Configuration

dns-monitor reads a single YAML file at startup, by default ./config.yaml. Pass --config /path/to/file.yaml to override.

Top-level fields

Field	Type	Default	Description
interval	duration	60s	How often every target is re-resolved. Accepts Go duration strings (30s, 5m, 1h).
listen	string	:8080	HTTP listen address for the dashboard.
db_path	string	dns-monitor.db	Path to the SQLite history database. Created on first run.
targets	list	[]	See below.

targets[]

Field	Type	Description
name	string	Human-readable identifier. Shown in the dashboard and used as the primary key for MCP tools and history queries.
host	string	Hostname to resolve.
type	string	Record type. One of A, AAAA, CNAME, MX, TXT, NS. Case-insensitive.
expect	list of strings	Expected answer set. A check is flagged if the resolved set diverges. Use an empty list (or omit) to skip drift detection.

Type-specific answer formats

The values stored in expect are compared against the stringified resolver output:

• A / AAAA — IP literals, e.g. 93.184.216.34, 2606:2800:220:1:248:1893:25c8:1946.
• CNAME — the canonical hostname, trailing dot stripped.
• MX — the mail exchange hostname only (priority is not matched).
• NS — the nameserver hostname, trailing dot stripped.
• TXT — the raw string content of each record.

Example

interval: 30s
listen: ":8080"
db_path: "/data/dns-monitor.db"
targets:
  - name: apex-a
    host: example.com
    type: A
    expect:
      - 93.184.216.34

  - name: apex-aaaa
    host: example.com
    type: AAAA

  - name: mx
    host: example.com
    type: MX
    expect:
      - .

  - name: spf
    host: example.com
    type: TXT
    expect:
      - "v=spf1 -all"