diff options
| -rw-r--r-- | lib/custodian/protocoltest/http.rb | 75 |
1 files changed, 74 insertions, 1 deletions
diff --git a/lib/custodian/protocoltest/http.rb b/lib/custodian/protocoltest/http.rb index a3f34cc..71388c8 100644 --- a/lib/custodian/protocoltest/http.rb +++ b/lib/custodian/protocoltest/http.rb @@ -337,8 +337,80 @@ module Custodian rescue Curl::Err::TooManyRedirectsError errors << "#{protocol_msg}: More than 10 redirections." rescue Curl::Err::HostResolutionError => x - # Log the DNS error-message. + + # + # We've been beset by a series of false-alerts in the recent + # past which have all occurred at this point: + # + # * We get bogus errors in resolving DNS from curb/libcurl. + # + # * These errors go away on retry. + # + # * But the retry isn't fast enough to outrace the + # supression-time of our alerts. + # + # For the moment we're going to _temporarily_ ignore these + # errors. + # + # * If a host has Connection-Refused, the wrong status-cde + # or similar failure it will be handled as normal. + # + # * If the host has genuinely lost DNS then we're going to + # raise an alert, but if it is this false-error then we + # will silently disable this test-run. + # + # + + # IP addresses we found for the host + ips = [] + + # Get the hostname we're connecting to. + u = URI.parse(test_url) + target = u.host + + # + # Resolve the target to an IP, unless it is already an address. + # + if (target =~ /^([0-9]+)\.([0-9]+)\.([0-9]+)\.([0-9]+)$/) || + (target =~ /^([0-9a-f:]+)$/) + ips.push(target) + else + + # + # OK if it didn't look like an IP address then attempt to + # look it up, as both IPv4 and IPv6. + # + begin + timeout(30) do + + Resolv::DNS.open do |dns| + + ress = dns.getresources(target, Resolv::DNS::Resource::IN::A) + ress.map { |r| ips.push(r.address.to_s) } + + ress = dns.getresources(target, Resolv::DNS::Resource::IN::AAAA) + ress.map { |r| ips.push(r.address.to_s) } + end + end + rescue Timeout::Error => _e + # NOP + end + end + + # + # At this point we either have: + # + # "ips" containing entries - because the hostname resolved + # + # "ips" being empty because the DNS failure was genuine + # + return Custodian::TestResult::TEST_SKIPPED unless ips.empty? + + # + # Log the DNS error-message, as this is genuine. + # resolution_errors << "#{protocol_msg}: #{x.class}: #{x.message}\n #{x.backtrace.join("\n ")}." + rescue => x errors << "#{protocol_msg}: #{x.class}: #{x.message}\n #{x.backtrace.join("\n ")}." end @@ -361,6 +433,7 @@ module Custodian # uh-oh! Resolution failed on both protocols! if resolution_errors.length > 1 errors << "DNS Error when resolving host - #{resolution_errors.join(',')}" + end if !errors.empty? |