the `-cf-migration` copy of your app, created by `jakarta-java25-migration` or `neo-to-cf-migration-orchestrator`. If your current directory does not end in `-cf-migration`, switch to it before proceeding.


Before invoking this skill, ensure you have invoked:

1. **sdk-replacement** - `Use the sdk-replacement skill`
   - Sets up SAP Cloud SDK
   - REQUIRED before this skill

2. **destinations** - `Use the destinations skill`
   - Configures Destination service
   - REQUIRED before this skill

Also required:
- Cloud Connector installed and configured

## Transformation Steps

### Step 1: Remove AuthenticationHeaderProvider from web.xml

If present, remove the AuthenticationHeaderProvider resource reference:
```xml
<resource-ref>
    <res-ref-name>authenticationHeaderProvider</res-ref-name>
    <res-type>com.sap.core.connectivity.api.authentication.AuthenticationHeaderProvider</res-type>
</resource-ref>

Note: The SAP Cloud SDK handles authentication headers automatically for on-premise connections.

Step 2: Remove Manual Proxy Handling

The SAP Cloud SDK handles all proxy configuration automatically when ProxyType=OnPremise is detected in the destination.

Before (Neo) - REMOVE ALL THIS CODE:

private Proxy getProxy(String proxyType) {
    Proxy proxy = Proxy.NO_PROXY;
    String proxyHost = null;
    String proxyPort = null;

    if (ON_PREMISE_PROXY.equals(proxyType)) {
        // Get proxy for on-premise destinations
        proxyHost = System.getenv("HC_OP_HTTP_PROXY_HOST");
        proxyPort = System.getenv("HC_OP_HTTP_PROXY_PORT");
    } else {
        proxyHost = System.getProperty("https.proxyHost");
        proxyPort = System.getProperty("https.proxyPort");
    }

    if (proxyPort != null && proxyHost != null) {
        int proxyPortNumber = Integer.parseInt(proxyPort);
        proxy = new Proxy(Proxy.Type.HTTP, new InetSocketAddress(proxyHost, proxyPortNumber));
    }

    return proxy;
}

private void injectHeader(HttpURLConnection urlConnection, String proxyType) {
    if (ON_PREMISE_PROXY.equals(proxyType)) {
        urlConnection.setRequestProperty("SAP-Connectivity-ConsumerAccount",
            tenantContext.getTenant().getAccount().getId());
    }
}

After (Cloud Foundry) - Simple and automatic:

import com.sap.cloud.sdk.cloudplatform.connectivity.DestinationAccessor;
import com.sap.cloud.sdk.cloudplatform.connectivity.HttpDestination;
import org.apache.http.client.HttpClient;
import static com.sap.cloud.sdk.cloudplatform.connectivity.HttpClientAccessor.getHttpClient;

public void doGet(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {

    String destinationName = request.getParameter("destname");
    if (destinationName == null) {
        destinationName = "on-premise-destination";
    }

    try {
        // SAP Cloud SDK handles all proxy configuration automatically!
        HttpDestination destination = DestinationAccessor.getDestination(destinationName).asHttp();

        // Get HTTP client - SDK automatically:
        // - Configures proxy for on-premise destinations
        // - Adds required headers (SAP-Connectivity-ConsumerAccount, etc.)
        // - Handles Cloud Connector integration
        HttpClient httpClient = getHttpClient(destination);
        HttpGet httpGet = new HttpGet(destination.getUri());

        HttpResponse destinationResponse = httpClient.execute(httpGet);

        int statusCode = destinationResponse.getStatusLine().getStatusCode();
        if (statusCode != HttpServletResponse.SC_OK) {
            response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR,
                "Destination returned: " + statusCode);
            return;
        }

        destinationResponse.getEntity().writeTo(response.getOutputStream());

    } catch (Exception e) {
        throw new ServletException("Connectivity failed: " + e.getMessage(), e);
    }
}

Step 2: Remove Resource References

Remove from web.xml:

<!-- REMOVE -->
<resource-ref>
    <res-ref-name>connectivityConfiguration</res-ref-name>
    <res-type>com.sap.core.connectivity.api.configuration.ConnectivityConfiguration</res-type>
</resource-ref>

<!-- REMOVE if present -->
<resource-ref>
    <res-ref-name>TenantContext</res-ref-name>
    <res-type>com.sap.cloud.account.TenantContext</res-type>
</resource-ref>

Step 3: Update MTA Descriptor

Add both destination and connectivity services to mtad.yaml:

modules:
  - name: ${app-name}
    type: java.tomcat
    path: target/<artifactId>.war
    parameters:
      buildpack: sap_java_buildpack_jakarta
      disk-quota: 1024M
