feat(trigger/command): implement trigger command

This commit implements support for running "command" triggers in the
shim, based on https://github.com/fermyon/spin-trigger-command.

Specifically, it runs a WASI command component to completion, with
support for both classical WASI preview 1 core modules and WASI preview
2 CLI components.

Finally, this supports passing Kubernetes arguments:

```yaml
      - name: spin-command
        image: <command-component-that-prints-args>
        args: ["these", "are", "some", "args"]
```

These arguments are passed in the component and can be read at runtime
using WASI.

Signed-off-by: Radu Matei <[email protected]>

Author: radu-matei

Cargo.lock

@@ -22,6 +22,7 @@ spin-trigger = { git = "https://github.com/fermyon/spin", tag = "v2.4.2", featur
 spin-trigger-http = { git = "https://github.com/fermyon/spin", tag = "v2.4.2" }
 spin-trigger-redis = { git = "https://github.com/fermyon/spin", tag = "v2.4.2" }
 trigger-sqs = { git = "https://github.com/fermyon/spin-trigger-sqs", rev = "dbfc599560ab54e759bfa586fe7315848f00a7f6" }
+trigger-command = { git = "https://github.com/fermyon/spin-trigger-command" , rev = "af3cf1148573ab10e1e819b66cd920a04a789e50" }
 spin-manifest = { git = "https://github.com/fermyon/spin", tag = "v2.4.2" }
 spin-loader = { git = "https://github.com/fermyon/spin", tag = "v2.4.2" }
 spin-oci = { git = "https://github.com/fermyon/spin", tag = "v2.4.2" }

containerd-shim-spin/Cargo.toml

@@ -21,6 +21,7 @@ use std::net::SocketAddr;
 use std::net::ToSocketAddrs;
 use std::path::{Path, PathBuf};
 use tokio::runtime::Runtime;
+use trigger_command::CommandTrigger;
 use trigger_sqs::SqsTrigger;
 use url::Url;
 
@@ -190,11 +191,13 @@ impl SpinEngine {
         let trigger_cmd = trigger_command_for_resolved_app_source(&resolved_app_source)
             .with_context(|| format!("Couldn't find trigger executor for {app_source:?}"))?;
         let locked_app = self.load_resolved_app_source(resolved_app_source).await?;
-        self.run_trigger(&trigger_cmd, locked_app, app_source).await
+        self.run_trigger(ctx, &trigger_cmd, locked_app, app_source)
+            .await
     }
 
     async fn run_trigger(
         &self,
+        ctx: &impl RuntimeContext,
         trigger_type: &str,
         app: LockedApp,
         app_source: AppSource,
@@ -232,6 +235,17 @@ impl SpinEngine {
                 info!(" >>> running spin trigger");
                 sqs_trigger.run(spin_trigger::cli::NoArgs)
             }
+            CommandTrigger::TRIGGER_TYPE => {
+                let command_trigger: CommandTrigger = self
+                    .build_spin_trigger(working_dir, app, app_source)
+                    .await
+                    .context("failed to build spin trigger")?;
+
+                info!(" >>> running spin trigger");
+                command_trigger.run(trigger_command::CliArgs {
+                    guest_args: ctx.args().to_vec(),
+                })
+            }
             _ => {
                 todo!("Only Http, Redis and SQS triggers are currently supported.")
             }
@@ -442,11 +456,12 @@ fn trigger_command_for_resolved_app_source(resolved: &ResolvedAppSource) -> Resu
     let trigger_type = resolved.trigger_type()?;
 
     match trigger_type {
-        RedisTrigger::TRIGGER_TYPE | HttpTrigger::TRIGGER_TYPE | SqsTrigger::TRIGGER_TYPE => {
-            Ok(trigger_type.to_owned())
-        }
+        RedisTrigger::TRIGGER_TYPE
+        | HttpTrigger::TRIGGER_TYPE
+        | SqsTrigger::TRIGGER_TYPE
+        | CommandTrigger::TRIGGER_TYPE => Ok(trigger_type.to_owned()),
         _ => {
-            todo!("Only Http, Redis and SQS triggers are currently supported.")
+            todo!("Only Http, Redis, SQS, and command triggers are currently supported.")
         }
     }
 }