Adding New Resource Types

This guide explains how to extend the Nitric CLI to support custom resource types, covering both deployment (nitric up) and local development (nitric start).

This guide is for contributors who want to add entirely new resource types to Nitric's core. If you want to replace existing resources in a provider or build a custom provider, see Extending Standard Providers or Building Custom Providers.

Overview

Adding a new resource type to Nitric requires changes across three repositories:

nitric/core - Proto definitions and gRPC service interfaces
nitric/cli - Resource collection, spec building, and local development
Your custom provider - Cloud-specific deployment logic

Architecture

The following diagram shows how resources flow through the Nitric system:

Your application code makes SDK calls that are sent via gRPC to the Nitric CLI's collector. The collector builds a deployment spec (protobuf), which is then sent to your provider for cloud-specific resource creation.

Part 1: Nitric Core Changes

The first step is defining your new resource type in the nitric/core repository.

Clone the Repository

git clone https://github.com/nitrictech/nitric.git

Add Resource Type Enum

The proto source files are in nitric/proto/, and Go code is generated into core/pkg/proto/.

In nitric/proto/resources/v1/resources.proto, add your new resource type to the ResourceType enum:

enum ResourceType {
  // ... existing types ...
  YourResourceType = N;  // Use the next available number
}

Define Resource Proto Message

In the same file, add a message for your resource configuration:

message YourResource {
  // Resource-specific configuration fields
  string some_config = 1;
}

Update ResourceDeclareRequest

Add your resource to the ResourceDeclareRequest oneof:

message ResourceDeclareRequest {
  ResourceIdentifier id = 1;
  oneof config {
    // ... existing configs ...
    YourResource your_resource = N;
  }
}

Add Deployment Resource

If your resource needs deployment-specific configuration, update nitric/proto/deployments/v1/deployments.proto:

message YourDeploymentResource {
  // Deployment-specific fields (image URIs, targets, etc.)
}

message Resource {
  // In the config oneof:
  oneof config {
    // ... existing configs ...
    YourDeploymentResource your_resource = N;
  }
}

Regenerate Proto Code

Run the proto generation in the core directory to create Go code from your proto definitions:

cd core && make generate-proto

Part 2: CLI Changes - Resource Collection

These changes enable nitric up to collect your new resource type from application code.

Update ServiceRequirements Struct

In pkg/collector/service.go, add a field for your new resource in the ServiceRequirements struct:

type ServiceRequirements struct {
    // ... existing fields ...

    yourResources map[string]*resourcespb.YourResource
}

Handle Resource Declaration

Add a case in the Declare() method to handle your resource type:

func (s *ServiceRequirements) Declare(ctx context.Context, req *resourcespb.ResourceDeclareRequest) (*resourcespb.ResourceDeclareResponse, error) {
    s.resourceLock.Lock()
    defer s.resourceLock.Unlock()

    // ... existing validation ...

    switch req.Id.Type {
    // ... existing cases ...

    case resourcespb.ResourceType_YourResourceType:
        s.yourResources[req.Id.GetName()] = req.GetYourResource()
    }

    return &resourcespb.ResourceDeclareResponse{}, nil
}

Initialize the Map

In NewServiceRequirements(), initialize your map:

func NewServiceRequirements(serviceName string, serviceFile string, serviceType string) *ServiceRequirements {
    requirements := &ServiceRequirements{
        // ... existing initializations ...
        yourResources: make(map[string]*resourcespb.YourResource),
    }
    return requirements
}

Update BatchRequirements

If your resource should be available to batch jobs, make similar changes in pkg/collector/batch.go:

Add field to BatchRequirements struct
Add case in Declare() method
Initialize in NewBatchRequirements()

Build Deployment Spec

In pkg/collector/spec.go, create a builder function for your resource:

func buildYourResourceRequirements(allServiceRequirements []*ServiceRequirements, allBatchRequirements []*BatchRequirements, projectErrors *ProjectErrors) ([]*deploymentspb.Resource, error) {
    resources := []*deploymentspb.Resource{}

    for _, serviceRequirements := range allServiceRequirements {
        for resourceName, config := range serviceRequirements.yourResources {
            _, exists := lo.Find(resources, func(item *deploymentspb.Resource) bool {
                return item.Id.Name == resourceName
            })

            if !exists {
                res := &deploymentspb.Resource{
                    Id: &resourcespb.ResourceIdentifier{
                        Name: resourceName,
                        Type: resourcespb.ResourceType_YourResourceType,
                    },
                    Config: &deploymentspb.Resource_YourResource{
                        YourResource: &deploymentspb.YourDeploymentResource{
                            // Map configuration
                        },
                    },
                }
                resources = append(resources, res)
            }
        }
    }

    // Similar loop for batch requirements if needed

    return resources, nil
}

Call Your Builder

Add your builder call in ServiceRequirementsToSpec():

func ServiceRequirementsToSpec(...) (*deploymentspb.Spec, error) {
    // ... existing code ...

    yourResources, err := buildYourResourceRequirements(allServiceRequirements, allBatchRequirements, projectErrors)
    if err != nil {
        return nil, err
    }
    newSpec.Resources = append(newSpec.Resources, yourResources...)

    // ... rest of function ...
}

Part 3: CLI Changes - Local Development

To support your new resource in nitric start, you'll need to implement a local service.

