Build a CPB

You can build a CPB from your CPK files using one of the following:

• Gradle
• Corda CLI

Build a CPB Using Gradle

To build a CPB using Gradle:

1. Add the CPB plugin to your project by adding the following to the start of the build.gradle file of your CorDapp Corda Distributed Application. A Java (or any JVM targeting language) application built using the Corda build toolchain and CorDapp API to solve some problem that is best solved in a decentralized manner. Gradle project:

   plugins {
       id 'net.corda.plugins.cordapp-cpb2'
   }
   

2. To sign your CPB, add a cordapp/signing section to the project settings.gradle file.

   By default, the CPB plugin signs with a default key. This key should only be used for local testing. You can deploy locally on a static network, using the CorDapp template. CPBs for deployment on a dynamic network must be signed with a key that you can share with the Network Operator responsible for building the CPI from the CPB. You should always sign test CPBs with a different key used only for testing. The final key that the Network Operator uses should not be used for signing until you are ready to release. You can re-sign a CPB without building the project from source, using the Corda CLI.

3. Run the cbp Gradle task:

   ./gradlew cpb
   

Build a CPB Using the Corda CLI

To build a CPB using the Corda CLI A command line tool that supports various Corda-related tasks, including Corda Package Installer (CPI) creation and Corda cluster management. :

1. Generate a code signing key. For example:

   keytool -genkeypair -alias "<key-alias>" -keystore <signingkeys.pfx> -storepass "<keystore-password>" -dname "cn=<CPI Plugin Example - Signing Key 1, o=R3, L=London, c=GB>" -keyalg <RSA> -storetype <pkcs12> -validity <4000>
   

   CPBs for deployment on a dynamic network must be signed with a key that you can share with the Network Operator responsible for building the CPI from the CPB. You should always sign test CPBs with a different key used only for testing. The final key that the Network Operator uses should not be used for signing until you are ready to release.
   Never commit your keystore to git.

2. Use the Corda CLI package command, specifying the CPK files, the name, version, and file name of the CPB, and the details of the signing key:

   • Bash
   • PowerShell

   ./corda-cli.sh package create-cpb \
    <mycpk0.jar> <mycpk1.jar> \
    --cpb-name <manifest-attribute-cpb-name> \
    --cpb-version <manifest-attribute-cpb-version> \
    --file <output.cpb> \
    --keystore <signingkeys.pfx> \
    --storepass <"keystore password"> \
    --key <"signing key 1">
   

    ./corda-cli.cmd package create-cpb `
    <mycpk0.jar> <mycpk1.jar> `
    --cpb-name <manifest-attribute-cpb-name> `
    --cpb-version <manifest-attribute-cpb-version> `
    --file <output.cpb> `
    --keystore <signingkeys.pfx> `
    --storepass <"keystore password"> `
    --key <"signing key 1">
   

   For more information about the Corda CLI package command, see the Corda CLI Reference section.