Pillar is an interface for Salt designed to offer global values that can be distributed to minions. Pillar data is managed in a similar way as the Salt State Tree.
Pillar was added to Salt in version 0.9.8
Note
Storing sensitive data
Pillar data is compiled on the master. Additionally, pillar data for a given minion is only accessible by the minion for which it is targeted in the pillar configuration. This makes pillar useful for storing sensitive data specific to a particular minion.
The Salt Master server maintains a pillar_roots
setup that
matches the structure of the file_roots
used in the Salt file
server. Like file_roots
, the pillar_roots
option
maps environments to directories. The pillar data is then mapped to minions
based on matchers in a top file which is laid out in the same way as the state
top file. Salt pillars can use the same matcher types as the standard top
file.
conf_master:pillar_roots is configured just like file_roots
.
For example:
pillar_roots:
base:
- /srv/pillar
This example configuration declares that the base environment will be located
in the /srv/pillar
directory. It must not be in a subdirectory of the
state tree.
The top file used matches the name of the top file used for States, and has the same structure:
/srv/pillar/top.sls
base:
'*':
- packages
In the above top file, it is declared that in the base
environment, the
glob matching all minions will have the pillar data found in the packages
pillar available to it. Assuming the pillar_roots
value of /srv/pillar
taken from above, the packages
pillar would be located at
/srv/pillar/packages.sls
.
Any number of matchers can be added to the base environment. For example, here is an expanded version of the Pillar top file stated above:
/srv/pillar/top.sls:
base:
'*':
- packages
'web*':
- vim
In this expanded top file, minions that match web*
will have access to the
/srv/pillar/packages.sls
file, as well as the /srv/pillar/vim.sls
file.
Another example shows how to use other standard top matching types to deliver specific salt pillar data to minions with different properties.
Here is an example using the grains
matcher to target pillars to minions
by their os
grain:
dev:
'os:Debian':
- match: grain
- servers
Pillar definitions can also take a keyword argument ignore_missing
.
When the value of ignore_missing
is True
, all errors for missing
pillar files are ignored. The default value for ignore_missing
is
False
.
Here is an example using the ignore_missing
keyword parameter to ignore
errors for missing pillar files:
base:
'*':
- servers
- systems
- ignore_missing: True
Assuming that the pillar servers
exists in the fileserver backend
and the pillar systems
doesn't, all pillar data from servers
pillar is delivered to minions and no error for the missing pillar
systems
is noted under the key _errors
in the pillar data
delivered to minions.
Should the ignore_missing
keyword parameter have the value False
,
an error for the missing pillar systems
would produce the value
Specified SLS 'servers' in environment 'base' is not available on the salt master
under the key _errors
in the pillar data delivered to minions.
/srv/pillar/packages.sls
{% if grains['os'] == 'RedHat' %}
apache: httpd
git: git
{% elif grains['os'] == 'Debian' %}
apache: apache2
git: git-core
{% endif %}
company: Foo Industries
Important
See Is Targeting using Grain Data Secure? for important security information.
The above pillar sets two key/value pairs. If a minion is running RedHat, then
the apache
key is set to httpd
and the git
key is set to the value
of git
. If the minion is running Debian, those values are changed to
apache2
and git-core
respectively. All minions that have this pillar
targeting to them via a top file will have the key of company
with a value
of Foo Industries
.
Consequently this data can be used from within modules, renderers, State SLS files, and more via the shared pillar dictionary:
apache:
pkg.installed:
- name: {{ pillar['apache'] }}
git:
pkg.installed:
- name: {{ pillar['git'] }}
Finally, the above states can utilize the values provided to them via Pillar. All pillar values targeted to a minion are available via the 'pillar' dictionary. As seen in the above example, Jinja substitution can then be utilized to access the keys and values in the Pillar dictionary.