Create Local Service

Create a new file pkg/cloud/yourresource/yourresource.go:

package yourresource

import (
    "context"
    "sync"

    "github.com/asaskevich/EventBus"
    yourpb "github.com/nitrictech/nitric/core/pkg/proto/yourresource/v1"
)

type LocalYourResourceState struct {
    // State that the dashboard/gateway needs to see
}

type LocalYourResourceService struct {
    stateLock sync.RWMutex
    state     LocalYourResourceState
    bus       EventBus.Bus
}

func (s *LocalYourResourceService) SubscribeToState(fn func(LocalYourResourceState)) {
    _ = s.bus.Subscribe("your_resource_topic", fn)
}

func (s *LocalYourResourceService) SomeMethod(ctx context.Context, req *yourpb.SomeRequest) (*yourpb.SomeResponse, error) {
    // Implementation
    return &yourpb.SomeResponse{}, nil
}

func NewLocalYourResourceService() (*LocalYourResourceService, error) {
    return &LocalYourResourceService{
        bus: EventBus.New(),
    }, nil
}

Register with LocalCloud

In pkg/cloud/cloud.go:

Import your package:

import (
    // ... existing imports ...
    "github.com/nitrictech/cli/pkg/cloud/yourresource"
)

Add field to LocalCloud struct:

type LocalCloud struct {
    // ... existing fields ...
    YourResource *yourresource.LocalYourResourceService
}

Initialize in New() function:

func New(projectName string, opts LocalCloudOptions) (*LocalCloud, error) {
    // ... existing initializations ...

    localYourResource, err := yourresource.NewLocalYourResourceService()
    if err != nil {
        return nil, err
    }

    return &LocalCloud{
        // ... existing fields ...
        YourResource: localYourResource,
    }, nil
}

Wire into server plugins in AddService() and AddBatch():

nitricRuntimeServer, _ := server.New(
    // ... existing plugins ...
    server.WithYourResourcePlugin(lc.YourResource),
    // ...
)

You'll need to add the WithYourResourcePlugin option to the nitric/core server package.

Update Local Resources Service

In pkg/cloud/resources/resources.go, if your resource should be tracked in the dashboard:

Add to LocalResourcesState:

type LocalResourcesState struct {
    // ... existing fields ...
    YourResources *ResourceRegistrar[resourcespb.YourResource]
}

Handle in Declare() method:

case resourcespb.ResourceType_YourResourceType:
    err = l.state.YourResources.Register(req.Id.Name, serviceName, req.GetYourResource())

Initialize in NewLocalResourcesService():

YourResources: NewResourceRegistrar[resourcespb.YourResource](),

Clear in ClearServiceResources():

l.state.YourResources.ClearRequestingService(serviceName)

Part 4: Provider Implementation

Your custom provider receives the deployment spec via gRPC and creates cloud resources.

Handle New Resource in Provider

In your provider's deployment handler, add a case for your resource type:

func (p *Provider) deployResource(resource *deploymentspb.Resource) error {
    switch resource.Id.Type {
    // ... existing cases ...

    case resourcespb.ResourceType_YourResourceType:
        config := resource.GetYourResource()
        // Create your cloud resource here using config
    }
    return nil
}

Implement gRPC Runtime Service

If your resource has runtime operations (e.g., read/write), first create a service proto in nitric/proto/yourresource/v1/yourresource.proto:

syntax = "proto3";
package nitric.proto.yourresource.v1;

option go_package = "github.com/nitrictech/nitric/core/pkg/proto/yourresource/v1;yourresourcepb";

service YourResource {
  rpc Get (GetRequest) returns (GetResponse);
  rpc Set (SetRequest) returns (SetResponse);
  rpc Delete (DeleteRequest) returns (DeleteResponse);
}

// Define request/response messages...

See nitric/proto/storage/v1/storage.proto or nitric/proto/kvstore/v1/kvstore.proto for complete examples. Run make generate-proto again after adding this file.

Then implement the generated service interface in your provider.

Part 5: Update go.mod

Point to your forked nitric/core:

replace github.com/nitrictech/nitric/core => github.com/your-org/nitric/core v0.0.0-xxxxx

Or for local development:

replace github.com/nitrictech/nitric/core => ../path/to/your/nitric/core

Key Files Reference

Purpose	File Path
Service resource collection	`pkg/collector/service.go`
Batch resource collection	`pkg/collector/batch.go`
Spec building	`pkg/collector/spec.go`
Deployment flow	`cmd/stack.go`
Provider interface	`pkg/provider/provider.go`
Deployment client	`pkg/provider/client.go`
Local cloud setup	`pkg/cloud/cloud.go`
Local resources	`pkg/cloud/resources/resources.go`

Deployment Flow Summary

Build - CLI builds Docker images for services
Collect - CLI starts gRPC server, runs containers, collects resource declarations
Spec - CLI converts collected requirements to deployment spec
Provider Start - CLI starts provider binary
Deploy - CLI sends spec to provider via gRPC
Events - Provider streams deployment progress back to CLI

Testing Your Changes

Build the CLI:

make build

Test resource collection:

./nitric up -s your-stack --debug

For local development testing:

./nitric start

Notes

The CLI uses proto definitions from github.com/nitrictech/nitric/core
Proto packages are imported from github.com/nitrictech/nitric/core/pkg/proto/*/v1
Resources must have valid names (checked by validation.IsValidResourceName())
Policies are handled specially - principals are auto-populated with service names