support task-selectable SIP trunks

deploy/render_asterisk.py

@@ -13,6 +13,7 @@ from pathlib import Path
 
 PUBLIC_IP = "123.56.71.98"
 CODEC_TO_ASTERISK = {"PCMA": "alaw", "PCMU": "ulaw"}
+TRUNK_ID_RE = re.compile(r"[A-Za-z0-9][A-Za-z0-9_.-]{0,127}")
 
 
 def scalar(value, name, secret=False):
@@ -115,6 +116,47 @@ def endpoint(name, data, env):
     return text + auth
 
 
+def _trunks(cfg):
+    if "trunks" not in cfg:
+        primary_data = cfg.get("primary", {})
+        if not isinstance(primary_data, dict):
+            raise ValueError("primary must be an object")
+        rows = [("provider-primary", primary_data)]
+        backup_data = cfg.get("backup")
+        if backup_data is not None and not isinstance(backup_data, dict):
+            raise ValueError("backup must be an object when configured")
+        if backup_data:
+            rows.append(("provider-backup", backup_data))
+            if (primary_data.get("host"), primary_data.get("port", 5060)) == (
+                backup_data.get("host"),
+                backup_data.get("port", 5060),
+            ):
+                raise ValueError(
+                    "primary and backup targets must be distinct; shared failure domains still require validation"
+                )
+        return rows
+    if "primary" in cfg or "backup" in cfg:
+        raise ValueError("use trunks instead of mixing arbitrary trunks with primary/backup")
+    raw = cfg["trunks"]
+    if not isinstance(raw, list) or not raw:
+        raise ValueError("trunks must be a non-empty list")
+    rows = []
+    seen = set()
+    for index, data in enumerate(raw):
+        if not isinstance(data, dict):
+            raise TypeError(f"trunks[{index}] must be an object")
+        name = data.get("trunk_id")
+        if not isinstance(name, str) or not TRUNK_ID_RE.fullmatch(name):
+            raise ValueError(
+                f"trunks[{index}].trunk_id must be a safe Asterisk endpoint identifier"
+            )
+        if name in seen:
+            raise ValueError(f"duplicate trunk_id: {name}")
+        seen.add(name)
+        rows.append((name, data))
+    return rows
+
+
 def render(cfg, env):
     if cfg.get("public_ip") != PUBLIC_IP or cfg.get("transport") != "udp":
         raise ValueError(
@@ -138,32 +180,20 @@ def render(cfg, env):
     password = scalar(env.get("ARI_PASSWORD"), "ARI_PASSWORD", secret=True)
     if len(password) < 32:
         raise ValueError("ARI_PASSWORD must have at least 32 characters")
-    primary_data = cfg.get("primary", {})
-    primary = endpoint("provider-primary", primary_data, env)
-    backup_data = cfg.get("backup")
-    if backup_data is not None and not isinstance(backup_data, dict):
-        raise ValueError("backup must be an object when configured")
-    sections = [primary]
-    if backup_data:
-        backup = endpoint("provider-backup", backup_data, env)
-        if (primary_data["host"], primary_data.get("port", 5060)) == (
-            backup_data["host"],
-            backup_data.get("port", 5060),
-        ):
-            raise ValueError(
-                "primary and backup targets must be distinct; shared failure domains still require validation"
-            )
-        sections.append(backup)
+    trunks = _trunks(cfg)
+    sections = [endpoint(name, data, env) for name, data in trunks]
+    primary_name, primary_data = trunks[0]
     transport = f"[global]\ntype=global\nuser_agent=agent-call\n\n[transport-udp]\ntype=transport\nprotocol=udp\nbind=0.0.0.0:5060\nlocal_net={network}\nexternal_signaling_address={PUBLIC_IP}\nexternal_media_address={PUBLIC_IP}\n\n"
     caller = primary_data.get("caller_id") or primary_data.get("from_user")
     extensions = "[deny-inbound]\nexten => s,1,Hangup()\nexten => _.,1,Hangup()\n"
     if caller:
-        caller = scalar(caller, "primary.caller_id")
+        caller = scalar(caller, f"{primary_name}.caller_id")
         extensions += (
             "\n[outbound]\n"
-            "exten => _X.,1,NoOp(agent-call outbound)\n"
+            "; ARI Cell calls select an approved endpoint with PJSIP/<number>@<trunk_id>.\n"
+            "exten => _X.,1,NoOp(agent-call outbound fallback)\n"
             f" same => n,Set(CALLERID(all)={caller})\n"
-            " same => n,Dial(PJSIP/${EXTEN}@provider-primary,60)\n"
+            f" same => n,Dial(PJSIP/${{EXTEN}}@{primary_name},60)\n"
             " same => n,Hangup()\n"
         )
     return {