Checkmk Werk 6972: Support SQL-style quoting for filtering dict-valued columns

ID: 6972 Title: Support SQL-style quoting for filtering dict-valued columns Component: Livestatus Level: 1 Class: New feature Version: 1.7.0i1 Some Livestatus columns do not contain a simple value or a list of such values, they contain a dictionary of key/value pairs. More concretely, the <ul> <li><tt>custom_variables</tt></li> <li><tt>label_sources</tt></li> <li><tt>labels</tt></li> <li><tt>tags</tt></li> </ul> columns in the <ul> <li><tt>contacts</tt></li> <li><tt>hosts</tt></li> <li><tt>hostsbygroup</tt></li> <li><tt>services</tt></li> <li><tt>servicesbygroup</tt></li> <li><tt>servicesbyhostgroup</tt></li> </ul> tables contain dictionary values. Livestatus filter for such columns have a special syntax: C+: Filter: COLUMN OPERATOR KEY VALUE C-: As an example, the query: C+: GET hosts Filter: tag = agent cmk-agent C-: returns all hosts where the tag "agent" has the value "cmk-agent". Note that the key and the value are separated by whitespace. But this makes it impossible to query for a tag name with spaces. To support more general keys and values in such filters, Livestatus now additionally supports SQL-style quoting for such column filters: C+: Filter: labels = 'It''s so' 'cool, man!' C-: This filter matches a label with key "It's so" and value "cool, man!". Note the use of 2 consecutive single quotes to represent 1 single quote. The previous syntax still works, the new syntax is triggered by a leading single quote in the key and/or value.