DNS Monitor Configuration

DNS monitors require a hostname and support assertions against resolution results, response times, and specific record values.

Define this in code. YAML format · Terraform

Config fields

Field	Type	Required	Default	Description
`config.hostname`	string	Yes	—	Domain name to resolve
`config.recordTypes`	array of string	No	`["A", "AAAA"]`	Record types to query: `A`, `AAAA`, `CNAME`, `MX`, `NS`, `TXT`, `SRV`, `SOA`, `CAA`, `PTR`
`config.nameservers`	array of string	No	`["8.8.8.8", "1.1.1.1"]`	Custom nameservers to query, tried in order
`config.timeoutMs`	integer	No	`1500`	Per-resolver timeout in milliseconds
`config.totalTimeoutMs`	integer	No	`4000`	Total timeout for all queries in milliseconds

Assertions

Assertion	Required fields	Description
`dns_resolves`	(none)	Passes if the hostname resolves at all
`dns_response_time`	`maxMs`	Fails if resolution takes longer than threshold
`dns_response_time_warn`	`warnMs`	Records degraded hint for elevated resolution time
`dns_expected_ips`	`ips` (array)	Fails if resolved IPs don’t match expected set
`dns_expected_cname`	`value`	Fails if CNAME target doesn’t match
`dns_record_contains`	`recordType`, `substring`	Fails if record value doesn’t contain substring
`dns_record_equals`	`recordType`, `value`	Fails if record value doesn’t match exactly
`dns_txt_contains`	`substring`	Fails if no TXT record contains substring
`dns_min_answers`	`recordType`, `min`	Fails if answer count is below minimum
`dns_max_answers`	`recordType`, `max`	Fails if answer count exceeds maximum
`dns_ttl_low`	`minTtl`	Fails if TTL is below minimum
`dns_ttl_high`	`maxTtl`	Fails if TTL exceeds maximum

Examples

Basic resolution check

monitors:
  - name: Domain resolves
    type: DNS
    config:
      hostname: example.com
    assertions:
      - config:
          type: dns_resolves
        severity: fail

Full validation with expected IPs

monitors:
  - name: Production DNS
    type: DNS
    config:
      hostname: api.example.com
      recordTypes: [A, AAAA]
      nameservers: ["8.8.8.8", "1.1.1.1"]
    frequencySeconds: 300
    regions: [us-east, eu-west]
    assertions:
      - config:
          type: dns_resolves
        severity: fail
      - config:
          type: dns_expected_ips
          ips: ["203.0.113.10", "203.0.113.11"]
        severity: fail
      - config:
          type: dns_response_time
          maxMs: 500
        severity: fail
      - config:
          type: dns_ttl_low
          minTtl: 60
        severity: warn

SPF record validation

monitors:
  - name: SPF record
    type: DNS
    config:
      hostname: example.com
      recordTypes: [TXT]
    assertions:
      - config:
          type: dns_txt_contains
          substring: "v=spf1"
        severity: fail

DNS Monitor Configuration

Config fields

Assertions

Examples

Basic resolution check

Full validation with expected IPs

SPF record validation

Next steps

DNS overview

Regions

​Config fields

​Assertions

​Examples

​Basic resolution check

​Full validation with expected IPs

​SPF record validation

​Next steps

DNS overview

Regions

Config fields

Assertions

Examples

Basic resolution check

Full validation with expected IPs

SPF record validation

Next steps