corda/docs/source/generating-a-node.rst

Creating nodes locally

Handcrafting a node

A node can be created manually by creating a folder that contains the following items:

• The Corda JAR

  • Can be downloaded from https://r3.bintray.com/corda/net/corda/corda/ (under /VERSION_NUMBER/corda-VERSION_NUMBER.jar)

• A node configuration file entitled node.conf, configured as per corda-configuration-file

• A folder entitled cordapps containing any CorDapp JARs you want the node to load

• Optional: A webserver JAR entitled corda-webserver.jar that will connect to the node via RPC

  • The (deprecated) default webserver can be downloaded from http://r3.bintray.com/corda/net/corda/corda-webserver/ (under /VERSION_NUMBER/corda-VERSION_NUMBER.jar)
  • A Spring Boot alternative can be found here: https://github.com/corda/spring-webserver

The remaining files and folders described in node-structure will be generated at runtime.

The Cordform task

Corda provides a gradle plugin called Cordform that allows you to automatically generate and configure a set of nodes for testing and demos. Here is an example Cordform task called deployNodes that creates three nodes, defined in the Kotlin CorDapp Template:

task deployNodes(type: net.corda.plugins.Cordform, dependsOn: ['jar']) {
    directory "./build/nodes"
    node {
        name "O=Notary,L=London,C=GB"
        // The notary will offer a validating notary service.
        notary = [validating : true]
        p2pPort  10002
        rpcSettings {
            port 10003
            adminPort 10023
        }
        // No webport property, so no webserver will be created.
        h2Port   10004
        // Starts an internal SSH server providing a management shell on the node.
        sshdPort 2223
        // Includes the corda-finance CorDapp on our node.
        cordapps = ["net.corda:corda-finance:$corda_release_version"]
        extraConfig = [
            // Setting the JMX reporter type.
            jmxReporterType: 'JOLOKIA',
            // Setting the H2 address.
            h2Settings: [ address: 'localhost:10030' ]
        ]
    }
    node {
        name "O=PartyA,L=London,C=GB"
        p2pPort  10005
        rpcSettings {
            port 10006
            adminPort 10026
        }
        webPort  10007
        h2Port   10008
        cordapps = ["net.corda:corda-finance:$corda_release_version"]
        // Grants user1 all RPC permissions.
        rpcUsers = [[ user: "user1", "password": "test", "permissions": ["ALL"]]]
    }
    node {
        name "O=PartyB,L=New York,C=US"
        p2pPort  10009
        rpcSettings {
            port 10010
            adminPort 10030
        }
        webPort  10011
        h2Port   10012
        cordapps = ["net.corda:corda-finance:$corda_release_version"]
        // Grants user1 the ability to start the MyFlow flow.
        rpcUsers = [[ user: "user1", "password": "test", "permissions": ["StartFlow.net.corda.flows.MyFlow"]]]
    }
}

Running this task will create three nodes in the build/nodes folder:

• A Notary node that:
  • Offers a validating notary service
  • Will not have a webserver (since webPort is not defined)
  • Is running the corda-finance CorDapp
• PartyA and PartyB nodes that:
  • Are not offering any services
  • Will have a webserver (since webPort is defined)
  • Are running the corda-finance CorDapp
  • Have an RPC user, user1, that can be used to log into the node via RPC

Additionally, all three nodes will include any CorDapps defined in the project's source folders, even though these CorDapps are not listed in each node's cordapps entry. This means that running the deployNodes task from the template CorDapp, for example, would automatically build and add the template CorDapp to each node.

You can extend deployNodes to generate additional nodes.

Warning

When adding nodes, make sure that there are no port clashes!

To extend node configuration beyond the properties defined in the deployNodes task use the configFile property with the path (relative or absolute) set to an additional configuration file. This file should follow the standard corda-configuration-file format, as per node.conf. The properties from this file will be appended to the generated node configuration. Note, if you add a property already created by the 'deployNodes' task, both properties will be present in the file. The path to the file can also be added while running the Gradle task via the -PconfigFile command line option. However, the same file will be applied to all nodes. Following the previous example PartyB node will have additional configuration options added from a file none-b.conf:

task deployNodes(type: net.corda.plugins.Cordform, dependsOn: ['jar']) {
    [...]
    node {
        name "O=PartyB,L=New York,C=US"
        [...]
        // Grants user1 the ability to start the MyFlow flow.
        rpcUsers = [[ user: "user1", "password": "test", "permissions": ["StartFlow.net.corda.flows.MyFlow"]]]
        configFile = "samples/trader-demo/src/main/resources/node-b.conf"
    }
}

