CLI Trigger

Wick’s CLI Trigger executes whenever an application is executed on the command line (which is almost always). It delegates CLI args and STDIO to an operation which can optionally depend on arbitrary other components to provide dynamic CLI behavior.

Example

Example showing how to wire together a WebAssembly component with a SQL component into a CLI Trigger.

This app configuration starts off with the common Application kind and a name field.

kind: wick/app@v1
name: db_cli

The CLI trigger is configured with an operation that accepts args: string[] and interactive: { stdin: bool, stdout: bool, stderr: bool } as input.

This example uses two components, one that provides the CLI interface:

import:
- component:
    kind: wick/component/manifest@v1
    provide:
      db: MYDB
    ref: ../../crates/integration/test-cli-with-db/component.yaml
  name: CLI

And another that the first component requires, called MYDB. This is a SQL component that provides an interface whose implementation is backed by a SQL query vs compiled code. It’s implementation isn’t important for this example, but you can see it in the full configuration included at the end of this page.

The trigger configuration delegates operation to the main operation on our CLI component:

triggers:
- kind: wick/trigger/cli@v1
  operation: CLI::main

Our CLI trigger will execute when we run wick run on the command line.

The full configuration is located at examples/cli/wasm-calling-postgres.wick. Run this application locally by cloning the wick repository and using wick run (or cargo run -p wick-cli -- run to run from source)

git clone https://github.com/candlecorp/wick && cd wick
wick run examples/cli/wasm-calling-postgres.wick

Complete Example

Note: Examples may require environment variables and execution from within the wick project’s root to access any local files.

The full example configuration is included below,

name: db_cli
kind: wick/app@v1
metadata:
  description: Example showing how to wire together a WebAssembly component with a SQL component into a CLI Trigger.
  version: 0.0.1
  authors:
    - 'Wick Maintainers'
  vendors:
    - 'Candle Corporation'
  licenses:
    - Apache-2.0
resources:
  - name: DBADDR
    resource:
      kind: wick/resource/url@v1
      url: postgres://postgres:{{ ctx.env.TEST_PASSWORD }}@{{ ctx.env.TEST_HOST }}:{{ ctx.env.POSTGRES_PORT }}/wick_test
import:
  - name: MYDB
    component:
      kind: wick/component/sql@v1
      resource: DBADDR
      tls: false
      operations:
        - name: get_user
          inputs:
            - name: id
              type: i32
          query: SELECT name FROM users WHERE id = $1
          arguments:
            - id
  - name: CLI
    component:
      kind: wick/component/manifest@v1
      ref: ../../crates/integration/test-cli-with-db/component.yaml
      provide:
        db: MYDB
triggers:
  - kind: wick/trigger/cli@v1
    operation: CLI::main