salt/doc/topics/jinja/index.rst

Understanding Jinja

Jinja is the default templating language in SLS files.

Jinja in States

Jinja is evaluated before YAML, which means it is evaluated before the States are run.

The most basic usage of Jinja in state files is using control structures to wrap conditional or redundant state elements:

{% if grains['os'] != 'FreeBSD' %}
tcsh:
    pkg:
        - installed
{% endif %}

motd:
  file.managed:
    {% if grains['os'] == 'FreeBSD' %}
    - name: /etc/motd
    {% elif grains['os'] == 'Debian' %}
    - name: /etc/motd.tail
    {% endif %}
    - source: salt://motd

In this example, the first if block will only be evaluated on minions that aren't running FreeBSD, and the second block changes the file name based on the os grain.

Writing if-else blocks can lead to very redundant state files however. In this case, using pillars<pillar>, or using a previously defined variable might be easier:

{% set motd = ['/etc/motd'] %}
{% if grains['os'] == 'Debian' %}
  {% set motd = ['/etc/motd.tail', '/var/run/motd'] %}
{% endif %}

{% for motdfile in motd %}
{{ motdfile }}:
  file.managed:
    - source: salt://motd
{% endfor %}

Using a variable set by the template, the for loop will iterate over the list of MOTD files to update, adding a state block for each file.

The filter_by function can also be used to set variables based on grains:

{% set auditd = salt['grains.filter_by']({
'RedHat': { 'package': 'audit' },
'Debian': { 'package': 'auditd' },
}) %}

Include and Import

Includes and imports can be used to share common, reusable state configuration between state files and between files.

{% from 'lib.sls' import test %}

This would import the test template variable or macro, not the test state element, from the file lib.sls. In the case that the included file performs checks against grains, or something else that requires context, passing the context into the included file is required:

{% from 'lib.sls' import test with context %}

Including Context During Include/Import

By adding with context to the include/import directive, the current context can be passed to an included/imported template.

{% import 'openssl/vars.sls' as ssl with context %}

Macros

Macros are helpful for eliminating redundant code. Macros are most useful as mini-templates to repeat blocks of strings with a few parameterized variables. Be aware that stripping whitespace from the template block, as well as contained blocks, may be necessary to emulate a variable return from the macro.

# init.sls
{% from 'lib.sls' import pythonpkg with context %}

python-virtualenv:
  pkg.installed:
    - name: {{ pythonpkg('virtualenv') }}

python-fabric:
  pkg.installed:
    - name: {{ pythonpkg('fabric') }}

# lib.sls
{% macro pythonpkg(pkg) -%}
  {%- if grains['os'] == 'FreeBSD' -%}
    py27-{{ pkg }}
  {%- elif grains['os'] == 'Debian' -%}
    python-{{ pkg }}
  {%- endif -%}
{%- endmacro %}

This would define a macro that would return a string of the full package name, depending on the packaging system's naming convention. The whitespace of the macro was eliminated, so that the macro would return a string without line breaks, using whitespace control.

Template Inheritance

Template inheritance works fine from state files and files. The search path starts at the root of the state tree or pillar.

Filters

Saltstack extends builtin filters with these custom filters:

strftime

Converts any time related object into a time based string. It requires a valid strftime directives <python2:strftime-strptime-behavior>. An exhaustive list <python2:strftime-strptime-behavior> can be found in the official Python documentation.

{% set curtime = None | strftime() %}

Fuzzy dates require the timelib Python module is installed.

{{ "2002/12/25"|strftime("%y") }}
{{ "1040814000"|strftime("%Y-%m-%d") }}
{{ datetime|strftime("%u") }}
{{ "tomorrow"|strftime }}

sequence

Ensure that parsed data is a sequence.

yaml_encode

Serializes a single object into a YAML scalar with any necessary handling for escaping special characters. This will work for any scalar YAML data type: ints, floats, timestamps, booleans, strings, unicode. It will not work for multi-objects such as sequences or maps.

