Adding discovery of capacities after the fact.

libdaggy/include/daggy/executors/task/DaggyRunnerTaskExecutor.hpp

@@ -15,6 +15,11 @@ namespace daggy::executors::task {
     {
       ssize_t cores;
       ssize_t memoryMB;
+      void operator==(const Capacity &other)
+      {
+        cores    = other.cores;
+        memoryMB = other.memoryMB;
+      }
     };
 
     std::string capacityToJSON(const Capacity &cap);

libdaggy/src/executors/task/DaggyRunnerTaskExecutor.cpp

@@ -139,11 +139,23 @@ std::future<AttemptRecord> DaggyRunnerTaskExecutor::execute(
 
   {
     std::lock_guard<std::mutex> lock(runnersGuard_);
-    for (const auto &[runner, caps] : runners_) {
+    for (auto &[runner, caps] : runners_) {
       const auto result = HTTP_REQUEST(runner + "/ready");
       if (result.code != 200)
         continue;
 
+      // Set capacities if they haven't been discovered yet
+      if (caps.total.cores == 0) {
+        const auto &[code, json] = JSON_HTTP_REQUEST(runner + "/v1/capacity");
+        if (code != HTTPCode::Ok) {
+          std::cerr << "Runner " << runner
+                    << " appears to be up, but cannot retrieve capacity";
+          continue;
+        }
+        caps.current = capacityFromJSON(json["current"]);
+        caps.total   = capacityFromJSON(json["total"]);
+      }
+
       double cores    = (caps.current.cores - taskUsed.cores);
       double memoryMB = (caps.current.memoryMB - taskUsed.memoryMB);
 
@@ -203,10 +215,14 @@ void DaggyRunnerTaskExecutor::addRunner(const std::string &url)
   // Try and get the capacity
   const auto &[code, doc] = JSON_HTTP_REQUEST(url + "/v1/capacity");
   if (code != HTTPCode::Ok) {
-    std::cerr << "Failed to add runner " << url << ": "
+    std::cerr << "Failed to contact runner " << url << ": "
-              << doc["error"].GetString() << std::endl;
+              << doc["error"].GetString()
+              << ", will attempt to set capacities later" << std::endl;
+
+    runners_.emplace(url, RunnerCapacity{});
     return;
   }
+
   RunnerCapacity caps{.current = capacityFromJSON(doc["current"]),
                       .total   = capacityFromJSON(doc["total"])};
   std::lock_guard<std::mutex> lock(runnersGuard_);