feat: add incus facts (#325)

- incus container counts
- incus profile list
- allocated memory/cpu

Reviewed-on: https://git.query.consul/unkinben/puppet-prod/pulls/325

modules/incus/lib/facter/incus_facts.rb

@@ -0,0 +1,70 @@
+# frozen_string_literal: true
+
+require 'json'
+
+Facter::Util::Resolution.define_singleton_method(:incus_data) do
+  raw = Facter::Util::Resolution.exec('incus list --format=json')
+  return [] unless raw
+
+  JSON.parse(raw)
+rescue StandardError
+  []
+end
+
+Facter.add(:incus_container_count) do
+  confine kernel: 'Linux'
+  setcode do
+    Facter::Util::Resolution.incus_data.size
+  end
+end
+
+Facter.add(:incus_container_count_running) do
+  confine kernel: 'Linux'
+  setcode do
+    Facter::Util::Resolution.incus_data.count { |c| c['status'] == 'Running' }
+  end
+end
+
+Facter.add(:incus_allocated_mb) do
+  confine kernel: 'Linux'
+  setcode do
+    Facter::Util::Resolution.incus_data.sum do |c|
+      mem_str = c.dig('expanded_config', 'limits.memory')
+      if mem_str&.match(/^(\d+)(MB|GB)$/i)
+        value = Regexp.last_match(1).to_i
+        unit = Regexp.last_match(2).upcase
+        unit == 'GB' ? value * 1024 : value
+      else
+        0
+      end
+    end
+  end
+end
+
+Facter.add(:incus_allocated_cpu) do
+  confine kernel: 'Linux'
+  setcode do
+    Facter::Util::Resolution.incus_data.sum do |c|
+      cpu_str = c.dig('expanded_config', 'limits.cpu')
+      cpu_str ? cpu_str.to_i : 0
+    end
+  end
+end
+
+Facter.add(:incus_profile_names) do
+  confine kernel: 'Linux'
+  setcode do
+    Facter::Util::Resolution.incus_data.flat_map { |c| c['profiles'] }.uniq.sort
+  end
+end
+
+Facter.add(:incus_profile_usage_count) do
+  confine kernel: 'Linux'
+  setcode do
+    usage = Hash.new(0)
+    Facter::Util::Resolution.incus_data.each do |c|
+      c['profiles'].each { |profile| usage[profile] += 1 }
+    end
+    usage
+  end
+end