About Search¶
Search indexes allow queries to be made for any type of data that is indexed by the Chef server, including data bags (and data bag items), environments, nodes, and roles. A defined query syntax is used to support search patterns like exact, wildcard, range, and fuzzy. A search is a full-text query that can be done from several locations, including from within a recipe, by using the search
subcommand in knife, the search
method in the Recipe DSL, the search box in the Chef management console, and by using the /search
or /search/INDEX
endpoints in the Chef server API. The search engine is based on Apache Solr and is run from the Chef server.
Many of the examples in this section use knife, but the search indexes and search query syntax can be used in many locations, including from within recipes and when using the Chef server API.
Search Indexes¶
A search index is a full-text list of objects that are stored on the Chef server, against which search queries can be made. The following search indexes are built:
Search Index Name | Description |
---|---|
client |
API client |
DATA_BAG_NAME |
A data bag is a global variable that is stored as JSON data and is accessible from a Chef server. The name of the search index is the name of the data bag. For example, if the name of the data bag was “admins” then a corresponding search query might look something like search(:admins, "*:*") . |
environment |
An environment is a way to map an organization’s real-life workflow to what can be configured and managed when using Chef server. |
node |
A node is any server or virtual server that is configured to be maintained by a chef-client. |
role |
A role is a way to define certain patterns and processes that exist across nodes in an organization as belonging to a single job function. |
Using Knife¶
Use the knife search
subcommand to run a search query for information that is indexed on a Chef server.
Search by platform ID
To search for the IDs of all nodes running on the Amazon EC2 platform, enter:
$ knife search node 'ec2:*' -i
to return something like:
4 items found
ip-0A7CA19F.ec2.internal
ip-0A58CF8E.ec2.internal
ip-0A58E134.ec2.internal
ip-0A7CFFD5.ec2.internal
Search by instance type
To search for the instance type (flavor) of all nodes running on the Amazon EC2 platform, enter:
$ knife search node 'ec2:*' -a ec2.instance_type
to return something like:
4 items found
ec2.instance_type: m1.large
id: ip-0A7CA19F.ec2.internal
ec2.instance_type: m1.large
id: ip-0A58CF8E.ec2.internal
ec2.instance_type: m1.large
id: ip-0A58E134.ec2.internal
ec2.instance_type: m1.large
id: ip-0A7CFFD5.ec2.internal
Search by recipe
To search for recipes that are used by a node, use the recipes
attribute to search for the recipe names, enter something like:
$ knife search node 'recipes:recipe_name'
or:
$ knife search node '*:*' -a recipes | grep 'recipe_name'
Search by cookbook, then recipe
To search for cookbooks on a node, use the recipes
attribute followed by the cookbook::recipe
pattern, escaping both of the :
characters. For example:
$ knife search node 'recipes:cookbook_name\:\:recipe_name'
Search by node
To search for all nodes running Ubuntu, enter:
$ knife search node 'platform:ubuntu'
Search by node and environment
To search for all nodes running CentOS in the production environment, enter:
$ knife search node 'chef_environment:production AND platform:centos'
Search for nested attributes
To find a nested attribute, use a pattern similar to the following:
$ knife search node <query_to_run> -a <main_attribute>.<nested_attribute>
Search for multiple attributes
To build a search query to use more than one attribute, use an underscore (_
) to separate each attribute. For example, the following query will search for all nodes running a specific version of Ruby:
$ knife search node "languages_ruby_version:1.9.3"
Search for nested attributes using a search query
To build a search query that can find a nested attribute:
$ knife search node name:<node_name> -a kernel.machine
Use a test query
To test a search query that will be used in a knife ssh
subcommand:
$ knife search node "role:web NOT name:web03"
where the query in the previous example will search all servers that have the web
role, but not on the server named web03
.
