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c6febe6250
* Add pkg/fall for Fallthrough Move this into it's own package to facilitate tests. Important bug was fixed: make the names fully qualified. Add fall package to hosts, reverse, etcd, and fix kubernetes and any tests. The k8s tests are still as-is, might need a future cleanup.
97 lines
3.1 KiB
Markdown
97 lines
3.1 KiB
Markdown
# reverse
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## Name
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*reverse* - allows for dynamic responses to PTR and the related A/AAAA requests.
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## Description
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If a request matches a regular expression (see Template Syntax below) this plugin will generate a
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response. This is only done for "address" records (PTR, A and AAAA).
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## Syntax
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~~~
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reverse NETWORK... {
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hostname TEMPLATE
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[ttl TTL]
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[fallthrough [ZONES...]]
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[wildcard]
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~~~
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* **NETWORK** one or more CIDR formatted networks to respond on.
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* `hostname` injects the IP and zone to a template for the hostname. Defaults to "ip-{IP}.{zone[1]}". See below for template.
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* `ttl` defaults to 60
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* `fallthrough` if zone matches and no record can be generated, pass request to the next plugin.
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If **[ZONES...]** is omitted, then fallthrough happens for all zones for which the plugin
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is authoritative. If specific zones are listed (for example `in-addr.arpa` and `ip6.arpa`), then only
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queries for those zones will be subject to fallthrough.
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* `wildcard` allows matches to catch all subdomains as well.
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### Template Syntax
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The template for the hostname is used for generating the PTR for a reverse lookup and matching the
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forward lookup back to an IP.
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#### `{ip}`
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The `{ip}` symbol is **required** to make reverse work.
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For IPv4 lookups the IP is directly extracted
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With IPv6 lookups the ":" is removed, and any zero ranged are expanded, e.g.,
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"ffff::ffff" results in "ffff000000000000000000000000ffff"
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#### `{zone[i]}`
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The `{zone[i]}` symbol is **optional** and can be replaced by a fixed (zone) string.
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The zone will be matched by the zones listed in *this* configuration stanza.
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`i` needs to be replaced with the index of the configured listener zones, starting with 1.
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## Examples
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~~~ corefile
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arpa compute.internal {
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# proxy unmatched requests
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proxy . 8.8.8.8
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# answer requests for IPs in this network
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# PTR 1.0.32.10.in-addr.arpa. 3600 ip-10.0.32.1.compute.internal.
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# A ip-10.0.32.1.compute.internal. 3600 10.0.32.1
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# v6 is also possible
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# PTR 1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.1.0.d.f.ip6.arpa. 3600 ip-fd010000000000000000000000000001.compute.internal.
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# AAAA ip-fd010000000000000000000000000001.compute.internal. 3600 fd01::1
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reverse 10.32.0.0/16 fd01::/16 {
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# template of the ip injection to hostname, zone resolved to compute.internal.
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hostname ip-{ip}.{zone[2]}
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ttl 3600
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# Forward unanswered or unmatched requests to proxy
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# without this flag, requesting A/AAAA records on compute.internal. will end here.
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fallthrough
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}
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}
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~~~
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~~~ corefile
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32.10.in-addr.arpa.arpa arpa.company.org {
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reverse 10.32.0.0/16 {
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# template of the ip injection to hostname, zone resolved to arpa.company.org.
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hostname "ip-{ip}.v4.{zone[2]}"
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ttl 3600
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# fallthrough is not required, v4.arpa.company.org. will be only answered here
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}
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# cidr closer to the ip wins, so we can overwrite the "default"
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reverse 10.32.2.0/24 {
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# its also possible to set fix domain suffix
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hostname ip-{ip}.fix.arpa.company.org.
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ttl 3600
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}
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}
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~~~
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