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backport ipaddr grammar fixes (#44974)
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@samccann
samccann authored and Alicia Cozine committed Aug 31, 2018
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156 changes: 90 additions & 66 deletions docs/docsite/rst/user_guide/playbooks_filters_ipaddr.rst
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Expand Up @@ -5,16 +5,16 @@ ipaddr filter

.. versionadded:: 1.9

``ipaddr()`` is a Jinja2 filter designed to provide an interface to `netaddr`_
``ipaddr()`` is a Jinja2 filter designed to provide an interface to the `netaddr`_
Python package from within Ansible. It can operate on strings or lists of
items, test various data to check if they are valid IP addresses and manipulate
the input data to extract requested information. ``ipaddr()`` works both with
IPv4 and IPv6 addresses in various forms, there are also additional functions
items, test various data to check if they are valid IP addresses, and manipulate
the input data to extract requested information. ``ipaddr()`` works with both
IPv4 and IPv6 addresses in various forms. There are also additional functions
available to manipulate IP subnets and MAC addresses.

To use this filter in Ansible, you need to install `netaddr`_ Python library on
To use this filter in Ansible, you need to install the `netaddr`_ Python library on
a computer on which you use Ansible (it is not required on remote hosts).
It can usually be installed either via your system package manager, or using
It can usually be installed with either your system package manager or using
``pip``::

pip install netaddr
Expand All @@ -30,8 +30,8 @@ Basic tests
^^^^^^^^^^^

``ipaddr()`` is designed to return the input value if a query is True, and
``False`` if query is False. This way it can be very easily used in chained
filters. To use the filter, pass a string to it
``False`` if a query is False. This way it can be easily used in chained
filters. To use the filter, pass a string to it:

.. code-block:: none
Expand All @@ -41,7 +41,7 @@ You can also pass the values as variables::

{{ myvar | ipaddr }}

Here are some example tests of various input strings::
Here are some example test results of various input strings::

# These values are valid IP addresses or network ranges
'192.168.0.1' -> 192.168.0.1
Expand All @@ -50,7 +50,7 @@ Here are some example tests of various input strings::
45443646733 -> ::a:94a7:50d
'523454/24' -> 0.7.252.190/24

# Values that are not valid IP addresses or network ranges:
# Values that are not valid IP addresses or network ranges
'localhost' -> False
True -> False
'space bar' -> False
Expand All @@ -59,18 +59,18 @@ Here are some example tests of various input strings::
':' -> False
'fe80:/10' -> False

Sometimes you need either IPv4 or IPv6 addresses. To filter only for particular
Sometimes you need either IPv4 or IPv6 addresses. To filter only for a particular
type, ``ipaddr()`` filter has two "aliases", ``ipv4()`` and ``ipv6()``.

Example us of an IPv4 filter::
Example use of an IPv4 filter::

{{ myvar | ipv4 }}

And similar example of an IPv6 filter::
A similar example of an IPv6 filter::

{{ myvar | ipv6 }}

Here's an example test to look for IPv4 addresses::
Here's some example test results to look for IPv4 addresses::

'192.168.0.1' -> 192.168.0.1
'192.168.32.0/24' -> 192.168.32.0/24
Expand Down Expand Up @@ -110,7 +110,7 @@ Wrapping IPv6 addresses in [ ] brackets
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Some configuration files require IPv6 addresses to be "wrapped" in square
brackets (``[ ]``). To accomplish that, you can use ``ipwrap()`` filter. It
brackets (``[ ]``). To accomplish that, you can use the ``ipwrap()`` filter. It
will wrap all IPv6 addresses and leave any other strings intact::

# {{ test_list | ipwrap }}
Expand All @@ -128,7 +128,7 @@ chain both filters together::
Basic queries
^^^^^^^^^^^^^

You can provide single argument to each ``ipaddr()`` filter. Filter will then
You can provide a single argument to each ``ipaddr()`` filter. The filter will then
treat it as a query and return values modified by that query. Lists will
contain only values that you are querying for.

