Mta Descriptor

MTA Descriptor Generation

Generate a Multi-Target Application deployment descriptor (mtad.yaml) for deploying Neo-migrated applications to SAP BTP Cloud Foundry.

Usage

Generate an mtad.yaml for my migrated application
Create MTA descriptor with XSUAA and HANA services

Overview

The MTA descriptor (mtad.yaml) defines:

• Application modules (Java app, approuter)
• Required Cloud Foundry services (XSUAA, HANA, Destination, etc.)
• Service bindings between modules and services
• Build and deployment parameters

This skill analyzes which migration skills were applied to your application and generates the appropriate mtad.yaml configuration.

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 all required migration skills:

1. jakarta-java25-migration - Use the jakarta-java25-migration skill (REQUIRED)
2. sdk-replacement - Use the sdk-replacement skill (REQUIRED)
3. Any feature skills that apply to your application

Also required:

• Application successfully compiles: mvn clean compile
• Understanding of which CF services your application requires

Determine Required Services

Based on the migration skills you've applied, identify required CF services:

MTA Templates

Template Selection

Choose the appropriate base template:

Precondition — pom.xml MUST configure maven-war-plugin with <warName>${project.artifactId}</warName>

This skill owns the WAR filename rule (next section), which only holds if pom.xml actually writes the WAR under <artifactId>.war. Maven's default WAR filename is <artifactId>-<version>.war, which does NOT match what this skill writes into mtad.yaml (target/<artifactId>.war) — the deploy then fails with:

Error retrieving MTA: Error building MTA Archive: file path .../target/<artifactId>.war not found

The other migration skills (sdk-replacement, tomee-runtime, …) are dependency-management skills and do not own build packaging. Verify and, if needed, add the <build> block below to pom.xml before emitting the descriptor.

Required <build> block in pom.xml:

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-war-plugin</artifactId>
            <version>3.4.0</version>
            <configuration>
                <warName>${project.artifactId}</warName>
                <failOnMissingWebXml>false</failOnMissingWebXml>
            </configuration>
        </plugin>
    </plugins>
</build>

Why 3.4.0 specifically: the default maven-war-plugin:2.2 is incompatible with Java 25 and fails with Cannot access defaults field of Properties. The Common Issues section below has the same fix.

Self-check before continuing — run this from the project root; it must print exactly 1:

grep -A 10 'maven-war-plugin' pom.xml | grep -c '<warName>${project.artifactId}</warName>'

If the count is 0, the plugin is missing or <warName> is set to something else (often the leftover <warName>ROOT</warName> from older templates). Fix pom.xml before emitting mtad.yaml; the build will otherwise succeed but the descriptor and the WAR will disagree at deploy time.

If pom.xml legitimately needs a different <warName> (e.g. the project must serve at / and uses <warName>ROOT</warName>), update the descriptor's path: to match — the rule is "descriptor follows pom", not "pom follows descriptor".

WAR filename rule — read it from pom.xml, write it literally

The templates below show path: target/<artifactId>.war as a placeholder. Before emitting mtad.yaml, open pom.xml, read the <artifactId> value, and substitute it literally — for a project whose <artifactId> is connectivity, write path: target/connectivity.war.

Why this matters in concrete terms:

• cf deploy reads path: as a literal filesystem path under the descriptor's directory. It does NOT evaluate Maven property expressions, so a descriptor that says path: target/${project.artifactId}.war fails at deploy time with Error building MTA Archive: file path target/${project.artifactId}.war not found.
• maven-war-plugin in the shipped pom templates is configured with <warName>${project.artifactId}</warName> — Maven writes a WAR named after the artifactId (e.g. target/connectivity.war). The descriptor must match what Maven actually writes, not a placeholder string.

Consequence to communicate downstream: sap_java_buildpack_jakarta always serves the app at / (ROOT context). It additionally registers the app at /<warName>/ only if web.xml has a servlet mapped to url-pattern: /. Integration tests and approuter destinations should use / — not /<artifactId>/ — unless the app explicitly maps a default servlet.

