Docs: PuppetDB 1.2 » API » v2 » Query Operators


PuppetDB 1.2 » API » v2 » Query Operators

PuppetDB’s query strings can use several common operators.

Note: The operators below apply to version 2 of the query API. Not all of them are available to version 1 queries.

Binary Operators

Each of these operators accepts two arguments: a field, and a value. These operators are non-transitive: their syntax must always be:

["<OPERATOR>", "<FIELD>", "<VALUE>"]

The available fields for each endpoint are listed in that endpoint’s documentation.

= (equality)

Matches if: the field’s actual value is exactly the same as the provided value. Note that this does not coerce values — the provided value must be the same data type as the field. In particular, be aware that:

  • Most fields are strings.
  • Some fields are booleans.
  • Numbers in resource parameters from Puppet are usually stored as strings, and equivalent numbers will not match — if the value of someparam were “0”, then ["=", "someparam", "0.0"] wouldn’t match.

> (greater than)

Matches if: the field is greater than the provided value. Coerces both the field and value to floats or integers; if they can’t be coerced, the operator will not match.

< (less than)

Matches if: the field is less than the provided value. Coerces both the field and value to floats or integers; if they can’t be coerced, the operator will not match.

>= (less than or equal to)

Matches if: the field is greater than or equal to the provided value. Coerces both the field and value to floats or integers; if they can’t be coerced, the operator will not match.

<= (greater than or equal to)

Matches if: the field is less than or equal to the provided value. Coerces both the field and value to floats or integers; if they can’t be coerced, the operator will not match.

~ (regexp match)

Matches if: the field’s actual value matches the provided regular expression. The provided value must be a regular expression represented as a JSON string:

  • The regexp must not be surrounded by the slash characters (/rexegp/) that delimit regexps in many languages.
  • Every backslash character must be escaped with an additional backslash. Thus, a sequence like \d would be represented as \\d, and a literal backslash (represented in a regexp as a double-backslash \\) would be represented as a quadruple-backslash (\\\\).

The following example would match if the certname field’s actual value resembled something like www03.example.com:

["~", "certname", "www\\d+\\.example\\.com"]

Note: Regular expression matching is performed by the database backend, and the available regexp features are backend-dependent. For best results, use the simplest and most common features that can accomplish your task. See the links below for details:

Boolean Operators

Every argument of these operators should be a complete query string in its own right. These operators are transitive: the order of their arguments does not matter.

and

Matches if: all of its arguments would match. Accepts any number of query strings as its arguments.

or

Matches if: at least one of its arguments would match. Accepts any number of query strings as its arguments.

not

Matches if: its argument would not match. Accepts a single query string as its argument.

Subquery Operators

Subqueries allow you to correlate data from multiple sources or multiple rows. (For instance, a query such as “fetch the IP addresses of all nodes with Class[Apache]” would have to use both facts and resources to return a list of facts.)

Subqueries are unlike the other operators listed above:

  • The in operator results in a complete query string. The extract operator and the subqueries do not.
  • An in statement must contain a field and an extract statement.
  • An extract statement must contain a field and a subquery.

These statements work together as follows (working “outward” and starting with the subquery):

  • The subquery collects a group of PuppetDB objects (specifically, a group of resources or a group of facts). Each of these objects has many fields.
  • The extract statement collects the value of a single field across every object returned by the subquery.
  • The in statement matches if the value of its field is present in the list returned by the extract statement.
Subquery Extract In
Every resource whose type is “Class” and title is “Apache.” (Note that all resource objects have a certname field, among other fields.) Every certname field from the results of the subquery. Match if the certname field is present in the list from the extract statement.

The complete in statement described in the table above would match any object that shares a certname with a node that has Class[Apache]. This could be combined with a boolean operator to get a specific fact from every node that matches the in statement.

in

An in statement constitutes a full query string, which can be used alone or as an argument for a boolean operator.

“In” statements are non-transitive and take two arguments:

  • The first argument must be a valid field for the endpoint being queried.
  • The second argument must be an extract statement, which acts as a list of possible values for the field.

Matches if: the field’s actual value is included in the list of values created by the extract statement.

extract

An extract statement does not constitute a full query string. It may only be used as the second argument of an in statement.

“Extract” statements are non-transitive and take two arguments:

  • The first argument must be a valid field for the endpoint being subqueried (see second argument).
  • The second argument must be a subquery.

As the second argument of an in statement, an extract statement acts as a list of possible values. This list is compiled by extracting the value of the requested field from every result of the subquery.

Available Subqueries

A subquery may only be used as the second argument of an extract statement, where it acts as a collection of PuppetDB objects. Each of the objects returned by the subquery has many fields; the extract statement takes the value of one field from each of those objects, and passes that list of values to the in statement that contains it.

In version 2 of the query API, the available subqueries are:

select-resources

A select-resources subquery may only be used as the second argument of an extract statement.

It takes a single argument, which must be a complete query string which would be valid for the /v2/resources endpoint. (Note that /v2/resources/<TYPE> and /v2/resources/<TYPE>/<TITLE> cannot be directly subqueried.) Since the argument is a normal query string, it can itself include any number of in statements and subqueries.

select-facts

A select-facts subquery may only be used as the second argument of an extract statement.

It takes a single argument, which must be a complete query string which would be valid for the /v2/facts endpoint. (Note that /v2/facts/<NAME> and /v2/facts/<NAME>/<VALUE> cannot be directly subqueried.) Since the argument is a normal query string, it can itself include any number of in statements and subqueries.

Subquery Examples

This query string queries the /facts endpoint for the IP address of all nodes with Class[Apache]:

["and",
  ["=", "name", "ipaddress"],
  ["in", "certname",
    ["extract", "certname",
      ["select-resources",
        ["and",
          ["=", "type", "Class"],
          ["=", "title", "Apache"]]]]]]

This query string queries the /nodes endpoint for all nodes with Class[Apache]:

["in", "name",
  ["extract", "certname",
    ["select-resources",
      ["and",
        ["=", "type", "Class"],
        ["=", "title", "Apache"]]]]]]

This query string queries the /facts endpoint for the IP address of all Debian nodes.

["and",
  ["=", "name", "ipaddress"],
  ["in", "certname",
    ["extract", "certname",
      ["select-facts",
        ["and",
          ["=", "name", "operatingsystem"],
          ["=", "value", "Debian"]]]]]]

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