Files
marcredhat-siem-toolkit-pat…/backend/routers/quality.py
T
marc 8dbd38f3bb Fix Parser Test Runner JSON mode, Filter Simulator PQ syntax, dropdown source
- backend/routers/quality.py
 * Add GET /api/quality/parsers (lists actual files in /app/parsers)
 * Support SDL JSON auto-extract parsers ($=json{parse=json}$)
 * Apply parser rewrite blocks with correct $0/$N backref translation
 * Accept single JSON / JSON array / NDJSON in test-parser body
 * Flatten JSON inside 'message' for Field Population coverage
- backend/routers/ingest.py
 * Rewrite simulate-filter PowerQuery to valid SDL syntax
 * Correct field name: src.name -> dataSource.name
- frontend/index.html
 * Parser dropdown loads from /api/quality/parsers
 * Add 'Last 7d' lookback option
 * Render JSON-mode test results with badges + payload counter
2026-05-20 19:40:24 +02:00

391 lines
14 KiB
Python

from fastapi import APIRouter, HTTPException
from pydantic import BaseModel
from datetime import datetime, timedelta
from services import s1_client
import os
import re
router = APIRouter()
@router.get("/parsers")
def list_parser_files():
"""List parser filenames available under /app/parsers/ for the Test Runner."""
parsers_dir = "/app/parsers"
try:
names = sorted(
e.name for e in os.scandir(parsers_dir)
if e.is_file() and not e.name.startswith(".")
)
except FileNotFoundError:
names = []
return {"parsers": names, "count": len(names)}
def _date_range_hours(hours: int) -> tuple[str, str]:
now = datetime.utcnow()
return (
(now - timedelta(hours=hours)).strftime("%Y-%m-%dT%H:%M:%S.000Z"),
now.strftime("%Y-%m-%dT%H:%M:%S.000Z"),
)
# ---------------------------------------------------------------------------
# Models
# ---------------------------------------------------------------------------
class SampleEventsRequest(BaseModel):
source: str
limit: int = 20
hours: int = 1
class FieldPopulationRequest(BaseModel):
source: str
hours: int = 24
fields: list[str] = [
"src.ip",
"src.port",
"dst.ip",
"dst.port",
"user.name",
"event.type",
"src.process.name",
"src.process.cmdline",
"tgt.file.path",
"network.direction",
"dataSource.name",
]
class TestParserRequest(BaseModel):
parser_name: str
log_line: str
# ---------------------------------------------------------------------------
# Helpers
# ---------------------------------------------------------------------------
def _flatten_dict(d: dict, prefix: str = "", out: dict | None = None) -> dict:
"""Recursively flatten a nested dict into dotted keys."""
if out is None:
out = {}
if not isinstance(d, dict):
return out
for k, v in d.items():
key = f"{prefix}.{k}" if prefix else k
if isinstance(v, dict):
_flatten_dict(v, key, out)
else:
out[key] = v
return out
def _flatten_event(event: dict) -> dict:
"""Return a flat field→value dict from a PowerQuery result row.
If the row only carries a JSON-stringified payload in `message` (i.e. the
parser wasn't applied at query time), parse and flatten it inline so the
UI can measure field population accurately. The original raw `message`
is preserved under its own key.
"""
if not isinstance(event, dict):
return {}
flat = dict(event)
msg = flat.get("message")
if isinstance(msg, str) and msg.startswith("{") and msg.endswith("}"):
try:
parsed = __import__("json").loads(msg)
if isinstance(parsed, dict):
flat.update(_flatten_dict(parsed))
except Exception:
pass
return flat
def _extract_format_strings(content: str) -> list[str]:
"""
Extract SDL format string values from augmented-JSON parser content.
Matches: "format": "..." (double-quoted value, supports escaped quotes).
"""
pattern = re.compile(r'"format"\s*:\s*"((?:[^"\\]|\\.)*)"')
return pattern.findall(content)
def _sdl_format_to_regex(fmt: str) -> tuple[re.Pattern, dict[str, str]]:
"""
Convert an SDL format string to a compiled Python regex.
Returns (compiled_pattern, py_group_to_sdl_field) mapping so callers can
translate group names back to the original SDL field names.
Raises re.error if the resulting pattern cannot be compiled.