Note that you cannot just list key/value-information in top.sls
. Instead,
target a minion to a pillar file and then list the keys and values in the
pillar. Here is an example top file that illustrates this point:
base:
'*':
- common_pillar
And the actual pillar file at '/srv/pillar/common_pillar.sls':
foo: bar
boo: baz
Note
When working with multiple pillar environments, assuming that each pillar
environment has its own top file, the jinja placeholder {{ saltenv }}
can be used in place of the environment name:
{{ saltenv }}:
'*':
- common_pillar
Yes, this is {{ saltenv }}
, and not {{ pillarenv }}
. The reason for
this is because the Pillar top files are parsed using some of the same code
which parses top files when running states, so
the pillar environment takes the place of {{ saltenv }}
in the jinja
context.
If environment __env__
is specified in pillar_roots
, all
environments that are not explicitly specified in pillar_roots
will map to the directories from __env__
. This allows one to use dynamic
git branch based environments for state/pillar files with the same file-based
pillar applying to all environments. For example:
pillar_roots:
__env__:
- /srv/pillar
ext_pillar:
- git:
- __env__ https://example.com/git-pillar.git
New in version 2017.7.5,2018.3.1.
Taking it one step further, __env__
can also be used in the pillar_root
filesystem path. It will be replaced with the actual pillarenv
and searched
for Pillar data to provide to the minion. Note this substitution ONLY occurs for
the __env__
environment. For instance, this configuration:
pillar_roots:
__env__:
- /srv/__env__/pillar
is equivalent to this static configuration:
pillar_roots:
dev:
- /srv/dev/pillar
test:
- /srv/test/pillar
prod:
- /srv/prod/pillar
New in version 3005.
The separate pillar SLS files all merge down into a single dictionary of key-value pairs. When the same key is defined in multiple SLS files, this can result in unexpected behavior if care is not taken to how the pillar SLS files are laid out.
For example, given a top.sls
containing the following:
base:
'*':
- packages
- services
with packages.sls
containing:
bind: bind9
and services.sls
containing:
bind: named
Then a request for the bind
pillar key will only return named
. The
bind9
value will be lost, because services.sls
was evaluated later.
Note
Pillar files are applied in the order they are listed in the top file.
Therefore conflicting keys will be overwritten in a 'last one wins' manner!
For example, in the above scenario conflicting key values in services
will overwrite those in packages
because it's at the bottom of the list.
It can be better to structure your pillar files with more hierarchy. For
example the package.sls
file could be configured like so:
packages:
bind: bind9
This would make the packages
pillar key a nested dictionary containing a
bind
key.
If the same pillar key is defined in multiple pillar SLS files, and the keys in both files refer to nested dictionaries, then the content from these dictionaries will be recursively merged.
For example, keeping the top.sls
the same, assume the following
modifications to the pillar SLS files:
packages.sls
:
bind:
package-name: bind9
version: 9.9.5
services.sls
:
bind:
port: 53
listen-on: any
The resulting pillar dictionary will be:
$ salt-call pillar.get bind
local:
----------
listen-on:
any
package-name:
bind9
port:
53
version:
9.9.5
Since both pillar SLS files contained a bind
key which contained a nested
dictionary, the pillar dictionary's bind
key contains the combined contents
of both SLS files' bind
keys.
New in version 0.16.0.
Pillar SLS files may include other pillar files, similar to State files. Two syntaxes are available for this purpose. The simple form simply includes the additional pillar as if it were part of the same file:
include:
- users
The full include form allows two additional options -- passing default values to the templating engine for the included pillar file as well as an optional key under which to nest the results of the included pillar:
include:
- users:
defaults:
sudo: ['bob', 'paul']
key: users
With this form, the included file (users.sls) will be nested within the 'users' key of the compiled pillar. Additionally, the 'sudo' value will be available as a template variable to users.sls.
Since compiling pillar data is computationally expensive, the minion will
maintain a copy of the pillar data in memory to avoid needing to ask the master
to recompile and send it a copy of the pillar data each time pillar data is
requested. This in-memory pillar data is what is returned by the
pillar.item
, pillar.get
, and pillar.raw
functions.
