def load(self, data, *, many=None, partial=None, unknown=None, **kwargs):
# When being passed in via the query string, we may get the raw JSON string instead of
# the deserialized dictionary. We need to unpack it ourselves.
if isinstance(data, str):
try:
data = json.loads(data)
except json.decoder.JSONDecodeError as exc:
raise ValidationError({
"_schema": [
f"Invalid JSON value: '{data}'",
str(exc),
],
})
elif isinstance(data, QueryExpression):
return data
if not self.context or "table" not in self.context:
raise RuntimeError(f"No table in context for field {self}")
if not data:
return NothingExpression()
try:
tree_to_expr(data, self.context["table"])
except ValueError as e:
raise ValidationError(str(e)) from e
return super().load(data,
many=many,
partial=partial,
unknown=unknown,
**kwargs)
def __init__(
self,
columns: List[Column],
filter_expr: QueryExpression = NothingExpression(),
):
"""A representation of a livestatus query.
Args:
columns:
A list of `Column` instances, these have to be defined as properties on a
`Table` class.
filter_expr:
A filter-expression. These can be created by comparing `Column` instances to
something or comparing `LiteralExpression` instances to something.
"""
self.columns = columns
self.column_names = [col.query_name for col in columns]
self.filter_expr = filter_expr
_tables = {column.table for column in columns}
if len(_tables) != 1:
raise ValueError(
f"Query doesn't specify a single table: {_tables!r}")
self.table: Type[Table] = _tables.pop()
def from_string(
cls,
string_query: str,
) -> 'Query':
"""Constructs a Query instance from a string based LiveStatus-Query
Args:
string_query:
A LiveStatus query as a string.
Examples:
>>> q = Query.from_string('GET services\\n'
... 'Columns: service_service_description\\n'
... 'Filter: service_service_description = \\n')
>>> query_text = ('''GET services
... Columns: host_address host_check_command host_check_type host_custom_variable_names host_custom_variable_values host_downtimes_with_extra_info host_file name host_has_been_checked host_name host_scheduled_downtime_depth host_state service_accept_passive_checks service_acknowledged service_action_url_expanded service_active_checks_enabled service_cache_interval service_cached_at service_check_command service_check_type service_comments_with_extra_info service_custom_variable_names service_custom_variable_values service_custom_variables service_description service_downtimes service_downtimes_with_extra_info service_has_been_checked service_host_name service_icon_image service_in_check_period service_in_notification_period service_in_passive_check_period service_in_service_period service_is_flapping service_last_check service_last_state_change service_modified_attributes_list service_notes_url_expanded service_notifications_enabled service_perf_data service_plugin_output service_pnpgraph_present service_scheduled_downtime_depth service_service_description service_staleness service_state
... Filter: service_state = 0
... Filter: service_has_been_checked = 1
... And: 2
... Negate:
... Filter: service_has_been_checked = 1
... Filter: service_scheduled_downtime_depth = 0
... Filter: host_scheduled_downtime_depth = 0
... And: 2
... Filter: service_acknowledged = 0
... Filter: host_state = 1
... Filter: host_has_been_checked = 1
... And: 2
... Negate:
... Filter: host_state = 2
... Filter: host_has_been_checked = 1
... And: 2
... Negate:
... ''')
>>> q = Query.from_string(query_text)
We can faithfully recreate this query as a dict-representation.
