working out the worker/execution interface

packs/core/actions/download_packs.yaml

@@ -0,0 +1,120 @@
+# Download Packs Action
+# Downloads packs from various sources (git repositories, HTTP archives, or pack registry)
+
+name: download_packs
+ref: core.download_packs
+description: "Download packs from git repositories, HTTP archives, or pack registry to a temporary directory"
+enabled: true
+runner_type: shell
+entry_point: download_packs.sh
+
+# Parameter delivery: stdin for secure parameter passing (no env vars)
+parameter_delivery: stdin
+parameter_format: json
+
+# Output format: json (structured data parsing enabled)
+output_format: json
+
+# Action parameters schema
+parameters:
+  type: object
+  properties:
+    packs:
+      type: array
+      description: "List of packs to download (git URLs, HTTP URLs, or pack refs)"
+      items:
+        type: string
+      minItems: 1
+    destination_dir:
+      type: string
+      description: "Destination directory for downloaded packs"
+    registry_url:
+      type: string
+      description: "Pack registry URL for resolving pack refs (optional)"
+      default: "https://registry.attune.io/index.json"
+    ref_spec:
+      type: string
+      description: "Git reference to checkout (branch, tag, or commit) - applies to all git URLs"
+    timeout:
+      type: integer
+      description: "Download timeout in seconds per pack"
+      default: 300
+      minimum: 10
+      maximum: 3600
+    verify_ssl:
+      type: boolean
+      description: "Verify SSL certificates for HTTPS downloads"
+      default: true
+    api_url:
+      type: string
+      description: "Attune API URL for making registry lookups"
+      default: "http://localhost:8080"
+  required:
+    - packs
+    - destination_dir
+
+# Output schema: describes the JSON structure written to stdout
+# Note: stdout/stderr/exit_code are captured automatically by the execution system
+output_schema:
+  type: object
+  properties:
+    downloaded_packs:
+      type: array
+      description: "List of successfully downloaded packs"
+      items:
+        type: object
+        properties:
+          source:
+            type: string
+            description: "Original pack source (URL or ref)"
+          source_type:
+            type: string
+            description: "Type of source"
+            enum:
+              - git
+              - http
+              - registry
+          pack_path:
+            type: string
+            description: "Local filesystem path to downloaded pack"
+          pack_ref:
+            type: string
+            description: "Pack reference (from pack.yaml)"
+          pack_version:
+            type: string
+            description: "Pack version (from pack.yaml)"
+          git_commit:
+            type: string
+            description: "Git commit hash (for git sources)"
+          checksum:
+            type: string
+            description: "Directory checksum"
+    failed_packs:
+      type: array
+      description: "List of packs that failed to download"
+      items:
+        type: object
+        properties:
+          source:
+            type: string
+            description: "Pack source that failed"
+          error:
+            type: string
+            description: "Error message"
+    total_count:
+      type: integer
+      description: "Total number of packs requested"
+    success_count:
+      type: integer
+      description: "Number of packs successfully downloaded"
+    failure_count:
+      type: integer
+      description: "Number of packs that failed"
+
+# Tags for categorization
+tags:
+  - pack
+  - download
+  - git
+  - installation
+  - registry