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

agent/test/fixtures/zfs/zfs_list.json

@@ -0,0 +1,37 @@
+{
+  "output_version": { "command": "zfs list", "vers_major": 0, "vers_minor": 1 },
+  "datasets": {
+    "rpool": {
+      "name": "rpool",
+      "type": "FILESYSTEM",
+      "properties": {
+        "used": { "value": "200000000000" },
+        "available": { "value": "300000000000" },
+        "usedbysnapshots": { "value": "5000000000" }
+      }
+    },
+    "rpool/data": {
+      "name": "rpool/data",
+      "type": "FILESYSTEM",
+      "properties": {
+        "used": { "value": "100000000000" },
+        "available": { "value": "300000000000" },
+        "usedbysnapshots": { "value": "2000000000" }
+      }
+    },
+    "rpool/data@daily-2026-04-20": {
+      "name": "rpool/data@daily-2026-04-20",
+      "type": "SNAPSHOT",
+      "properties": {
+        "creation": { "value": "1745107200" }
+      }
+    },
+    "rpool/data@daily-2026-04-21": {
+      "name": "rpool/data@daily-2026-04-21",
+      "type": "SNAPSHOT",
+      "properties": {
+        "creation": { "value": "1745193600" }
+      }
+    }
+  }
+}

agent/test/fixtures/zfs/zpool_list.json

@@ -0,0 +1,23 @@
+{
+  "output_version": { "command": "zpool list", "vers_major": 0, "vers_minor": 1 },
+  "pools": {
+    "rpool": {
+      "name": "rpool",
+      "size": 500000000000,
+      "alloc": 200000000000,
+      "free": 300000000000,
+      "frag": 17,
+      "cap": 40,
+      "health": "ONLINE"
+    },
+    "tank": {
+      "name": "tank",
+      "size": 8000000000000,
+      "alloc": 6000000000000,
+      "free": 2000000000000,
+      "frag": 55,
+      "cap": 75,
+      "health": "DEGRADED"
+    }
+  }
+}

agent/test/fixtures/zfs/zpool_status.json

@@ -0,0 +1,45 @@
+{
+  "output_version": { "command": "zpool status", "vers_major": 0, "vers_minor": 1 },
+  "pools": {
+    "rpool": {
+      "name": "rpool",
+      "state": "ONLINE",
+      "scan": {
+        "function": "scrub",
+        "state": "FINISHED",
+        "end_time": "Sat Apr 19 02:00:00 2026"
+      },
+      "error_count": "0",
+      "vdevs": {
+        "mirror-0": {
+          "name": "mirror-0",
+          "vdev_type": "mirror",
+          "state": "ONLINE",
+          "read_errors": "0",
+          "write_errors": "0",
+          "checksum_errors": "0"
+        }
+      }
+    },
+    "tank": {
+      "name": "tank",
+      "state": "DEGRADED",
+      "scan": {
+        "function": "scrub",
+        "state": "FINISHED",
+        "end_time": "Tue Mar 01 08:00:00 2026"
+      },
+      "error_count": "2",
+      "vdevs": {
+        "raidz2-0": {
+          "name": "raidz2-0",
+          "vdev_type": "raidz2",
+          "state": "DEGRADED",
+          "read_errors": "0",
+          "write_errors": "0",
+          "checksum_errors": "2"
+        }
+      }
+    }
+  }
+}

agent/test/proxmox_agent/collectors/zfs_test.exs

@@ -0,0 +1,62 @@
+defmodule ProxmoxAgent.Collectors.ZfsTest do
+  use ExUnit.Case, async: true
+
+  alias ProxmoxAgent.Collectors.Zfs
+
+  @fixtures Path.expand("../../fixtures/zfs", __DIR__)
+
+  defp fake_runner do
+    fn
+      "zpool", ["list", "-j", "--json-int"] ->
+        {:ok, File.read!(Path.join(@fixtures, "zpool_list.json"))}
+
+      "zpool", ["status", "-j", "--json-flat-vdevs", "--json-int"] ->
+        {:ok, File.read!(Path.join(@fixtures, "zpool_status.json"))}
+
+      "zfs", ["list", "-j", "--json-int", "-t", "all"] ->
+        {:ok, File.read!(Path.join(@fixtures, "zfs_list.json"))}
+    end
+  end
+
+  describe "collect_pools/1" do
+    test "returns a summary per pool" do
+      sample = Zfs.collect_pools(runner: fake_runner())
+      assert is_list(sample.pools)
+      assert length(sample.pools) == 2
+      rpool = Enum.find(sample.pools, &(&1.name == "rpool"))
+      tank = Enum.find(sample.pools, &(&1.name == "tank"))
+
+      assert rpool.health == "ONLINE"
+      assert rpool.capacity_percent == 40
+      assert rpool.fragmentation_percent == 17
+      assert rpool.size_bytes == 500_000_000_000
+      assert rpool.error_count == 0
+      assert rpool.degraded_vdev_count == 0
+
+      assert tank.health == "DEGRADED"
+      assert tank.error_count == 2
+      assert tank.degraded_vdev_count == 1
+    end
+
+    test "populates errors list when zpool fails" do
+      failing = fn _, _ -> {:error, {:enoent, "zpool"}} end
+      sample = Zfs.collect_pools(runner: failing)
+      assert sample.pools == []
+      assert length(sample.errors) >= 1
+    end
+  end
+
+  describe "collect_datasets/1" do
+    test "returns datasets and per-dataset snapshot summary" do
+      sample = Zfs.collect_datasets(runner: fake_runner())
+      assert length(sample.datasets) == 2
+
+      rpool_data = Enum.find(sample.datasets, &(&1.name == "rpool/data"))
+      assert rpool_data.used_bytes == 100_000_000_000
+      assert rpool_data.usedbysnapshots_bytes == 2_000_000_000
+      assert rpool_data.snapshot_count == 2
+      assert rpool_data.newest_snapshot_unix == 1_745_193_600
+      assert rpool_data.oldest_snapshot_unix == 1_745_107_200
+    end
+  end
+end