Trust the estate CA when fetching ENC facts (#529)

Facter runs under Puppet's vendored Ruby, which reads its own bundled CA file and never the system trust store. The ENC fact now fetches over HTTPS, so every node fails certificate verification and falls back to its cached value.

- set ca_file on the request to the vaultca anchor bundle
- keep VERIFY_PEER on, and fall through to the existing cache path when the anchor is absent

Reviewed-on: #529
Co-authored-by: unkin-agent <unkin-agent@unkin.net>
Co-committed-by: unkin-agent <unkin-agent@unkin.net>

modules/libs/lib/facter/enc_direct_facts.rb

@@ -3,6 +3,7 @@
 require 'facter'
 require 'yaml'
 require 'net/http'
+require 'openssl'
 require 'uri'
 require 'fileutils'
 
@@ -10,6 +11,13 @@ require 'fileutils'
 module EncapiENC
   CACHE_FILE = '/var/cache/puppet_enc.yaml'
   CACHE_TTL = 7 * 24 * 60 * 60 # 7 days in seconds
+  # Facter runs under Puppet's vendored ruby, whose OpenSSL trusts only
+  # /opt/puppetlabs/puppet/ssl/cert.pem and never the system trust store, so the
+  # estate CA anchor profiles::pki::vaultca installs has to be named explicitly.
+  CA_BUNDLE_PATHS = [
+    '/etc/pki/ca-trust/source/anchors/vaultcaroot.pem',
+    '/usr/local/share/ca-certificates/vaultcaroot.pem'
+  ].freeze
   @enc_data = nil # In-memory cache for the ENC response
 
   def self.read_cache
@@ -29,9 +37,22 @@ module EncapiENC
     File.write(CACHE_FILE, cache_data.to_yaml)
   end
 
+  def self.ca_bundle
+    CA_BUNDLE_PATHS.find { |path| File.exist?(path) }
+  end
+
+  def self.http_client(uri)
+    client = Net::HTTP.new(uri.host, uri.port)
+    client.use_ssl = true
+    client.verify_mode = OpenSSL::SSL::VERIFY_PEER
+    bundle = ca_bundle
+    client.ca_file = bundle if bundle
+    client
+  end
+
   def self.fetch_from_encapi
     uri = URI("https://encapi.k8s.syd1.au.unkin.net/cblr/svc/op/puppet/hostname/#{Facter.value(:fqdn) || Facter.value(:hostname)}")
-    response = Net::HTTP.get_response(uri)
+    response = http_client(uri).request(Net::HTTP::Get.new(uri))
 
     raise "Failed to fetch ENC data. HTTP #{response.code}" unless response.is_a?(Net::HTTPSuccess)