Merge pull request #71 from supabase/fix/22

fix: converts the slot_name to lower case so that it matches Postgres

README.md

@@ -143,7 +143,7 @@ DB_NAME       # {string} Postgres database name
 DB_USER       # {string} Database user
 DB_PASSWORD   # {string} Database password
 DB_PORT       # {number} Database port
-SLOT_NAME     # {string} A unique name for Postgres to track where this server has "listened until". If the server dies, it can pick up from the last position.
+SLOT_NAME     # {string} A unique name for Postgres to track where this server has "listened until". If the server dies, it can pick up from the last position. This should be lowercase.
 PORT          # {number} Port which you can connect your client/listeners
 ```
 

server/README.md

@@ -1,4 +1,23 @@
-# Realtime Elixir Instructions
+# Realtime server
+
+## Run locally
+
+```sh
+SECRET_KEY_BASE=SOMETHING_SECRET \
+PORT=4000 \
+HOSTNAME=localhost \
+DB_USER=postgres \
+DB_HOST=localhost \
+DB_PASSWORD=postgres \
+DB_NAME=postgres \
+DB_PORT=5432 \
+DB_PORT=5432 \
+SLOT_NAME=TEST_SLOT \
+mix phx.server
+```
+
+
+## Realtime Elixir Instructions
 
 Create the release:
 
@@ -27,6 +46,7 @@ DB_HOST=localhost \
 DB_PASSWORD=postgres \
 DB_NAME=postgres \
 DB_PORT=5432 \
+DB_PORT=5432 \
 _build/prod/rel/realtime/bin/realtime start
 ```
 

server/config/config.exs

@@ -7,19 +7,31 @@
 # General application configuration
 import Config
 
-# These configs mirror the defaults in releases.exs, remember not to change one
+# These defaults mirror the ones in config.exs, remember not to change one
 # without changing the other.
+app_hostname = System.get_env("HOSTNAME", "localhost")
+app_port = String.to_integer(System.get_env("PORT", "4000"))
+db_host = System.get_env("DB_HOST", "localhost")
+db_port = String.to_integer(System.get_env("DB_PORT", "5432"))
+db_name = System.get_env("DB_NAME", "postgres")
+db_user = System.get_env("DB_USER", "postgres")
+db_password = System.get_env("DB_PASSWORD", "postgres")
+# HACK: There's probably a better way to set boolean from env
+db_ssl = System.get_env("DB_SSL", "true") === "true"
+slot_name = System.get_env("SLOT_NAME") || :temporary
+configuration_file = System.get_env("CONFIGURATION_FILE") || nil
+
 config :realtime,
-  app_hostname: "localhost",
-  app_port: 4000,
-  db_host: "localhost",
-  db_port: 5432,
-  db_name: "postgres",
-  db_user: "postgres",
-  db_password: "postgres",
-  db_ssl: true,
-  slot_name: :temporary,
-  configuration_file: nil
+  app_hostname: app_hostname,
+  app_port: app_port,
+  db_host: db_host,
+  db_port: db_port,
+  db_name: db_name,
+  db_user: db_user,
+  db_password: db_password,
+  db_ssl: db_ssl,
+  slot_name: slot_name,
+  configuration_file: configuration_file
 
 # Configures the endpoint
 config :realtime, RealtimeWeb.Endpoint,

server/lib/adapters/postgres/epgsql_implementation.ex

@@ -3,6 +3,7 @@
 
 defmodule Realtime.Adapters.Postgres.EpgsqlImplementation do
   @behaviour Realtime.Adapters.Postgres.AdapterBehaviour
+  require Logger
 
   alias Realtime.Replication.State
 
@@ -58,13 +59,11 @@ defmodule Realtime.Adapters.Postgres.EpgsqlImplementation do
       case slot do
         name when is_binary(name) ->
           # Simple query for replication mode so no prepared statements are supported
-          escaped_name = String.replace(name, "'", "\\'")
+          escaped_name = String.downcase(String.replace(name, "'", "\\'"))
+          query =
+            "SELECT COUNT(*) >= 1 FROM pg_replication_slots WHERE slot_name = '#{escaped_name}'"
 
-          {:ok, _, [{existing_slot}]} =
-            :epgsql.squery(
-              epgsql_pid,
-              "SELECT COUNT(*) >= 1 FROM pg_replication_slots WHERE slot_name = '#{escaped_name}'"
-            )
+          {:ok, _, [{existing_slot}]} = :epgsql.squery(epgsql_pid, query)
 
           case existing_slot do
             "t" ->

server/lib/realtime/application.ex

@@ -10,8 +10,10 @@ defmodule Realtime.Application do
     # Hostname must be a char list for some reason
     # Use this var to convert to sigil at connection
     host = Application.fetch_env!(:realtime, :db_host)
+
     # Use a named replication slot if you want realtime to pickup from where
     # it left after a restart because of, for example, a crash.
+    # This will always be converted to lower-case.
     # You can get a list of active replication slots with
     # `select * from pg_replication_slots`
     slot_name = Application.get_env(:realtime, :slot_name)