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

Creating nodes locally

Node structure

Each Corda node has the following structure:

.
├── certificates            // The node's certificates
├── corda-webserver.jar     // The built-in node webserver
├── corda.jar               // The core Corda libraries
├── logs                    // The node logs
├── node.conf               // The node's configuration files
├── persistence.mv.db       // The node's database
└── cordapps                // The CorDapps jars installed on the node

The node is configured by editing its node.conf file. You install CorDapps on the node by dropping the CorDapp JARs into the cordapps folder.

Node naming

A node's name must be a valid X.500 distinguished name. In order to be compatible with other implementations (particularly TLS implementations), we constrain the allowed X.500 attribute types to a subset of the minimum supported set for X.509 certificates (specified in RFC 3280), plus the locality attribute:

• Organization (O)
• State (ST)
• Locality (L)
• Country (C)
• Organizational-unit (OU)
• Common name (CN) (only used for service identities)

The name must also obey the following constraints:

• The organisation, locality and country attributes are present

  • The state, organisational-unit and common name attributes are optional

• The fields of the name have the following maximum character lengths:

  • Common name: 64
  • Organisation: 128
  • Organisation unit: 64
  • Locality: 64
  • State: 64

• The country attribute is a valid ISO 3166-1 two letter code in upper-case

• All attributes must obey the following constraints:

  • Upper-case first letter
  • Has at least two letters
  • No leading or trailing whitespace
  • Does not include the following characters: , , = , $ , " , ' , \
  • Is in NFKC normalization form
  • Does not contain the null character
  • Only the latin, common and inherited unicode scripts are supported

• The organisation field of the name also obeys the following constraints:

  • No double-spacing

    • This is to avoid right-to-left issues, debugging issues when we can't pronounce names over the phone, and character confusability attacks

The Cordform task

Corda provides a gradle plugin called Cordform that allows you to automatically generate and configure a set of nodes. 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"
    networkMap "O=NetworkMapAndNotary,L=London,C=GB"
    node {
        name "O=NetworkMapAndNotary,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
        // Includes the corda-finance CorDapp on our node.
        cordapps = ["net.corda:corda-finance:$corda_release_version"]
    }
    node {
        name "O=PartyA,L=London,C=GB"
        p2pPort  10005
        rpcSettings {
            port 10006
            adminPort 10026
        }
        webPort  10007
        h2Port   10008
        cordapps = ["net.corda:corda-finance:$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"]]]
    }
}

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. 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/none-b.conf"
    }
}

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

• A NetworkMapAndNotary node that:
  • Serves as the network map
  • 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 pointing at the NetworkMapAndNotary as the network map service
  • 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. The only requirement is that you must specify a single node to run the network map service, by putting its name in the networkMap field.

Warning

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

The Dockerform task

The `Dockerform is a sister task of Cordform. It has nearly the same syntax and produces very similar results - enhanced by an extra file to enable easy spin up of nodes using docker-compose. Below you can find the example task from the IRS Demo<https://github.com/corda/corda/blob/release-V3.0/samples/irs-demo/cordapp/build.gradle#L111>` 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 prepareDockerNodes(type: net.corda.plugins.Dockerform, dependsOn: ['jar']) {

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

There is no need to specify the ports, as every node is a separated container, so no ports conflict will occur. Running the task will create the same folders structure as described in The Cordform task with an additional `Dockerfile in each node directory, and `docker-compose.yml in build/nodes` directory. Every node by default exposes port 10003 which is the default one for RPC connections.

Warning

Webserver is not supported by this task!

Warning

Nodes are run without the local shell enabled!

Running deployNodes

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.

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