If you do not want to use my code, try (untested)

my $json = Cpanel::JSON::Dump( map { ( { 'dns_record' => $_ } ) } @dns
+_record );
[download]

Thanks for your reply, I have tried below code

my $json = Cpanel::JSON::Dump( map { ( { 'dns_record' => $_ } ) } @dns_record );

But return only first record

{"dns_record":{"ip":"@","ttl":"86400","name":"86400","hostname":"sysadmin.brainhost.com","type":"SOA"}}

I need all records same as below

  {"dns_record":{"ip":"@","ttl":"86400","name":"86400","hostname":"sys
+admin.brainhost.com","type":"SOA"}},
  {"dns_record":{"ip":"@","ttl":"86400","name":"86400","hostname":"192
+.64.179.10","type":"A"}},
  {"dns_record":{"ip":"localhost","ttl":"14400","name":"14400","hostna
+me":"127.0.0.1","type":"A"}},
  {"dns_record":{"ip":"@","ttl":"86400","name":"86400","hostname":"sac
+hin.com.","type":"MX","mx_priority":"0"}},
  {"dns_record":{"ip":"mail","ttl":"14400","name":"14400","hostname":"
+sachin.com.","type":"CNAME"}},
  {"dns_record":{"ip":"www","ttl":"14400","name":"14400","hostname":"s
+achin.com.","type":"CNAME"}},
  {"dns_record":{"ip":"ftp","ttl":"14400","name":"14400","hostname":"s
+achin.com.","type":"CNAME"}}
[download]

Here is my full code which I believe creates the desired output:

use strict;
use warnings;
use JSON;

my $input='{"dns_zone": {"created_at":"2013-07-08T02:21:57-05:00","id"
+:752,"name":"aresstest.com","updated_at":"2013-07-08T02:21:57-05:00",
+"user_id":136,"records":{"SOA":[{"dns_record":{"expire":2419200,"host
+master":"ns1.qwkdns.com","id":122329,"minimum":10800,"name":"@","prim
+aryNs":"ns1.qwkdns.com","refresh":7200,"retry":900,"serial":201303211
+2,"ttl":86400,"type":"SOA"}}],  "NS":[{"dns_record":{"hostname":"ns1.
+qwkdns.com","id":122325,"name":"aresstest.com","ttl":86400,"type":"NS
+"}},{"dns_record":{"hostname":"ns2.qwkdns.com","id":122326,"name":"ar
+esstest.com","ttl":86400,"type":"NS"}},{"dns_record":{"hostname":"ns3
+.qwkdns.com","id":122327,"name":"aresstest.com","ttl":86400,"type":"N
+S"}},{"dns_record":{"hostname":"ns4.qwkdns.com","id":122328,"name":"a
+resstest.com","ttl":86400,"type":"NS"}}],  "A":[{"dns_record":{"id":1
+22332,"ip":"173.236.102.246","name":"localhost.aresstest.com","ttl":1
+4400,"type":"A"}},{"dns_record":{"id":122333,"ip":"173.236.102.246","
+name":"ftp","ttl":14400,"type":"A"}},{"dns_record":{"id":122334,"ip":
+"173.236.36.138","name":"mail","ttl":14400,"type":"A"}},{"dns_record"
+:{"id":122335,"ip":"173.236.102.246","name":"webmail","ttl":14400,"ty
+pe":"A"}},{"dns_record":{"id":122337,"ip":"173.236.36.138","name":"au
+todiscover","ttl":14400,"type":"A"}}],  "CNAME":[{"dns_record":{"host
+name":"aresstest.com","id":122336,"name":"www","ttl":14400,"type":"CN
+AME"}}],  "MX":[{"dns_record":{"hostname":"mail.aresstest.com","id":1
+22330,"name":"@","priority":0,"ttl":14400,"type":"MX"}}],  "TXT":[{"d
+ns_record":{"id":122331,"name":"@","ttl":14400,"txt":"v=spf1 ip4:173.
+236.102.246 +a +mx +ip4:173.236.36.138 ?all","type":"TXT"}}]}}}';

my $output = to_json [ map { @$_ } values %{ (from_json $input)->{dns_
+zone}->{records} } ];

$output =~ s/{"dns/\n  {"dns/g; # beautifying only, can be removed
$output =~ s/\]/\n]/;           # beautifying only, can be removed
print $output;
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Outout is

[
  {"dns_record":{"priority":0,"ttl":14400,"name":"@","type":"MX","id":
+122330,"hostname":"mail.aresstest.com"}},
  {"dns_record":{"ttl":14400,"ip":"173.236.102.246","name":"localhost.
+aresstest.com","type":"A","id":122332}},
  {"dns_record":{"ttl":14400,"ip":"173.236.102.246","name":"ftp","type
+":"A","id":122333}},
  {"dns_record":{"ttl":14400,"ip":"173.236.36.138","name":"mail","type
+":"A","id":122334}},
  {"dns_record":{"ttl":14400,"ip":"173.236.102.246","name":"webmail","
+type":"A","id":122335}},
  {"dns_record":{"ttl":14400,"ip":"173.236.36.138","name":"autodiscove
+r","type":"A","id":122337}},
  {"dns_record":{"ttl":14400,"name":"@","type":"TXT","txt":"v=spf1 ip4
+:173.236.102.246 +a +mx +ip4:173.236.36.138 ?all","id":122331}},
  {"dns_record":{"ttl":14400,"name":"www","type":"CNAME","id":122336,"
+hostname":"aresstest.com"}},
  {"dns_record":{"ttl":86400,"name":"aresstest.com","type":"NS","id":1
+22325,"hostname":"ns1.qwkdns.com"}},
  {"dns_record":{"ttl":86400,"name":"aresstest.com","type":"NS","id":1
+22326,"hostname":"ns2.qwkdns.com"}},
  {"dns_record":{"ttl":86400,"name":"aresstest.com","type":"NS","id":1
+22327,"hostname":"ns3.qwkdns.com"}},
  {"dns_record":{"ttl":86400,"name":"aresstest.com","type":"NS","id":1
+22328,"hostname":"ns4.qwkdns.com"}},
  {"dns_record":{"minimum":10800,"ttl":86400,"serial":2013032112,"host
+master":"ns1.qwkdns.com","primaryNs":"ns1.qwkdns.com","name":"@","ret
+ry":900,"refresh":7200,"type":"SOA","id":122329,"expire":2419200}}
]
[download]