Template: Basic Application (mtad-base.yaml)

For applications without user authentication:

_schema-version: "3.3"
ID: my-app
version: 1.0.0
parameters:
parameters:
  enable-parallel-deployments: true


modules:
  - name: my-app-backend
    type: java.tomcat
    path: target/<artifactId>.war      # ← substitute the literal artifactId from pom.xml

    parameters:
      memory: 1024M
      disk-quota: 1024M

      buildpack: sap_java_buildpack_jakarta
    properties:
      # Pin SapMachine JRE 25 explicitly. Always set this — never rely on the buildpack's
      # implicit JRE choice, and keep maven.compiler.target in pom.xml at the same major
      # version. Use SAPMachineJRE (bundled, offline) — NOT SAPMachineJDK (heavyweight,
      # online-only).
      JBP_CONFIG_COMPONENTS: "jres: ['com.sap.xs.java.buildpack.jre.SAPMachineJRE']"
      JBP_CONFIG_SAP_MACHINE_JRE: "{ version: 25.+ }"
      TARGET_RUNTIME: tomcat
    build-parameters:
      builder: maven
      build-result: target/*.war
    provides:
      - name: backend-api
        properties:
          url: ${default-url}
    requires:
      # Add service bindings here based on needs
      - name: my-app-hana          # If using persistence-hana
      - name: my-app-destination   # If using destinations

resources:
  # Add required services here

Template: Application with XSUAA (mtad-with-approuter.yaml)

For user-facing web applications:

_schema-version: "3.2"
ID: my-app
version: 0.0.1

parameters:
  enable-parallel-deployments: true

modules:
  # Approuter module for authentication
  - name: my-app-approuter
    type: nodejs
    path: approuter
    parameters:
      memory: 256M
      disk-quota: 256M
      routes:
        - route: '${protocol}://my-app.${default-domain}'
          protocol: http1
    properties:
      XS_APP_LOG_LEVEL: debug
      TENANT_HOST_PATTERN: '(.*).cfapps.sap.hana.ondemand.com'
      CF_NODEJS_LOGGING_LEVEL: "info"
    requires:
      - name: my-app-xsuaa
      - name: my-app-java-app
        group: destinations
        properties:
          name: backend-app-destination
          url: '~{neo-app-url}'
          forwardAuthToken: true

  # Backend Java application
  - name: my-app-backend
    type: java.tomcat
    path: target/<artifactId>.war      # ← substitute the literal artifactId from pom.xml
    parameters:
      memory: 1024M
      disk-quota: 1024M
      buildpack: sap_java_buildpack_jakarta
    properties:
      ENABLE_SECURITY_JAVA_API_V2: true
      # Pin SapMachine JRE 25 explicitly. Always set this — never rely on the buildpack's
      # implicit JRE choice, and keep maven.compiler.target in pom.xml at the same major
      # version. Use SAPMachineJRE (bundled, offline) — NOT SAPMachineJDK (heavyweight,
      # online-only).
      JBP_CONFIG_COMPONENTS: "jres: ['com.sap.xs.java.buildpack.jre.SAPMachineJRE']"
      JBP_CONFIG_SAP_MACHINE_JRE: "{ version: 25.+ }"
      TARGET_RUNTIME: tomcat
      SET_LOGGING_LEVEL: 'ROOT: INFO'
    provides:
      - name: my-app-java-app
        properties:
          neo-app-url: '${default-url}'
    requires:
      - name: my-app-xsuaa
      - name: my-app-destination

resources:
  - name: my-app-xsuaa
    type: org.cloudfoundry.managed-service
    parameters:
      service: xsuaa
      service-plan: application
      path: ./xs-security.json

  - name: my-app-destination
    type: org.cloudfoundry.managed-service
    parameters:
      service: destination
      service-plan: lite

Critical: The Java backend path must point to the actual WAR file Maven produces — read the <artifactId> from pom.xml and substitute it literally (e.g. path: target/connectivity.war for a project whose artifactId is connectivity). See the "WAR filename rule" callout above this section. Note: sap_java_buildpack_jakarta always serves the app at / — the WAR filename does not affect the runtime context path.

Note on type: nodejs vs type: approuter.nodejs: Use type: nodejs when deploying the approuter with your own approuter/ directory and package.json (which is the standard pattern for migrated Neo applications). The type approuter.nodejs is for the "managed approuter" pattern which is used only in specific multi-tenant scenarios.