{%- set bar = 7 %}
{%- set baz = none %}
{%- set zip = true %}
{%- set zap = 'The word of the day is "salty"' %}

{%- load_yaml as foo %}
bar: {{ bar|yaml_encode }}
baz: {{ baz|yaml_encode }}
baz: {{ zip|yaml_encode }}
baz: {{ zap|yaml_encode }}
{%- endload %}

In the above case {{ bar }} and {{ foo.bar }} should be identical and {{ baz }} and {{ foo.baz }} should be identical.

yaml_dquote

Serializes a string into a properly-escaped YAML double-quoted string. This is useful when the contents of a string are unknown and may contain quotes or unicode that needs to be preserved. The resulting string will be emitted with opening and closing double quotes.

{%- set bar = '"The quick brown fox . . ."' %}
{%- set baz = 'The word of the day is "salty".' %}

{%- load_yaml as foo %}
bar: {{ bar|yaml_dquote }}
baz: {{ baz|yaml_dquote }}
{%- endload %}

In the above case {{ bar }} and {{ foo.bar }} should be identical and {{ baz }} and {{ foo.baz }} should be identical. If variable contents are not guaranteed to be a string then it is better to use yaml_encode which handles all YAML scalar types.

yaml_squote

Similar to the yaml_dquote filter but with single quotes. Note that YAML only allows special escapes inside double quotes so yaml_squote is not nearly as useful (viz. you likely want to use yaml_encode or yaml_dquote).

to_bool

Returns the logical value of an element.

Example:

{{ 'yes' | to_bool }}
{{ 'true' | to_bool }}
{{ 1 | to_bool }}
{{ 'no' | to_bool }}

Will be rendered as:

True
True
True
False

exactly_n_true

Tests that exactly N items in an iterable are "truthy" (neither None, False, nor 0).

Example:

{{ ['yes', 0, False, 'True'] | exactly_n_true(2) }}

Returns:

True

exactly_one_true

Tests that exactly one item in an iterable is "truthy" (neither None, False, nor 0).

Example:

{{ ['yes', False, 0, None] | exactly_one_true }}

Returns:

True

quote

Wraps a text around quoutes.

regex_search

Scan through string looking for a location where this regular expression produces a match. Returns None in case there were no matches found

Example:

{{ 'abcdefabcdef' | regex_search('BC(.*)', ignorecase=True) }}

Returns:

('defabcdef',)

regex_match

If zero or more characters at the beginning of string match this regular expression, otherwise returns None.

Example:

{{ 'abcdefabcdef' | regex_match('BC(.*)', ignorecase=True) }}

Returns:

None

uuid

Return a UUID.

Example:

{{ 'random' | uuid }}

Returns:

3652b285-26ad-588e-a5dc-c2ee65edc804

is_list

Return if an object is list.

Example:

{{ [1, 2, 3] | is_list }}

Returns:

True

is_iter

Return if an object is iterable.

Example:

{{ [1, 2, 3] | is_iter }}

Returns:

True

min

Return the minimum value from a list.

Example:

{{ [1, 2, 3] | min }}

Returns:

1

max

Returns the maximum value from a list.

Example:

{{ [1, 2, 3] | max }}

Returns:

3

avg

Returns the average value of the elements of a list

Example:

{{ [1, 2, 3] | avg }}

Returns:

2

union

Return the union of two lists.

Example:

{{ [1, 2, 3] | union([2, 3, 4]) | join(', ') }}

Returns:

1, 2, 3, 4

intersect

Return the intersection of two lists.

Example:

{{ [1, 2, 3] | intersect([2, 3, 4]) | join(', ') }}

Returns:

2, 3

difference

Return the difference of two lists.

Example:

{{ [1, 2, 3] | difference([2, 3, 4]) | join(', ') }}

Returns:

1

symmetric_difference

Return the symmetric difference of two lists.

Example:

{{ [1, 2, 3] | symmetric_difference([2, 3, 4]) | join(', ') }}

Returns:

1, 4

is_sorted

Return is an iterable object is already sorted.

Example:

{{ [1, 2, 3] | is_sorted }}

Returns:

True

compare_lists

Compare two lists and return a dictionary with the changes.

Example:

{{ [1, 2, 3] | compare_lists([1, 2, 4]) }}

Returns:

{'new': 4, 'old': 3}

compare_dicts

Compare two dictionaries and return a dictionary with the changes.