Expand All @@ -149,21 +149,21 @@ Here's our test list again::
# Example list of values
test_list = ['192.24.2.1', 'host.fqdn', '::1', '192.168.32.0/24', 'fe80::100/10', True, '', '42540766412265424405338506004571095040/64']

Lets take above list and get only those elements that are host IP addresses,
Let's take the list above and get only those elements that are host IP addresses
and not network ranges::

# {{ test_list | ipaddr('address') }}
['192.24.2.1', '::1', 'fe80::100']

As you can see, even though some values had a host address with a CIDR prefix,
it was dropped by the filter. If you want host IP addresses with their correct
CIDR prefixes (as is common with IPv6 addressing), you can use
they were dropped by the filter. If you want host IP addresses with their correct
CIDR prefixes (as is common with IPv6 addressing), you can use the
``ipaddr('host')`` filter::

# {{ test_list | ipaddr('host') }}
['192.24.2.1/32', '::1/128', 'fe80::100/10']

Filtering by IP address types also works::
Filtering by IP address type also works::

# {{ test_list | ipv4('address') }}
['192.24.2.1']
Expand All @@ -190,34 +190,36 @@ You can also check how many IP addresses can be in a certain range::
# {{ test_list | ipaddr('net') | ipaddr('size') }}
[256, 18446744073709551616L]

By specifying a network range as a query, you can check if given value is in
By specifying a network range as a query, you can check if a given value is in
that range::

# {{ test_list | ipaddr('192.0.0.0/8') }}
['192.24.2.1', '192.168.32.0/24']

If you specify a positive or negative integer as a query, ``ipaddr()`` will
treat this as an index and will return specific IP address from a network
treat this as an index and will return the specific IP address from a network
range, in the 'host/prefix' format::

# First IP address (network address)
# {{ test_list | ipaddr('net') | ipaddr('0') }}
['192.168.32.0/24', '2001:db8:32c:faad::/64']

# Second IP address (usually gateway host)
# Second IP address (usually the gateway host)
# {{ test_list | ipaddr('net') | ipaddr('1') }}
['192.168.32.1/24', '2001:db8:32c:faad::1/64']

# Last IP address (broadcast in IPv4 networks)
# Last IP address (the broadcast address in IPv4 networks)
# {{ test_list | ipaddr('net') | ipaddr('-1') }}
['192.168.32.255/24', '2001:db8:32c:faad:ffff:ffff:ffff:ffff/64']

You can also select IP addresses from a range by their index, from the start or
end of the range::

# Returns from the start of the range
# {{ test_list | ipaddr('net') | ipaddr('200') }}
['192.168.32.200/24', '2001:db8:32c:faad::c8/64']

# Returns from the end of the range
# {{ test_list | ipaddr('net') | ipaddr('-200') }}
['192.168.32.56/24', '2001:db8:32c:faad:ffff:ffff:ffff:ff38/64']

Expand All @@ -228,8 +230,8 @@ end of the range::
Getting information from host/prefix values
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Very frequently you use combination of IP addresses and subnet prefixes
("CIDR"), this is even more common with IPv6. ``ipaddr()`` filter can extract
You frequently use a combination of IP addresses and subnet prefixes
("CIDR"), this is even more common with IPv6. The ``ipaddr()`` filter can extract
useful data from these prefixes.

Here's an example set of two host prefixes (with some "control" values)::
Expand All @@ -242,7 +244,7 @@ just subnets or single IP addresses::
# {{ host_prefix | ipaddr('host/prefix') }}
['2001:db8:deaf:be11::ef3/64', '192.0.2.48/24']

In Debian-based systems, network configuration stored in ``/etc/network/interfaces`` file uses combination of IP address, network address, netmask and broadcast address to configure IPv4 network interface. We can get these values from a single 'host/prefix' combination:
In Debian-based systems, the network configuration stored in the ``/etc/network/interfaces`` file uses a combination of IP address, network address, netmask and broadcast address to configure an IPv4 network interface. We can get these values from a single 'host/prefix' combination:

.. code-block:: jinja
Expand All @@ -261,11 +263,13 @@ In Debian-based systems, network configuration stored in ``/etc/network/interfac
netmask 255.255.255.0
broadcast 192.0.2.255
In above example, we needed to handle the fact that values were stored in
a list, which is unusual in IPv4 networks, where only single IP address can be
In the above example, we needed to handle the fact that values were stored in
a list, which is unusual in IPv4 networks, where only a single IP address can be
set on an interface. However, IPv6 networks can have multiple IP addresses set
on an interface::

