Posts Tagged ‘Linode API’

Linode Dynamic DNS Ash Script

Monday, May 11th, 2009

After my post last night regarding a bash script to update Linode's DNS Manager, opello from #linode on OFTC provided some sed commands to parse the JSON output. Using his commands, I made another version of the script.  I've tested this on my router running the Tomato firmware (which runs BusyBox).

I found that the wget command built into the version of BusyBox does not support HTTP POST. It also does not support https urls, only http. This means your Linode API key would be transmitted in clear text, which probably isn't a good thing.

Another solution that was suggested was to simply wget a CGI script running on your webserver, which could update the Linode DNS Manager using perl or python over secure channels. That would reduce the complexity on the home router side and allow you to use the developed Linode API libraries.

Therefor, I wouldn't recommend using this unless you are able to send the requests over ssl channels. I am glad to have a slightly better understanding of sed. I'll probably modify the original bash script to use that as well.

#!/bin/ash
#
# Script to update Linode's DNS Manager for a given name.
#

# Things you need to change.
APIKEY=$(cat /home/root/linode-apikey)
LASTIP="/tmp/lastip"
DOMAIN="domain.com"
SOAEMAIL="hostmaster@domain.com"
STATUS="1"
RRTYPE="A"
RRNAME="home"
IFACE="vlan1"

# Shouldn't need to change anything below here.

WGET="wget -qO - http://api.linode.com/api/?api_key=$APIKEY"
NEWIP=$(ifconfig $IFACE | head -n2 | tail -n1 | cut -d: -f2 | cut -d' ' -f1)
test -e $LASTIP && OLDIP=$(cat $LASTIP) || OLDIP=""

if [ x"$OLDIP" = x"$NEWIP" ]; then
  logger "No IP address change detected. Keeping $NEWIP"
else
   DOMAINID=$($WGET"&action=domainList" | 
        sed -nr "s#.*"DOMAIN":"$DOMAIN","DOMAINID":([0-9]+),.*#1#p")
   RESOURCEID=$($WGET"&action=domainResourceList&DomainID=$DOMAINID" | 
        sed -nr "s#.*"RESOURCEID":([0-9]+),"DOMAINID":$DOMAINID,"TYPE":"$RRTYPE","NAME":"$RRNAME".*#1#p")
   $WGET"&action=domainResourceSave&ResourceID=$RESOURCEID&DomainID=$DOMAINID&Name=$RRNAME&Type=$RRTYPE&Target=$NEWIP"; echo
   $WGET"&action=domainSave&DomainID=$DOMAINID&Domain=$DOMAIN&Type=master&Status=$STATUS&SOA_Email=$SOAEMAIL"; echo
   echo $NEWIP > $LASTIP
   logger "Updated IP address to $NEWIP"
fi

Linode Dynamic DNS Bash Script

Monday, May 11th, 2009

So Mark Walling was working on an ash script for his router running OpenWRT to update Linode's DNS Manager with his IP address. I liked the idea of a simple shell script to update without needing to install libraries for Perl or Python.  I took his script and tried to adapt it to get the DOMAINID and RESOURCEID using sed or awk.  Those utilities seem great for manipulating multiline files of text, but I wasn't getting anywhere trying to parse one line of JSON from wget.  So I used perl to extract the id numbers.  I believe OpenWRT has some sort of perl with limited functionality, so maybe this will work with that or at least be easily adapted.  This could also be easily modified to use curl instead of wget. I suspect someone out there will find this useful.

#!/bin/bash
#
# Script to update Linode's DNS Manager for a given name.
#

# Things you need to change.
APIKEY=$(cat ~/.linode-apikey)
LASTIP="/tmp/lastip"
DOMAIN="domain.com"
SOAEMAIL="hostmaster@domain.com"
STATUS="1"
RRTYPE="A"
RRNAME="home"
IFACE="eth0"

