Advanced Queries

For more advanced use of pypuppetdb you will want to use queries in one of the two available languages:

  • PQL (Puppet Query Language) - newer, arguably more human-friendly. Available since PuppetDB v. 4.0.
  • AST (Abstract Syntax Tree) - older, using the Reverse Polish Notation.

PQL query with rich types

Making a PQL query using pql() method without using projection for one of the supported types (nodes, edges, facts, resources, catalogs, events, reports, inventory) will return the rich types.

For example the below code returns objects of the type Node:

>>> nodes = db.pql("""
>>>     nodes {
>>>       facts {
>>>         name = "operatingsystem"
>>>         and value = "Debian"
>>>       }
>>>     }
>>> """
>>> for node in nodes:
>>>     print(node.name)
foo.example.com
bar.example.com

PQL query returning raw dicts

If you do use projections (fields/functions) in your PQL query or you query for a unsupported type, you will get JSON like you would querying PuppetDB directly, just converted into a Python dicts or list of dicts.

For example if you want to get just a list of certnames of nodes that have the fact “operatingsystem” set to “Debian”:

>>> nodes = db.pql("""
>>>     nodes[certname] {
>>>       facts {
>>>         name = "operatingsystem"
>>>         and value = "Debian"
>>>       }
>>>     }
>>> """
>>> for node in nodes:
>>>     print(node)
{'certname': 'foo.example.com'}
{'certname': 'bar.example.com'}

Please see the official PQL documentation for more examples.

AST query

Alternatively to use the AST query language, use one of these methods:

nodes(), edges(), facts(), resources(), catalogs(), events(), reports(), inventory(), event_counts(), aggregate_event_counts(), environments(), factsets(), fact_contents(), fact_paths()

…and pass the AST query in the query parameter.

An example of the same query as above but rewritten in AST:

>>> nodes = db.nodes(query="""
>>>     ["subquery", "facts",
>>>       ["and",
>>>         ["=", "name", "operatingsystem"],
>>>         ["=", "value", "Debian"]
>>>       ]
>>>     ]
>>> """
>>> for node in nodes:
>>>     print(node.name)
foo.example.com
bar.example.com

Please see the official AST documentation for more examples .

AST QueryBuilder

pypuppetdb laso comes shipped with a QueryBuilder component that, as the name suggests, allows users to build PuppetDB AST queries in an Object-Oriented fashion. In many cases adding additional clauses to fulfill new requirements is superior to constructing long strings.

Above example rewritten using it:

>>> from pypuppetdb.QueryBuilder import *
>>> op = InOperator('certname')
>>> query = ExtractOperator()
>>> query.add_field(str('certname'))
>>> subquery = SubqueryOperator('facts')
>>> _add = AndOperator()
>>> _add.add(EqualsOperator('name', 'operatingsystem'))
>>> _add.add(EqualsOperator('value', 'Debian'))
>>> subquery.add_query(_add)
>>> query.add_query(subquery)
>>> op.add_query(query)
>>> print(op)
["in", "certname", ["extract", ["certname"], ["select_facts", ["and", ["=", "name", "operatingsystem"], ["=", "value", "Debian"]]]]]
>>> nodes = db.nodes(query=query)
>>> for node in nodes:
>>>     print(node.name)
foo.example.com
bar.example.com

The following code will build a query for the Nodes endpoint to find all nodes belonging to the production environment.

>>> from pypuppetdb.QueryBuilder import *
>>> op = AndOperator()
>>> op.add(EqualsOperator('catalog_environment', 'production'))
>>> op.add(EqualsOperator('facts_environment', 'production'))
>>> print(op)
["and",["=", "catalog_environment", "production"],["=", "facts_environment", "production"]]

Subqueries are implemented using corresponding operators (like documented).

  • SubqueryOperator
  • InOperator
  • ExtractOperator
>>> from pypuppetdb.QueryBuilder import *
>>> op = InOperator('certname')
>>> ex = ExtractOperator()
>>> ex.add_field(str('certname'))
>>> sub = SubqueryOperator('events')
>>> sub.add_query(EqualsOperator('status', 'noop'))
>>> ex.add_query(sub)
>>> op.add_query(ex)
>>> print(op)
["in","certname",["extract",["certname"],["select_events",["=", "status", "noop"]]]]

Or using in <array> querying:

>>> from pypuppetdb.QueryBuilder import *
>>> op = InOperator('certname')
>>> op.add_array(["prod1.server.net", "prod2.server.net"])
>>> print(op)
["in","certname",["array", ['prod1.server.net', 'prod2.server.net']]]

You can also access different entities from a single query on the root endpoint with the FromOperator:

>>> op = InOperator('certname')
>>> ex = ExtractOperator()
>>> ex.add_field('certname')
>>> fr = FromOperator('fact_contents')
>>> nd = AndOperator()
>>> nd.add(EqualsOperator("path", ["networking", "eth0", "macaddresses", 0]))
>>> nd.add(EqualsOperator("value", "aa:bb:cc:dd:ee:00"))
>>> ex.add_query(nd)
>>> fr.add_query(ex)
>>> op.add_query(fr)
>>> print(op)
["in","certname",["from","fact_contents",["extract",["certname"],["and",["=", "path", ['networking', 'eth0', 'macaddresses', 0]],["=", "value", "aa:bb:cc:dd:ee:00"]]]]]