Also, for those writing custom execution modules, or contributing to Salt's
existing execution modules, the in-memory pillar data is available as the
__pillar__
dunder dictionary.
The in-memory pillar data is generated on minion start, and can be refreshed
using the saltutil.refresh_pillar
function:
salt '*' saltutil.refresh_pillar
This function triggers the minion to asynchronously refresh the in-memory
pillar data and will always return None
.
In contrast to in-memory pillar data, certain actions trigger pillar data to be compiled to ensure that the most up-to-date pillar data is available. These actions include:
Running states
Running pillar.items
Performing these actions will not refresh the in-memory pillar data. So, if
pillar data is modified, and then states are run, the states will see the
updated pillar data, but pillar.item
,
pillar.get
, and pillar.raw
will not see this data unless refreshed using
saltutil.refresh_pillar
.
If you are using the Pillar Cache and have set pillar_cache
to True,
the pillar cache can be updated either when you run saltutil.refresh_pillar
, or using the pillar runner function
pillar.clear_pillar_cache
:
salt-run pillar.clear_pillar_cache 'minion'
The pillar will not be updated when running pillar.items
or a state for example. If you are
using a Salt version before 3003, you would need to manually delete the cache
file, located in Salt's master cache. For example, on linux the file would be
in this directory: /var/cache/salt/master/pillar_cache/
When multiple pillar environments are used, the default behavior is for the pillar data from all environments to be merged together. The pillar dictionary will therefore contain keys from all configured environments.
The pillarenv
minion config option can be used to force the
minion to only consider pillar configuration from a single environment. This
can be useful in cases where one needs to run states with alternate pillar
data, either in a testing/QA environment or to test changes to the pillar data
before pushing them live.
For example, assume that the following is set in the minion config file:
pillarenv: base
This would cause that minion to ignore all other pillar environments besides
base
when compiling the in-memory pillar data. Then, when running states,
the pillarenv
CLI argument can be used to override the minion's
pillarenv
config value:
salt '*' state.apply mystates pillarenv=testing
The above command will run the states with pillar data sourced exclusively from
the testing
environment, without modifying the in-memory pillar data.
Note
When running states, the pillarenv
CLI option does not require a
pillarenv
option to be set in the minion config file. When
pillarenv
is left unset, as mentioned above all configured
environments will be combined. Running states with pillarenv=testing
in
this case would still restrict the states' pillar data to just that of the
testing
pillar environment.
Starting in the 2017.7.0 release, it is possible to pin the pillarenv to the
effective saltenv, using the pillarenv_from_saltenv
minion
config option. When this is set to True
, if a specific saltenv is specified
when running states, the pillarenv
will be the same. This essentially makes
the following two commands equivalent:
salt '*' state.apply mystates saltenv=dev
salt '*' state.apply mystates saltenv=dev pillarenv=dev
However, if a pillarenv is specified, it will override this behavior. So, the
following command will use the qa
pillar environment but source the SLS
files from the dev
saltenv:
salt '*' state.apply mystates saltenv=dev pillarenv=qa
So, if a pillarenv
is set in the minion config file,
pillarenv_from_saltenv
will be ignored, and passing a
pillarenv
on the CLI will temporarily override
pillarenv_from_saltenv
.
To view pillar data, use the pillar
execution
module. This module includes several functions, each of them with their own
use. These functions include:
pillar.item
- Retrieves the value of
one or more keys from the in-memory pillar data.
pillar.items
- Compiles a fresh pillar
dictionary and returns it, leaving the in-memory pillar data untouched. If pillar keys are passed to this function
however, this function acts like pillar.item
and returns their values from the in-memory
pillar data.
pillar.raw
- Like pillar.items
, it returns the entire pillar dictionary, but
from the in-memory pillar data instead of compiling
fresh pillar data.
pillar.get
- Described in detail below.
pillar.get
Function¶New in version 0.14.0.