Service Configuration Examples

Add these resource definitions based on services your application needs:

XSUAA (Authentication)

resources:
  - name: ${app-name}-xsuaa
    type: org.cloudfoundry.managed-service
    parameters:
      service: xsuaa
      service-plan: application
      path: ./xs-security.json  # Created by authentication-xsuaa skill

Module requires:

requires:
  - name: ${app-name}-xsuaa

Destination Service

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

Module requires:

requires:
  - name: ${app-name}-destination

Connectivity Service (On-Premise)

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

Module requires:

requires:
  - name: ${app-name}-connectivity
  - name: ${app-name}-destination  # Connectivity requires Destination

HANA Schema

CRITICAL — do NOT add service: hana or service-plan: hdi-shared under type: com.sap.xs.hana-schema.

❌ Anti-pattern that breaks deploy:

- name: ${app-name}-hana
  type: com.sap.xs.hana-schema
  parameters:
    service: hana              # ← WRONG for hana-schema
    service-plan: hdi-shared   # ← WRONG for hana-schema

service: and service-plan: are keys for the GENERIC type: org.cloudfoundry.managed-service (xsuaa, destination, credstore, sdm, …). com.sap.xs.hana-schema is a dedicated MTA resource type that already implies the broker, the service, and the plan. Setting them explicitly causes the controller to reject the create-service call:

CF-UnprocessableEntity(10008): Invalid service plan. ... Ensure that the service plan is visible in your current space ...

resources:
  - name: ${app-name}-hana
    type: com.sap.xs.hana-schema

NO parameters: block on the hana-schema resource. Specifically, do NOT set schema-name:, service:, or service-plan: here. MTA's com.sap.xs.hana-schema type does not support any of these at the resource level — the deployer drops them with Parameter(s) "{<name>-hana=[schema-name]}" are not supported in the specified scope, or referenced by any other entities. These parameters are not processed and will be lost. The deploy still completes, but the warning is noisy and signals a malformed descriptor. The reference scenarios use only the two-line form above.

Module requires:

requires:
  - name: ${app-name}-hana

The bare - name: is enough — MTA binds the resource into VCAP_SERVICES under the resource's name:, and Tomcat's context.xml (or resources.xml for TomEE) looks up the DataSource by that same name via service_name_for_DefaultDB. No ~{...} cross-references or TARGET_CONTAINER parameters are needed for the standard persistence path.

Document Management (SDM)

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

Module requires:

requires:
  - name: ${app-name}-sdm

Credential Store

resources:
  - name: ${app-name}-credstore
    type: org.cloudfoundry.managed-service
    parameters:
      service: credstore
      service-plan: standard
      config:
        encryption:
          user_key_name: "credstore-key"

Module requires:

requires:
  - name: ${app-name}-credstore

Generation Steps

1. Analyze Application Requirements

Identify which services your application needs:

# Check for XSUAA dependencies
grep -r "com.sap.cloud.security.xsuaa" pom.xml

# Check for destination dependencies
grep -r "com.sap.cloud.sdk.cloudplatform.connectivity" pom.xml

# Check for HANA dependencies
grep -r "javax.sql.DataSource\|jakarta.persistence" src/main/java/

# Check for SDM dependencies
grep -r "com.sap.ecm.api" src/main/java/

2. Select Base Template

Copy the appropriate template:

# For basic app
cp skills/mta-descriptor/assets/mtad-base.yaml mtad.yaml

# For app with authentication
cp skills/mta-descriptor/assets/mtad-with-approuter.yaml mtad.yaml

3. Customize Application Properties

Update the mtad.yaml with your application details:

ID: my-application-name          # Unique identifier
version: 1.0.0                    # Your app version

modules:
  - name: my-app-backend          # Your module name
    path: target/<artifactId>.war  # Substitute the literal artifactId from pom.xml
    parameters:
      memory: 1024M                # Adjust based on needs
      disk-quota: 1024M            # Minimum 1GB — 512M causes deployment errors

WAR naming: The descriptor's path: must match exactly what Maven writes to target/. The pom templates ship maven-war-plugin with <warName>${project.artifactId}</warName>, so the WAR is named after the artifactId (e.g. target/connectivity.war). Open pom.xml, read the <artifactId> value, and write it literally into mtad.yaml — Maven property expressions like ${project.artifactId} are NOT evaluated by cf deploy and will fail with "file path … not found". Note: sap_java_buildpack_jakarta always serves the app at / — use / in approuter targets and integration tests, not /<artifactId>/.

4. Add Required Services

Based on your analysis in step 1, add the necessary service resources and module requirements.

