The latest release is always available from GitHub at
- Introduction
- Supported Providers
- Configuration
- Custom DDNS Providers
- Build & Install
- Building from GIT
- Origin & References
Inadyn, or In-a-Dyn, is a small and simple Dynamic DNS, DDNS, client with HTTPS support. Commonly available in many GNU/Linux distributions, used in off the shelf routers and Internet gateways to automate the task of keeping your Internet name in sync with your public¹ IP address. It can also be used in installations with redundant (backup) connections to the Internet.
Most people are unaware they share a pool of Internet addresses with other users of the same Internet Service Provider (ISP). Protocols like DHCP, PPPoE, or PPPoA are used to give you an address and a way to connect to the Internet, but usually not a way for others to connect to you. If you want to run an Internet server on such a connection you risk losing your IP address every time you reconnect, or as in the case of DHCP even when the lease is renegotiated.
By using a DDNS client like inadyn you can register an Internet name
with a DDNS provider, like FreeDNS. The
DDNS client updates your DNS record periodically and/or on demand when
your IP address changes. Inadyn can maintain multiple host records with
the same IP address, use a combination of a script, the address from an
Internet-facing interface, or default to using the IP address change
detector of the DDNS provider.
__
¹ Public IP address is the default, private addresses can also be used.
Some of these services are free of charge for non-commercial use, some take a small fee, but also provide more domains to choose from:
- https://freedns.afraid.org
- https://www.nsupdate.info
- https://duckdns.org
- https://freemyip.com
- https://www.loopia.com
- https://www.dyndns.org, https://dyn.com
- https://www.noip.com
- https://www.easydns.com
- https://www.dnsomatic.com
- https://dns.he.net
- https://www.tunnelbroker.net
- https://www.sitelutions.com
- https://www.dnsexit.com, parent of https://www.zoneedit.com
- https://www.changeip.com
- https://www.dhis.org
- https://www.namecheap.com
- https://domains.google
- https://www.ovh.com
- https://giradns.com
- https://www.duiadns.net
- https://ddnss.de
- https://dynv6.com
- https://spdyn.de
- https://www.cloudxns.net
- https://www.pubyun.com, formerly http://www.3322.org
- https://www.dnspod.cn
- https://www.dynu.com
- https://www.selfhost.de
- https://connect.yandex.ru
- https://www.cloudflare.com
DDNS providers not supported natively like http://twoDNS.de, can be enabled using the generic DDNS plugin. See below for configuration examples.
In-A-Dyn defaults to HTTPS, but not all providers may support this, so
try disabling SSL for the update (ssl = false) or the checkip phase
(checkip-ssl = false) in the provider section, in case you run into
problems.
HTTPS is enabled by default since it protects your credentials from being snooped and reduces the risk of someone hijacking your account.
In-A-Dyn supports updating several DDNS servers, several accounts even on
different DDNS providers. The following /etc/inadyn.conf example show
how this can be done. To verify your configuration, without starting the
daemon, use:
inadyn --check-config
This looks for the default .conf file, to check any file, use:
inadyn --check-config -f /path/to/file.conf
# In-A-Dyn v2.0 configuration file format
period = 300
user-agent = Mozilla/5.0
# The FreeDNS username must be in lower case
# The password (max 16 chars) is case sensitive
provider freedns {
username = lower-case-username
password = case-sensitive-pwd
hostname = some.example.com
}
provider freemyip {
password = YOUR_TOKEN
hostname = YOUR_DOMAIN.freemyip.com
}
provider dyn {
ssl = false
username = charlie
password = snoopy
hostname = { peanuts, woodstock }
user-agent = Mozilla/4.0
}
# Google Domains - notice use of '@' to update root entry
provider domains.google.com {
hostname = @.mydomain.com
username = your_username
password = your_password
}
provider duckdns.org {
username = YOUR_TOKEN
password = noPasswordForDuckdns
hostname = YOUR_DOMAIN.duckdns.org
}
# With multiple usernames at the same provider, index with :#
provider no-ip.com:1 {
username = ian
password = secret
hostname = flemming.no-ip.com
user-agent = inadyn/2.2
}
# With multiple usernames at the same provider, index with :#
provider no-ip.com:2 {
username = james
password = bond
hostname = spectre.no-ip.com
checkip-ssl = false
checkip-server = api.ipify.org
}
# With multiple usernames at the same provider, index with :#
provider no-ip.com:3 {
username = spaceman
password = bowie
hostname = spaceman.no-ip.com
checkip-command = "/sbin/ifconfig eth0 | grep 'inet6 addr'"
}
# Note: hostname == update-key from Advanced tab in the Web UI
provider tunnelbroker.net {
username = futurekid
password = dreoadsad/+dsad21321 # update-key-in-advanced-tab
hostname = 1234534245321 # tunnel-id
}
provider dynv6.com {
username = your_token
password = n/a
hostname = { host1.dynv6.net, host2.dynv6.net }
}
provider cloudxns.net {
username = your_api_key
password = your_secret_key
hostname = yourhost.example.com
}
provider dnspod.cn {
username = your_api_id
password = your_api_token
hostname = yourhost.example.com
}
# Create a unique API token with the following Permissions:
# Zone: Zone - Read
# Zone: DNS - Edit
#
# If the token is limited to a specific zone (it should be)
# it will also need the following permission:
# Account: Account Settings - Read
#
# For more information, see this Cloudflare Community post:
# https://community.cloudflare.com/t/bug-zone-detail-by-name-requires-zone-list-permission/128042
#
# Note: global API keys are NOT supported for security reasons
provider cloudflare.com {
username = unused (but currently something must be entered)
password = your_api_token
hostname = yourhost.example.com
}
Notice how the config has three different users of the No-IP provider --
this is achieved by appending a :ID to the provider name.
