feat(agent): zfs collector for pools + datasets/snapshots with fixture tests

agent/lib/proxmox_agent/collectors/zfs.ex

@@ -0,0 +1,138 @@
+defmodule ProxmoxAgent.Collectors.Zfs do
+  @moduledoc """
+  Collects ZFS pool health (fast path) and dataset/snapshot info (medium path).
+  Delegates shelling out to an injectable runner so tests can supply fixtures.
+  """
+
+  @type pool_summary :: %{
+          name: String.t(),
+          health: String.t(),
+          size_bytes: non_neg_integer(),
+          allocated_bytes: non_neg_integer(),
+          free_bytes: non_neg_integer(),
+          fragmentation_percent: non_neg_integer(),
+          capacity_percent: non_neg_integer(),
+          error_count: non_neg_integer(),
+          vdev_count: non_neg_integer(),
+          degraded_vdev_count: non_neg_integer(),
+          last_scrub_end: String.t() | nil
+        }
+
+  @spec collect_pools(keyword()) :: %{pools: [pool_summary()], errors: [map()]}
+  def collect_pools(opts \\ []) do
+    runner = runner(opts)
+
+    {list_result, list_err} = decode(runner.("zpool", ["list", "-j", "--json-int"]), :zpool_list)
+
+    {status_result, status_err} =
+      decode(runner.("zpool", ["status", "-j", "--json-flat-vdevs", "--json-int"]), :zpool_status)
+
+    pools = merge_pools(list_result, status_result)
+    errors = Enum.filter([list_err, status_err], & &1)
+    %{pools: pools, errors: errors}
+  end
+
+  @type dataset_summary :: %{
+          name: String.t(),
+          used_bytes: non_neg_integer(),
+          usedbysnapshots_bytes: non_neg_integer(),
+          snapshot_count: non_neg_integer(),
+          newest_snapshot_unix: non_neg_integer() | nil,
+          oldest_snapshot_unix: non_neg_integer() | nil
+        }
+
+  @spec collect_datasets(keyword()) :: %{datasets: [dataset_summary()], errors: [map()]}
+  def collect_datasets(opts \\ []) do
+    runner = runner(opts)
+
+    {list_result, err} =
+      decode(runner.("zfs", ["list", "-j", "--json-int", "-t", "all"]), :zfs_list)
+
+    datasets = summarize_datasets(list_result)
+    errors = if err, do: [err], else: []
+    %{datasets: datasets, errors: errors}
+  end
+
+  defp runner(opts), do: Keyword.get(opts, :runner, &ProxmoxAgent.Shell.run/2)
+
+  defp decode({:ok, body}, _tag) do
+    case Jason.decode(body) do
+      {:ok, map} -> {map, nil}
+      {:error, e} -> {nil, %{tag: "decode", message: Exception.message(e)}}
+    end
+  end
+
+  defp decode({:error, reason}, tag),
+    do: {nil, %{tag: Atom.to_string(tag), message: inspect(reason)}}
+
+  defp merge_pools(nil, _), do: []
+  defp merge_pools(_, nil), do: []
+
+  defp merge_pools(%{"pools" => list_pools}, %{"pools" => status_pools}) do
+    Enum.map(list_pools, fn {name, list_info} ->
+      status_info = Map.get(status_pools, name, %{})
+      vdevs = Map.get(status_info, "vdevs", %{}) |> Map.values()
+
+      %{
+        name: name,
+        health: Map.get(list_info, "health"),
+        size_bytes: Map.get(list_info, "size", 0),
+        allocated_bytes: Map.get(list_info, "alloc", 0),
+        free_bytes: Map.get(list_info, "free", 0),
+        fragmentation_percent: Map.get(list_info, "frag", 0),
+        capacity_percent: Map.get(list_info, "cap", 0),
+        error_count: to_int(Map.get(status_info, "error_count", "0")),
+        vdev_count: length(vdevs),
+        degraded_vdev_count: Enum.count(vdevs, &(&1["state"] != "ONLINE")),
+        last_scrub_end: get_in(status_info, ["scan", "end_time"])
+      }
+    end)
+  end
+
+  defp summarize_datasets(nil), do: []
+
+  defp summarize_datasets(%{"datasets" => datasets}) do
+    by_type = Enum.group_by(datasets, fn {_, d} -> d["type"] end)
+
+    filesystems = Map.get(by_type, "FILESYSTEM", [])
+    snapshots_by_ds = group_snapshots(Map.get(by_type, "SNAPSHOT", []))
+
+    Enum.map(filesystems, fn {_name, ds} ->
+      name = ds["name"]
+      snaps = Map.get(snapshots_by_ds, name, [])
+
+      %{
+        name: name,
+        used_bytes: get_prop_int(ds, "used"),
+        usedbysnapshots_bytes: get_prop_int(ds, "usedbysnapshots"),
+        snapshot_count: length(snaps),
+        newest_snapshot_unix: snaps |> Enum.map(& &1.creation) |> max_or_nil(),
+        oldest_snapshot_unix: snaps |> Enum.map(& &1.creation) |> min_or_nil()
+      }
+    end)
+  end
+
+  defp group_snapshots(snapshots) do
+    Enum.reduce(snapshots, %{}, fn {_, snap}, acc ->
+      [parent | _] = String.split(snap["name"], "@", parts: 2)
+      creation = get_prop_int(snap, "creation")
+      entry = %{name: snap["name"], creation: creation}
+      Map.update(acc, parent, [entry], &[entry | &1])
+    end)
+  end
+
+  defp get_prop_int(ds, key) do
+    case get_in(ds, ["properties", key, "value"]) do
+      nil -> 0
+      v -> to_int(v)
+    end
+  end
+
+  defp to_int(v) when is_integer(v), do: v
+  defp to_int(v) when is_binary(v), do: String.to_integer(v)
+
+  defp max_or_nil([]), do: nil
+  defp max_or_nil(list), do: Enum.max(list)
+  defp min_or_nil([]), do: nil
+  defp min_or_nil(list), do: Enum.min(list)
+end