      memory: 1024M
    properties:
      ENABLE_SECURITY_JAVA_API_V2: true
      SET_LOGGING_LEVEL: 'ROOT: INFO'
    requires:
      - name: ${app-name}-destination
      - name: ${app-name}-connectivity

resources:
  - name: ${app-name}-destination
    type: org.cloudfoundry.managed-service
    parameters:
      service: destination
      service-plan: lite

  - name: ${app-name}-connectivity
    type: org.cloudfoundry.managed-service
    parameters:
      service: connectivity
      service-plan: lite

Step 4: Configure Cloud Connector

In Cloud Connector Administration:

Add Subaccount
- Region: Your CF region
- Subaccount: Your subaccount ID
- Display Name: Descriptive name
Add Virtual Host Mapping
- Click "Cloud to On-Premise"
- Add new mapping:
  - Back-end Type: Non-SAP System / HTTP
  - Protocol: HTTP or HTTPS
  - Internal Host: your-onprem-server.local
  - Internal Port: 8080
  - Virtual Host: onprem-virtual
  - Virtual Port: 8080
Add Resources
- Path: / (or specific paths)
- Access Policy: Allow

Step 5: Create On-Premise Destination

In BTP Cockpit, create destination:

Property	Value
Name	`on-premise-destination`
Type	HTTP
URL	`http://onprem-virtual:8080`
Proxy Type	OnPremise
Authentication	NoAuthentication (or as needed)
Location ID	(Optional) Cloud Connector location ID

For destinations with Location ID:

{
    "Name": "on-premise-destination",
    "Type": "HTTP",
    "URL": "http://onprem-virtual:8080",
    "ProxyType": "OnPremise",
    "Authentication": "NoAuthentication",
    "CloudConnectorLocationId": "my-location-id"
}

Step 6: Check Proxy Type Programmatically (if needed)

import com.sap.cloud.sdk.cloudplatform.connectivity.ProxyType;

HttpDestination destination = DestinationAccessor.getDestination(name).asHttp();

// Check if on-premise
if (destination.getProxyType() == ProxyType.ON_PREMISE) {
    // On-premise handling (SDK handles proxy automatically)
    logger.info("Using on-premise connectivity");
}

Configuration Files

No new configuration files in the application. Cloud Connector and destinations are configured externally.

CF Services

Service	Plan	Purpose
`destination`	lite	Destination configuration
`connectivity`	lite	On-premise connectivity proxy

Verification

1. Compile Check

mvn clean compile

2. Verify Cloud Connector Connection

In Cloud Connector Administration:

Check connection status (should show "Connected")
Verify virtual host mappings

3. Test On-Premise Connectivity

# Deploy application
cf deploy . -f

# Test on-premise destination
curl "https://${app-url}/connectivity?destname=on-premise-destination"

4. Check Logs for Connectivity

cf logs ${app-name} --recent | grep -i "connectivity\|proxy"

Common Issues

Issue: Connection refused

Cause: Cloud Connector not connected or misconfigured. Solution:

Check Cloud Connector status
Verify virtual host mapping
Check Location ID in destination matches Cloud Connector

Issue: 403 Forbidden on on-premise resource

Cause: Cloud Connector resource access policy. Solution: Add the path to allowed resources in Cloud Connector.

Issue: Timeout connecting to on-premise

Cause: Network issue or Cloud Connector firewall. Solution:

Verify on-premise server is reachable from Cloud Connector host
Check firewall rules
Increase timeout in destination if needed

Issue: "No connectivity service bound"

Cause: Connectivity service not bound to application. Solution: Verify ${app-name}-connectivity is in requires section of mtad.yaml.

Architecture Overview

┌─────────────────┐     ┌──────────────────┐     ┌─────────────────┐
│  CF Application │────▶│ Connectivity     │────▶│ Cloud Connector │
│  (Your App)     │     │ Service Proxy    │     │ (On-Premise)    │
└─────────────────┘     └──────────────────┘     └────────┬────────┘
                                                          │
                                                          ▼
                                                 ┌─────────────────┐
                                                 │ On-Premise      │
                                                 │ Backend System  │
                                                 └─────────────────┘

The SAP Cloud SDK automatically:

Detects that the destination has ProxyType=OnPremise
Routes the request through the connectivity service proxy
Adds required headers (SAP-Connectivity-ConsumerAccount)
Cloud Connector forwards to the actual on-premise system

Next Steps

After completing this skill, proceed to:

../mail-destinations/SKILL.md - For on-premise mail server configuration