We also define a custom cache directory, default is to use /var/cache.
In our case /mnt is a system specific persistent store for caching
your IP address as reported to each provider. Inadyn use this to ensure
you are not locked out of your account for excessive updates, which may
happen if your device Internet gateway running inadyn gets stuck in a
reboot loop, or similar.
However, for the caching mechanism to be 100% foolproof the system clock
must be set correctly -- if you have issues with the system clock not
being set properly at boot, e.g. pending receipt of an NTP message, use
the command line option --startup-delay=SEC. To tell inadyn it is
OK to proceed before the SEC timeout, use SIGUSR2.
The last system defined is the IPv6 https://tunnelbroker.net service
provided by Hurricane Electric. Here hostname is set to the tunnel ID
and password must be the Update key found in the Advanced
configuration tab.
Sometimes the default checkip-server for a DDNS provider can be very
slow to respond, to this end Inadyn now supports overriding this server
with a custom one, like for custom DDNS provider, or even a custom
command. See the man pages, or the below section, for more information.
Some providers require using a specific browser to send updates, this
can be worked around using the user-agent = STRING setting, as shown
above. It is available both on a global and on a per-provider level.
NOTE: In a multi-user server setup, make sure to chmod your .conf
to 600 (read-write only by you/root) to protect against other users
reading your DDNS server credentials.
In addition to the default DDNS providers supported by Inadyn, custom
DDNS providers can be defined in the config file. Use custom {} in
instead of the provider {} section used in examples above.
In-A-Dyn use HTTP basic authentication (base64 encoded) to communicate username and password to the server. If you do not have a username and/or password, you can leave these fields out. Basic authentication, will still be used in communication with the server, but with empty username and password.
A DDNS provider like http://twoDNS.de can be setup like this:
custom twoDNS {
username = myuser
password = mypass
checkip-server = checkip.two-dns.de
checkip-path = /
ddns-server = update.twodns.de
ddns-path = "/update?hostname="
hostname = myhostname.dd-dns.de
}
For https://www.namecheap.com DDNS can look as follows. Notice how the hostname syntax differs between these two DDNS providers. You need to investigate details like this yourself when using the generic/custom DDNS plugin:
custom namecheap {
username = myuser
password = mypass
ddns-server = dynamicdns.park-your-domain.com
ddns-path = "/update?domain=YOURDOMAIN.TLD&password=mypass&host="
hostname = { "alpha", "beta", "gamma" }
}
Here three hostnames are updated, one HTTP GET update request for every DDNS provider is performed, for every listed hostname. Some providers, like FreeDNS, support setting up CNAME records (aliases) to reduce the amount of records you need to update. FreeDNS even default to linking multiple records to the same update, which may be very confusing if you want each DNS record to be updated from a unique IP address -- make sure to check your settings at the DDNS provider!
Your hostname is automatically appended to the end of the ddns-path,
as is customary, before it is communicated to the server. Username is
your Namecheap username, and password would be the one given to you in
the Dynamic DNS panel from Namecheap. Here is an alternative config to
illustrate how the hostname setting works:
custom kruskakli {
username = myuser
password = mypass
ddns-server = dynamicdns.park-your-domain.com
ddns-path = "/update?password=mypass&domain="
hostname = YOURDOMAIN.TLD
}
The generic plugin can also be used with providers that require the
client's new IP address in the update request. Here is an example of
how this can be done if we pretend that http://dyn.com is not
supported by inadyn. The ddns-path differs between providers and is
something you must figure out. The support pages sometimes list this
under an API section, or similar.
# This emulates dyndns.org
custom dyn {
username = DYNUSERNAME
password = DYNPASSWORD
ddns-server = members.dyndns.org
ddns-path = "/nic/update?hostname=%h.dyndns.org&myip=%i"
hostname = { YOURHOST, alias }
}
Here a fully custom ddns-path with format specifiers are used, see the
inadyn.conf(5) man page for details on this.
When using the generic plugin you should first inspect the response from
the DDNS provider. By default Inadyn looks for a 200 HTTP response OK
code and the strings "good", "OK", "true", or "updated" in the
HTTP response body. If the DDNS provider returns something else you can
add a list of possible ddns-response = { Arrr, kilroy }, or just a
single ddns-response = Cool -- if your provider does give any response
then use ddns-response = "".
