feat(docker): the Swarm page is laid out by node: role, what its containers use, and the services placed on each (#5303)

#5303 "Swarm page laid out by node: role, resources and the tasks placed on each"

A verdict line first, then the nodes that are down or drained and the
services short of replicas, then one card per node. A node with a Steward
agent shows what its swarm tasks use against the machine's cores and memory,
service by service. A node without one lists Swarm's placement, by count.
The services table moved to the Docker overview, where it can be filtered.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/plugins/docker/test_overview.py

@@ -205,3 +205,74 @@ async def test_a_service_log_line_names_its_task(app):
                                              lines=[], name="web", filtered=False, service=True)
     assert f"1 · {TASK[:10]}</span>" in page and "&lt;b&gt;boom&lt;/b&gt;" in page
     assert "one of its tasks" in empty
+
+
+def _node(nid, hostname, role="worker", status="ready", availability="active", leader=False):
+    return NS(node_id=nid, hostname=hostname, role=role, status=status, availability=availability,
+              leader=leader)
+
+
+def _swarm_svc(name, placement):
+    import json
+    return NS(service_name=name, placement_json=json.dumps(placement))
+
+
+def _task(name, service, node, cpu, mem, status="running"):
+    return NS(name=name, service_name=service, node_id=node, status=status, cpu_pct=cpu,
+              mem_usage_bytes=mem)
+
+
+def test_each_node_lists_what_runs_on_it_and_what_that_uses():
+    """#5303: a node with an agent has figures; one without is Swarm's placement only."""
+    from plugins.docker.swarm_nodes import node_cards
+    nodes = [_node("n1", "docker02", role="manager", leader=True), _node("n2", "edge01"),
+             _node("n3", "docker03", availability="drain")]
+    services = [_swarm_svc("arr_radarr", [{"node_id": "n1", "running": 1}]),
+                _swarm_svc("web", [{"node_id": "n1", "running": 2}, {"node_id": "n2", "running": 1}]),
+                _swarm_svc("db", [{"node_id": "n1", "running": 1}])]
+    containers = [_task("arr_radarr.1.x", "arr_radarr", "n1", 150.0, 300),
+                  _task("web.1.x", "web", "n1", 10.0, 100), _task("web.2.x", "web", "n1", 20.0, 100),
+                  _task("web.0.old", "web", "n1", 99.0, 999, status="exited"),
+                  _task("traefik", None, None, 5.0, 5)]
+    cards = node_cards(nodes, services, containers, node_host={"n1": "h1"}, host_names={"h1": "docker02"},
+                       capacity={"h1": (8, 16 << 30)},
+                       service_state={"arr_radarr": "healthy", "web": "healthy", "db": "down"})
+    assert [c["hostname"] for c in cards] == ["docker03", "docker02", "edge01"]   # drained first, then managers
+    n1 = cards[1]
+    assert n1["host_id"] == "h1" and n1["leader"] and n1["agent"]
+    assert [t["name"] for t in n1["tasks"]] == ["db", "arr_radarr", "web"]       # trouble, then busiest
+    assert n1["tasks"][0]["cores"] is None and not n1["tasks"][0]["measured"]    # placed, not reported
+    web = n1["tasks"][2]
+    assert web["tasks"] == 2 and web["cores"] == 0.3 and web["mem_bytes"] == 200
+    assert n1["cores_used"] == 1.8 and n1["mem_used"] == 500 and n1["cores"] == 8
+    edge = cards[2]
+    assert not edge["agent"] and edge["cores_used"] is None
+    assert edge["tasks"] == [{"name": "web", "tasks": 1, "cpu_pct": None, "mem_bytes": None, "measured": False,
+                              "state": "healthy", "cores": None}]
+    assert not cards[0]["ok"] and cards[0]["tasks"] == []
+
+
+async def test_the_swarm_page_is_a_card_per_node(app):
+    from plugins.docker.swarm_nodes import node_cards
+    nodes = [_node("n1", "docker02", role="manager", leader=True), _node("n2", "edge01", status="down")]
+    cards = node_cards(nodes, [_swarm_svc("web", [{"node_id": "n2", "running": 1}])],
+                       [_task("arr.1.x", "arr", "n1", 50.0, 1 << 30)], node_host={"n1": "h1"},
+                       host_names={"h1": "docker02"}, capacity={"h1": (4, 8 << 30)},
+                       service_state={"arr": "healthy", "web": "degraded"})
+    troubled = [{"name": "web", "running": 1, "desired": 2, "state": "degraded", "crash_looping": False,
+                 "trouble_since": None, "last_error": {"state": "failed", "error": "no suitable node", "node": None}}]
+    async with app.test_request_context("/plugins/docker/swarm"):
+        session["user_role"] = "viewer"
+        page = await render_plugin_template(app, "docker", "docker/swarm.html", swarms=[{
+            "managers": ["docker02"], "services_total": 2, "services_healthy": 1, "troubled": troubled,
+            "nodes": cards}])
+    page = re.sub(r">\s+<", "><", " ".join(page.split()))
+    assert "2 need attention" in page and '<span class="tone-warn">1/2</span> services healthy' in page
+    problems = page[page.index('class="problem-list"'):]
+    assert "Node down" in problems and "edge01" in problems
+    assert '<a href="/plugins/docker/service/web">web</a>' in problems and "last task failed: no suitable node" in problems
+    assert page.index('id="node-n2"') < page.index('id="node-n1"')              # the down node first
+    assert '<a href="/hosts/h1">docker02</a><span class="chip">leader</span>' in page
+    assert "Containers use <strong>0.50 cores</strong> of 4 · <strong>1.0 GiB</strong> of 8.0 GiB" in page
+    assert "No Steward agent" in page
+    assert '<a href="/plugins/docker/service/arr" title="arr">arr</a>' in page