Enable support of `sqlfluff` context

[KulykDmytro]

Is your feature request related to a problem? Please describe

As soon as dialect-based parsing use sqlfluff to parse SQL it will be great to support sqlfluff context (from .sqlfluff files) where we can use/set templater and other options

Describe the solution you'd like

sqlfluff.core.linter.Linter have optional config: FluffConfig parameter. Need to pass it or ensure that default is used

Additional context

dmytro.kulyk@MAC-570022 datalake % sqllineage -f transform/airflow/dags/queries/aws_transforms/aggregate/pokermatch_payment.partitions_range.sql
Traceback (most recent call last):
  File "/opt/homebrew/bin/sqllineage", line 8, in <module>
    sys.exit(main())
             ^^^^^^
  File "/opt/homebrew/lib/python3.11/site-packages/sqllineage/cli.py", line 125, in main
    runner.print_table_lineage()
  File "/opt/homebrew/lib/python3.11/site-packages/sqllineage/runner.py", line 175, in print_table_lineage
    print(str(self))
          ^^^^^^^^^
  File "/opt/homebrew/lib/python3.11/site-packages/sqllineage/runner.py", line 26, in wrapper
    self._eval()
  File "/opt/homebrew/lib/python3.11/site-packages/sqllineage/runner.py", line 195, in _eval
    stmt_holder = analyzer.analyze(stmt, session.metadata_provider)
                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/homebrew/lib/python3.11/site-packages/sqllineage/core/parser/sqlfluff/analyzer.py", line 48, in analyze
    raise UnsupportedStatementException(
sqllineage.exceptions.UnsupportedStatementException: SQLLineage cannot parse SQL:{%- set task_id = 'ph2_transaction.data_processing' %}
{%- set transaction_date = ti.xcom_pull(task_ids=task_id, key='new_partitions') %}
{% if transaction_date|length > 0 %}
    select
        row_num,
        min(as_of_date) as start_date,
        max(as_of_date) as end_date,
        array_agg(as_of_date) as dates
    from (
        select
...

running sqlfluff directly:

dmytro.kulyk@MAC-570022 datalake % sqlfluff parse transform/airflow/dags/queries/aws_transforms/aggregate/pokermatch_payment.partitions_range.sql --verbose | more
==== sqlfluff ====
sqlfluff:                2.3.5 python:                 3.11.6
implementation:        cpython verbosity:                   1
dialect:                athena templater:               jinja
rules:                                all
=== [ path: transform/airflow/dags/queries/aws_transforms/aggregate/pokermatch_payment.partitions_range.sql ] ===

[L:  1, P:  1]      |file:
[L:  1, P:  1]      |    [META] placeholder:                                       [Type: 'templated', Raw: "{%- set task_id = 'ph2_transaction.data_processing' %}"]
[L:  1, P: 55]      |    [META] placeholder:                                       [Type: 'literal', Raw: '\n']
[L:  2, P:  1]      |    [META] placeholder:                                       [Type: 'templated', Raw: "{%- set transaction_date = ti.xcom_pull(task_ids=task_id, key='new_partitions') %}"]
[L:  2, P: 83]      |    newline:                                                  '\n'
[L:  3, P:  1]      |    [META] placeholder:                                       [Type: 'block_start', Raw: '{% if transaction_date|length > 0 %}', Block: 'd42817']
[L:  3, P: 37]      |    [META] indent:                                            [Block: 'd42817']
[L:  3, P: 37]      |    newline:                                                  '\n'
[L:  4, P:  1]      |    whitespace:                                               '    '
[L:  4, P:  5]      |    statement:
[L:  4, P:  5]      |        select_statement:
[L:  4, P:  5]      |            select_clause:
[L:  4, P:  5]      |                keyword:                                      'select'
[L:  4, P: 11]      |                [META] indent:
[L:  4, P: 11]      |                newline:                                      '\n'
[L:  5, P:  1]      |                whitespace:                                   '        '
[L:  5, P:  9]      |                select_clause_element:
[L:  5, P:  9]      |                    column_reference:
[L:  5, P:  9]      |                        naked_identifier:                     'row_num'
...

.sqlfluff example

[sqlfluff]
templater = jinja
output_line_length = 180
exclude_rules = AL07, AM02, AM03, AM05, CV10, LT08, ST05, ST06, ST07
warnings = RF01
dialect = athena
large_file_skip_char_limit = 0
large_file_skip_byte_limit = 0
max_line_length = 120

[sqlfluff:rules:references.consistent]
single_table_references = consistent

[sqlfluff:rules:references.keywords]
ignore_words =
    account, domain, language, operator, rank, result, source, type, uid, position, format, state, offset, name,
    location, role, user, comment, method, date, quarter, hour, week, weekday, days

[sqlfluff:templater:jinja]
library_path = operation/deploy/lint
apply_dbt_builtins = false

[reata]

It makes sense to be support analyzing templated SQL so lineage can analyzed based on what's in orchestration system instead of merely on SQL logs.

Quick question: do you require any configuration in sqlfluff other than templating? Because supports all sqlfluff configuration looks like a overkill for me.

[KulykDmytro]

we use both sqlfluff and sqllineage (which is using sqlfluff) and looks like templating configuration is ignored

[reata]

Thanks for your confirmation. I'll see what we can do.