Add GR_SATELLITES_SUBMIT_TLM env variable to control tlm submit

This reads the environment variable GR_SATELLITES_SUBMIT_TLM
from the gr-satellites core flowgraph. If the variable exists
and can be converted into an int, its truth value forces/disables
telemetry submission, ignoring the value in the config file.

This is used in the test.sh script to disable telemetry submission
as suggested in #214

(cherry picked from commit 79ab942)

CHANGELOG.md

@@ -13,6 +13,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Support for TAUSAT-1 and TSURU
 - 2k4 downlink for MEZNSAT
 - Support for SMOG-1
+- Env variable GR_SATELLITES_SUBMIT_TLM to force/disable telemetry submission
 
 ### Fixed
 - RS basis options swapped in CCSDS Reed-Solomon encoder GRC block

python/core/gr_satellites_flowgraph.py

@@ -23,6 +23,7 @@
 import yaml
 import argparse
 import itertools
+import os
 import shlex
 
 def set_options(cl, *args, **kwargs):
@@ -183,8 +184,17 @@ def _init_additional_datasinks(self):
                                                                               self.options.kiss_server))
         if self.options is not None and self.options.zmq_pub:
             self._additional_datasinks.append(zeromq.pub_msg_sink(self.options.zmq_pub))
-        if self.config.getboolean('Groundstation', 'submit_tlm'):
+
+        # The GR_SATELLITES_SUBMIT_TLM environment variable takes precendence
+        # over the configuration to choose whether to enable telemetry submission
+        tlm_env = os.environ.get('GR_SATELLITES_SUBMIT_TLM')
+        if tlm_env is not None:
+            tlm_submit = bool(int(tlm_env))
+        else:
+            tlm_submit = self.config.getboolean('Groundstation', 'submit_tlm')    
+        if tlm_submit:
             self._additional_datasinks.extend(self.get_telemetry_submitters(self.satyaml, self.config, self.options))
+
         if self.options is not None and self.options.hexdump:
             self._additional_datasinks.append(datasinks.hexdump_sink())
 

test.sh

@@ -1,5 +1,7 @@
 #!/bin/sh
 
+export GR_SATELLITES_SUBMIT_TLM=0
+
 echo 1KUNS-PF
 gr_satellites 1KUNS-PF --wavfile satellite-recordings/1kuns_pf.wav
 echo 3CAT-1