.. code-block:: jinja

# Jinja2 template
iface eth0 inet6 static
{% set ipv6_list = host_prefix | unique | ipv6('host/prefix') %}
Expand All @@ -281,7 +285,7 @@ on an interface::
iface eth0 inet6 static
address 2001:db8:deaf:be11::ef3/64

If needed, you can extract subnet and prefix information from 'host/prefix' value::
If needed, you can extract subnet and prefix information from the 'host/prefix' value::

# {{ host_prefix | ipaddr('host/prefix') | ipaddr('subnet') }}
['2001:db8:deaf:be11::/64', '192.0.2.0/24']
Expand All @@ -292,27 +296,27 @@ If needed, you can extract subnet and prefix information from 'host/prefix' valu
Converting subnet masks to CIDR notation
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Given a subnet in the form of network address and subnet mask, it can be converted into CIDR notation using ``ipaddr()``. This can be useful for converting Ansible facts gathered about network configuration from subnet masks into CIDR format::
Given a subnet in the form of network address and subnet mask, the ``ipaddr()`` filter can convert it into CIDR notation. This can be useful for converting Ansible facts gathered about network configuration from subnet masks into CIDR format::

ansible_default_ipv4: {
address: "192.168.0.11",
alias: "eth0",
broadcast: "192.168.0.255",
gateway: "192.168.0.1",
interface: "eth0",
macaddress: "fa:16:3e:c4:bd:89",
mtu: 1500,
netmask: "255.255.255.0",
network: "192.168.0.0",
address: "192.168.0.11",
alias: "eth0",
broadcast: "192.168.0.255",
gateway: "192.168.0.1",
interface: "eth0",
macaddress: "fa:16:3e:c4:bd:89",
mtu: 1500,
netmask: "255.255.255.0",
network: "192.168.0.0",
type: "ether"
}

First concatenate network and netmask::
First concatenate the network and netmask::

net_mask = "{{ ansible_default_ipv4.network }}/{{ ansible_default_ipv4.netmask }}"
'192.168.0.0/255.255.255.0'

This result can be canonicalised with ``ipaddr()`` to produce a subnet in CIDR format::
This result can be converted to canonical form with ``ipaddr()`` to produce a subnet in CIDR format::

# {{ net_mask | ipaddr('prefix') }}
'24'
Expand All @@ -339,7 +343,7 @@ Converting from IPv6 to IPv4 works very rarely::
# {{ test_list | ipv6('ipv4') }}
['0.0.0.1/32']

But we can make double conversion if needed::
But we can make a double conversion if needed::

# {{ test_list | ipaddr('ipv6') | ipaddr('ipv4') }}
['192.24.2.1/32', '0.0.0.1/32', '192.168.32.0/24']
Expand All @@ -362,17 +366,17 @@ You can convert IP addresses to PTR records::
0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.d.a.a.f.c.2.3.0.8.b.d.0.1.0.0.2.ip6.arpa.


Converting IPv4 address to 6to4 address
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Converting IPv4 address to a 6to4 address
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

`6to4`_ tunnel is a way to access IPv6 Internet from IPv4-only network. If you
have a public IPv4 address, you automatically can configure it's IPv6
equivalent in ``2002::/16`` network range - after conversion you will gain
A `6to4`_ tunnel is a way to access the IPv6 Internet from an IPv4-only network. If you
have a public IPv4 address, you can automatically configure its IPv6
equivalent in the ``2002::/16`` network range. After conversion you will gain
access to a ``2002:xxxx:xxxx::/48`` subnet which could be split into 65535
``/64`` subnets if needed.

To convert your IPv4 address, just send it through ``'6to4'`` filter. It will
be automatically converted to a router address (with ``::1/48`` host address)::
To convert your IPv4 address, just send it through the ``'6to4'`` filter. It will
be automatically converted to a router address (with a ``::1/48`` host address)::

# {{ '193.0.2.0' | ipaddr('6to4') }}
2002:c100:0200::1/48
Expand All @@ -383,15 +387,15 @@ be automatically converted to a router address (with ``::1/48`` host address)::
Subnet manipulation
^^^^^^^^^^^^^^^^^^^

``ipsubnet()`` filter can be used to manipulate network subnets in several ways.
The ``ipsubnet()`` filter can be used to manipulate network subnets in several ways.

