probe_ip_addr_hash is not changed in dns prober

[hillbun]

Host operating system: output of uname -a

Linux node1 4.18.0-240.22.1.el8_3.x86_64 #1 SMP Thu Apr 8 19:01:30 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

blackbox_exporter version: output of blackbox_exporter --version

blackbox_exporter, version 0.19.0 (branch: HEAD, revision: 5d575b8)
build user: root@2b0258d5a55a
build date: 20210510-12:56:44
go version: go1.16.4
platform: linux/amd64

What is the blackbox.yml module config.

dns_test1:
prober: dns
timeout: 5s
dns:
query_name: "test1.xxx.com"
query_type: "A"
valid_rcodes:
- NOERROR

What is the prometheus.yml scrape config.

• job_name: 'blackbox-dns-test1'
  metrics_path: /probe
  params:
  module: [dns_test1]
  static_configs:
  • targets:
    • 12.34.56.78
      relabel_configs:
  • source_labels: [address]
    target_label: __param_target
  • source_labels: [__param_target]
    target_label: instance
  • target_label: address
    replacement: 1.2.3.4:9115

What logging output did you get from adding &debug=true to the probe URL?

curl "1.2.3.4:9115/probe?module=dns_test1&target=12.34.56.78&&debug=true"
Logs for the probe:
ts=2022-01-27T09:27:48.237763964Z caller=main.go:320 module=dns_test1 target=12.34.56.78 level=info msg="Beginning probe" probe=dns timeout_seconds=5
ts=2022-01-27T09:27:48.238059891Z caller=dns.go:195 module=dns_test1 target=12.34.56.78 level=info msg="Resolving target address" ip_protocol=ip6
ts=2022-01-27T09:27:48.238124206Z caller=dns.go:195 module=dns_test1 target=12.34.56.78 level=info msg="Resolving target address" ip_protocol=ip4
ts=2022-01-27T09:27:48.23817272Z caller=dns.go:195 module=dns_test1 target=12.34.56.78 level=info msg="Resolved target address" ip=12.34.56.78
ts=2022-01-27T09:27:48.238256811Z caller=main.go:130 module=dns_test1 target=12.34.56.78 level=info msg="Making DNS query" target=12.34.56.78:53 dial_protocol=udp4 query=test1.xxx.com type=1 class=1
ts=2022-01-27T09:27:48.239203899Z caller=main.go:130 module=dns_test1 target=12.34.56.78 level=info msg="Got response" response=";; opcode: QUERY, status: NOERROR, id: 37799\n;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0\n\n;; QUESTION SECTION:\n;test1.xxx.com.\tIN\t A\n\n;; ANSWER SECTION:\ntest1.xxx.com.\t36\tIN\tA\t103.106.208.5\n"
ts=2022-01-27T09:27:48.239326977Z caller=dns.go:292 module=dns_test1 target=12.34.56.78 level=info msg="Rcode is valid" rcode=0 string_rcode=NOERROR
ts=2022-01-27T09:27:48.239382811Z caller=main.go:130 module=dns_test1 target=12.34.56.78 level=info msg="Validating Answer RRs"
ts=2022-01-27T09:27:48.239483169Z caller=dns.go:296 module=dns_test1 target=12.34.56.78 level=info msg="Validating RR" rr="test1.xxx.com.\t36\tIN\tA\t103.106.208.5"
ts=2022-01-27T09:27:48.23954682Z caller=main.go:130 module=dns_test1 target=12.34.56.78 level=info msg="Validating Authority RRs"
ts=2022-01-27T09:27:48.239589233Z caller=main.go:130 module=dns_test1 target=12.34.56.78 level=info msg="Validating Additional RRs"
ts=2022-01-27T09:27:48.239637943Z caller=main.go:320 module=dns_test1 target=12.34.56.78 level=info msg="Probe succeeded" duration_seconds=0.001761885



Metrics that would have been returned:
# HELP probe_dns_additional_rrs Returns number of entries in the additional resource record list
# TYPE probe_dns_additional_rrs gauge
probe_dns_additional_rrs 0
# HELP probe_dns_answer_rrs Returns number of entries in the answer resource record list
# TYPE probe_dns_answer_rrs gauge
probe_dns_answer_rrs 1
# HELP probe_dns_authority_rrs Returns number of entries in the authority resource record list
# TYPE probe_dns_authority_rrs gauge
probe_dns_authority_rrs 0
# HELP probe_dns_duration_seconds Duration of DNS request by phase
# TYPE probe_dns_duration_seconds gauge
probe_dns_duration_seconds{phase="connect"} 0.000309708
probe_dns_duration_seconds{phase="request"} 0.000563098
probe_dns_duration_seconds{phase="resolve"} 0.000159811
# HELP probe_dns_lookup_time_seconds Returns the time taken for probe dns lookup in seconds
# TYPE probe_dns_lookup_time_seconds gauge
probe_dns_lookup_time_seconds 0.000159811
# HELP probe_duration_seconds Returns how long the probe took to complete in seconds
# TYPE probe_duration_seconds gauge
probe_duration_seconds 0.001761885
# HELP probe_ip_addr_hash Specifies the hash of IP address. It's useful to detect if the IP address changes.
# TYPE probe_ip_addr_hash gauge
probe_ip_addr_hash 1.761043098e+09
# HELP probe_ip_protocol Specifies whether probe ip protocol is IP4 or IP6
# TYPE probe_ip_protocol gauge
probe_ip_protocol 4
# HELP probe_success Displays whether or not the probe was a success
# TYPE probe_success gauge
probe_success 1



Module configuration:
prober: dns
timeout: 5s
http:
    ip_protocol_fallback: true
    follow_redirects: true
tcp:
    ip_protocol_fallback: true
icmp:
    ip_protocol_fallback: true
dns:
    ip_protocol_fallback: true
    query_name: test1.xxx.com
    query_type: A
    valid_rcodes:
        - NOERROR

What did you do that produced an error?

probe_ip_addr_hash always return value of 1.761043098e+09 when IP address changed

What did you expect to see?

probe_ip_addr_hash should return different value when IP address changed

What did you see instead?

[SuperQ]

This is probably fixed by #863, which will be in the next release.

[dgl]

Note probe_ip_addr_hash is the hash of the DNS server used, not the result of query. i.e. in this example it is the hash of 12.34.56.78. Use validate_answer_rrs to check the results of the query.

[hillbun]

@dgl @SuperQ

How to config and monitor with validate_answer_rrs or probe_ip_addr_hash in my sample?

when domain of test1.xxx.com resolve IP or IPs changed.

please advice. thanks

[hillbun]

@dgl @SuperQ

any advice to monitor IP resolved changed? thanks,

[SuperQ]

Use a normal http, icmp, or tcp probe.