Query Syntax¶
A search query is comprised of two parts: the key and the search pattern. A search query has the following syntax:
key:search_pattern
where key
is a field name that is found in the JSON description of an indexable object on the Chef server (a role, node, client, environment, or data bag) and search_pattern
defines what will be searched for, using one of the following search patterns: exact, wildcard, range, or fuzzy matching. Both key
and search_pattern
are case-sensitive; key
has limited support for multiple character wildcard matching using an asterisk (“*”) (and as long as it is not the first character).
Note
Search queries may not contain newlines.
Filter Search Results¶
Use :filter_result
as part of a search query to filter the search output based on the pattern specified by a Hash. Only attributes in the Hash will be returned.
The syntax for the search
method that uses :filter_result
is as follows:
search(:index, 'query',
:filter_result => { 'foo' => [ 'abc' ],
'bar' => [ '123' ],
'baz' => [ 'sea', 'power' ]
}
).each do |result|
puts result['foo']
puts result['bar']
puts result['baz']
end
where:
:index
is of name of the index on the Chef server against which the search query will run::client
,:data_bag_name
,:environment
,:node
, and:role
'query'
is a valid search query against an object on the Chef server:filter_result
defines a Hash of values to be returned
For example:
search(:node, 'role:web',
:filter_result => { 'name' => [ 'name' ],
'ip' => [ 'ipaddress' ],
'kernel_version' => [ 'kernel', 'version' ]
}
).each do |result|
puts result['name']
puts result['ip']
puts result['kernel_version']
end
Keys¶
A field name/description pair is available in the JSON object. Use the field name when searching for this information in the JSON object. Any field that exists in any JSON description for any role, node, chef-client, environment, or data bag can be searched.
Nested Fields¶
A nested field appears deeper in the JSON data structure. For example, information about a network interface might be several layers deep: node[:network][:interfaces][:en1]
. When nested fields are present in a JSON structure, the chef-client will extract those nested fields to the top-level, flattening them into compound fields that support wildcard search patterns.
By combining wildcards with range-matching patterns and wildcard queries, it is possible to perform very powerful searches, such as using the vendor part of the MAC address to find every node that has a network card made by the specified vendor.
Consider the following snippet of JSON data:
{"network":
[
//snipped...
"interfaces",
{"en1": {
"number": "1",
"flags": [
"UP",
"BROADCAST",
"SMART",
"RUNNING",
"SIMPLEX",
"MULTICAST"
],
"addresses": {
"fe80::fa1e:dfff:fed8:63a2": {
"scope": "Link",
"prefixlen": "64",
"family": "inet6"
},
"f8:1e:df:d8:63:a2": {
"family": "lladdr"
},
"192.0.2.0": {
"netmask": "255.255.255.0",
"broadcast": "192.168.0.255",
"family": "inet"
}
},
"mtu": "1500",
"media": {
"supported": {
"autoselect": {
"options": [
]
}
},
"selected": {
"autoselect": {
"options": [
]
}
}
},
"type": "en",
"status": "active",
"encapsulation": "Ethernet"
},
//snipped...
Before this data is indexed on the Chef server, the nested fields are extracted into the top level, similar to:
"broadcast" => "192.168.0.255",
"flags" => ["UP", "BROADCAST", "SMART", "RUNNING", "SIMPLEX", "MULTICAST"]
"mtu" => "1500"
which allows searches like the following to find data that is present in this node:
node "broadcast:192.168.0.*"
or:
node "mtu:1500"
or:
node "flags:UP"
This data is also flattened into various compound fields, which follow the same pattern as the JSON hierarchy and use underscores (_
) to separate the levels of data, similar to:
