generating service content

home.admin/config.scripts/internet.sshtunnel.py

@@ -1,6 +1,7 @@
 #!/usr/bin/python3
 
 import sys, subprocess
+from pathlib import Path
 
 # display config script info
 if len(sys.argv) <= 1 or sys.argv[1] == "-h" or sys.argv[1] == "help":
@@ -9,20 +10,102 @@ if len(sys.argv) <= 1 or sys.argv[1] == "-h" or sys.argv[1] == "help":
     print("note that [INTERNAL-PORT]:[EXTERNAL-PORT] can one or multiple forwardings")
     sys.exit(1)
 
+#
+# CONSTANTS
+#
+
+SERVICENAME="autossh-tunnel.service"
+SERVICEFILE="/etc/systemd/system/"+SERVICENAME
+SERVICETEMPLATE="""# see config script internet.sshtunnel.py
+[Unit]
+Description=AutoSSH tunnel service
+After=network.target
+
+[Service]
+User=root
+Group=root
+Environment="AUTOSSH_GATETIME=0"
+ExecStart=/usr/bin/autossh -M 0 -N -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -o "ServerAliveInterval 30" -o "ServerAliveCountMax 3" [PLACEHOLDER]
+StandardOutput=journal
+
+[Install]
+WantedBy=multi-user.target
+"""
+
 #
 # SWITCHING ON
 #
 
 if sys.argv[1] == "on":
 
-    # check if already running -> systemctl is-enabled autossh-tunnel.service
-    alreadyRunning = subprocess.check_output('systemctl is-enabled autossh-tunnel.service' ,shell=True, universal_newlines=True)
-    print(alreadyRunning)
-    if str(alreadyRunning).count("enabled") > 0:
-        print("already running - run 'internet.sshtunnel.py off' first")
+    # check if already running
+    already_running = subprocess.check_output(f"systemctl is-enabled {SERVICENAME}" ,shell=True, universal_newlines=True)
+    if str(already_running).count("enabled") > 0:
+        print("already ON - run 'internet.sshtunnel.py off' first")
         sys.exit(1)
 
-    print ("TODO: Switch ON")
+    # check server address
+    ssh_server = sys.argv[2]
+    if ssh_server.count("@") != 1:
+        print(f"[USER]@[SERVER] wrong - use 'internet.sshtunnel.py -h' for help")
+        sys.exit(1)
+
+    # check minimal forwardings
+    if len(sys.argv) < 4:
+        print("[INTERNAL-PORT]:[EXTERNAL-PORT] missing - run 'internet.sshtunnel.py off' first")
+        sys.exit(1)
+
+    # genenate additional parameter for autossh (forwarding ports)
+    additional_parameters=""
+    i = 3
+    while i < len(sys.argv):
+
+        # check forwarding format
+        if sys.argv[i].count(":") != 1:
+            print(f"[INTERNAL-PORT]:[EXTERNAL-PORT] wrong format '{sys.argv[i]}'")
+            sys.exit(1)
+
+        # get ports
+        ports = sys.argv[i].split(":")
+        port_internal = ports[0]
+        port_external = ports[1]
+        if port_internal.isdigit() == False:
+            print(f"[INTERNAL-PORT]:[EXTERNAL-PORT] internal not number '{sys.argv[i]}'")
+            sys.exit(1)
+        if port_external.isdigit() == False:
+            print(f"[INTERNAL-PORT]:[EXTERNAL-PORT] external not number '{sys.argv[i]}'")
+            sys.exit(1) 
+
+        additional_parameters= additional_parameters + f"-R {port_external}:localhost:{port_internal} "
+        i=i+1
+
+    # genenate additional parameter for autossh (server)
+    additional_parameters= additional_parameters + ssh_server
+
+    # generate custom service config
+    service_data = SERVICETEMPLATE.replace("[PLACEHOLDER]", additional_parameters)
+
+    # DEBUG exit
+    print("****** SERVICE ******")
+    print(service_data)
+    sys.exit(0)
+
+    # write service file
+    service_file = open(SERVICEFILE, "w")
+    service_file.write(service_data)
+    service_file.close()
+
+    # enable service
+    print(f"*** Enabling systemd service: {{SERVICENAME}}")
+    subprocess.call(f"systemctl daemon-reload", shell=True)
+    subprocess.call(f"systemctl enable {SERVICENAME}", shell=True)
+    print()
+
+    # final info (can be ignored if run by other script)
+    print(f"*** OK - SSH TUNNEL SERVICE STARTED ***")
+    print(f"- Make sure the SSH pub key of this RaspiBlitz is in 'authorized_keys' of {} ")
+    print(f"- Tunnel service needs final reboot to start.")
+    print(f"- After reboot check logs: sudo journalctl -f -u {SERVICENAME}")
 
 #
 # SWITCHING OFF
@@ -30,6 +113,12 @@ if sys.argv[1] == "on":
 
 elif sys.argv[1] == "off":
 
+    # check if already disabled
+    alreadyRunning = subprocess.check_output(f"systemctl is-enabled {SERVICENAME}" ,shell=True, universal_newlines=True)
+    if str(alreadyRunning).count("enabled") == 0:
+        print("Was already OFF")
+        sys.exit(0)
+
     print ("TODO: Switch OFF")
 
 #