Refactor docker locations and README.

This addresses #3224

1 files changed, 66 insertions, 0 deletions

diff --git a/docker/start.py b/docker/start.py
new file mode 100755
index 0000000000..90e8b9c51a
--- /dev/null
+++ b/docker/start.py
@@ -0,0 +1,66 @@
+#!/usr/local/bin/python
+
+import jinja2
+import os
+import sys
+import subprocess
+import glob
+
+# Utility functions
+convert = lambda src, dst, environ: open(dst, "w").write(jinja2.Template(open(src).read()).render(**environ))
+
+def check_arguments(environ, args):
+    for argument in args:
+        if argument not in environ:
+            print("Environment variable %s is mandatory, exiting." % argument)
+            sys.exit(2)
+
+def generate_secrets(environ, secrets):
+    for name, secret in secrets.items():
+        if secret not in environ:
+            filename = "/data/%s.%s.key" % (environ["SYNAPSE_SERVER_NAME"], name)
+            if os.path.exists(filename):
+                with open(filename) as handle: value = handle.read()
+            else:
+                print("Generating a random secret for {}".format(name))
+                value = os.urandom(32).encode("hex")
+                with open(filename, "w") as handle: handle.write(value)
+            environ[secret] = value
+
+# Prepare the configuration
+mode = sys.argv[1] if len(sys.argv) > 1 else None
+environ = os.environ.copy()
+ownership = "{}:{}".format(environ.get("UID", 991), environ.get("GID", 991))
+args = ["python", "-m", "synapse.app.homeserver"]
+
+# In generate mode, generate a configuration, missing keys, then exit
+if mode == "generate":
+    check_arguments(environ, ("SYNAPSE_SERVER_NAME", "SYNAPSE_REPORT_STATS", "SYNAPSE_CONFIG_PATH"))
+    args += [
+        "--server-name", environ["SYNAPSE_SERVER_NAME"],
+        "--report-stats", environ["SYNAPSE_REPORT_STATS"],
+        "--config-path", environ["SYNAPSE_CONFIG_PATH"],
+        "--generate-config"
+    ]
+    os.execv("/usr/local/bin/python", args)
+
+# In normal mode, generate missing keys if any, then run synapse
+else:
+    # Parse the configuration file
+    if "SYNAPSE_CONFIG_PATH" in environ:
+        args += ["--config-path", environ["SYNAPSE_CONFIG_PATH"]]
+    else:
+        check_arguments(environ, ("SYNAPSE_SERVER_NAME", "SYNAPSE_REPORT_STATS"))
+        generate_secrets(environ, {
+            "registration": "SYNAPSE_REGISTRATION_SHARED_SECRET",
+            "macaroon": "SYNAPSE_MACAROON_SECRET_KEY"
+        })
+        environ["SYNAPSE_APPSERVICES"] = glob.glob("/data/appservices/*.yaml")
+        if not os.path.exists("/compiled"): os.mkdir("/compiled")
+        convert("/conf/homeserver.yaml", "/compiled/homeserver.yaml", environ)
+        convert("/conf/log.config", "/compiled/log.config", environ)
+        subprocess.check_output(["chown", "-R", ownership, "/data"])
+        args += ["--config-path", "/compiled/homeserver.yaml"]
+    # Generate missing keys and start synapse
+    subprocess.check_output(args + ["--generate-keys"])
+    os.execv("/sbin/su-exec", ["su-exec", ownership] + args)