# ...snip...
"network_interfaces_en1_addresses_192.0.2.0_broadcast" => "192.168.0.255",
"network_interfaces_en1_addresses_fe80::fa1e:tldr_family" => "inet6",
"network_interfaces_en1_addresses" => ["fe80::fa1e:tldr","f8:1e:df:tldr","192.0.2.0"]
# ...snip...
which allows searches like the following to find data that is present in this node:
node "network_interfaces_en1_addresses:192.0.2.0"
This flattened data structure also supports using wildcard compound fields, which allow searches to omit levels within the JSON data structure that are not important to the search query. In the following example, an asterisk (*
) is used to show where the wildcard can exist when searching for a nested field:
"network_interfaces_*_flags" => ["UP", "BROADCAST", "SMART", "RUNNING", "SIMPLEX", "MULTICAST"]
"network_interfaces_*_addresses" => ["fe80::fa1e:dfff:fed8:63a2", "192.0.2.0", "f8:1e:df:d8:63:a2"]
"network_interfaces_en0_media_*" => ["autoselect", "none", "1000baseT", "10baseT/UTP", "100baseTX"]
"network_interfaces_en1_*" => ["1", "UP", "BROADCAST", "SMART", "RUNNING", "SIMPLEX", "MULTICAST",
"fe80::fa1e:dfff:fed8:63a2", "f8:1e:df:d8:63:a2", "192.0.2.0",
"1500", "supported", "selected", "en", "active", "Ethernet"]
For each of the wildcard examples above, the possible values are shown contained within the brackets. When running a search query, the query syntax for wildcards is to simply omit the name of the node (while preserving the underscores), similar to:
network_interfaces__flags
This query will search within the flags
node, within the JSON structure, for each of UP
, BROADCAST
, SMART
, RUNNING
, SIMPLEX
, and MULTICAST
.
Examples¶
To see the available keys for a node, enter the following (for a node named staging
):
$ knife node show staging -Fj | less
to return a full JSON description of the node and to view the available keys with which any search query can be based.
To use a question mark (?
) to replace a single character in a wildcard search, enter the following:
$ knife search node 'platfor?:ubuntu'
To use an asterisk (*
) to replace zero (or more) characters in a wildcard search, enter the following:
$ knife search node 'platfo*:ubuntu'
To find all IP address that are on the same network, enter the following:
$ knife search node 'ipaddress:192.168*'
where 192.168*
is the network address for which the search will be run.
To use a range search to find IP addresses within a subnet, enter the following:
$ knife search node 'ipaddress:[192.168.0.* TO 192.0.2.*]'
where 192.168.0.* TO 192.0.2.*
defines the subnet range.
Patterns¶
A search pattern is a way to fine-tune search results by returning anything that matches some type of incomplete search query. There are four types of search patterns that can be used when searching the search indexes on the Chef server: exact, wildcard, range, and fuzzy.
Exact Matching¶
An exact matching search pattern is used to search for a key with a name that exactly matches a search query. If the name of the key contains spaces, quotes must be used in the search pattern to ensure the search query finds the key. The entire query must also be contained within quotes, so as to prevent it from being interpreted by Ruby or a command shell. The best way to ensure that quotes are used consistently is to quote the entire query using single quotes (‘ ‘) and a search pattern with double quotes (” “).
To search in a specific data bag for a specific data bag item, enter the following:
$ knife search admins 'id:charlie'
where admins
is the name of the data bag and charlie
is the name of the data bag item. Something similar to the following will be returned:
1 items found
_rev: 1-39ff4099f2510f477b4c26bef81f75b9
chef_type: data_bag_item
comment: Charlie the Unicorn
data_bag: admins
gid: ops
id: charlie
shell: /bin/zsh
uid: 1005
To search in a specific data bag using a string to find any matching data bag item, enter the following:
$ knife search admins 'comment:"Charlie the Unicorn"'
where admins
is the name of the data bag and Charlie the Unicorn
is the string that will be used during the search. Something similar to the following will be returned:
1 items found
_rev: 1-39ff4099f2510f477b4c26bef81f75b9
chef_type: data_bag_item
comment: Charlie the Unicorn
data_bag: admins
gid: ops
id: charlie
shell: /bin/zsh
uid: 1005
Wildcard Matching¶
A wildcard matching search pattern is used to query for substring matches that replace zero (or more) characters in the search pattern with anything that could match the replaced character. There are two types of wildcard searches:
- A question mark (
?