Cordform parameter drivers of the node entry lists paths of the files to be copied to the ./drivers subdirectory of the node. To copy the same file to all nodes ext.drivers can be defined in the top level and reused for each node via drivers=ext.drivers`.

task deployNodes(type: net.corda.plugins.Cordform, dependsOn: ['jar']) {
    ext.drivers = ['lib/my_common_jar.jar']
    [...]
    node {
        name "O=PartyB,L=New York,C=US"
        [...]
        drivers = ext.drivers + ['lib/my_specific_jar.jar']
    }
}

Specifying a custom webserver

By default, any node listing a web port will use the default development webserver, which is not production-ready. You can use your own webserver JAR instead by using the webserverJar argument in a Cordform node configuration block:

node {
    name "O=PartyA,L=New York,C=US"
    webPort 10005
    webserverJar "lib/my_webserver.jar"
}

The webserver JAR will be copied into the node's build folder with the name corda-webserver.jar.

Warning

This is an experimental feature. There is currently no support for reading the webserver's port from the node's node.conf file.

The Dockerform task

The Dockerform is a sister task of Cordform that provides an extra file allowing you to easily spin up nodes using docker-compose. It supports the following configuration options for each node:

• name
• notary
• cordapps
• rpcUsers
• useTestClock

There is no need to specify the nodes' ports, as every node has a separate container, so no ports conflict will occur. Every node will expose port 10003 for RPC connections.

The nodes' webservers will not be started. Instead, you should interact with each node via its shell over SSH (see the node configuration options <corda-configuration-file>). You have to enable the shell by adding the following line to each node's node.conf file:

sshd { port = 2222 }

Where 2222 is the port you want to open to SSH into the shell.

Below you can find the example task from the IRS Demo included in the samples directory of main Corda GitHub repository:

def rpcUsersList = [
    ['username' : "user",
     'password' : "password",
     'permissions' : [
             "StartFlow.net.corda.irs.flows.AutoOfferFlow\$Requester",
             "StartFlow.net.corda.irs.flows.UpdateBusinessDayFlow\$Broadcast",
             "StartFlow.net.corda.irs.api.NodeInterestRates\$UploadFixesFlow",
             "InvokeRpc.vaultQueryBy",
             "InvokeRpc.networkMapSnapshot",
             "InvokeRpc.currentNodeTime",
             "InvokeRpc.wellKnownPartyFromX500Name"
     ]]
]

// (...)

task deployNodes(type: net.corda.plugins.Dockerform, dependsOn: ['jar']) {

    node {
        name "O=Notary Service,L=Zurich,C=CH"
        notary = [validating : true]
        cordapps = ["$corda_release_group:corda-finance:$corda_release_version"]
        rpcUsers = rpcUsersList
        useTestClock true
    }
    node {
        name "O=Bank A,L=London,C=GB"
        cordapps = ["$corda_release_group:corda-finance:$corda_release_version"]
        rpcUsers = rpcUsersList
        useTestClock true
    }
    node {
        name "O=Bank B,L=New York,C=US"
        cordapps = ["$corda_release_group:corda-finance:$corda_release_version"]
        rpcUsers = rpcUsersList
        useTestClock true
    }
    node {
        name "O=Regulator,L=Moscow,C=RU"
        cordapps = ["$corda_release_group:corda-finance:$corda_release_version"]
        rpcUsers = rpcUsersList
        useTestClock true
    }
}

Running the Cordform/Dockerform tasks

To create the nodes defined in our deployNodes task, run the following command in a terminal window from the root of the project where the deployNodes task is defined:

• Linux/macOS: ./gradlew deployNodes
• Windows: gradlew.bat deployNodes

This will create the nodes in the build/nodes folder. There will be a node folder generated for each node defined in the deployNodes task, plus a runnodes shell script (or batch file on Windows) to run all the nodes at once for testing and development purposes. If you make any changes to your CorDapp source or deployNodes task, you will need to re-run the task to see the changes take effect.

If the task is a Dockerform task, running the task will also create an additional Dockerfile in each node directory, and a docker-compose.yml file in the build/nodes directory.

You can now run the nodes by following the instructions in Running a node <running-a-node>.