Implement configurable stats reporting

SYN-287

This requires that HS owners either opt in or out of stats reporting.

When --generate-config is passed, --report-stats must be specified
If an already-generated config is used, and doesn't have the
report_stats key, it is requested to be set.

14 files changed, 58 insertions, 19 deletions

diff --git a/synapse/config/_base.py b/synapse/config/_base.py
index 8a75c48733..b9983f72a2 100644
--- a/synapse/config/_base.py
+++ b/synapse/config/_base.py
@@ -26,6 +26,16 @@ class ConfigError(Exception):
 
 class Config(object):
 
+    stats_reporting_begging_spiel = (
+        "We would really appreciate it if you could help our project out by "
+        "reporting anonymized usage statistics from your homeserver. Only very "
+        "basic aggregate data (e.g. number of users) will be reported, but it "
+        "helps us to track the growth of the Matrix community, and helps us to "
+        "make Matrix a success, as well as to convince other networks that they "
+        "should peer with us.\n"
+        "Thank you."
+    )
+
     @staticmethod
     def parse_size(value):
         if isinstance(value, int) or isinstance(value, long):
@@ -111,11 +121,14 @@ class Config(object):
                 results.append(getattr(cls, name)(self, *args, **kargs))
         return results
 
-    def generate_config(self, config_dir_path, server_name):
+    def generate_config(self, config_dir_path, server_name, report_stats=None):
         default_config = "# vim:ft=yaml\n"
 
         default_config += "\n\n".join(dedent(conf) for conf in self.invoke_all(
-            "default_config", config_dir_path, server_name
+            "default_config",
+            config_dir_path=config_dir_path,
+            server_name=server_name,
+            report_stats=report_stats,
         ))
 
         config = yaml.load(default_config)
@@ -140,6 +153,12 @@ class Config(object):
             help="Generate a config file for the server name"
         )
         config_parser.add_argument(
+            "--report-stats",
+            action="store",
+            help="Stuff",
+            choices=["yes", "no"]
+        )
+        config_parser.add_argument(
             "--generate-keys",
             action="store_true",
             help="Generate any missing key files then exit"
@@ -189,6 +208,11 @@ class Config(object):
                     config_files.append(config_path)
 
         if config_args.generate_config:
+            if config_args.report_stats is None:
+                config_parser.error(
+                    "Please specify either --report-stats=yes or --report-stats=no\n\n" +
+                    cls.stats_reporting_begging_spiel
+                )
             if not config_files:
                 config_parser.error(
                     "Must supply a config file.\nA config file can be automatically"
@@ -211,7 +235,9 @@ class Config(object):
                     os.makedirs(config_dir_path)
                 with open(config_path, "wb") as config_file:
                     config_bytes, config = obj.generate_config(
-                        config_dir_path, server_name
+                        config_dir_path=config_dir_path,
+                        server_name=server_name,
+                        report_stats=(config_args.report_stats == "yes"),
                     )
                     obj.invoke_all("generate_files", config)
                     config_file.write(config_bytes)
@@ -261,9 +287,20 @@ class Config(object):
             specified_config.update(yaml_config)
 
         server_name = specified_config["server_name"]
-        _, config = obj.generate_config(config_dir_path, server_name)
+        _, config = obj.generate_config(
+            config_dir_path=config_dir_path,
+            server_name=server_name
+        )
         config.pop("log_config")
         config.update(specified_config)
+        if "report_stats" not in config:
+            sys.stderr.write(
+                "Please opt in or out of reporting anonymized homeserver usage "
+                "statistics, by setting the report_stats key in your config file "
+                " ( " + config_path + " ) " +
+                "to either True or False.\n\n" +
+                Config.stats_reporting_begging_spiel + "\n")
+            sys.exit(1)
 
         if generate_keys:
             obj.invoke_all("generate_files", config)
diff --git a/synapse/config/appservice.py b/synapse/config/appservice.py
index 38f41933b7..b8d301995e 100644
--- a/synapse/config/appservice.py
+++ b/synapse/config/appservice.py
@@ -20,7 +20,7 @@ class AppServiceConfig(Config):
     def read_config(self, config):
         self.app_service_config_files = config.get("app_service_config_files", [])
 