) can be used to replace exactly one character (as long as that character is not the first character in the search pattern) - An asterisk (
*
) can be used to replace any number of characters (including zero)
To search for any node that contains the specified key, enter the following:
$ knife search node 'foo:*'
where foo
is the name of the node.
To search for a node using a partial name, enter one of the following:
$ knife search node 'name:app*'
or:
$ knife search node 'name:app1*.example.com'
or:
$ knife search node 'name:app?.example.com'
or:
$ knife search node 'name:app1.example.???'
to return app1.example.com
(and any other node that matches any of the string searches above).
Range Matching¶
A range matching search pattern is used to query for values that are within a range defined by upper and lower boundaries. A range matching search pattern can be inclusive or exclusive of the boundaries. Use square brackets (“[ ]”) to denote inclusive boundaries and curly braces (“{ }”) to denote exclusive boundaries and with the following syntax:
boundary TO boundary
where TO
is required (and must be capitalized).
A data bag named sample
contains four data bag items: abc
, bar
, baz
, and quz
. All of the items in-between bar
and foo
, inclusive, can be searched for using an inclusive search pattern.
To search using an inclusive range, enter the following:
$ knife search sample "id:[bar TO foo]"
where square brackets ([ ]
) are used to define the range.
A data bag named sample
contains four data bag items: abc
, bar
, baz
, and quz
. All of the items that are exclusive to bar
and foo
can be searched for using an exclusive search pattern.
To search using an exclusive range, enter the following:
$ knife search sample "id:{bar TO foo}"
where curly braces ({ }
) are used to define the range.
Fuzzy Matching¶
A fuzzy matching search pattern is used to search based on the proximity of two strings of characters. An (optional) integer may be used as part of the search query to more closely define the proximity. A fuzzy matching search pattern has the following syntax:
"search_query"~edit_distance
where search_query
is the string that will be used during the search and edit_distance
is the proximity. A tilde (“~”) is used to separate the edit distance from the search query.
To use a fuzzy search pattern enter something similar to:
$ knife search client "name:boo~"
where boo~
defines the fuzzy search pattern. This will return something similar to:
{
"total": 1,
"start": 0,
"rows": [
{
"public_key": "too long didn't read",
"name": "foo",
"_rev": "1-f11a58043906e33d39a686e9b58cd92f",
"json_class": "Chef::ApiClient",
"admin": false,
"chef_type": "client"
}
]
}
Operators¶
An operator can be used to ensure that certain terms are included in the results, are excluded from the results, or are not included even when other aspects of the query match. Searches can use the following operators:
Operator | Description |
---|---|
AND |
Use to find a match when both terms exist. |
OR |
Use to find a match if either term exists. |
NOT |
Use to exclude the term after NOT from the search results. |
Operators must be in ALL CAPS. Parentheses can be used to group clauses and to form sub-queries.
Warning
Using AND NOT
together may trigger an error. For example:
ERROR: knife search failed: invalid search query:
'datacenter%3A123%20AND%20NOT%20hostname%3Adev-%20AND%20NOT%20hostanem%3Asyslog-'
Parse error at offset: 38 Reason: Expected one of \ at line 1, column 42 (byte 42) after AND
Use -
instead of NOT
. For example:
$ knife search sample "id:foo AND -id:bar"
AND¶
To join queries using the AND
boolean operator, enter the following:
$ knife search sample "id:b* AND animal:dog"
to return something like:
{
"total": 1,
"start": 0,
"rows": [
{
"comment": "an item named baz",
"id": "baz",
"animal": "dog"
}
]
}
Or, to find all of the computers running on the Microsoft Windows platform that are associated with a role named jenkins
, enter:
$ knife search node 'platform:windows AND roles:jenkins'
to return something like:
2 items found
Node Name: windows-server-2008r2.domain.com
Environment: _default
FQDN: windows-server-2008r2
IP: 0000::0000:0000:0000:0000
Run List: role[jenkins-windows]
Roles: jenkins-windows, jenkins
Recipes: jenkins-client::windows, jenkins::node_windows
Platform: windows 6.1.7601
Tags:
