Closes #150: Port BIRD AS_Path/Community handling from hyperglass-agent

hyperglass/execution/drivers/_construct.py

@@ -12,11 +12,7 @@ from operator import attrgetter
 
 # Project
 from hyperglass.log import log
-from hyperglass.constants import (  # APPEND_NEWLINE,
-    TRANSPORT_REST,
-    TARGET_FORMAT_SPACE,
-    TARGET_JUNIPER_ASPATH,
-)
+from hyperglass.constants import TRANSPORT_REST, TARGET_FORMAT_SPACE
 from hyperglass.configuration import commands
 
 
@@ -24,12 +20,7 @@ class Construct:
     """Construct SSH commands/REST API parameters from validated query data."""
 
     def __init__(self, device, query_data):
-        """Initialize command construction.
-
-        Arguments:
-            device {object} -- Device object
-            query_data {object} -- Validated query object
-        """
+        """Initialize command construction."""
         log.debug(
             "Constructing {} query for '{}'",
             query_data.query_type,
@@ -61,8 +52,8 @@ class Construct:
                 )
                 if v is not None and self.query_data.query_target.version == v.version
             ]
-        elif self.query_data.query_type in ("bgp_aspath", "bgp_community"):
 
+        with Formatter(self.device.nos, self.query_data.query_type) as formatter:
             # For AS Path/Community queries, AFIs are just enabled VRF -> AFI
             # definitions, no IP version checking is performed (since there is no IP).
             self.afis = [
@@ -73,39 +64,10 @@ class Construct:
                 )
                 if v is not None
             ]
-
-            # For devices that follow Juniper's AS_PATH regex standards,
-            # filter out Cisco-style special characters.
-
-            if (
-                self.device.nos in TARGET_JUNIPER_ASPATH
-                and self.query_data.query_type in ("bgp_aspath",)
-            ):
-                query = str(self.query_data.query_target)
-                asns = re.findall(r"\d+", query)
-                was_modified = False
-                if bool(re.match(r"^\_", query)):
-                    # Replace `_65000` with `.* 65000`
-                    asns.insert(0, r".*")
-                    was_modified = True
-                if bool(re.match(r".*(\_)$", query)):
-                    # Replace `65000_` with `65000 .*`
-                    asns.append(r".*")
-                    was_modified = True
-                if was_modified:
-                    self.target = " ".join(asns)
-                else:
-                    self.target = query
+            self.target = formatter(self.query_data.query_target)
 
     def json(self, afi):
-        """Return JSON version of validated query for REST devices.
-
-        Arguments:
-            afi {object} -- AFI object
-
-        Returns:
-            {str} -- JSON query string
-        """
+        """Return JSON version of validated query for REST devices."""
         log.debug("Building JSON query for {q}", q=repr(self.query_data))
         return _json.dumps(
             {
@@ -118,14 +80,7 @@ class Construct:
         )
 
     def scrape(self, afi):
-        """Return formatted command for 'Scrape' endpoints (SSH).
-
-        Arguments:
-            afi {object} -- AFI object
-
-        Returns:
-            {str} -- Command string
-        """
+        """Return formatted command for 'Scrape' endpoints (SSH)."""
         if self.device.structured_output:
             cmd_paths = (
                 self.device.nos,
@@ -144,11 +99,7 @@ class Construct:
         )
 
     def queries(self):
-        """Return queries for each enabled AFI.
-
-        Returns:
-            {list} -- List of queries to run
-        """
+        """Return queries for each enabled AFI."""
         query = []
 
         for afi in self.afis:
@@ -159,3 +110,92 @@ class Construct:
 
         log.debug("Constructed query: {}", query)
         return query
+
+
+class Formatter:
+    """Modify query target based on the device's NOS requirements and the query type."""
+
+    def __init__(self, nos: str, query_type: str) -> None:
+        """Initialize target formatting."""
+        self.nos = nos
+        self.query_type = query_type
+
+    def __enter__(self):
+        """Get the relevant formatter."""
+        return self._get_formatter()
+
+    def __exit__(self, exc_type, exc_value, exc_traceback):
+        """Handle context exit."""
+        if exc_type is not None:
+            log.error(exc_traceback)
+        pass
+
+    def _get_formatter(self):
+        if self.nos in ("juniper", "juniper_junos"):
+            if self.query_type == "bgp_aspath":
+                return self._juniper_bgp_aspath
+        if self.nos in ("bird", "bird_ssh"):
+            if self.query_type == "bgp_aspath":
+                return self._bird_bgp_aspath
+            elif self.query_type == "bgp_community":
+                return self._bird_bgp_community
+        return self._default
+
+    def _default(self, target: str) -> str:
+        """Don't format targets by default."""
+        return target
+
+    def _juniper_bgp_aspath(self, target: str) -> str:
+        """Convert from Cisco AS_PATH format to Juniper format."""
+        query = str(target)
+        asns = re.findall(r"\d+", query)
+        was_modified = False
+
+        if bool(re.match(r"^\_", query)):
+            # Replace `_65000` with `.* 65000`
+            asns.insert(0, r".*")
+            was_modified = True
+
+        if bool(re.match(r".*(\_)$", query)):
+            # Replace `65000_` with `65000 .*`
+            asns.append(r".*")
+            was_modified = True
+
+        if was_modified:
+            modified = " ".join(asns)
+            log.debug("Modified target '{}' to '{}'", target, modified)
+            return modified
+
+        return query
+
+    def _bird_bgp_aspath(self, target: str) -> str:
+        """Convert from Cisco AS_PATH format to BIRD format."""
+
+        # Extract ASNs from query target string
+        asns = re.findall(r"\d+", target)
+        was_modified = False
+
+        if bool(re.match(r"^\_", target)):
+            # Replace `_65000` with `.* 65000`
+            asns.insert(0, "*")
+            was_modified = True
+
+        if bool(re.match(r".*(\_)$", target)):
+            # Replace `65000_` with `65000 .*`
+            asns.append("*")
+            was_modified = True
+
+        asns.insert(0, "[=")
+        asns.append("=]")
+
+        result = " ".join(asns)
+
+        if was_modified:
+            log.debug("Modified target '{}' to '{}'", target, result)
+
+        return result
+
+    def _bird_bgp_community(self, target: str) -> str:
+        """Convert from standard community format to BIRD format."""
+        parts = target.split(":")
+        return f'({",".join(parts)})'