Differences

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--- simple-bpq-telnet-application [2024/11/28 17:20] – [Configuring this as a service] kc2ihx
+++ simple-bpq-telnet-application [2024/11/29 14:57] (current) – kc2ihx
@@ Line 1: / Line 1: @@
 ====== Creating a simple BPQ Application ======
 This tutorial shows you how to set up a simple python script [[https://www.cantab.net/users/john.wiseman/Documents/LinBPQ%20Applications%20Interface.html|connected to linbpq as a telnet application]].
+In order to do this we'll do the following:
+  - Create a location for the script, data, and a python ''venv''
+  - Write the script
+  - Add the application to ''BPQ32.cfg''
+  - Setup a ''systemd'' service to keep it running.
+===== Setup =====
+To organize this project, I created a python virtual environment called ''bpq-apps'' in my ''.local'' directory, and installed the ''telnetlib3'' module that it depends on.  Within the ''bpq-apps'' virtual environment directory, I also created a folder called scripts and a folder called data.  I'm going to install various small BPQ applications here.
+I'm using the python virtual environment framework to help manage the various dependencies I might want to use for these scripts.
+<code>
+$ cd ~/.local
+$ python -m venv bpq-apps
+$ cd ./bpq-apps
+$ mkdir scripts data
+$ source ./bin/activate
+(bpq-apps)$ pip install telnetlib3
+</code>
 ===== Writing the program =====
 I chose to write this in Python to be a //little// more clear than the Perl application provided in the link above.
-This program, called ''ROLL'' uses a file called ''messages.json'' to provide it a welcome message and the blocks of text.
+The BPQ Application, called ''ROLL'' uses a file called ''messages.json'' to provide it a welcome message and the blocks of text.  The script itself was placed under the ''scripts'' directory created above, saved as ''rick.py''
-I saved both of these to ''~/.local/bpq-apps/roll''
 ==== Program Code ====
@@ Line 29: / Line 47: @@
     writer.write("\r\n%s" % messages["welcome"])
     textblocks = messages["text"].copy()
-    inp = await reader.readline()
+    leave = False #inp[0].upper() in ["Q", "B"]
-    leave = inp[0].upper() in ["Q", "B"]
+    rolled = False
+    inp = await reader.read(1)
     while inp and not leave and len(textblocks) > 0:
         print("writing next block")
-        writer.write(textblocks.pop())
+        writer.write(textblocks.pop(0))
         await writer.drain()
         inp = await reader.readline()
-        leave = inp[0].upper() in ["Q", "B"]
+        if not rolled: print("%s rickrolled" % incall)
+        rolled = True
+        leave = inp[0].upper() in ["Q", "B"] and rolled
     writer.close()
@@ Line 76: / Line 97: @@
 ===== Configuring this as a service =====
 Next we'll configure a ''systemd'' service to make sure this script is always running and ready to accept connections.
-//todo write block describing adding a service to run this script//
+I created this file as a "user" service, as ''~/.config/systemd/user/rick.service'', but it should probably run as a system service:
+<code>
+# service for RRoAX25 server
+# replace USER with the username under which you created the bpq-apps venv
+[Unit]
+Description="RRoAX25 service"
+After=network.target
+[Service]
+Type=simple
+WorkingDirectory=/home/USER/.local/bpq-apps/
+ExecStart=/home/USER/.local/bpq-apps/bin/python /home/USER/.local/bpq-apps/scripts/rick.py -p 10001 -f /home/USER/.local/bpq-apps/data/messages.json
+Restart=always
+[Install]
+WantedBy=default.target
+</code>
+Activate it by running:
+<code>
+systemctl --user enable rick.service
+systemctl --user start rick.service
+</code>
+Then check the status to confirm it is working:
+<code>
+systemctl --user status rick.service
+</code>
+If you need to edit the service file, reload it with:
+<code>
+systemctl --user daemon-reload
+</code>