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Update README.md (#1373)

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Just some textual cleanup:  A few misspellings and a few clarifications.
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cricketliu 2018-01-10 15:08:08 -08:00 • committed by John Belamaric
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plugin/template/README.md
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@ -6,7 +6,7 @@
## Description
The *template* plugin allows you to dynamically repond to queries by just writing a (Go) template.
The *template* plugin allows you to dynamically respond to queries by just writing a (Go) template.
## Syntax
@ -27,9 +27,9 @@ template CLASS TYPE [ZONE...] {
* **ZONE** the zone scope(s) for this template. Defaults to the server zones.
* **REGEX** [Go regexp](https://golang.org/pkg/regexp/) that are matched against the incoming question name. Specifying no regex matches everything (default: `.*`). First matching regex wins.
* `answer|additional|authority` **RR** A [RFC 1035](https://tools.ietf.org/html/rfc1035#section-5) style resource record fragment
build by a [Go template](https://golang.org/pkg/text/template/) that contains the reply.
built by a [Go template](https://golang.org/pkg/text/template/) that contains the reply.
* `rcode` **CODE** A response code (`NXDOMAIN, SERVFAIL, ...`). The default is `SUCCESS`.
* `fallthrough` Continue with the next plugin if the zone matched but no regex did not match.
* `fallthrough` Continue with the next plugin if the zone matched but no regex matched.
If specific zones are listed (for example `in-addr.arpa` and `ip6.arpa`), then only queries for
those zones will be subject to fallthrough.
@ -49,7 +49,7 @@ Each resource record is a full-featured [Go template](https://golang.org/pkg/tex
* `.Message` the complete incoming DNS message.
* `.Question` the matched question section.
The output of the template must be a [RFC 1035](https://tools.ietf.org/html/rfc1035) style resource record line (commonly refered to as a "zone file").
The output of the template must be a [RFC 1035](https://tools.ietf.org/html/rfc1035) style resource record (commonly refered to as a "zone file").
**WARNING** there is a syntactical problem with Go templates and CoreDNS config files. Expressions
like `{{$var}}` will be interpreted as a reference to an environment variable by CoreDNS (and
@ -98,16 +98,16 @@ The `.invalid` domain is a reserved TLD (see [RFC-2606 Reserved Top Level DNS Na
~~~
1. A query to .invalid will result in NXDOMAIN (rcode)
2. A dummy SOA record is send to hand out a TTL of 60s for caching
3. Querying `.invalid` of `CH` will also cause a NXDOMAIN/SOA response
2. A dummy SOA record is sent to hand out a TTL of 60s for caching purposes
3. Querying `.invalid` in the `CH` class will also cause a NXDOMAIN/SOA response
4. The default regex is `.*`
### Block invalid search domain completions
Imagine you run `example.com` with a datacenter `dc1.example.com`. The datacenter domain
is part of the DNS search domain.
However `something.example.com.dc1.example.com` would indicates a fully qualified
domain name (`something.example.com`) that inadvertely has the default domain or search
However `something.example.com.dc1.example.com` would indicate a fully qualified
domain name (`something.example.com`) that inadvertently has the default domain or search
path (`dc1.example.com`) added.
~~~ corefile
@ -136,7 +136,7 @@ A more verbose regex based equivalent would be
}
~~~
The regex based version can do more complex matching/templating while zone based templating is easier to read and use.
The regex-based version can do more complex matching/templating while zone-based templating is easier to read and use.
### Resolve A/PTR for .example
@ -161,10 +161,10 @@ The regex based version can do more complex matching/templating while zone based
}
~~~
An IPv4 address consists of 4 bytes, `a.b.c.d`. Named groups make it less error prone to reverse the
ip in the PTR case. Try to use named groups to explain what your regex and template are doing.
An IPv4 address consists of 4 bytes, `a.b.c.d`. Named groups make it less error-prone to reverse the
IP address in the PTR case. Try to use named groups to explain what your regex and template are doing.
Note that the A record is actually a wildcard, any subdomain of the ip will resolve to the ip.
Note that the A record is actually a wildcard: any subdomain of the IP address will resolve to the IP address.
Having templates to map certain PTR/A pairs is a common pattern.
@ -187,7 +187,7 @@ Fallthrough is needed for mixed domains where only some responses are templated.
Named capture groups can be used to template one response for multiple patterns.
### Resolve A and MX records for ip templates in .example
### Resolve A and MX records for IP templates in .example
~~~ corefile
. {