The pillar.get
function works much in the same
way as the get
method in a python dict, but with an enhancement: nested
dictionaries can be traversed using a colon as a delimiter.
If a structure like this is in pillar:
foo:
bar:
baz: qux
Extracting it from the raw pillar in an sls formula or file template is done this way:
{{ pillar['foo']['bar']['baz'] }}
Now, with the new pillar.get
function the data
can be safely gathered and a default can be set, allowing the template to fall
back if the value is not available:
{{ salt['pillar.get']('foo:bar:baz', 'qux') }}
This makes handling nested structures much easier.
Note
pillar.get()
vs salt['pillar.get']()
It should be noted that within templating, the pillar
variable is just
a dictionary. This means that calling pillar.get()
inside of a
template will just use the default dictionary .get()
function which
does not include the extra :
delimiter functionality. It must be
called using the above syntax (salt['pillar.get']('foo:bar:baz',
'qux')
) to get the salt function, instead of the default dictionary
behavior.
Pillar data can be set at the command line like the following example:
salt '*' state.apply pillar='{"cheese": "spam"}'
This will add a pillar key of cheese
with its value set to spam
.
Note
Be aware that when sending sensitive data via pillar on the command-line that the publication containing that data will be received by all minions and will not be restricted to the targeted minions. This may represent a security concern in some cases.
Salt's renderer system can be used to decrypt pillar data. This allows for pillar items to be stored in an encrypted state, and decrypted during pillar compilation.
New in version 2017.7.0.
Consider the following pillar SLS file:
secrets:
vault:
foo: |
-----BEGIN PGP MESSAGE-----
hQEMAw2B674HRhwSAQgAhTrN8NizwUv/VunVrqa4/X8t6EUulrnhKcSeb8sZS4th
W1Qz3K2NjL4lkUHCQHKZVx/VoZY7zsddBIFvvoGGfj8+2wjkEDwFmFjGE4DEsS74
ZLRFIFJC1iB/O0AiQ+oU745skQkU6OEKxqavmKMrKo3rvJ8ZCXDC470+i2/Hqrp7
+KWGmaDOO422JaSKRm5D9bQZr9oX7KqnrPG9I1+UbJyQSJdsdtquPWmeIpamEVHb
VMDNQRjSezZ1yKC4kCWm3YQbBF76qTHzG1VlLF5qOzuGI9VkyvlMaLfMibriqY73
zBbPzf6Bkp2+Y9qyzuveYMmwS4sEOuZL/PetqisWe9JGAWD/O+slQ2KRu9hNww06
KMDPJRdyj5bRuBVE4hHkkP23KrYr7SuhW2vpe7O/MvWEJ9uDNegpMLhTWruGngJh
iFndxegN9w==
=bAuo
-----END PGP MESSAGE-----
bar: this was unencrypted already
baz: |
-----BEGIN PGP MESSAGE-----
hQEMAw2B674HRhwSAQf+Ne+IfsP2IcPDrUWct8sTJrga47jQvlPCmO+7zJjOVcqz
gLjUKvMajrbI/jorBWxyAbF+5E7WdG9WHHVnuoywsyTB9rbmzuPqYCJCe+ZVyqWf
9qgJ+oUjcvYIFmH3h7H68ldqbxaAUkAOQbTRHdr253wwaTIC91ZeX0SCj64HfTg7
Izwk383CRWonEktXJpientApQFSUWNeLUWagEr/YPNFA3vzpPF5/Ia9X8/z/6oO2
q+D5W5mVsns3i2HHbg2A8Y+pm4TWnH6mTSh/gdxPqssi9qIrzGQ6H1tEoFFOEq1V
kJBe0izlfudqMq62XswzuRB4CYT5Iqw1c97T+1RqENJCASG0Wz8AGhinTdlU5iQl
JkLKqBxcBz4L70LYWyHhYwYROJWjHgKAywX5T67ftq0wi8APuZl9olnOkwSK+wrY
1OZi
=7epf
-----END PGP MESSAGE-----
qux:
- foo
- bar
- |
-----BEGIN PGP MESSAGE-----
hQEMAw2B674HRhwSAQgAg1YCmokrweoOI1c9HO0BLamWBaFPTMblOaTo0WJLZoTS
ksbQ3OJAMkrkn3BnnM/djJc5C7vNs86ZfSJ+pvE8Sp1Rhtuxh25EKMqGOn/SBedI