Example:

{{ {'a': 'b'} | compare_lists({'a': 'c'}) }}

Returns:

{'a': {'new': 'c', 'old': 'b'}}

is_hex

Return True if the value is hexazecimal.

Example:

{{ '0xabcd' | is_hex }}
{{ 'xyzt' | is_hex }}

Returns:

True
False

contains_whitespace

Return True if a text contains whitespaces.

Example:

{{ 'abcd' | contains_whitespace }}
{{ 'ab cd' | contains_whitespace }}

Returns:

False
True

substring_in_list

Return is a substring is found in a list of string values.

Example:

{{ 'abcd' | substring_in_list(['this', 'is', 'an abcd example']) }}

Returns:

True

check_whitelist_blacklist

Check a whitelist and/or blacklist to see if the value matches it.

Example:

{{ 5 | check_whitelist_blacklist(whitelist=[5, 6, 7]) }}
{{ 5 | check_whitelist_blacklist(blacklist=[5, 6, 7]) }}

Returns:

True

date_format

Converts unix timestamp into human-readable string.

Example:

{{ 1457456400 | date_format }}
{{ 1457456400 | date_format('%d.%m.%Y %H:%M') }}

Returns:

2017-03-08
08.03.2017 17:00

str_to_num

Converts a string to its numerical value.

Example:

{{ '5' | str_to_num }}

Returns:

5

to_bytes

Converts string-type object to bytes.

Example:

{{ 'wall of text' | to_bytes }}

json_decode_list

JSON decodes as unicode, Jinja needs bytes.

Example:

{{ [1, 2, 3] | json_decode_list }}

Returns:

[1, 2, 3]

json_decode_dict

JSON decodes as unicode, Jinja needs bytes.

Example:

{{ {'a': 'b'} | json_decode_dict }}

Returns:

{'a': 'b'}

rand_str

Generate a random string and applies a hash. Default hashing: md5.

Example:

{% set passwd_length = 17 %}
{{ passwd_length | rand_str }}
{{ passwd_length | rand_str('sha512') }}

Returns:

43ec517d68b6edd3015b3edc9a11367b
d94a45acd81f8e3107d237dbc0d5d195f6a52a0d188bc0284c0763ece1eac9f9496fb6a531a296074c87b3540398dace1222b42e150e67c9301383fde3d66ae5

md5

Return the md5 digest of a string.

Example:

{{ 'random' | md5 }}

Returns:

7ddf32e17a6ac5ce04a8ecbf782ca509

sha256

Return the sha256 digest of a string.

Example:

{{ 'random' | sha256 }}

Returns:

a441b15fe9a3cf56661190a0b93b9dec7d04127288cc87250967cf3b52894d11

sha512

Return the sha512 digest of a string.

Example:

{{ 'random' | sha512 }}

Returns:

811a90e1c8e86c7b4c0eef5b2c0bf0ec1b19c4b1b5a242e6455be93787cb473cb7bc9b0fdeb960d00d5c6881c2094dd63c5c900ce9057255e2a4e271fc25fef1

base64_encode

Encode a string as base64.

Example:

{{ 'random' | base64_encode }}

Returns:

cmFuZG9t

base64_decode

Decode a base64-encoded string.

{{ 'Z2V0IHNhbHRlZA==' | base64_decode }}

Returns:

get salted

hmac

Verify a challenging hmac signature against a string / shared-secret. Returns a boolean value.

Example:

{{ 'get salted' | hmac('shared secret', 'eBWf9bstXg+NiP5AOwppB5HMvZiYMPzEM9W5YMm/AmQ=') }}

Returns:

True

http_query

Return the HTTP reply object from a URL.

Example:

{{ 'http://jsonplaceholder.typicode.com/posts/1' | http_query }}

Returns:

{
  'body': '{
    "userId": 1,
    "id": 1,
    "title": "sunt aut facere repellat provident occaecati excepturi optio reprehenderit",
    "body": "quia et suscipit\\nsuscipit recusandae consequuntur expedita et cum\\nreprehenderit molestiae ut ut quas totam\\nnostrum rerum est autem sunt rem eveniet architecto"
  }'
}

Networking Filters

The following networking-related filters are supported:

is_ip

Return if a string is a valid IP Address.