# Shouldn't need to change anything below here.

WGET="wget -qO - https://api.linode.com/api/"
NEWIP=$(ifconfig $IFACE | head -n2 | tail -n1 | cut -d: -f2 | cut -d' ' -f1)
test -e $LASTIP && OLDIP=$(cat $LASTIP) || OLDIP=""

if [ x"$OLDIP" = x"$NEWIP" ]; then
  logger "No IP address change detected. Keeping $NEWIP"
else
   DOMAINID=$($WGET --post-data "api_key=$APIKEY&action=domainList" | 
        perl -e 'if ( =~ /"DOMAIN":"'"$DOMAIN"'","DOMAINID":([0-9]+),/) { print $1; }')
   RESOURCEID=$($WGET --post-data "api_key=$APIKEY&action=domainResourceList&DomainID=$DOMAINID" | 
        perl -e 'if ( =~ /"RESOURCEID":([0-9]+),"DOMAINID":'"$DOMAINID"',"TYPE":"'"$RRTYPE"'","NAME":"'"$RRNAME"'"/) { print $1; }')
   $WGET --post-data "api_key=$APIKEY&action=domainResourceSave&ResourceID=$RESOURCEID&DomainID=$DOMAINID&Name=$RRNAME&Type=$RRTYPE&Target=$NEWIP"; echo
   $WGET --post-data "api_key=$APIKEY&action=domainSave&DomainID=$DOMAINID&Domain=$DOMAIN&Type=master&Status=$STATUS&SOA_Email=$SOAEMAIL"; echo
   echo $NEWIP > $LASTIP
   logger "Updated IP address to $NEWIP"
fi

Using Linode DNS Manager for Google Apps

Monday, December 8th, 2008

I've hosted a few websites for other people and have used Google Apps to handle mail and calendar needs. This way I'm just using my Linode to only host the webpages. After manually creating the Google Apps DNS records a few times, I decided it'd be best to write a script using Linode's API to automate the process.

Since I haven't written a Perl script from scratch in awhile, I thought it would be good to use that. Michael Greb, who works at Linode, published a Perl module on CPAN called "WebService::Linode". Mike also posted some really helpful information regarding the installation of Perl modules under Ubuntu Linux. Instead of downloading, compiling, and installing the module the old fashioned manual way, you can use dh-make-perl. The dh-make-perl program will do all of that for you and create a Debian package file to install. This way if the CPAN module is ever upgraded or becomes part of the distro, it'll be handled automatically. I used the following commands to install the module (I also had to do the same thing for JSON because my installed version was too old).

$ dh-make-perl --cpan JSON --build
$ dh-make-perl --cpan WebService::Linode --build
$ sudo dpkg -i libjson-perl_2.12-1_all.deb libwebservice-linode-perl_0.02-1_all.deb

On the first run it will prompt for the Linode API key and store it in ~/.linode-api. Subsequent runs will simply read the key from that file. Below is an example of how it's usage.

$ googleapps-dns.pl -h
Usage:
    googleapps-dns.pl [ -d domainname ] [ -m ] [ -c ] [ -f ] [ -v ] [ -h ]

Options:
            -d domainname
                    Specify the domain name for adding the records.  This field is
                    required.
            -c      Add Google Chat's Jabber and XMPP records to route external
                    chat program to Google's services.
            -g      Add CNAMES that point calendar.domainname, docs.domainname,
                    mail.domainname, sites.domainname, and start.domainname to
                    ghs.google.com.
            -m      Add MX and SPF records for routing mail to Google Apps.
            -f      Force deletion of any conflicting records.
            -v      Enable verbose debugging messages.
            -h      Display help and options.

$ googleapps-dns.pl -d example.com -g -m -c
Would you like to delete any conflicting dns records? [Y/n] y
Please enter your Linode API Key: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
$

I hope this is helpful for other people managing sites hosted on Google Apps. The code is below.

#!/usr/bin/perl
#
# googleapps-dns.pl
#
# Script to populate the Linode's DNS Manager for Google Apps.
#
# Copyright (c) 2008 Patrick Hennessy 
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
#

use strict;
use warnings;

use Getopt::Long;
use Pod::Usage;
use WebService::Linode::DNS;

# File to store apikey.  If undefined or blank, use ~/.linode-apikey.
#
my $apiKeyFile = '';

# Default resource record templates.
#
my %mailTemplate = ( resourceid => 0,  name => '', type => 'MX' );
my %xmppTemplate = ( resourceid => 0, name => '_xmpp-server', protocol => '_tcp', type => 'SRV', weight => 0, port => 5269 );
my %jabberTemplate = ( resourceid => 0, name => '_jabber', protocol => '_tcp', type => 'SRV', weight => 0, port => 5269 );
my %ghsTemplate = ( resourceid => 0, type => 'CNAME', target => 'ghs.google.com' );

