prometheus/node: update textfile collector apt_info (replaces apt)

1 files changed, 104 insertions, 0 deletions

diff --git a/roles/monitoring/prometheus/exporter/node/templates/textfile-collector-scripts/apt_info.j2 b/roles/monitoring/prometheus/exporter/node/templates/textfile-collector-scripts/apt_info.j2
new file mode 100644
index 00000000..20cfdf4f
--- /dev/null
+++ b/roles/monitoring/prometheus/exporter/node/templates/textfile-collector-scripts/apt_info.j2
@@ -0,0 +1,104 @@
+#!/usr/bin/env {{ python_basename }}
+#
+# Description: Expose metrics from apt. This is inspired by and
+# intended to be a replacement for the original apt.sh.
+#
+# Dependencies: python3-apt, python3-prometheus-client
+#
+# Authors: Kyle Fazzari <kyrofa@ubuntu.com>
+#          Daniel Swarbrick <dswarbrick@debian.org>
+
+import apt
+import collections
+import contextlib
+import os
+from prometheus_client import CollectorRegistry, Gauge, generate_latest
+
+_UpgradeInfo = collections.namedtuple("_UpgradeInfo", ["labels", "count"])
+
+
+def _convert_candidates_to_upgrade_infos(candidates):
+    changes_dict = collections.defaultdict(lambda: collections.defaultdict(int))
+
+    for candidate in candidates:
+        origins = sorted(
+            {f"{o.origin}:{o.codename}/{o.archive}" for o in candidate.origins}
+        )
+        changes_dict[",".join(origins)][candidate.architecture] += 1
+
+    changes_list = list()
+    for origin in sorted(changes_dict.keys()):
+        for arch in sorted(changes_dict[origin].keys()):
+            changes_list.append(
+                _UpgradeInfo(
+                    labels=dict(origin=origin, arch=arch),
+                    count=changes_dict[origin][arch],
+                )
+            )
+
+    return changes_list
+
+
+def _write_pending_upgrades(registry, cache):
+    # Discount any changes that apply to packages that aren't installed (e.g.
+    # count an upgrade to package A that adds a new dependency on package B as
+    # only one upgrade, not two). See the following issue for more details:
+    # https://github.com/prometheus-community/node-exporter-textfile-collector-scripts/issues/85
+    candidates = {
+        p.candidate for p in cache.get_changes() if p.is_installed and p.marked_upgrade
+    }
+    upgrade_list = _convert_candidates_to_upgrade_infos(candidates)
+
+    if upgrade_list:
+        g = Gauge('apt_upgrades_pending', "Apt packages pending updates by origin",
+                  ['origin', 'arch'], registry=registry)
+        for change in upgrade_list:
+            g.labels(change.labels['origin'], change.labels['arch']).set(change.count)
+
+
+def _write_held_upgrades(registry, cache):
+    held_candidates = {p.candidate for p in cache if p.is_upgradable and p.marked_keep}
+    upgrade_list = _convert_candidates_to_upgrade_infos(held_candidates)
+
+    if upgrade_list:
+        g = Gauge('apt_upgrades_held', "Apt packages pending updates but held back.",
+                  ['origin', 'arch'], registry=registry)
+        for change in upgrade_list:
+            g.labels(change.labels['origin'], change.labels['arch']).set(change.count)
+
+
+def _write_autoremove_pending(registry, cache):
+    autoremovable_packages = {p for p in cache if p.is_auto_removable}
+    g = Gauge('apt_autoremove_pending', "Apt packages pending autoremoval.",
+              registry=registry)
+    g.set(len(autoremovable_packages))
+
+
+def _write_reboot_required(registry):
+    g = Gauge('node_reboot_required', "Node reboot is required for software updates.",
+              registry=registry)
+    g.set(int(os.path.isfile('/run/reboot-required')))
+
+
+def _main():
+    cache = apt.cache.Cache()
+
+    # First of all, attempt to update the index. If we don't have permission
+    # to do so (or it fails for some reason), it's not the end of the world,
+    # we'll operate on the old index.
+    with contextlib.suppress(apt.cache.LockFailedException, apt.cache.FetchFailedException):
+        cache.update()
+
+    cache.open()
+    cache.upgrade(True)
+
+    registry = CollectorRegistry()
+    _write_pending_upgrades(registry, cache)
+    _write_held_upgrades(registry, cache)
+    _write_autoremove_pending(registry, cache)
+    _write_reboot_required(registry)
+    print(generate_latest(registry).decode(), end='')
+
+
+if __name__ == "__main__":
+    _main()