dig Command Reference: Flags, Usage & CI Examples

dig queries DNS records from the command line.

dig (from bind-utils/dnsutils) performs DNS lookups and shows the full query and answer. In CI it verifies that a service hostname resolves before a job tries to connect or deploy.

Common flags and usage

dig <name>: full lookup with query details
+short: print just the answer records
A / AAAA / CNAME / MX / TXT: query a record type
@<server>: query a specific resolver
+trace: follow the delegation from the root
-x <ip>: reverse lookup

Example

shell

dig +short db.internal.example.com
dig +short A api.example.com @1.1.1.1

In CI

dig +short is the cleanest way to assert a hostname resolves before a deploy or connection step. Querying a specific resolver with @<server> helps debug split-horizon or private DNS that differs from the public answer.

Key takeaways

dig performs DNS lookups with full query and answer detail.
+short trims output to just the records, ideal for scripts.
@<server> targets a specific resolver to debug private DNS.

Related guides

nslookup Command Reference: Usage & CI ExamplesReference for nslookup: querying A/MX/TXT records, specifying a server, the dig comparison, and a CI example… getent Command Reference: Databases, Usage & CI ExamplesReference for getent: hosts, passwd, group, the NSS-aware lookup advantage, and a CI example that resolves a… ping Command Reference: Flags, Usage & CI ExamplesReference for ping: -c, -W, -i, the ICMP-blocked caveat, and a CI example that checks basic host reachability…