# Google Apps DNS Records
#
my @googleMailRR = (
        { %mailTemplate, target => 'aspmx.l.google.com', priority => 10 },
        { %mailTemplate, target => 'alt1.aspmx.l.google.com', priority => 20 },
        { %mailTemplate, target => 'alt2.aspmx.l.google.com', priority => 20 },
        { %mailTemplate, target => 'aspmx2.googlemail.com', priority => 30 },
        { %mailTemplate, target => 'aspmx3.googlemail.com', priority => 30 },
        { %mailTemplate, target => 'aspmx4.googlemail.com', priority => 30 },
        { %mailTemplate, target => 'aspmx5.googlemail.com', priority => 30 },
        { %mailTemplate, type => 'TXT', target => 'v=spf1 a mx include:aspmx.googlemail.com -all' },
);

my @googleXMPPJabberRR = (
        { %xmppTemplate, target => 'xmpp-server.l.google.com', priority => 5 },
        { %xmppTemplate, target => 'xmpp-server1.l.google.com', priority => 20 },
        { %xmppTemplate, target => 'xmpp-server2.l.google.com', priority => 20 },
        { %xmppTemplate, target => 'xmpp-server3.l.google.com', priority => 20 },
        { %xmppTemplate, target => 'xmpp-server4.l.google.com', priority => 20 },
        { %jabberTemplate, target => 'xmpp-server.l.google.com', priority => 5 },
        { %jabberTemplate, target => 'xmpp-server1.l.google.com', priority => 20 },
        { %jabberTemplate, target => 'xmpp-server2.l.google.com', priority => 20 },
        { %jabberTemplate, target => 'xmpp-server3.l.google.com', priority => 20 },
        { %jabberTemplate, target => 'xmpp-server4.l.google.com', priority => 20 },
);

my @googleGHSRR = (
        { %ghsTemplate, name => 'calendar' },
        { %ghsTemplate, name => 'docs' },
        { %ghsTemplate, name => 'mail' },
        { %ghsTemplate, name => 'sites' },
        { %ghsTemplate, name => 'start' },
);

# =============================================================================
# Do not change anything below this line.
# =============================================================================
#
die "This script needs to be run interactively." if (! -t STDIN);

# Handle options.
#
my ($chat, $debug, $domainName, $force, $ghs, $help, $mail);
my $result = GetOptions(
        'd=s'           => $domainName,
        'c'             => $chat,
        'f'             => $force,
        'g'             => $ghs,
        'm'             => $mail,
        'v'             => $debug,
        'help|h|?'      => $help
);

# Usage
#
pod2usage(1) if $help;
pod2usage(1) if ! $domainName;
pod2usage(1) if (! $chat) && (! $ghs) && (! $mail);

# Prompt to see if we should delete conflicting records or just add the new Google records.
#
if (! defined($force)) {
        $force = parseresp(prompt("Would you like to delete any conflicting dns records? [Y/n] "));
}

# Get API key and create api object.
#
my $apiKey = getApiKey($apiKeyFile);
my $api = new WebService::Linode::DNS( apikey => $apiKey );

# Get domain object.
#
my $domain = $api->domainGet( domain => $domainName ) ||
        die "ERROR: Domain not found, please create the initial records first.n";

# XMPP+Jabber Records
#
processRRs($api, $domain, @googleXMPPJabberRR, $force) if $chat;

# Mail Records
#
processRRs($api, $domain, @googleMailRR, $force) if $mail;

# GHS Records
#
processRRs($api, $domain, @googleGHSRR, $force) if $ghs;
# Save the domain.
#
$api->domainSave(%$domain) || die "Couldn't save $domainNamen";

# All done.
#
exit(0);

# Subroutines
#
sub processRRs {
        my $api = shift;
        my $domain = shift;
        my $resourceRecords = shift;
        my $force = shift;