Here is some example IP address and subnet::
Here is an example IP address and subnet::

address = '192.168.144.5'
subnet = '192.168.0.0/16'

To check if a given string is a subnet, pass it through the filter without any
arguments. If given string is an IP address, it will be converted into
arguments. If the given string is an IP address, it will be converted into
a subnet::

# {{ address | ipsubnet }}
Expand All @@ -400,15 +404,15 @@ a subnet::
# {{ subnet | ipsubnet }}
192.168.0.0/16

If you specify a subnet size as first parameter of ``ipsubnet()`` filter, and
subnet size is **smaller than current one**, you will get number of subnets
If you specify a subnet size as the first parameter of the ``ipsubnet()`` filter, and
the subnet size is **smaller than the current one**, you will get the number of subnets
a given subnet can be split into::

# {{ subnet | ipsubnet(20) }}
16

Second argument of ``ipsubnet()`` filter is an index number; by specifying it
you can get new subnet with specified size::
The second argument of the ``ipsubnet()`` filter is an index number; by specifying it
you can get a new subnet with the specified size::

# First subnet
# {{ subnet | ipsubnet(20, 0) }}
Expand All @@ -427,8 +431,8 @@ you can get new subnet with specified size::
192.168.176.0/20

If you specify an IP address instead of a subnet, and give a subnet size as
a first argument, ``ipsubnet()`` filter will instead return biggest subnet that
contains a given IP address::
the first argument, the ``ipsubnet()`` filter will instead return the biggest subnet that
contains that given IP address::

# {{ address | ipsubnet(20) }}
192.168.128.0/20
Expand All @@ -452,22 +456,44 @@ smaller subnets::
# {{ address | ipsubnet(18, -5) }}
192.168.144.0/27

You can use ``ipsubnet()`` filter with ``ipaddr()`` filter to for example split
given ``/48`` prefix into smaller, ``/64`` subnets::
By specifying another subnet as a second argument, if the second subnet includes
the first, you can determine the rank of the first subnet in the second ::

# The rank of the IP in the subnet (the IP is the 36870nth /32 of the subnet)
# {{ address | ipsubnet(subnet) }}
36870

# The rank in the /24 that contain the address
# {{ address | ipsubnet('192.168.144.0/24') }}
6

# An IP with the subnet in the first /30 in a /24
# {{ '192.168.144.1/30' | ipsubnet('192.168.144.0/24') }}
1

# The fifth subnet /30 in a /24
# {{ '192.168.144.16/30' | ipsubnet('192.168.144.0/24') }}
5

If the second subnet doesn't include the first subnet, the ``ipsubnet()`` filter raises an error.


You can use the ``ipsubnet()`` filter with the ``ipaddr()`` filter to, for example, split
a given ``/48`` prefix into smaller ``/64`` subnets::

# {{ '193.0.2.0' | ipaddr('6to4') | ipsubnet(64, 58820) | ipaddr('1') }}
2002:c100:200:e5c4::1/64

Because of the size of IPv6 subnets, iteration over all of them to find the
correct one may take some time on slower computers, depending on the size
difference between subnets.
difference between the subnets.

Subnet Merging
^^^^^^^^^^^^^^

.. versionadded:: 2.6

The `cidr_merge` filter can be used to merge subnets or individual addresses
The ``cidr_merge()`` filter can be used to merge subnets or individual addresses
into their minimal representation, collapsing overlapping subnets and merging
adjacent ones wherever possible::

Expand All @@ -489,7 +515,7 @@ subnet which contains all of the inputs::
MAC address filter
^^^^^^^^^^^^^^^^^^

You can use ``hwaddr()`` filter to check if a given string is a MAC address or
You can use the ``hwaddr()`` filter to check if a given string is a MAC address or
convert it between various formats. Examples::

# Example MAC address
Expand Down Expand Up @@ -527,5 +553,3 @@ convert it between various formats. Examples::
Have a question? Stop by the google group!
`irc.freenode.net <http://irc.freenode.net>`_
#ansible IRC chat channel


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