{{ '192.168.0.1' | is_ip }}

Additionally accepts the following options:

• global
• link-local
• loopback
• multicast
• private
• public
• reserved
• site-local
• unspecified

Example - test if a string is a valid loopback IP address.

{{ '192.168.0.1' | is_ip(options='loopback') }}

is_ipv4

Returns if a string is a valid IPv4 address. Supports the same options as is_ip.

{{ '192.168.0.1' | is_ipv4 }}

is_ip6

Returns if a string is a valid IPv6 address. Supports the same options as is_ip.

{{ 'fe80::' | is_ipv6 }}

ipaddr

From a list, returns only valid IP entries. Supports the same options as is_ip. The list can contains also IP interfaces/networks.

Example:

{{ ['192.168.0.1', 'foo', 'bar', 'fe80::'] | ipaddr }}

Returns:

['192.168.0.1', 'fe80::']

ipv4

From a list, returns only valid IPv4 entries. Supports the same options as is_ip. The list can contains also IP interfaces/networks.

Example:

{{ ['192.168.0.1', 'foo', 'bar', 'fe80::'] | ipv4 }}

Returns:

['192.168.0.1']

ipv6

From a list, returns only valid IPv6 entries. Supports the same options as is_ip. The list can contains also IP interfaces/networks.

Example:

{{ ['192.168.0.1', 'foo', 'bar', 'fe80::'] | ipv4 }}

Returns:

['fe80::']

network_hosts

Return the list of hosts within a networks.

Example:

{{ '192.168.0.1/30' | network_hosts }}

Returns:

['192.168.0.1', '192.168.0.2']

network_size

Return the size of the network.

Example:

{{ '192.168.0.1/8' | network_size }}

Returns:

16777216

gen_mac

Generates a MAC address with the defined OUI prefix.

Common prefixes:

• 00:16:3E -- Xen
• 00:18:51 -- OpenVZ
• 00:50:56 -- VMware (manually generated)
• 52:54:00 -- QEMU/KVM
• AC:DE:48 -- PRIVATE

Example:

{{ '00:50' | gen_mac }}

Returns:

00:50:71:52:1C

mac_str_to_bytes

Converts a string representing a valid MAC address to bytes.

Example:

{{ '00:11:22:33:44:55' | mac_str_to_bytes }}

dns_check

Return the ip resolved by dns, but do not exit on failure, only raise an exception. Obeys system preference for IPv4/6 address resolution.

Example:

{{ 'www.google.com' | dns_check }}

Returns:

'172.217.3.196'

File filters

is_text_file

Return if a file is text.

Uses heuristics to guess whether the given file is text or binary, by reading a single block of bytes from the file. If more than 30% of the chars in the block are non-text, or there are NUL ('x00') bytes in the block, assume this is a binary file.

Example:

{{ '/etc/salt/master' | is_text_file }}

Returns:

True

is_binary_file

Return if a file is binary.

Detects if the file is a binary, returns bool. Returns True if the file is a bin, False if the file is not and None if the file is not available.

Example:

{{ '/etc/salt/master' | is_binary_file }}

Returns:

False

is_empty_file

Return if a file is empty.

Example:

{{ '/etc/salt/master' | is_empty_file }}

Returns:

False

file_hashsum

Return the hashsum of a file.

Example:

{{ '/etc/salt/master' | file_hashsum }}

Returns:

02d4ef135514934759634f10079653252c7ad594ea97bd385480c532bca0fdda

list_files

Return a recursive list of files under a specific path.

Example:

{{ '/etc/salt/' | list_files | join('\n') }}

Returns:

/etc/salt/master
/etc/salt/proxy
/etc/salt/minion
/etc/salt/pillar/top.sls
/etc/salt/pillar/device1.sls

path_join

Joins absolute paths.

Example:

{{ '/etc/salt/' | path_join('pillar', 'device1.sls') }}

Returns:

/etc/salt/pillar/device1.sls

which

Python clone of /usr/bin/which.

