When tor or i2p options are present, confirm we have txi2p or txtorcon

We mock out some import methods and provide tests for providing
server-side or client-side tor/i2p options

src/allmydata/scripts/create_node.py

@@ -92,6 +92,11 @@ def validate_where_options(o):
 
 def validate_tor_options(o):
     use_tor = "tor" in o["listen"].split(",")
+    if use_tor or any((o["tor-launch"], o["tor-control-port"])):
+        if tor_provider._import_txtorcon() is None:
+            raise UsageError(
+                "Specifying any Tor options requires the 'txtorcon' module"
+            )
     if not use_tor:
         if o["tor-launch"]:
             raise UsageError("--tor-launch requires --listen=tor")
@@ -102,6 +107,11 @@ def validate_tor_options(o):
 
 def validate_i2p_options(o):
     use_i2p = "i2p" in o["listen"].split(",")
+    if use_i2p or any((o["i2p-launch"], o["i2p-sam-port"])):
+        if i2p_provider._import_txi2p() is None:
+            raise UsageError(
+                "Specifying any I2P options requires the 'txi2p' module"
+            )
     if not use_i2p:
         if o["i2p-launch"]:
             raise UsageError("--i2p-launch requires --listen=i2p")
@@ -117,6 +127,16 @@ class _CreateBaseOptions(BasedirOptions):
         ("hide-ip", None, "prohibit any configuration that would reveal the node's IP address"),
         ]
 
+    def postOptions(self):
+        super(_CreateBaseOptions, self).postOptions()
+        if self['hide-ip']:
+            if tor_provider._import_txtorcon() is None and i2p_provider._import_txi2p() is None:
+                raise UsageError(
+                    "--hide-ip was specified but neither 'txtorcon' nor 'txi2p' "
+                    "are installed.\nTo do so:\n   pip install tahoe-lafs[tor]\nor\n"
+                    "   pip install tahoe-lafs[i2p]"
+                )
+
 class CreateClientOptions(_CreateBaseOptions):
     synopsis = "[options] [NODEDIR]"
     description = "Create a client-only Tahoe-LAFS node (no storage server)."
@@ -154,6 +174,7 @@ class CreateNodeOptions(CreateClientOptions):
         validate_tor_options(self)
         validate_i2p_options(self)
 
+
 class CreateIntroducerOptions(NoDefaultBasedirOptions):
     subcommand_name = "create-introducer"
     description = "Create a Tahoe-LAFS introducer."
@@ -167,6 +188,7 @@ class CreateIntroducerOptions(NoDefaultBasedirOptions):
         validate_tor_options(self)
         validate_i2p_options(self)
 
+
 @defer.inlineCallbacks
 def write_node_config(c, config):
     # this is shared between clients and introducers

src/allmydata/test/cli/test_create.py

@@ -43,10 +43,43 @@ class Config(unittest.TestCase):
         self.assertEqual(cfg.get("node", "tub.location"), "disabled")
         self.assertFalse(cfg.has_section("connections"))
 
+    @defer.inlineCallbacks
+    def test_client_hide_ip_no_i2p_txtorcon(self):
+        # hmm, I must be doing something weird, these don't work as
+        # @mock.patch decorators for some reason
+        txi2p = mock.patch('allmydata.util.i2p_provider._import_txi2p', return_value=None)
+        txtorcon = mock.patch('allmydata.util.tor_provider._import_txtorcon', return_value=None)
+        with txi2p, txtorcon:
+            basedir = self.mktemp()
+            rc, out, err = yield run_cli("create-client", "--hide-ip", basedir)
+            print(rc, out, err)
+            self.assertTrue(rc != 0, out)
+            self.assertTrue('pip install tahoe-lafs[i2p]' in out)
+            self.assertTrue('pip install tahoe-lafs[tor]' in out)
+
+    @defer.inlineCallbacks
+    def test_client_i2p_option_no_txi2p(self):
+        txi2p = mock.patch('allmydata.util.i2p_provider._import_txi2p', return_value=None)
+        with txi2p:
+            basedir = self.mktemp()
+            rc, out, err = yield run_cli("create-node", "--listen=i2p", "--i2p-launch", basedir)
+            self.assertTrue(rc != 0)
+            self.assertTrue("Specifying any I2P options requires the 'txi2p' module" in out)
+
+    @defer.inlineCallbacks
+    def test_client_tor_option_no_txtorcon(self):
+        txtorcon = mock.patch('allmydata.util.tor_provider._import_txtorcon', return_value=None)
+        with txtorcon:
+            basedir = self.mktemp()
+            rc, out, err = yield run_cli("create-node", "--listen=tor", "--tor-launch", basedir)
+            self.assertTrue(rc != 0)
+            self.assertTrue("Specifying any Tor options requires the 'txtorcon' module" in out)
+
     @defer.inlineCallbacks
     def test_client_hide_ip(self):
         basedir = self.mktemp()
         rc, out, err = yield run_cli("create-client", "--hide-ip", basedir)
+        self.assertEqual(0, rc)
         cfg = read_config(basedir)
         self.assertEqual(cfg.getboolean("node", "reveal-IP-address"), False)
         self.assertEqual(cfg.get("connections", "tcp"), "tor")