        # Remove any existing records.
        #
        if ($force) {
                for my $nRecord (@$resourceRecords) {
                        for my $eRecord (domainGetRRs($api, $domain->{domainid}, $nRecord->{type})) {
                                if (($eRecord->{type} =~ m/mx/i) && ($eRecord->{name} eq "")) {
                                        deleteRR($api, $eRecord);
                                } elsif (($eRecord->{type} =~ m/txt/i) && ($eRecord->{target} =~ m/v=spf/i)) {
                                        deleteRR($api, $eRecord);
                                } elsif (($eRecord->{type} =~ m/srv/i) && ($eRecord->{name} =~ m/_xmpp-server/i)) {
                                        deleteRR($api, $eRecord);
                                } elsif (($eRecord->{type} =~ m/srv/i) && ($eRecord->{name} =~ m/_jabber/i)) {
                                        deleteRR($api, $eRecord);
                                } elsif (($eRecord->{type} =~ m/cname/i) && ($eRecord->{target} =~ m/ghs.google.com/i)) {
                                        deleteRR($api, $eRecord);
                                }
                        }
                }
        }

        # Create new records.
        #
        for my $record (@$resourceRecords) {
                debug("SAVING RR: TYPE=$record->{type} NAME=$record->{name} TARGET=$record->{target}");
                my $rr = $api->domainResourceSave( 'domainid' => $domain->{domainid}, %$record ) ||
                        die "Could not save TYPE=$record->{type} NAME=$record->{name} TARGET=$record->{target}n";
        }
}

sub deleteRR {
        my $api = shift;
        my $record = shift;

        debug("DELETING RR: TYPE=$record->{type} NAME=$record->{name} TARGET=$record->{target}");
        my $result = $api->domainResourceDelete( resourceid => $record->{resourceid} ) ||
                warn "WARNING: Could not delete TYPE=$record->{type} NAME=$record->{name} TARGET=$record->{target}n";

        return $result;
}

sub domainGetRRs {
        my $api = shift;
        my $domainId = shift;
        my $domainRRType = shift;
        my @domainRRs = ();

        my $rrs = $api->domainResourceList( domainid => $domainId ) ||
                die "ERROR: Could not retrieve domain resource list.n";
        for my $rr (@$rrs) {
                push(@domainRRs, $rr) if ($rr->{type} =~ m/^$domainRRType$/i);
        }

        return @domainRRs;
}

sub getApiKey {
        my $apiKeyFile = shift;
        my $apiKey;

        if (!length($apiKeyFile)) {
                $apiKeyFile = (getpwnam(getlogin()))[7] . '/.linode-apikey';
        }

        if (-f $apiKeyFile) {
                chomp ($apiKey = `cat $apiKeyFile`);
        } else {
                $apiKey = prompt("Please enter your Linode API Key: ");
                system "echo '$apiKey' > $apiKeyFile";
        }

        return $apiKey;
}

sub parseresp {
        my $response = shift;
        my $val = 0;

        chomp($response);
        $val = 1 if ($response =~ m/^y/i );
        $val = 1 if ($response eq "");

        return $val;
}

sub prompt {
        my $promptstring = shift;

        print $promptstring;
        chomp (my $retstring = );

        return $retstring;
}

sub debug {
        my $msg = shift;

        print STDERR $msg, "n" if $debug;
}

__END__

=head1 NAME

googleapps-dns.pl - Create Google Apps DNS Records in Linode DNS Manager

=head1 SYNOPSIS

googleapps-dns.pl [ -d domainname ] [ -m ] [ -c ] [ -f ] [ -v ] [ -h ] 

=head1 OPTIONS

        -d domainname
                Specify the domain name for adding the records.  This field is 
                required.
        -c      Add Google Chat's Jabber and XMPP records to route external
                chat program to Google's services.
        -g      Add CNAMES that point calendar.domainname, docs.domainname, 
                mail.domainname, sites.domainname, and start.domainname to
                ghs.google.com.
        -m      Add MX and SPF records for routing mail to Google Apps.
        -f      Force deletion of any conflicting records.
        -v      Enable verbose debugging messages.
        -h      Display help and options.

=head1 DESCRIPTION

B provides a wizard to populate DNS records in the Linode 
DNS manager for Google Apps.  It requires that the domain already exist.  It 
would create the standard DNS entries which can be pruned manually later.

=cut


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