Install gpg2 if required when adding apt keys

Not installed by default in many docker containers

bootstrap/bootstrap.py

@@ -28,8 +28,7 @@ def main():
         print('Setting up hub environment')
         initial_setup = True
         subprocess.check_output(['apt-get', 'update', '--yes'])
-        # gnupg2 is needed for nodesource to work
-        subprocess.check_output(['apt-get', 'install', '--yes', 'python3', 'python3-venv', 'gnupg2'])
+        subprocess.check_output(['apt-get', 'install', '--yes', 'python3', 'python3-venv'])
         os.makedirs(hub_prefix, exist_ok=True)
         subprocess.check_output(['python3', '-m', 'venv', hub_prefix])
 

tljh/apt.py

@@ -11,6 +11,9 @@ def trust_gpg_key(key):
 
     key is a GPG public key (bytes) that can be passed to apt-key add via stdin.
     """
+    # If gpg2 doesn't exist, install it.
+    if not os.path.exists('/usr/bin/gpg2'):
+        install_packages(['gnupg2'])
     subprocess.run(['apt-key', 'add', '-'], input=key, check=True)