Node Name: 123-windows-2008r2-amd64-builder
Environment: _default
FQDN: ABC-1234567890AB
IP: 123.45.6.78
Run List: role[123-windows-2008r2-amd64-builder]
Roles: 123-windows-2008r2-amd64-builder, jenkins
Recipes: jenkins::node_windows, git_windows
Platform: windows 6.1.7601
Tags:
NOT¶
To negate search results using the NOT
boolean operator, enter the following:
$ knife search sample "(NOT id:foo)"
to return something like:
{
"total": 4,
"start": 0,
"rows": [
{
"comment": "an item named bar",
"id": "bar",
"animal": "cat"
},
{
"comment": "an item named baz",
"id": "baz"
"animal": "dog"
},
{
"comment": "an item named abc",
"id": "abc",
"animal": "unicorn"
},
{
"comment": "an item named qux",
"id": "qux",
"animal", "penguin"
}
]
}
OR¶
To join queries using the OR
boolean operator, enter the following:
$ knife search sample "id:foo OR id:abc"
to return something like:
{
"total": 2,
"start": 0,
"rows": [
{
"comment": "an item named foo",
"id": "foo",
"animal": "pony"
},
{
"comment": "an item named abc",
"id": "abc",
"animal": "unicorn"
}
]
}
Special Characters¶
A special character can be used to fine-tune a search query and to increase the accuracy of the search results. The following characters can be included within the search query syntax, but each occurrence of a special character must be escaped with a backslash (\
), also (/
) must be escaped against the Elasticsearch:
+ - && | | ! ( ) { } [ ] ^ " ~ * ? : \ /
For example:
\(1\+1\)\:2
Targets¶
A search target is any object that has been indexed on the Chef server, including roles (and run-lists), nodes, environments, data bags, and any API client.
Roles in Run-lists¶
A search query can be made for roles that are at the top-level of a run-list and also for a role that is part of an expanded run-list.
Note
The roles
field is updated each time the chef-client is run; changes to a run-list will not affect roles
until the next time the chef-client is run on the node.
Role Location | Description |
---|---|
Top-level | To find a node with a role in the top-level of its run-list, search within the role:ROLE_NAME
where |
Expanded | To find a node with a role in an expanded run-list, search within the roles:ROLE_NAME
where |
To search a top-level run-list for a role named load_balancer
use the knife search
subcommand from the command line or the search
method in a recipe. For example:
$ knife search node role:load_balancer
and from within a recipe:
search(:node, 'role:load_balancer')
To search an expanded run-list for all nodes with the role load_balancer
use the knife search
subcommand from the command line or the search
method in a recipe. For example:
$ knife search node roles:load_balancer
and from within a recipe:
search(:node, 'roles:load_balancer')
Nodes¶
A node can be searched from a recipe by using the following syntax:
search(:node, "key:attribute")
A wildcard can be used to replace characters within the search query.
Expanded lists of roles (all of the roles that apply to a node, including nested roles) and recipes to the role and recipe attributes on a node are saved on the Chef server. The expanded lists of roles allows for searching within nodes that run a given recipe, even if that recipe is included by a role.
Note
The recipes
field is updated each time the chef-client is run; changes to a run-list will not affect recipes
until the next time the chef-client is run on the node.
Node Location | Description |
---|---|
In a specified recipe | To find a node with a specified recipe in the run-list, search within the search(:node, 'run_list:recipe\[foo\:\:bar\]')
where search(:node, %Q{run_list:"recipe[#{the_recipe}]"} )
|
In an expanded run-list | To find a node with a recipe in an expanded run-list, search within the recipes:RECIPE_NAME
where |
If you just want to use each result of the search and don’t care about the aggregate result you can provide a code block to the search method. Each result is then passed to the block:
# Print every node matching the search pattern
search(:node, "*:*").each do |matching_node|
puts matching_node.to_s
end
API Clients¶
An API client is any machine that has permission to use the Chef server API to communicate with the Chef server. An API client is typically a node (on which the chef-client runs) or a workstation (on which knife runs), but can also be any other machine configured to use the Chef server API.