gR6N5vGUNiIpG5Tf3DuYAMNFDUqw8uY0MyDJI+ZW3o3xrMUABzTH0ew+Piz85FDA
YrVgwZfqyL+9OQuu6T66jOIdwQNRX2NPFZqvon8liZUPus5VzD8E5cAL9OPxQ3sF
f7/zE91YIXUTimrv3L7eCgU1dSxKhhfvA2bEUi+AskMWFXFuETYVrIhFJAKnkFmE
uZx+O9R9hADW3hM5hWHKH9/CRtb0/cC84I9oCWIQPdI+AaPtICxtsD2N8Q98hhhd
4M7I0sLZhV+4ZJqzpUsOnSpaGyfh1Zy/1d3ijJi99/l+uVHuvmMllsNmgR+ZTj0=
=LrCQ
-----END PGP MESSAGE-----
When the pillar data is compiled, the results will be decrypted:
# salt myminion pillar.items
myminion:
----------
secrets:
----------
vault:
----------
bar:
this was unencrypted already
baz:
rosebud
foo:
supersecret
qux:
- foo
- bar
- baz
Salt must be told what portions of the pillar data to decrypt. This is done
using the decrypt_pillar
config option:
decrypt_pillar:
- 'secrets:vault': gpg
The notation used to specify the pillar item(s) to be decrypted is the same as
the one used in pillar.get
function.
If a different delimiter is needed, it can be specified using the
decrypt_pillar_delimiter
config option:
decrypt_pillar:
- 'secrets|vault': gpg
decrypt_pillar_delimiter: '|'
The name of the renderer used to decrypt a given pillar item can be omitted,
and if so it will fall back to the value specified by the
decrypt_pillar_default
config option, which defaults to gpg
.
So, the first example above could be rewritten as:
decrypt_pillar:
- 'secrets:vault'
New in version 2016.3.0.
The following functions support passing pillar data on the CLI via the
pillar
argument:
Triggering decryption of this CLI pillar data can be done in one of two ways:
Using the pillar_enc
argument:
# salt myminion pillar.items pillar_enc=gpg pillar='{foo: "-----BEGIN PGP MESSAGE-----\n\nhQEMAw2B674HRhwSAQf+OvPqEdDoA2fk15I5dYUTDoj1yf/pVolAma6iU4v8Zixn\nRDgWsaAnFz99FEiFACsAGDEFdZaVOxG80T0Lj+PnW4pVy0OXmXHnY2KjV9zx8FLS\nQxfvmhRR4t23WSFybozfMm0lsN8r1vfBBjbK+A72l0oxN78d1rybJ6PWNZiXi+aC\nmqIeunIbAKQ21w/OvZHhxH7cnIiGQIHc7N9nQH7ibyoKQzQMSZeilSMGr2abAHun\nmLzscr4wKMb+81Z0/fdBfP6g3bLWMJga3hSzSldU9ovu7KR8rDJI1qOlENj3Wm8C\nwTpDOB33kWIKMqiAjY3JFtb5MCHrafyggwQL7cX1+tI+AbSO6kZpbcDfzetb77LZ\nxc5NWnnGK4pGoqq4MAmZshw98RpecSHKMosto2gtiuWCuo9Zn5cV/FbjZ9CTWrQ=\n=0hO/\n-----END PGP MESSAGE-----"}'
The newlines in this example are specified using a literal \n
. Newlines
can be replaced with a literal \n
using sed
:
$ echo -n bar | gpg --armor --trust-model always --encrypt -r user@domain.tld | sed ':a;N;$!ba;s/\n/\\n/g'
Note
Using pillar_enc
will perform the decryption minion-side, so for
this to work it will be necessary to set up the keyring in
/etc/salt/gpgkeys
on the minion just as one would typically do on
the master. The easiest way to do this is to first export the keys from
the master:
# gpg --homedir /etc/salt/gpgkeys --export-secret-key -a user@domain.tld >/tmp/keypair.gpg
Then, copy the file to the minion, setup the keyring, and import:
# mkdir -p /etc/salt/gpgkeys
# chmod 0700 /etc/salt/gpgkeys
# gpg --homedir /etc/salt/gpgkeys --list-keys
# gpg --homedir /etc/salt/gpgkeys --import --allow-secret-key-import keypair.gpg
The --list-keys
command is run create a keyring in the newly-created
directory.
