tests/system/framework/roles/shadow.py: implement binding for `newgrp`

Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>

diff --git a/tests/system/framework/roles/shadow.py b/tests/system/framework/roles/shadow.py
index 6be27151ccdb53bc68852f858123c449c708e012..c05ab531a1249f6e9b0dd4028af7f145e847e7f2 100644 (file)
--- a/tests/system/framework/roles/shadow.py
+++ b/tests/system/framework/roles/shadow.py
@@ -3,17 +3,21 @@
 from __future__ import annotations
 
 import shlex
-from typing import Dict
+from typing import Dict, Tuple
 
 from pytest_mh.conn import ProcessLogLevel, ProcessResult
 
 from ..hosts.shadow import ShadowHost
+from ..misc.errors import ExpectScriptError
 from .base import BaseLinuxRole
 
 __all__ = [
     "Shadow",
 ]
 
+DEFAULT_INTERACTIVE_TIMEOUT: int = 60
+"""Default timeout for interactive sessions."""
+
 
 class Shadow(BaseLinuxRole[ShadowHost]):
     """
@@ -190,3 +194,80 @@ class Shadow(BaseLinuxRole[ShadowHost]):
         self.host.discard_file("/etc/gshadow")
 
         return cmd
+
+    def newgrp(self, *args, run_as: str = "root") -> Tuple[ProcessResult, int]:
+        """
+        Log in to a new group.
+
+        The newgrp command is used to change the current group ID during a login session.
+        Returns the process result and the group ID after the change.
+        """
+        args_dict = self._parse_args(args)
+
+        self.logger.info(f'Changing {run_as} to group "{args_dict["name"]}" on {self.host.hostname}')
+
+        # Use expect to handle the interactive newgrp session
+        result = self.host.conn.expect(
+            rf"""
+            set timeout {DEFAULT_INTERACTIVE_TIMEOUT}
+            set prompt "\[#\$>\] $"
+
+            if {{ "{run_as}" eq "root" }} {{
+                spawn newgrp {args[0]}
+            }} else {{
+                spawn su - {run_as}
+                expect {{
+                    -re $prompt {{send "newgrp {args[0]}\n"}}
+                    timeout {{puts "expect result: Timeout waiting for su prompt"; exit 201}}
+                    eof {{puts "expect result: Unexpected end of file"; exit 202}}
+                }}
+            }}
+
+            expect {{
+                -re $prompt {{send "id -g\n"}}
+                timeout {{puts "expect result: Timeout waiting for newgrp prompt"; exit 201}}
+                eof {{puts "expect result: Unexpected end of file"; exit 202}}
+            }}
+
+            expect {{
+                -re "(\[0-9\]+)" {{
+                    set gid $expect_out(1,string)
+                    send "exit\n"
+                    puts "newgrp_gid:$gid"
+                }}
+                timeout {{puts "expect result: Timeout waiting for id output"; exit 201}}
+                eof {{puts "expect result: Unexpected end of file"; exit 202}}
+            }}
+
+            if {{ "{run_as}" ne "root" }} {{
+                expect {{
+                    -re $prompt {{
+                        send "exit\n"
+                    }}
+                    timeout {{puts "expect result: Timeout waiting for original su prompt"; exit 201}}
+                }}
+            }}
+
+            expect {{
+                eof {{exit 0}}
+                timeout {{exit 201}}
+            }}
+            """,
+            verbose=False,
+        )
+
+        if result.rc > 200:
+            raise ExpectScriptError(result.rc)
+
+        gid_line = None
+        for line in result.stdout_lines:
+            if "newgrp_gid:" in line:
+                gid_line = line
+                break
+
+        if gid_line is None:
+            raise ValueError("Current GID is required for newgrp")
+
+        current_gid = int(gid_line.split(":")[1])
+
+        return result, current_gid