"""
# Split on $...$ tokens
token_pattern = re.compile(r'\$([^$]+)\$')
parts = token_pattern.split(fmt)
# parts alternates: literal, token, literal, token, ...
regex_parts: list[str] = []
py_group_to_sdl: dict[str, str] = {}
seen_groups: dict[str, int] = {}
for i, part in enumerate(parts):
if i % 2 == 0:
# Literal text
regex_parts.append(re.escape(part))
else:
# Token: either "field.name=PATTERN" or just "field.name"
if '=' in part:
field_name, pattern = part.split('=', 1)
else:
field_name = part
pattern = r'[^\s]+'
# Build a valid Python group name
safe = re.sub(r'[.\-]', '_', field_name)
if safe in seen_groups:
seen_groups[safe] += 1
safe = f"{safe}_{seen_groups[safe]}"
else:
seen_groups[safe] = 0
py_group_to_sdl[safe] = field_name
regex_parts.append(f'(?P<{safe}>{pattern})')
compiled = re.compile(''.join(regex_parts), re.IGNORECASE)
return compiled, py_group_to_sdl
# ---------------------------------------------------------------------------
# Endpoints
# ---------------------------------------------------------------------------
@router.post("/sample-events")
async def sample_events(req: SampleEventsRequest):
"""Return a sample of raw events from a given data source."""
query = f'| filter dataSource.name = "{req.source}" | limit {req.limit}'
from_dt, to_dt = _date_range_hours(req.hours)
result = await s1_client.run_powerquery(query, from_dt, to_dt)
rows = result if isinstance(result, list) else (result.get("rows") or result.get("events") or [])
events = [_flatten_event(row) for row in rows]
return {
"source": req.source,
"events": events,
"count": len(events),
"hours": req.hours,
}
@router.post("/field-population")
async def field_population(req: FieldPopulationRequest):
"""
Analyse how consistently each requested field is populated across a sample
of events from a data source.
"""
query = f'| filter dataSource.name = "{req.source}" | limit 500'
from_dt, to_dt = _date_range_hours(req.hours)
result = await s1_client.run_powerquery(query, from_dt, to_dt)
rows = result if isinstance(result, list) else (result.get("rows") or result.get("events") or [])
events = [_flatten_event(row) for row in rows]
if not events:
raise HTTPException(status_code=404, detail=f"No events found for source '{req.source}' in the last {req.hours} hours.")
total = len(events)
_empty = {None, "", "null"}
# Collect all field names seen across the sample (useful for surfacing what IS there)
all_seen_fields = sorted({k for ev in events for k in ev})
field_stats = []
for field in req.fields:
# dataSource.name is always 100% — we filtered by it; Scalyr just doesn't echo it back
if field == "dataSource.name":
populated = total
else:
populated = sum(1 for ev in events if ev.get(field) not in _empty)
rate = round((populated / total) * 100, 1)
field_stats.append({
"field": field,
"populated": populated,
"total": total,
"rate": rate,
})
# Sort ascending by rate (worst coverage first)
field_stats.sort(key=lambda x: x["rate"])
return {
"source": req.source,
"total_sampled": total,
"hours": req.hours,
"fields": field_stats,
"fields_seen_in_sample": all_seen_fields,
}
@router.post("/test-parser")
async def test_parser(req: TestParserRequest):
"""
Test a parser against a raw log line by extracting and matching SDL format
strings found in the parser file.
"""
parser_path = f"/app/parsers/{req.parser_name}"
try:
with open(parser_path, "r", encoding="utf-8") as fh:
content = fh.read()
except FileNotFoundError:
raise HTTPException(status_code=404, detail=f"Parser file not found: {req.parser_name}")
except OSError as exc:
raise HTTPException(status_code=500, detail=f"Could not read parser file: {exc}")
format_strings = _extract_format_strings(content)