Pillar data which is decrypted minion-side will still be securely transferred to the master, since the data sent between minion and master is encrypted with the master's public key.
Use the decrypt_pillar
option. This is less flexible in that
the pillar key passed on the CLI must be pre-configured on the master, but
it doesn't require a keyring to be setup on the minion. One other caveat to
this method is that pillar decryption on the master happens at the end of
pillar compilation, so if the encrypted pillar data being passed on the CLI
needs to be referenced by pillar or ext_pillar during pillar compilation,
it must be decrypted minion-side.
Those looking to add new renderers for decryption should look at the gpg
renderer for an example of how to do so. The function
that performs the decryption should be recursive and be able to traverse a
mutable type such as a dictionary, and modify the values in-place.
Once the renderer has been written, decrypt_pillar_renderers
should be modified so that Salt allows it to be used for decryption.
If the renderer is being submitted upstream to the Salt project, the renderer should be added in salt/renderers/. Additionally, the following should be done:
Both occurrences of decrypt_pillar_renderers
in
salt/config/__init__.py should be updated to include the name of the new
renderer so that it is included in the default value for this config option.
The documentation for the decrypt_pillar_renderers
config
option in the master config file and minion config file should be
updated to show the correct new default value.
The commented example for the decrypt_pillar_renderers
config
option in the master config template should be updated to show the correct
new default value.
Salt has partial support for binary pillar data.
Note
There are some situations (such as salt-ssh) where only text (ASCII or Unicode) is allowed.
The simplest way to embed binary data in your pillar is to make use of YAML's built-in binary data type, which requires base64 encoded data.
salt_pic: !!binary
iVBORw0KGgoAAAANSUhEUgAAAAoAAAAKCAMAAAC67D+PAAAABGdBTUEAALGPC/xhBQAAACBjSFJNAA
Then you can use it as a contents_pillar
in a state:
/tmp/salt.png:
file.managed:
- contents_pillar: salt_pic
It is also possible to add ASCII-armored encrypted data to pillars, as mentioned in the Pillar Encryption section.
For convenience the data stored in the master configuration file can be made available in all minion's pillars. This makes global configuration of services and systems very easy but may not be desired if sensitive data is stored in the master configuration. This option is disabled by default.
To enable the master config from being added to the pillar set
pillar_opts
to True
in the minion config file:
pillar_opts: True
Minion configuration options can be set on pillars. Any option that you want to modify, should be in the first level of the pillars, in the same way you set the options in the config file. For example, to configure the MySQL root password to be used by MySQL Salt execution module, set the following pillar variable:
mysql.pass: hardtoguesspassword
By default if there is an error rendering a pillar, the detailed error is hidden and replaced with:
Rendering SLS 'my.sls' failed. Please see master log for details.
The error is protected because it's possible to contain templating data which would give that minion information it shouldn't know, like a password!
To have the master provide the detailed error that could potentially carry
protected data set pillar_safe_render_error
to False
:
pillar_safe_render_error: False