Interactive REPL¶

The sloth-runner repl command drops you into an interactive Read-Eval-Print Loop (REPL) session. This is a powerful tool for debugging, exploration, and quick experimentation with the sloth-runner modules.

Starting the REPL¶

To start a session, simply run:

sloth-runner repl

You can also pre-load a workflow file to have its tasks, workflows, and helper functions available in the session. This is incredibly useful for debugging an existing pipeline.

sloth-runner repl -f /path/to/your/pipeline.sloth

Features¶

Live Environment¶

The REPL provides a live Lua environment where you can execute any Lua code. All the built-in sloth-runner modules (aws, docker, fs, log, etc.) are pre-loaded and ready to use.

sloth> log.info("Hello from the REPL!")
sloth> result = fs.read("README.md")
sloth> print(string.sub(result, 1, 50))

Autocompletion¶

The REPL has a sophisticated autocompletion system. - Start typing the name of a global variable or module (e.g., aws) and press Tab to see suggestions. - Type a module name followed by a dot (e.g., docker.) and press Tab to see all the functions available in that module.

History¶

The REPL keeps a history of your commands. Use the up and down arrow keys to navigate through previous commands.

Example Sessions¶

Testing Module Functions¶

Here is an example of using the REPL to debug a Docker command.

$ sloth-runner repl
Sloth-Runner Interactive REPL
Type 'exit' or 'quit' to leave.
sloth> result = docker.exec({"ps", "-a"})
sloth> print(result.stdout)
CONTAINER ID   IMAGE     COMMAND   CREATED   STATUS    PORTS     NAMES
sloth> -- Now let's try to build an image
sloth> build_result = docker.build({tag="my-test", path="./examples/docker"})
sloth> print(build_result.success)
true
sloth> exit
Bye!

Testing Modern DSL Tasks¶

You can also test and debug tasks using the modern DSL pattern in the REPL:

$ sloth-runner repl
Sloth-Runner Interactive REPL
Type 'exit' or 'quit' to leave.
sloth> -- Create a task using modern DSL
sloth> my_task = task("test_deploy")
sloth>     :description("Test deployment task")
sloth>     :command(function(this, params)
sloth>         log.info("Running deployment...")
sloth>         return true, "Deployment successful"
sloth>     end)
sloth>     :timeout("5m")
sloth>     :build()
sloth>
sloth> -- Test the task execution
sloth> result = my_task:execute()
sloth> print(result)
sloth> exit
Bye!

Testing Workflows¶

You can build and test complete workflows interactively:

$ sloth-runner repl
Sloth-Runner Interactive REPL
Type 'exit' or 'quit' to leave.
sloth> -- Define a simple task
sloth> check_task = task("check")
sloth>     :command(function(this, params)
sloth>         log.info("Checking environment...")
sloth>         return true, "Environment OK"
sloth>     end)
sloth>     :build()
sloth>
sloth> -- Create a workflow with the task
sloth> my_workflow = workflow.define("test_workflow")
sloth>     :description("Test workflow")
sloth>     :version("1.0.0")
sloth>     :tasks({ check_task })
sloth>
sloth> -- Execute the workflow
sloth> my_workflow:run()
sloth> exit
Bye!