>>> q.dict_repr()
{'op': 'and', 'expr': [\
{'op': 'not', 'expr': \
{'op': 'and', 'expr': [\
{'op': '=', 'left': 'services.state', 'right': '0'}, \
{'op': '=', 'left': 'services.has_been_checked', 'right': '1'}\
]}}, \
{'op': '=', 'left': 'services.has_been_checked', 'right': '1'}, \
{'op': 'and', 'expr': [\
{'op': '=', 'left': 'services.scheduled_downtime_depth', 'right': '0'}, \
{'op': '=', 'left': 'services.host_scheduled_downtime_depth', 'right': '0'}\
]}, \
{'op': '=', 'left': 'services.acknowledged', 'right': '0'}, \
{'op': 'not', 'expr': \
{'op': 'and', 'expr': [\
{'op': '=', 'left': 'services.host_state', 'right': '1'}, \
{'op': '=', 'left': 'services.host_has_been_checked', 'right': '1'}\
]}}, \
{'op': 'not', 'expr': \
{'op': 'and', 'expr': [\
{'op': '=', 'left': 'services.host_state', 'right': '2'}, \
{'op': '=', 'left': 'services.host_has_been_checked', 'right': '1'}\
]}}\
]}
>>> q.columns
[Column(services.host_address: string), Column(services.host_check_command: string), Column(services.host_check_type: int), Column(services.host_custom_variable_names: list), Column(services.host_custom_variable_values: list), Column(services.host_downtimes_with_extra_info: list), Column(services.host_has_been_checked: int), Column(services.host_name: string), Column(services.host_scheduled_downtime_depth: int), Column(services.host_state: int), Column(services.accept_passive_checks: int), Column(services.acknowledged: int), Column(services.action_url_expanded: string), Column(services.active_checks_enabled: int), Column(services.cache_interval: int), Column(services.cached_at: time), Column(services.check_command: string), Column(services.check_type: int), Column(services.comments_with_extra_info: list), Column(services.custom_variable_names: list), Column(services.custom_variable_values: list), Column(services.custom_variables: dict), Column(services.description: string), Column(services.downtimes: list), Column(services.downtimes_with_extra_info: list), Column(services.has_been_checked: int), Column(services.host_name: string), Column(services.icon_image: string), Column(services.in_check_period: int), Column(services.in_notification_period: int), Column(services.in_passive_check_period: int), Column(services.in_service_period: int), Column(services.is_flapping: int), Column(services.last_check: time), Column(services.last_state_change: time), Column(services.modified_attributes_list: list), Column(services.notes_url_expanded: string), Column(services.notifications_enabled: int), Column(services.perf_data: string), Column(services.plugin_output: string), Column(services.pnpgraph_present: int), Column(services.scheduled_downtime_depth: int), Column(services.description: string), Column(services.staleness: float), Column(services.state: int)]
>>> q = Query.from_string('GET hosts\\n'
... 'Columns: name service_description\\n'
... 'Filter: service_description = ')
Traceback (most recent call last):
...
ValueError: Table 'hosts': Could not decode line 'Filter: service_description = '
All unknown columns are ignored, as there are many places in Checkmk where queries
specify wrong or unnecessary columns. Livestatus would normally ignore them.
>>> _ = Query.from_string('GET hosts\\n'
... 'Columns: service_service_description\\n'
... 'Filter: service_description = ')
Traceback (most recent call last):
...
ValueError: Table 'hosts': Could not decode line 'Filter: service_description = '
>>> _ = Query.from_string('GET foobazbar\\n'
... 'Columns: name service_description\\n'
... 'Filter: service_description = ')
Traceback (most recent call last):
...
ValueError: Table foobazbar was not defined in the tables module.
>>> q = Query.from_string('GET hosts\\n'
... 'Columns: name\\n'
... 'Filter: name = heute\\n'
... 'Filter: alias = heute\\n'
... 'Or: 2')
>>> q.table.__name__
'Hosts'
>>> q.columns
[Column(hosts.name: string)]
>>> q.filter_expr
Or(Filter(name = heute), Filter(alias = heute))
>>> print(q)
GET hosts
Columns: name
Filter: name = heute
Filter: alias = heute
Or: 2
So in essence this says that round trips work
>>> assert str(q) == str(Query.from_string(str(q)))
Returns:
A Query instance.
Raises:
A ValueError if no Query() instance could be created.
"""
lines = string_query.split("\n")
for line in lines:
if line.startswith('GET '):
parts = line.split()
if len(parts) < 2:
raise ValueError(f"No table found in line: {line!r}")
table_name = parts[1]
try:
table_class: Type[Table] = getattr(tables,
table_name.title())
except AttributeError:
raise ValueError(
f"Table {table_name} was not defined in the tables module."
)
break
else:
raise ValueError("No table found")
for line in lines:
if line.startswith('Columns: '):
column_names = line.split(": ", 1)[1].lstrip().split()
columns: List[Column] = []
for col in column_names:
try:
columns.append(_get_column(table_class, col))
except AttributeError:
pass
break
else:
raise ValueError("No columns found")
filters: List[QueryExpression] = []
for line in lines:
if line.startswith('Filter: '):
try:
filters.append(_parse_line(table_class, line))
except AttributeError:
raise ValueError(
f"Table {table_name!r}: Could not decode line {line!r}"
)
elif line.startswith('Or: ') or line.startswith("And: "):
op, _count = line.split(": ")
count = int(_count)
# I'm sorry. :)
# We take the last `count` filters and pass them into the BooleanExpression
try:
expr = {
'or': Or,
'and': And
}[op.lower()](*filters[-count:])
except ValueError:
raise ValueError(f"Could not parse {op} for {filters!r}")
filters = filters[:-count]
filters.append(expr)
elif line.startswith('Negate:') or line.startswith('Not:'):
filters[-1] = Not(filters[-1])
if len(filters) > 1:
filters = [And(*filters)]
return cls(
columns=columns,
filter_expr=filters[0] if filters else NothingExpression(),
)