feat templater: Add IP lookup function

This introduces support for looking up IP addresses using local DNS resolver.

Function will return a list of all IP addresses associated with hostname.
Further processing can be achieved using supported list template functions.
This commit is contained in:
Stefan Magnus Landrø 2017-10-17 22:49:42 +02:00 committed by Vincent Ambo
parent b20bc5f57a
commit 68e2f99062
2 changed files with 35 additions and 0 deletions

34
templater/dns.go Normal file
View file

@ -0,0 +1,34 @@
// This file contains the implementation of a template function for retrieving IP addresses from DNS
package templater
import (
"fmt"
"github.com/polydawn/meep"
"net"
"os"
)
type DNSError struct {
meep.TraitAutodescribing
meep.TraitCausable
Output string
}
func GetIPsFromDNS(host string) ([]interface{}, error) {
fmt.Fprintf(os.Stderr, "Attempting to look up IP for %s in DNS\n", host)
ips, err := net.LookupIP(host)
if err != nil {
return nil, meep.New(
&DNSError{Output: "IP address lookup failed"},
meep.Cause(err),
)
}
var result []interface{} = make([]interface{}, len(ips))
for i, ip := range ips {
result[i] = ip
}
return result, nil
}

View file

@ -180,6 +180,7 @@ func templateFuncs() template.FuncMap {
return string(b)
}
m["passLookup"] = GetFromPass
m["lookupIPAddr"] = GetIPsFromDNS
return m
}