huskies: merge 1138 story In-container huskies self-update — huskies upgrade pulls a fresh binary without docker rebuild

server/src/http/gateway/mcp.rs

@@ -26,6 +26,8 @@ const GATEWAY_TOOLS: &[&str] = &[
     // Handled at the gateway so the Matrix bot's perm_rx listener is used
     // rather than the container's (which has no interactive session attached).
     "prompt_permission",
+    // Binary self-update: gateway serves its own binary and triggers upgrade on sleds.
+    "upgrade_sled",
 ];
 
 /// Gateway tool definitions.
@@ -121,6 +123,23 @@ pub(crate) fn gateway_tool_definitions() -> Vec<Value> {
                 "properties": {}
             }
         }),
+        json!({
+            "name": "upgrade_sled",
+            "description": "Trigger a binary self-update on a project sled. The sled downloads the new binary from `source_url` (defaults to this gateway's /api/huskies-binary endpoint), atomically replaces its own executable, drains CRDT persistence so no ops are lost, and re-execs. Without `project`, upgrades the active project.",
+            "inputSchema": {
+                "type": "object",
+                "properties": {
+                    "project": {
+                        "type": "string",
+                        "description": "Name of the project sled to upgrade. Defaults to the currently active project."
+                    },
+                    "source_url": {
+                        "type": "string",
+                        "description": "HTTP URL of the binary to install (e.g. 'http://gateway:3000/api/huskies-binary'). Defaults to this gateway's own binary endpoint."
+                    }
+                }
+            }
+        }),
     ]
 }
 
@@ -385,6 +404,7 @@ async fn handle_gateway_tool(
         "aggregate_pipeline_status" => handle_aggregate_pipeline_status_tool(state, id).await,
         "agents.list" => handle_agents_list_tool(id),
         "prompt_permission" => handle_prompt_permission_tool(params, state, id).await,
+        "upgrade_sled" => handle_upgrade_sled_tool(params, state, id).await,
         _ => JsonRpcResponse::error(id, -32601, format!("Unknown gateway tool: {tool_name}")),
     }
 }
@@ -769,6 +789,93 @@ fn handle_agents_list_tool(id: Option<Value>) -> JsonRpcResponse {
     )
 }
 
+/// Handle the `upgrade_sled` gateway tool.
+///
+/// Posts `{"source_url": "<url>"}` to the target sled's `/api/upgrade` endpoint,
+/// which triggers the sled to download the new binary, drain CRDT persistence,
+/// and re-exec.  Returns 202 text immediately — the sled connection will drop
+/// shortly after as `exec()` replaces the process.
+async fn handle_upgrade_sled_tool(
+    params: &Value,
+    state: &GatewayState,
+    id: Option<Value>,
+) -> JsonRpcResponse {
+    let args = params.get("arguments").unwrap_or(params);
+
+    // Resolve target project URL (explicit project arg or active project).
+    let project_name = args.get("project").and_then(|v| v.as_str());
+    let sled_url = if let Some(name) = project_name {
+        let projects = state.projects.read().await;
+        match projects.get(name).and_then(|e| e.url.clone()) {
+            Some(u) => u,
+            None => {
+                return JsonRpcResponse::error(
+                    id,
+                    -32602,
+                    format!("Project '{name}' not found or has no URL configured"),
+                );
+            }
+        }
+    } else {
+        match state.active_url().await {
+            Ok(u) => u,
+            Err(e) => return JsonRpcResponse::error(id, -32603, e.to_string()),
+        }
+    };
+
+    // Build the binary source URL: caller-supplied or this gateway's own endpoint.
+    let source_url = args
+        .get("source_url")
+        .and_then(|v| v.as_str())
+        .map(|s| s.to_string())
+        .unwrap_or_else(|| {
+            // Default: the gateway serves its own binary at /api/huskies-binary.
+            // Use the same host/port the gateway is bound to.
+            std::env::var("HUSKIES_GATEWAY_BINARY_URL")
+                .unwrap_or_else(|_| format!("http://gateway:{}/api/huskies-binary", state.port))
+        });
+
+    let upgrade_url = format!("{sled_url}/api/upgrade");
+    let body = serde_json::json!({ "source_url": source_url });
+
+    let active_name = project_name.map(|s| s.to_string()).unwrap_or_else(|| {
+        state
+            .active_project
+            .try_read()
+            .map(|g| g.clone())
+            .unwrap_or_default()
+    });
+
+    match state.client.post(&upgrade_url).json(&body).send().await {
+        Ok(resp) if resp.status().is_success() || resp.status().as_u16() == 202 => {
+            JsonRpcResponse::success(
+                id,
+                json!({
+                    "content": [{
+                        "type": "text",
+                        "text": format!(
+                            "Upgrade triggered on '{active_name}'. The sled is downloading the new binary from {source_url} and will re-exec momentarily."
+                        )
+                    }]
+                }),
+            )
+        }
+        Ok(resp) => JsonRpcResponse::error(
+            id,
+            -32603,
+            format!(
+                "Sled returned HTTP {} for upgrade request to {upgrade_url}",
+                resp.status()
+            ),
+        ),
+        Err(e) => JsonRpcResponse::error(
+            id,
+            -32603,
+            format!("Failed to send upgrade request to {upgrade_url}: {e}"),
+        ),
+    }
+}
+
 /// Handle the `pipeline.get` read-RPC — returns per-project item lists in the
 /// shape expected by the gateway web UI:
 /// `{ "active": "...", "projects": { "name": { "active": [...], "backlog_count": N } } }`.