bridge: bridge can now be set using environment variable:

The `LIBERVIA_BRIDGE_NAME` environment variable can now be used to specify the bridge to
use. If set and different from empty string, the environment has precedence over config
file value.

For `pb` bridge, the following environment variable can also be used:

- LIBERVIA_BRIDGE_PB_CONNECTION_TYPE
- LIBERVIA_BRIDGE_PB_HOST
- LIBERVIA_BRIDGE_PB_PORT

sat/bridge/bridge_constructor/constructors/pb/pb_core_template.py

@@ -19,6 +19,7 @@
 
 
 import dataclasses
+from functools import partial
 from pathlib import Path
 from twisted.spread import jelly, pb
 from twisted.internet import reactor
@@ -106,12 +107,8 @@ class Bridge(object):
         log.info("Init Perspective Broker...")
         self.root = PBRoot()
         conf = config.parseMainConf()
-        conn_type = config.getConfig(
-            conf,
-            "",
-            "bridge_pb_connection_type",
-            "unix_socket"
-        )
+        getConf = partial(config.getConf, conf, "bridge_pb", "")
+        conn_type = getConf("connection_type", "unix_socket")
         if conn_type == "unix_socket":
             local_dir = Path(config.getConfig(conf, "", "local_dir")).resolve()
             socket_path = local_dir / "bridge_pb"
@@ -120,12 +117,7 @@ class Bridge(object):
                 str(socket_path), pb.PBServerFactory(self.root), mode=0o600
             )
         elif conn_type == "socket":
-            port = int(config.getConfig(
-                conf,
-                "",
-                "bridge_pb_port",
-                8789
-            ))
+            port = int(getConf("port", 8789))
             log.info(f"using TCP Socket at port {port}")
             reactor.listenTCP(port, pb.PBServerFactory(self.root))
         else:

sat/bridge/bridge_constructor/constructors/pb/pb_frontend_template.py

@@ -140,29 +140,15 @@ class Bridge(object):
     def bridgeConnect(self, callback, errback):
         factory = pb.PBClientFactory()
         conf = config.parseMainConf()
-        conn_type = config.getConfig(
-            conf,
-            "",
-            "bridge_pb_connection_type",
-            "unix_socket"
-        )
+        getConf = partial(config.getConf, conf, "bridge_pb", "")
+        conn_type = getConf("connection_type", "unix_socket")
         if conn_type == "unix_socket":
             local_dir = Path(config.getConfig(conf, "", "local_dir")).resolve()
             socket_path = local_dir / "bridge_pb"
             reactor.connectUNIX(str(socket_path), factory)
         elif conn_type == "socket":
-            host = int(config.getConfig(
-                conf,
-                "",
-                "bridge_pb_host",
-                "localhost"
-            ))
-            port = int(config.getConfig(
-                conf,
-                "",
-                "bridge_pb_port",
-                8789
-            ))
+            host = getConf("host", "localhost")
+            port = int(getConf("port", 8789))
             reactor.connectTCP(host, port, factory)
         else:
             raise ValueError(f"Unknown pb connection type: {conn_type!r}")