Sometimes when a role isn’t fully defined (or implemented), it may be necessary for a machine to connect to a database, search engine, or some other service within an environment by using the settings located on another machine, such as a host name, IP address, or private IP address. The following example shows a simplified settings file:
username: "mysql"
password: "MoveAlong"
host: "10.40.64.202"
port: "3306"
where host
is the private IP address of the database server. Use the following knife query to view information about the node:
knife search node "name:name_of_database_server" --long
To access these settings as part of a recipe that is run on the web server, use code similar to:
db_server = search(:node, "name:name_of_database_server")
private_ip = "#{db_server[0][:rackspace][:private_ip]}"
puts private_ip
where the “[0]” is the 0 (zero) index for the db_server
identifier. A single document is returned because the node is being searched on its unique name. The identifier private_ip
will now have the value of the private IP address of the database server (10.40.64.202
) and can then be used in templates as a variable, among other possible uses.
Environments¶
An environment is a way to map an organization’s real-life workflow to what can be configured and managed when using Chef server. Every organization begins with a single environment called the _default
environment, which cannot be modified (or deleted). Additional environments can be created to reflect each organization’s patterns and workflow. For example, creating production
, staging
, testing
, and development
environments. Generally, an environment is also associated with one (or more) cookbook versions.
When searching, an environment is an attribute. This allows search results to be limited to a specified environment by using Boolean operators and extra search terms. For example, to use knife to search for all of the servers running CentOS in an environment named “QA”, enter the following:
knife search node "chef_environment:QA AND platform:centos"
Or, to include the same search in a recipe, use a code block similar to:
qa_nodes = search(:node,"chef_environment:QA")
qa_nodes.each do |qa_node|
# Do useful work specific to qa nodes only
end
Data Bags¶
Data bags store global variables as JSON data. Data bags are indexed for searching and can be loaded by a cookbook or accessed during a search.
Any search for a data bag (or a data bag item) must specify the name of the data bag and then provide the search query string that will be used during the search. For example, to use knife to search within a data bag named “admin_data” across all items, except for the “admin_users” item, enter the following:
$ knife search admin_data "(NOT id:admin_users)"
Or, to include the same search query in a recipe, use a code block similar to:
search(:admin_data, "NOT id:admin_users")
It may not be possible to know which data bag items will be needed. It may be necessary to load everything in a data bag (but not know what “everything” is). Using a search query is the ideal way to deal with that ambiguity, yet still ensure that all of the required data is returned. The following examples show how a recipe can use a series of search queries to search within a data bag named “admins”. For example, to find every administrator:
search(:admins, "*:*")
Or to search for an administrator named “charlie”:
search(:admins, "id:charlie")
Or to search for an administrator with a group identifier of “ops”:
search(:admins, "gid:ops")
Or to search for an administrator whose name begins with the letter “c”:
search(:admins, "id:c*")
Data bag items that are returned by a search query can be used as if they were a hash. For example:
charlie = search(:admins, "id:charlie").first
# => variable 'charlie' is set to the charlie data bag item
charlie["gid"]
# => "ops"
charlie["shell"]
# => "/bin/zsh"
The following recipe can be used to create a user for each administrator by loading all of the items from the “admins” data bag, looping through each admin in the data bag, and then creating a user resource so that each of those admins exist:
admins = data_bag('admins')
admins.each do |login|
admin = data_bag_item('admins', login)
home = "/home/#{login}"
user(login) do
uid admin['uid']
gid admin['gid']
shell admin['shell']
comment admin['comment']
home home
manage_home true
end
end
And then the same recipe, modified to load administrators using a search query (and using an array to store the results of the search query):
admins = []
search(:admins, "*:*").each do |admin|
login = admin["id"]
admins << login
home = "/home/#{login}"
user(login) do
uid admin['uid']
gid admin['gid']
shell admin['shell']
comment admin['comment']
home home
manage_home true
end
end