If your DDNS provider does not provide you with a checkip-server, you
can use other services, like http://ipify.org, which is the default if
you do not specify one for your custom provider config:
checkip-server = api.ipify.org
or even use a script or command:
checkip-command = /sbin/ifconfig eth0 | grep 'inet addr'
These two settings can also be used in standard provider{} sections.
Note: hostname is required, even if everything is encoded in the
ddns-path! The given hostname is appended to the ddns-path used for
updates, unless you use append-myip in which case your IP address will
be appended instead. When using append-myip you probably need to
encode your DNS hostname in the ddns-path instead, as is done in the
last example above.
curl -sS https://deb.troglobit.com/pubkey.gpg | sudo apt-key add -
echo "deb [arch=amd64] https://deb.troglobit.com/debian stable main" | sudo tee /etc/apt/sources.list.d/troglobit.list
sudo apt-get update && sudo apt-get install inadyn
Automatically built images available here:
A Dockerfile is provided to simplify building and running inadyn.
docker build -t inadyn:latest .
docker run --rm -v "$PWD/inadyn.conf:/etc/inadyn.conf" inadyn:latest
To run the latest stable version on macOS, type:
brew install inadyn
To run the latest version from the master branch, install the git tap instead:
brew install --HEAD troglobit/inadyn/inadyn
Either of these will install all dependencies.
First download the latest official In-A-Dyn release from GitHub:
In-A-Dyn requires a few libraries to build. The build system searches
for them, in their required versions, using the pkg-config tool:
- libConfuse (3.0+)
- LibreSSL, OpenSSL, or GnuTLS
They are available from most UNIX distributions as pre-built packages.
Make sure to install the -dev or -devel package of the distribution
packages when building Inadyn. On Debian/Ubuntu (derivatives):
$ sudo apt install gnutls-dev libconfuse-dev
To build you also need a C compiler, the pkg-config tool, and make:
$ sudo apt install build-essential pkg-config
When building with HTTPS (SSL/TLS) support, make sure to also install
the ca-certificates package on your system, otherwise Inadyn will not
be able to validate the DDNS provider's HTTPS certificates.
The GNU Configure & Build system use /usr/local as the default install
prefix. In many cases this is useful, but this means the configuration
files and cache files will also use that same prefix. Most users have
come to expect those files in /etc/ and /var/run/ and configure has
a few useful options that are recommended to use:
$ ./configure --prefix=/usr --sysconfdir=/etc --localstatedir=/var
$ make -j5
$ sudo make install-strip
You may want to remove the --prefix=/usr option.
By default inadyn tries to build with GnuTLS for HTTPS support. GnuTLS is the recommended SSL library to use on UNIX distributions which do not provide OpenSSL/LibreSSL as a system library. However, when OpenSSL or LibreSSL is available as a system library, for example in many embedded systems:
./configure --enable-openssl
To completely disable inadyn HTTPS support (not recommended!):
./configure --disable-ssl
For more details on the OpenSSL and GNU GPL license issue, see:
- https://lists.debian.org/debian-legal/2004/05/msg00595.html
- https://people.gnome.org/~markmc/openssl-and-the-gpl
On some systems the default configure installation path, /usr/local,
is disabled and not searched by tools like ldconfig and pkg-config.
So if configure fails to find the libConfuse libraries, or the .pc
files, create the file /etc/ld.so.conf.d/local.conf with this content:
/usr/local/lib
update the linker cache:
sudo ldconfig -v |egrep libconfuse
and run the Inadyn configure script like this:
PKG_CONFIG_PATH=/usr/local/lib/pkgconfig ./configure
For systemd integration you need to install pkg-config, which helps
the Inadyn build system figure out the systemd paths. When installed
simply call systemctl to enable and start inadyn:
$ sudo systemctl enable inadyn.service
$ sudo systemctl start inadyn.service
Check that it started properly by inspecting the system log, or:
$ sudo systemctl status inadyn.service
If you want to contribute, or simply just try out the latest but unreleased features, then you need to know a few things about the GNU build system:
configure.acand a per-directoryMakefile.amare key filesconfigureandMakefile.inare generated fromautogen.sh, they are not stored in GIT but automatically generated for the release tarballsMakefileis generated byconfigurescript
To build from GIT; clone the repository and run the autogen.sh script.
This requires the GNU tools automake, autoconf and libtool to be
installed on your system. Released tarballs do not require these tools.
$ sudo apt install git automake autoconf
Then you can clone the repository and create the configure script,
which is not part of the GIT repo:
git clone https://github.com/troglobit/inadyn.git
cd inadyn/
./autogen.sh
./configure && make
Building from GIT requires, at least, the previously mentioned library dependencies. GIT sources are a moving target and are not recommended for production systems, unless you know what you are doing!
This is the continuation of Narcis Ilisei's original INADYN. Now maintained by Joachim Nilsson. Please file bug reports, or send pull requests for bug fixes and proposed extensions at GitHub.