Example:

{{ 'salt-master' | which }}

Returns:

/usr/local/salt/virtualenv/bin/salt-master

Jinja in Files

Jinja can be used in the same way in managed files:

# redis.sls
/etc/redis/redis.conf:
    file.managed:
        - source: salt://redis.conf
        - template: jinja
        - context:
            bind: 127.0.0.1

# lib.sls
{% set port = 6379 %}

# redis.conf
{% from 'lib.sls' import port with context %}
port {{ port }}
bind {{ bind }}

As an example, configuration was pulled from the file context and from an external template file.

Note

Macros and variables can be shared across templates. They should not be starting with one or more underscores, and should be managed by one of the following tags: macro, set, load_yaml, load_json, import_yaml and import_json.

Escaping Jinja

Occasionally, it may be necessary to escape Jinja syntax. There are two ways to do this in Jinja. One is escaping individual variables or strings and the other is to escape entire blocks.

To escape a string commonly used in Jinja syntax such as {{, you can use the following syntax:

{{ '{{' }}

For larger blocks that contain Jinja syntax that needs to be escaped, you can use raw blocks:

{% raw %}
    some text that contains jinja characters that need to be escaped
{% endraw %}

See the Escaping section of Jinja's documentation to learn more.

A real-word example of needing to use raw tags to escape a larger block of code is when using file.managed with the contents_pillar option to manage files that contain something like consul-template, which shares a syntax subset with Jinja. Raw blocks are necessary here because the Jinja in the pillar would be rendered before the file.managed is ever called, so the Jinja syntax must be escaped:

{% raw %}
- contents_pillar: |
    job "example-job" {
      <snipped>
      task "example" {
          driver = "docker"

          config {
              image = "docker-registry.service.consul:5000/example-job:{{key "nomad/jobs/example-job/version"}}"
      <snipped>
{% endraw %}

Calling Salt Functions

The Jinja renderer provides a shorthand lookup syntax for the salt dictionary of execution function <Execution Function>.

2014.7.0

# The following two function calls are equivalent.
{{ salt['cmd.run']('whoami') }}
{{ salt.cmd.run('whoami') }}

Debugging

The show_full_context function can be used to output all variables present in the current Jinja context.

2014.7.0

Context is: {{ show_full_context() }}

Logs

Nitrogen

Yes, in Salt, one is able to debug a complex Jinja template using the logs. For example, making the call:

{%- do salt.log.error('testing jinja logging') -%}

Will insert the following message in the minion logs:

2017-02-01 01:24:40,728 [salt.module.logmod][ERROR   ][3779] testing jinja logging

Custom Execution Modules

Custom execution modules can be used to supplement or replace complex Jinja. Many tasks that require complex looping and logic are trivial when using Python in a Salt execution module. Salt execution modules are easy to write and distribute to Salt minions.

Functions in custom execution modules are available in the Salt execution module dictionary just like the built-in execution modules:

{{ salt['my_custom_module.my_custom_function']() }}

• How to Convert Jinja Logic to an Execution Module <tutorial-jinja_to_execution-module>
• Writing Execution Modules <writing-execution-modules>

Custom Jinja filters

Given that all execution modules are available in the Jinja template, one can easily define a custom module as in the previous paragraph and use it as a Jinja filter. However, please note that it will not be accessible through the pipe.

For example, instead of:

{{ my_variable | my_jinja_filter }}

The user will need to define my_jinja_filter function under an extension module, say my_filters and use as:

{{ salt.my_filters.my_jinja_filter(my_variable) }}

The greatest benefit is that you are able to access thousands of existing functions, e.g.:

• get the DNS AAAA records for a specific address using the dnsutil <salt.modules.dnsutil>:

  {{ salt.dnsutil.AAAA('www.google.com') }}

• retrieve a specific field value from a Redis <salt.modules.modredis> hash:

  {{ salt.redis.hget('foo_hash', 'bar_field') }}

• get the routes to 0.0.0.0/0 using the NAPALM route <salt.modules.napalm_route>:

  {{ salt.route.show('0.0.0.0/0') }}