Improve PG unix sockets configuration (#4202)

* improve pg unix sockets configuration

* changelog

* don't use test env in config tests

CHANGELOG.md

@@ -13,8 +13,10 @@ All notable changes to this project will be documented in this file.
 ### Removed
 - Deprecate `ECTO_IPV6` and `ECTO_CH_IPV6` env vars in CE plausible/analytics#4245
 - Remove support for importing data from no longer available Universal Analytics
+- Soft-deprecate `DATABASE_SOCKET_DIR` plausible/analytics#4202
 
 ### Changed
+- Support Unix sockets in `DATABASE_URL` plausible/analytics#4202
 
 - Realtime and hourly graphs now show visits lasting their whole duration instead when specific events occur
 - Increase hourly request limit for API keys in CE from 600 to 1000000 (practically removing the limit) plausible/analytics#4200

config/runtime.exs

@@ -88,15 +88,6 @@ case secret_key_base do
     nil
 end
 
-db_url =
-  get_var_from_path_or_env(
-    config_dir,
-    "DATABASE_URL",
-    "postgres://postgres:postgres@plausible_db:5432/plausible_db"
-  )
-
-db_socket_dir = get_var_from_path_or_env(config_dir, "DATABASE_SOCKET_DIR")
-
 super_admin_user_ids =
   get_var_from_path_or_env(config_dir, "ADMIN_USER_IDS", "")
   |> String.split(",")
@@ -333,7 +324,7 @@ config :plausible, PlausibleWeb.Endpoint,
   websocket_url: websocket_url,
   secure_cookie: secure_cookie
 
-maybe_ipv6 =
+db_maybe_ipv6 =
   if get_var_from_path_or_env(config_dir, "ECTO_IPV6") do
     if config_env() in [:ce, :ce_dev, :ce_test] do
       Logger.warning(
@@ -346,23 +337,63 @@ maybe_ipv6 =
     []
   end
 
+db_url =
+  get_var_from_path_or_env(
+    config_dir,
+    "DATABASE_URL",
+    "postgres://postgres:postgres@plausible_db:5432/plausible_db"
+  )
+
+if db_socket_dir = get_var_from_path_or_env(config_dir, "DATABASE_SOCKET_DIR") do
+  Logger.warning("""
+  DATABASE_SOCKET_DIR is deprecated, please use DATABASE_URL instead:
+
+      DATABASE_URL=postgresql://postgres:postgres@#{URI.encode_www_form(db_socket_dir)}/plausible_db
+
+  or
+
+      DATABASE_URL=postgresql:///plausible_db?host=#{db_socket_dir}"
+
+  """)
+end
+
 db_cacertfile = get_var_from_path_or_env(config_dir, "DATABASE_CACERTFILE", CAStore.file_path())
+%URI{host: db_host} = db_uri = URI.parse(db_url)
+db_socket_dir? = String.starts_with?(db_host, "%2F") or db_host == ""
+
+if db_socket_dir? do
+  [database] = String.split(db_uri.path, "/", trim: true)
+
+  socket_dir =
+    if db_host == "" do
+      db_host = (db_uri.query || "") |> URI.decode_query() |> Map.get("host")
+      db_host || raise ArgumentError, "DATABASE_URL=#{db_url} doesn't include host info"
+    else
+      URI.decode_www_form(db_host)
+    end
 
-if is_nil(db_socket_dir) do
+  config :plausible, Plausible.Repo,
+    socket_dir: socket_dir,
+    database: database
+
+  if userinfo = db_uri.userinfo do
+    [username, password] = String.split(userinfo, ":")
+
+    config :plausible, Plausible.Repo,
+      username: username,
+      password: password
+  end
+else
   config :plausible, Plausible.Repo,
     url: db_url,
-    socket_options: maybe_ipv6,
+    socket_options: db_maybe_ipv6,
     ssl_opts: [
       cacertfile: db_cacertfile,
       verify: :verify_peer,
       customize_hostname_check: [
         match_fun: :public_key.pkix_verify_hostname_match_fun(:https)
       ]
     ]
-else
-  config :plausible, Plausible.Repo,
-    socket_dir: db_socket_dir,
-    database: get_var_from_path_or_env(config_dir, "DATABASE_NAME", "plausible")
 end
 
 sentry_app_version = runtime_metadata[:version] || app_version

test/plausible/config_test.exs

@@ -347,6 +347,74 @@ defmodule Plausible.ConfigTest do
     end
   end
 
+  describe "postgres" do
+    test "default" do
+      env = [{"DATABASE_URL", nil}]
+      config = runtime_config(env)
+
+      assert get_in(config, [:plausible, Plausible.Repo]) == [
+               url: "postgres://postgres:postgres@plausible_db:5432/plausible_db",
+               socket_options: [],
+               ssl_opts: [
+                 cacertfile: CAStore.file_path(),
+                 verify: :verify_peer,
+                 customize_hostname_check: [
+                   match_fun: :public_key.pkix_verify_hostname_match_fun(:https)
+                 ]
+               ]
+             ]
+    end
+
+    test "socket_dir in hostname" do
+      env = [{"DATABASE_URL", "postgresql://postgres:postgres@%2Frun%2Fpostgresql/plausible_db"}]
+      config = runtime_config(env)
+
+      assert get_in(config, [:plausible, Plausible.Repo]) == [
+               socket_dir: "/run/postgresql",
+               database: "plausible_db",
+               username: "postgres",
+               password: "postgres"
+             ]
+    end
+
+    test "socket_dir in query" do
+      env = [{"DATABASE_URL", "postgresql:///plausible_db?host=/run/postgresql"}]
+      config = runtime_config(env)
+
+      assert get_in(config, [:plausible, Plausible.Repo]) == [
+               socket_dir: "/run/postgresql",
+               database: "plausible_db"
+             ]
+    end
+
+    test "socket_dir missing" do
+      env = [{"DATABASE_URL", "postgresql:///plausible_db"}]
+      assert_raise ArgumentError, ~r/doesn't include host info/, fn -> runtime_config(env) end
+    end
+
+    test "custom URL" do
+      env = [
+        {"DATABASE_URL",
+         "postgresql://your_username:[email protected]:25060/defaultdb"}
+      ]
+
+      config = runtime_config(env)
+
+      assert get_in(config, [:plausible, Plausible.Repo]) == [
+               url:
+                 "postgresql://your_username:[email protected]:25060/defaultdb",
+               socket_options: [],
+               ssl_opts: [
+                 cacertfile: CAStore.file_path(),
+                 verify: :verify_peer,
+                 customize_hostname_check: [
+                   match_fun: :public_key.pkix_verify_hostname_match_fun(:https)
+                 ]
+               ]
+             ]
+    end
+  end
+
   describe "extra config" do
     test "no-op when no extra path is set" do
       put_system_env_undo({"EXTRA_CONFIG_PATH", nil})