# wasmCloud Application Deployment Manager (wadm) Wadm is a Wasm-native orchestrator for managing and scaling declarative wasmCloud applications. ## Responsibilities **wadm** is powerful because it focuses on a small set of core responsibilities, making it efficient and easy to manage. - **Manage application specifications** - Manage applications which represent _desired state_. This includes the creation, deletion, upgrades and rollback of applications to previous versions. Application specifications are defined using the [Open Application Model](https://oam.dev/). For more information on wadm's specific OAM features, see our [OAM README](./oam/README.md). - **Observe state** - Monitor wasmCloud [CloudEvents](https://wasmcloud.com/docs/reference/cloud-event-list) from all hosts in a [lattice](https://wasmcloud.com/docs/deployment/lattice/) to build the current state. - **Reconcile with compensating commands** - When the current state doesn't match the desired state, issue commands to wasmCloud hosts in the lattice with the [control interface](https://wasmcloud.com/docs/hosts/lattice-protocols/control-interface) to reach desired state. Wadm is constantly reconciling and will react immediately to ensure applications stay deployed. For example, if a host stops, wadm will reconcile the `host_stopped` event and issue any necessary commands to start components on other available hosts. ## Using wadm [](https://github.com/codespaces/new?hide_repo_select=true&ref=main&repo=401352358&machine=standardLinux32gb&location=EastUs) ### Install & Run You can easily run **wadm** by downloading the [`wash`](https://wasmcloud.com/docs/installation) CLI, which automatically launches wadm alongside NATS and a wasmCloud host when you run `wash up`. You can use `wash` to query, create, and deploy applications. ```bash wash up -d # Start NATS, wasmCloud, and wadm in the background ``` Follow the [wasmCloud quickstart](https://wasmcloud.com/docs/tour/hello-world) to get started building and deploying an application, or follow the **Deploying an application** example below to simply try a deploy. If you prefer to run **wadm** separately and/or connect to running wasmCloud hosts, you can instead opt for using the latest GitHub release artifact and executing the binary. Simply replace the latest version, your operating system, and architecture below. Please note that wadm requires a wasmCloud host version >=0.63.0 ```bash # Install wadm curl -fLO https://github.com/wasmCloud/wadm/releases/download//wadm---.tar.gz tar -xvf wadm---.tar.gz cd wadm--- ./wadm ``` ### Deploying an application Copy the following manifest and save it locally as `hello.yaml` (you can also find it in the `oam` [directory](./oam/hello.yaml)): ```yaml # Metadata apiVersion: core.oam.dev/v1beta1 kind: Application metadata: name: hello-world annotations: description: 'HTTP hello world demo' spec: components: - name: http-component type: component properties: # Run components from OCI registries as below or from a local .wasm component binary. image: ghcr.io/wasmcloud/components/http-hello-world-rust:0.1.0 traits: # One replica of this component will run - type: spreadscaler properties: instances: 1 # The httpserver capability provider, started from the official wasmCloud OCI artifact - name: httpserver type: capability properties: image: ghcr.io/wasmcloud/http-server:0.22.0 traits: # Link the HTTP server and set it to listen on the local machine's port 8080 - type: link properties: target: http-component namespace: wasi package: http interfaces: [incoming-handler] source: config: - name: default-http properties: ADDRESS: 127.0.0.1:8080 ``` Then use `wash` to deploy the manifest: ```bash wash app deploy hello.yaml ``` 🎉 You've just launched your first application with **wadm**! Try `curl localhost:8080`. When you're done, you can use `wash` to undeploy the application: ```bash wash app undeploy hello-world ``` ### Modifying applications **wadm** supports upgrading applications by deploying new versions of manifests. Try changing the manifest you created above by updating the number of instances. ```yaml <> metadata: name: hello-world annotations: description: 'HTTP hello world demo' spec: components: - name: http-component type: component properties: image: ghcr.io/wasmcloud/components/http-hello-world-rust:0.1.0 traits: - type: spreadscaler properties: instances: 10 # Let's have 10! <> ``` Then simply deploy the new manifest: ```bash wash app deploy hello.yaml ``` Now wasmCloud is configured to automatically scale your component to 10 instances based on incoming load. ## 🚧 Advanced You can find a Docker Compose file for deploying an end-to-end multi-tenant example in the [test](https://github.com/wasmCloud/wadm/blob/main/tests/docker-compose-e2e-multitenant.yaml) directory. In advanced use cases, **wadm** is also capable of: - Monitoring multiple lattices. - Running multiple instances to distribute load among multiple processes, or for a high-availability architecture. 🚧 Multi-lattice and multi-process functionality is somewhat tested, but not as rigorously as a single instance monitoring a single lattice. Proceed with caution while we do further testing. ### API Interacting with **wadm** is done over NATS on the root topic `wadm.api.{prefix}` where `prefix` is the lattice namespace prefix. For more information on this API, please consult the [wadm Reference](https://wasmcloud.com/docs/ecosystem/wadm/). ## References The wasmCloud Application Deployment Manager (**wadm**) originally came from [the autonomous lattice controller RFC](https://github.com/wasmCloud/wasmcloud-otp/issues/177) and then was reworked in version `0.4` in response to [the tidying and productioning RFC](https://github.com/wasmCloud/wadm/issues/40). - [Autonomous Agents](https://www.sciencedirect.com/topics/computer-science/autonomous-agent) - [Autonomous Agent (Wikipedia)](https://en.wikipedia.org/wiki/Autonomous_agent) - [Control Loop](https://en.wikipedia.org/wiki/Control_loop) - [Hashicorp Vault](https://www.vaultproject.io/)