Example: App with XSUAA, Destination, and HANA:

modules:
  - name: my-app-backend
    # ... other properties ...
    requires:
      - name: my-app-xsuaa
      - name: my-app-destination
      - name: my-app-hana

resources:
  - name: my-app-xsuaa
    type: org.cloudfoundry.managed-service
    parameters:
      service: xsuaa
      service-plan: application
      path: ./xs-security.json

  - name: my-app-destination
    type: org.cloudfoundry.managed-service
    parameters:
      service: destination
      service-plan: lite

  - name: my-app-hana
    type: com.sap.xs.hana-schema

5. Configure TomEE Runtime (if applicable)

If you used the tomee-runtime skill:

modules:
  - name: my-app-backend
    properties:
      TARGET_RUNTIME: tomee        # Change from 'tomcat' to 'tomee'

6. Validate the Descriptor

Check the syntax and structure:

# Validate YAML syntax
yamllint mtad.yaml

# Or use basic validation
python3 -c "import yaml; yaml.safe_load(open('mtad.yaml'))"

Build and Deploy

After generating the mtad.yaml:

Deploy to Cloud Foundry

Primary flow — cf deploy . (recommended)

# Deploy directly from current directory
# cf deploy reads mtad.yaml and builds the MTA archive in-process
cf deploy . -f

This is the correct flow for migrated Neo applications. This skill generates mtad.yaml (a deployment descriptor), which cf deploy . reads directly. All 8 reference scenarios use this command.

CI/CD / archive flow — mbt build (requires extra step)

If you need a versioned .mtar archive (e.g. for CI/CD pipelines or distributing to other teams), you must first manually create an mta.yaml source descriptor — mbt build requires it and will fail without it. This skill does not generate mta.yaml.

# 1. Manually create mta.yaml (not generated by this skill)
# 2. Build the MTA archive
mbt build
# This creates: mta_archives/<app>_<version>.mtar

# 3. Deploy the archive
cf deploy mta_archives/*.mtar -f

mta.yaml vs mtad.yaml: mta.yaml is a source descriptor read by mbt build to compile and package the app. mtad.yaml is a deployment descriptor read directly by cf deploy. They serve different purposes — having one does not substitute for the other.

Verify Deployment

# Check application status
cf apps

# Check service bindings
cf services

# View recent logs
cf logs my-app-backend --recent

Common Configurations

Multi-Module Application

modules:
  - name: my-app-ui
    type: html5
    path: ui-module

  - name: my-app-backend
    type: java
    path: backend-module
    provides:
      - name: backend-api
        properties:
          url: ${default-url}

  - name: my-app-worker
    type: java
    path: worker-module
    requires:
      - name: backend-api

Environment Variables

modules:
  - name: my-app-backend
    properties:
      MY_CUSTOM_VAR: "production-value"
      SPRING_PROFILES_ACTIVE: "cloud"
      JBP_CONFIG_RESOURCE_CONFIGURATION: "[tomcat/webapps/ROOT/WEB-INF/web.xml: {'web-app/session-config/session-timeout': 60}]"

Health Check Configuration

modules:
  - name: my-app-backend
    parameters:
      health-check-type: http
      health-check-http-endpoint: /actuator/health
      health-check-timeout: 180

Troubleshooting

Issue: Service binding fails

Symptom: Application fails to bind to services during deployment

Solution: Verify service names in requires match service names in resources:

# Resource name
resources:
  - name: my-app-xsuaa  # This name...

# Must match in module requires
modules:
  - name: my-app-backend
    requires:
      - name: my-app-xsuaa  # ...must match exactly here

Issue: Module fails to build

Symptom: Build errors during cf deploy

Solution: Verify build parameters:

modules:
  - name: my-app-backend
    build-parameters:
      builder: maven               # Or 'npm', 'custom'
      build-result: target/*.war   # Verify path is correct

Issue: Memory errors

Symptom: Application crashes with out-of-memory errors

Solution: Increase memory allocation:

modules:
  - name: my-app-backend
    parameters:
      memory: 2048M      # Increase from 1024M
      disk-quota: 1024M  # Never use 512M — minimum is 1024M for Java buildpack

Issue: cf deploy fails immediately with Error building MTA Archive: file path … not found

Symptom: cf deploy exits non-zero within seconds, before any service is touched, with:

FAILED Error retrieving MTA: Error building MTA Archive: file path <project>/cf-ai-migrated/target/<X>.war not found

The Maven build step earlier in the pipeline reported BUILD SUCCESS. The build log line [INFO] Building war: …/target/<Y>.war shows a different filename than the descriptor declares.