# ── JSON auto-extract path ──────────────────────────────────────────────
# SDL parsers that use `$=json{parse=json}$` (or any format containing
# `parse=json`) auto-extract every top-level JSON key as an attribute.
# The regex-based path can't model that — handle it explicitly so users
# can test JSON-shaped logs against JSON-mode parsers.
log_input = req.log_line.strip()
is_json_mode = any("parse=json" in f for f in format_strings) or log_input.startswith("{")
if is_json_mode:
import json as _json
# Support multi-line input (one JSON object per line, or a JSON array)
lines = [ln for ln in (l.strip() for l in log_input.splitlines()) if ln]
payloads: list[dict] = []
parse_errors: list[str] = []
# Single line: try direct parse; if it's a JSON array, expand.
if len(lines) == 1:
try:
obj = _json.loads(lines[0])
except Exception as e:
return {
"parser_name": req.parser_name,
"matched": False,
"message": f"Parser expects JSON but log line could not be parsed as JSON: {e}",
"fields": [],
}
if isinstance(obj, list):
payloads = [x for x in obj if isinstance(x, dict)]
elif isinstance(obj, dict):
payloads = [obj]
else:
return {
"parser_name": req.parser_name,
"matched": False,
"message": "Parser expects a JSON object (got scalar).",
"fields": [],
}
else:
# Multi-line: one JSON object per line (NDJSON)
for i, ln in enumerate(lines, 1):
try:
obj = _json.loads(ln)
if isinstance(obj, dict):
payloads.append(obj)
else:
parse_errors.append(f"line {i}: not a JSON object")
except Exception as e:
parse_errors.append(f"line {i}: {e}")
if not payloads:
return {
"parser_name": req.parser_name,
"matched": False,
"message": "No valid JSON objects found. " + " | ".join(parse_errors[:3]),
"fields": [],
}
# Use the first payload for the detail table; report totals.
payload = payloads[0]
extracted = _flatten_dict(payload)
# Apply lightweight rewrites if present (input/output/match/replace blocks).
# We only handle simple literal/regex matches with $0 or string replacements;
# this is best-effort, intended for quick visual verification.
rewrites_applied = []
rewrite_re = re.compile(
r'\{\s*input:\s*"([^"]+)"\s*,\s*output:\s*"([^"]+)"\s*,\s*match:\s*"((?:[^"\\]|\\.)*)"\s*,\s*replace:\s*"((?:[^"\\]|\\.)*)"\s*\}',
re.DOTALL,
)
derived: dict[str, str] = {}
for m in rewrite_re.finditer(content):
in_field, out_field, match_pat, replace_val = m.group(1), m.group(2), m.group(3), m.group(4)
src_val = extracted.get(in_field)
if src_val is None:
continue
try:
m2 = re.search(match_pat, str(src_val))
except re.error:
continue
if not m2:
continue
# SDL uses $0 for whole match, $1.. for groups. Translate to Python
# \g<0>, \g<1>, ... so re.sub doesn't read \0 as a null byte.
def _to_py_backref(s: str) -> str:
return re.sub(r"\$(\d+)", lambda mm: f"\\g<{mm.group(1)}>", s)
try:
val = re.sub(match_pat, _to_py_backref(replace_val), str(src_val), count=1)
except re.error:
val = replace_val
derived[out_field] = val
rewrites_applied.append({
"input": in_field, "input_value": src_val,
"output": out_field, "matched_on": match_pat, "result": val,
})
fields = (
[{"field": k, "value": v, "source": "json-extract"} for k, v in sorted(extracted.items())]
+ [{"field": k, "value": v, "source": "rewrite"} for k, v in sorted(derived.items())]
)
return {
"parser_name": req.parser_name,
"matched": True,
"mode": "json",
"format_matched": "$=json{parse=json}$",
"fields": fields,
"rewrites_applied": rewrites_applied,
"extracted_count": len(extracted),
"derived_count": len(derived),
"payload_count": len(payloads),
"parse_errors": parse_errors,
"showing_payload": 1,
}
# ── Regex format-string path (original) ─────────────────────────────────
for fmt in format_strings:
try:
compiled, py_to_sdl = _sdl_format_to_regex(fmt)
except re.error:
# Skip unparseable format strings
continue
match = compiled.search(req.log_line)
if match:
fields = [
{"field": py_to_sdl.get(group, group), "value": value}
for group, value in match.groupdict().items()
if value is not None
]
return {
"parser_name": req.parser_name,
"matched": True,
"mode": "regex",
"format_matched": fmt,
"fields": fields,
}
return {
"parser_name": req.parser_name,
"matched": False,
"message": "No format pattern matched",
"fields": [],
}