Harden Datum container discovery

apps/api/src/datum/poller.ts

@@ -106,7 +106,15 @@ type DockerInspect = {
   };
 };
 
-let lastResolvedDatumUrl = config.datum.url;
+type DockerContainerSummary = {
+  Id: string;
+  Names?: string[];
+  Image?: string;
+  Labels?: Record<string, string>;
+  State?: string;
+};
+
+let lastResolvedDatumUrl: string | null = null;
 
 function dockerGetJson<T>(path: string): Promise<T> {
   return new Promise((resolve, reject) => {
@@ -141,11 +149,8 @@ async function resolveDatumUrl(): Promise<string> {
   if (!container || !network) return config.datum.url;
 
   try {
-    const inspected = await dockerGetJson<DockerInspect>(`/containers/${encodeURIComponent(container)}/json`);
-    const address = inspected.NetworkSettings?.Networks?.[network]?.IPAddress;
-    if (!address) {
-      throw new Error(`container ${container} has no IP on network ${network}`);
-    }
+    const inspected = await inspectDatumContainer(container);
+    const address = selectNetworkAddress(inspected, network);
     const port = new URL(config.datum.url).port || "21000";
     lastResolvedDatumUrl = `http://${address}:${port}`;
   } catch (err) {
@@ -153,9 +158,64 @@ async function resolveDatumUrl(): Promise<string> {
       { reason: formatErr(err), container, network, fallbackUrl: lastResolvedDatumUrl },
       "datum_docker_discovery_failed",
     );
+    if (!lastResolvedDatumUrl) throw err;
   }
 
-  return lastResolvedDatumUrl;
+  return lastResolvedDatumUrl ?? config.datum.url;
+}
+
+async function inspectDatumContainer(container: string): Promise<DockerInspect> {
+  try {
+    return await dockerGetJson<DockerInspect>(`/containers/${encodeURIComponent(container)}/json`);
+  } catch (err) {
+    logger.warn({ reason: formatErr(err), container }, "datum_named_container_inspect_failed");
+  }
+
+  const containers = await dockerGetJson<DockerContainerSummary[]>("/containers/json?all=1");
+  const candidates = containers
+    .filter(isLikelyDatumContainer)
+    .sort((a, b) => Number(b.State === "running") - Number(a.State === "running"));
+
+  for (const candidate of candidates) {
+    try {
+      return await dockerGetJson<DockerInspect>(`/containers/${candidate.Id}/json`);
+    } catch (err) {
+      logger.warn({ reason: formatErr(err), id: candidate.Id, names: candidate.Names }, "datum_candidate_inspect_failed");
+    }
+  }
+
+  throw new Error(
+    `Could not find a Datum container through Docker; checked ${containers.length} containers and expected ${container}`,
+  );
+}
+
+function isLikelyDatumContainer(container: DockerContainerSummary): boolean {
+  const names = (container.Names ?? []).join(" ").toLowerCase();
+  const image = (container.Image ?? "").toLowerCase();
+  const labels = Object.values(container.Labels ?? {}).join(" ").toLowerCase();
+  const haystack = `${names} ${image} ${labels}`;
+
+  if (haystack.includes("gashboard")) return false;
+  return (
+    image.includes("retropex/datum") ||
+    image.includes("datum_gateway") ||
+    names.includes("datum") ||
+    labels.includes("datum")
+  );
+}
+
+function selectNetworkAddress(inspected: DockerInspect, preferredNetwork: string): string {
+  const networks = inspected.NetworkSettings?.Networks ?? {};
+  const preferred = networks[preferredNetwork]?.IPAddress;
+  if (preferred) return preferred;
+
+  const entries = Object.entries(networks).filter(([, value]) => value.IPAddress);
+  const umbrel = entries.find(([name]) => name.toLowerCase().includes("umbrel"));
+  const first = umbrel ?? entries[0];
+  if (first?.[1].IPAddress) return first[1].IPAddress;
+
+  const networkNames = Object.keys(networks).join(", ") || "none";
+  throw new Error(`Datum container has no Docker network IP; networks: ${networkNames}`);
 }
 
 async function fetchNetworkStats(): Promise<NetworkStat> {
@@ -186,7 +246,19 @@ async function fetchNetworkStats(): Promise<NetworkStat> {
 
 async function pollOnce(): Promise<DatumSnapshot> {
   const fetchedAt = Date.now();
-  const datumUrl = await resolveDatumUrl();
+  let datumUrl: string;
+  try {
+    datumUrl = await resolveDatumUrl();
+  } catch (err) {
+    const reason = formatErr(err);
+    logger.warn({ reason }, "datum_discovery_failed");
+    return {
+      ...lastSnapshot,
+      ok: false,
+      fetchedAt,
+      error: { code: "DATUM_DISCOVERY_FAILED", message: reason },
+    };
+  }
 
   // /clients (admin Digest-gated) and /threads (public) in parallel.
   const clientsTimeout = abortableSignal(DEFAULT_TIMEOUT_MS);