Running Spin Applications

• Specifying the Application to Run
  • Testing HTTP Applications
• Application Output
• Persistent Logs
• Trigger-Specific Options
• Next Steps

Once you have created and built your application, it’s ready to run. To run an application, use the spin up command.

Specifying the Application to Run

By default, spin up looks for a file named spin.toml in the current directory.

If your manifest is named something different, or isn’t in your current directory, use the -f (--from) flag. You also use -f to run remote applications.

If Spin misunderstands a registry reference as a file name, or vice versa, you can use --from-file or --from-registry instead of -f to disambiguate.

If you see the error failed to resolve content at "example.wasm" (where example.wasm is the module file of a component), check that the application has been built.

Testing HTTP Applications

By default, HTTP applications listen on localhost:3000. You can override this with the --listen option. Spin prints links to the application components to make it easy to open them in the browser or copy them to curl commands for testing.

Application Output

By default, Spin prints application output, and any of its own error messages, to the console.

To hide application output, pass the --quiet flag:

$ spin up --quiet

To limit application output to specific components, pass the --follow flag:

$ spin up --follow cart --follow cart-api

Persistent Logs

By default:

• If you run an application from the file system (a TOML file), Spin saves a copy of the application output and error messages. This is saved in the .spin/logs directory, under the directory containing the manifest file.
• If you run an application from a registry reference, Spin does not save a copy of the application output and error messages; they are only printed to the console.

To control logging, pass the --log-dir flag. The logs will be saved to the specified directory (no matter whether the application is local or remote).

$ spin up --log-dir ~/dev/bugbash

Trigger-Specific Options

Some trigger types support additional spin up flags. For example, HTTP applications can have a --listen flag to specify an address and port to listen on. See the HTTP trigger and Redis trigger pages for more details.

Next Steps

• Learn how to create and update a Spin application
• Learn about how to configure your application at runtime
• See how to package and distribute your application
• Try deploying your application to run in the Fermyon Cloud