Cause: mtad.yaml's path: doesn't match what Maven actually writes. Two flavors:

1. The descriptor literally contains path: target/${project.artifactId}.war — Maven property expressions are NOT evaluated by cf deploy, so the literal string ${project.artifactId} is looked up on disk and not found.
2. The descriptor is left over from an older template that hard-coded target/ROOT.war, but the pom is configured with <warName>${project.artifactId}</warName> (the current default in this skill's templates) and writes target/<artifactId>.war.

Solution: Open pom.xml, read the <artifactId> value, and substitute it literally into mtad.yaml's path:. For a project whose <artifactId> is connectivity, the descriptor must say path: target/connectivity.war — not target/${project.artifactId}.war, not target/ROOT.war. After fixing the descriptor, re-run cf deploy (no rebuild needed).

Note: sap_java_buildpack_jakarta always serves the app at / (ROOT context) — the WAR filename does not affect the runtime context path. Integration tests and approuter destinations should use /, not /<artifactId>/.

Issue: 404 Not Found at runtime — app deployed but routes return 404

Symptom: Deploy succeeded; the app starts; every request to /<something> returns 404. Logs show Tomcat started and the WAR loaded.

Cause: sap_java_buildpack_jakarta deploys the WAR as ROOT context — the app is served at /, not at /<artifactId>. The 404 is likely caused by a missing servlet mapping in web.xml, a wrong security constraint, or approuter routes using /<artifactId>/ as a target prefix.

Solution: Check servlet mappings in web.xml. If using an approuter, verify that route targets do NOT include /<artifactId>/ as a prefix — the app serves at / directly. Run cf logs <app> --recent to see which paths Tomcat is actually receiving.

Issue: Routes quota exceeded

Symptom: cf deploy fails with Routes quota exceeded for organization '<org>'. quota: SUBSCRIPTION_QUOTA — total memory: 0, routes: 0

Cause: The CF org uses SUBSCRIPTION_QUOTA which has 0 routes and 0 memory by default. This is set by SAP's entitlement system.

Solution: A Global Account Administrator must assign CF Runtime memory in BTP Cockpit:

1. BTP Cockpit → Global Account → Entitlements → Entity Assignments
2. Select the subaccount → Configure Entitlements → Cloud Foundry Runtime → assign memory (e.g. 3GB)
3. BTP automatically creates a new org quota named <guid>-t-<subaccount-guid> and applies it

Note: cf create-space-quota and cf create-quota do NOT fix this — org-level route limits cannot be overridden by space quotas, and creating new org quotas requires CF admin rights.

Issue: maven-war-plugin fails with Cannot access defaults field of Properties

Symptom: Maven build fails with this error when using Java 25.

Cause: Default maven-war-plugin:2.2 is incompatible with Java 25.

Solution: Explicitly pin maven-war-plugin to 3.4.0 in pom.xml.

Integration with CF Plugin

After generating the mtad.yaml, use the cf-plugin skills for deployment:

# Use cf-plugin to deploy the MTA
/sap-btp-cf:cf-push-app my-app

# View deployment logs
/sap-btp-cf:cf-get-app-logs my-app

Post-Deployment Configuration

Assign Role Collections (XSUAA)

If using authentication-xsuaa:

1. Open SAP BTP Cockpit
2. Navigate to Security → Role Collections
3. Assign role collection to users/user groups
4. Verify by logging into the application

Create Destinations (Destination Service)

If using destinations skill:

1. Open SAP BTP Cockpit
2. Navigate to Connectivity → Destinations
3. Create destinations as defined in the destinations skill
4. Test connectivity from the application

Configure Cloud Connector (Connectivity)

If using connectivity-onpremise:

1. Install and configure Cloud Connector
2. Add virtual hosts matching destination configuration
3. Map to on-premise systems
4. Test connectivity

See Also

• authentication-xsuaa/SKILL.md - For xs-security.json and xs-app.json
• destinations/SKILL.md - For destination configuration
• connectivity-onpremise/SKILL.md - For Cloud Connector setup
• persistence-hana/SKILL.md - For HANA configuration
• tomee-runtime/SKILL.md - For TomEE-specific configuration

References

• MTA Development and Deployment
• MTA Deployment Descriptor Syntax
• SAP Java Buildpack