-    def default_config(cls, config_dir_path, server_name):
+    def default_config(cls, **kwargs):
         return """\
         # A list of application service config file to use
         app_service_config_files: []
diff --git a/synapse/config/captcha.py b/synapse/config/captcha.py
index 15a132b4e3..dd92fcd0dc 100644
--- a/synapse/config/captcha.py
+++ b/synapse/config/captcha.py
@@ -24,7 +24,7 @@ class CaptchaConfig(Config):
         self.captcha_bypass_secret = config.get("captcha_bypass_secret")
         self.recaptcha_siteverify_api = config["recaptcha_siteverify_api"]
 
-    def default_config(self, config_dir_path, server_name):
+    def default_config(self, **kwargs):
         return """\
         ## Captcha ##
 
diff --git a/synapse/config/database.py b/synapse/config/database.py
index f0611e8884..baeda8f300 100644
--- a/synapse/config/database.py
+++ b/synapse/config/database.py
@@ -45,7 +45,7 @@ class DatabaseConfig(Config):
 
         self.set_databasepath(config.get("database_path"))
 
-    def default_config(self, config, config_dir_path):
+    def default_config(self, **kwargs):
         database_path = self.abspath("homeserver.db")
         return """\
         # Database configuration
diff --git a/synapse/config/key.py b/synapse/config/key.py
index 23ac8a3fca..2c187065e5 100644
--- a/synapse/config/key.py
+++ b/synapse/config/key.py
@@ -40,7 +40,7 @@ class KeyConfig(Config):
             config["perspectives"]
         )
 
-    def default_config(self, config_dir_path, server_name):
+    def default_config(self, config_dir_path, server_name, **kwargs):
         base_key_name = os.path.join(config_dir_path, server_name)
         return """\
         ## Signing Keys ##
diff --git a/synapse/config/logger.py b/synapse/config/logger.py
index daca698d0c..bd0c17c861 100644
--- a/synapse/config/logger.py
+++ b/synapse/config/logger.py
@@ -70,7 +70,7 @@ class LoggingConfig(Config):
         self.log_config = self.abspath(config.get("log_config"))
         self.log_file = self.abspath(config.get("log_file"))
 
-    def default_config(self, config_dir_path, server_name):
+    def default_config(self, config_dir_path, server_name, **kwargs):
         log_file = self.abspath("homeserver.log")
         log_config = self.abspath(
             os.path.join(config_dir_path, server_name + ".log.config")
diff --git a/synapse/config/metrics.py b/synapse/config/metrics.py
index ae5a691527..825fec9a38 100644
--- a/synapse/config/metrics.py
+++ b/synapse/config/metrics.py
@@ -19,13 +19,15 @@ from ._base import Config
 class MetricsConfig(Config):
     def read_config(self, config):
         self.enable_metrics = config["enable_metrics"]
+        self.report_stats = config.get("report_stats", None)
         self.metrics_port = config.get("metrics_port")
         self.metrics_bind_host = config.get("metrics_bind_host", "127.0.0.1")
 
-    def default_config(self, config_dir_path, server_name):
-        return """\
+    def default_config(self, report_stats=None, **kwargs):
+        suffix = "" if report_stats is None else "report_stats: %(report_stats)s\n"
+        return ("""\
         ## Metrics ###
 
         # Enable collection and rendering of performance metrics
         enable_metrics: False
-        """
+        """ + suffix) % locals()
diff --git a/synapse/config/ratelimiting.py b/synapse/config/ratelimiting.py
index 76d9970e5b..611b598ec7 100644
--- a/synapse/config/ratelimiting.py
+++ b/synapse/config/ratelimiting.py
@@ -27,7 +27,7 @@ class RatelimitConfig(Config):
         self.federation_rc_reject_limit = config["federation_rc_reject_limit"]
         self.federation_rc_concurrent = config["federation_rc_concurrent"]
 
-    def default_config(self, config_dir_path, server_name):
+    def default_config(self, **kwargs):
         return """\
         ## Ratelimiting ##
 
diff --git a/synapse/config/registration.py b/synapse/config/registration.py
index 62de4b399f..fa98eced34 100644
--- a/synapse/config/registration.py
+++ b/synapse/config/registration.py
@@ -34,7 +34,7 @@ class RegistrationConfig(Config):
         self.registration_shared_secret = config.get("registration_shared_secret")
         self.macaroon_secret_key = config.get("macaroon_secret_key")
 
-    def default_config(self, config_dir, server_name):
+    def default_config(self, **kwargs):
         registration_shared_secret = random_string_with_symbols(50)
         macaroon_secret_key = random_string_with_symbols(50)
         return """\
diff --git a/synapse/config/repository.py b/synapse/config/repository.py
index 64644b9a7a..2fcf872449 100644
--- a/synapse/config/repository.py
+++ b/synapse/config/repository.py
@@ -60,7 +60,7 @@ class ContentRepositoryConfig(Config):
             config["thumbnail_sizes"]
         )
 
-    def default_config(self, config_dir_path, server_name):
+    def default_config(self, **kwargs):
         media_store = self.default_path("media_store")
         uploads_path = self.default_path("uploads")
         return """
diff --git a/synapse/config/saml2.py b/synapse/config/saml2.py
index 1532036876..4c6133cf22 100644
--- a/synapse/config/saml2.py
+++ b/synapse/config/saml2.py
@@ -41,7 +41,7 @@ class SAML2Config(Config):
             self.saml2_config_path = None
             self.saml2_idp_redirect_url = None
 
-    def default_config(self, config_dir_path, server_name):
+    def default_config(self, config_dir_path, server_name, **kwargs):
         return """
         # Enable SAML2 for registration and login. Uses pysaml2
         # config_path:      Path to the sp_conf.py configuration file
diff --git a/synapse/config/server.py b/synapse/config/server.py
index a03e55c223..4d12d49857 100644
--- a/synapse/config/server.py
+++ b/synapse/config/server.py
@@ -117,7 +117,7 @@ class ServerConfig(Config):
 
         self.content_addr = content_addr
 
-    def default_config(self, config_dir_path, server_name):
+    def default_config(self, server_name, **kwargs):
         if ":" in server_name:
             bind_port = int(server_name.split(":")[1])
             unsecure_port = bind_port - 400
diff --git a/synapse/config/tls.py b/synapse/config/tls.py
index e6023a718d..0ac2698293 100644
--- a/synapse/config/tls.py
+++ b/synapse/config/tls.py
@@ -50,7 +50,7 @@ class TlsConfig(Config):
             "use_insecure_ssl_client_just_for_testing_do_not_use"
         )
 
-    def default_config(self, config_dir_path, server_name):
+    def default_config(self, config_dir_path, server_name, **kwargs):
         base_key_name = os.path.join(config_dir_path, server_name)
 
         tls_certificate_path = base_key_name + ".tls.crt"
diff --git a/synapse/config/voip.py b/synapse/config/voip.py
index a1707223d3..a093354ccd 100644
--- a/synapse/config/voip.py
+++ b/synapse/config/voip.py
@@ -22,7 +22,7 @@ class VoipConfig(Config):
         self.turn_shared_secret = config["turn_shared_secret"]
         self.turn_user_lifetime = self.parse_duration(config["turn_user_lifetime"])
 
-    def default_config(self, config_dir_path, server_name):
+    def default_config(self, **kwargs):
         return """\
         ## Turn ##