server: limit length of event trigger names (close #5786) (#5826)

https://github.com/hasura/graphql-engine/pull/5826

CHANGELOG.md

@@ -58,6 +58,8 @@ This release contains the [PDV refactor (#4111)](https://github.com/hasura/graph
 - server: change `created_at` column type from `timestamp` to `timestamptz` for scheduled triggers tables (fix #5722)
 - server: allow configuring timeouts for actions (fixes #4966)
 - server: accept only non-negative integers for batch size and refetch interval (close #5653) (#5759)
+- server: limit the length of event trigger names (close #5786)
+**NOTE:** If you have event triggers with names greater than 42 chars, then you should update their names to avoid running into Postgres identifier limit bug (#5786)
 - console: allow user to cascade Postgres dependencies when dropping Postgres objects (close #5109) (#5248)
 - console: mark inconsistent remote schemas in the UI (close #5093) (#5181)
 - console: remove ONLY as default for ALTER TABLE in column alter operations (close #5512) #5706

console/src/components/Services/Events/EventTriggers/Add/Add.tsx

@@ -198,6 +198,7 @@ const Add: React.FC<Props> = props => {
               className={`${styles.tableNameInput} form-control`}
               value={name}
               onChange={handleTriggerNameChange}
+              maxLength={42}
             />
             <hr />
             <h4 className={styles.subheading_text}>

console/src/components/Services/Events/EventTriggers/Common/Tooltips.js

@@ -9,7 +9,8 @@ export const manualTriggerInfo = (
 
 export const triggerNameDescription = (
   <Tooltip id="tooltip-trigger-name-description">
-    Trigger name can be alphanumeric and can contain underscores and hyphens
+    Trigger name can be alphanumeric, can contain underscores and hyphens, and
+    must be at most 42 characters.
   </Tooltip>
 );
 

server/src-lib/Hasura/Eventing/ScheduledTrigger.hs

@@ -514,7 +514,7 @@ processScheduledEvent logEnv pgpool se@ScheduledEventFull {..} type' = Tracing.r
         (processSuccess pgpool se decodedHeaders type' webhookReqBodyJson)
         res
   where
-    traceNote = "Scheduled trigger" <> foldMap ((": " <>) . unNonEmptyText . unTriggerName) sefName
+    traceNote = "Scheduled trigger" <> foldMap ((": " <>) . triggerNameToTxt) sefName
 
 processError
   :: (MonadIO m, MonadError QErr m)

server/src-lib/Hasura/RQL/DDL/EventTrigger.hs

@@ -39,6 +39,8 @@ import qualified Text.Shakespeare.Text   as ST
 
 data OpVar = OLD | NEW deriving (Show)
 
+-- pgIdenTrigger is a method used to construct the name of the pg function
+-- used for event triggers which are present in the hdb_views schema.
 pgIdenTrigger:: Ops -> TriggerName -> T.Text
 pgIdenTrigger op trn = pgFmtIden . qualifyTriggerName op $ triggerNameToTxt trn
   where

server/src-lib/Hasura/RQL/Types/EventTrigger.hs

@@ -30,7 +30,7 @@ import           Data.Aeson.TH
 import           Hasura.Incremental         (Cacheable)
 import           Hasura.Prelude
 import           Hasura.RQL.DDL.Headers
-import           Hasura.RQL.Types.Common    (NonEmptyText (..), InputWebhook)
+import           Hasura.RQL.Types.Common    (NonEmptyText(..), InputWebhook)
 import           Hasura.SQL.Types
 import           Language.Haskell.TH.Syntax (Lift)
 
@@ -39,9 +39,17 @@ import qualified Data.Text                  as T
 import qualified Database.PG.Query          as Q
 import qualified Text.Regex.TDFA            as TDFA
 
+-- This change helps us create functions for the event triggers
+-- without the function name being truncated by PG, since PG allows
+-- for only 63 chars for identifiers. 
+-- Reasoning for the 42 characters:
+-- 63 - (notify_hasura_) - (_INSERT | _UPDATE | _DELETE)
+maxTriggerNameLength :: Int
+maxTriggerNameLength = 42
+
 -- | Unique name for event trigger.
 newtype TriggerName = TriggerName { unTriggerName :: NonEmptyText }
-  deriving (Show, Eq, Hashable, Lift, DQuote, FromJSON, ToJSON, ToJSONKey, Q.FromCol, Q.ToPrepArg, Generic, Arbitrary, NFData, Cacheable)
+  deriving (Show, Eq, Hashable, Lift, DQuote, FromJSON, ToJSON, ToJSONKey, Q.ToPrepArg, Generic, NFData, Cacheable, Arbitrary, Q.FromCol)
 
 triggerNameToTxt :: TriggerName -> Text
 triggerNameToTxt = unNonEmptyText . unTriggerName
@@ -116,7 +124,7 @@ instance ToJSON WebhookConf where
 instance FromJSON WebhookConf where
   parseJSON (Object o) = WCEnv <$> o .: "from_env"
   parseJSON t@(String _) =
-    case (fromJSON t) of
+    case fromJSON t of
       Error s   -> fail s
       Success a -> pure $ WCValue a
   parseJSON _          = fail "one of string or object must be provided for webhook"
@@ -146,25 +154,25 @@ data CreateEventTriggerQuery
 
 instance FromJSON CreateEventTriggerQuery where
   parseJSON (Object o) = do
-    name           <- o .: "name"
-    table          <- o .: "table"
-    insert         <- o .:? "insert"
-    update         <- o .:? "update"
-    delete         <- o .:? "delete"
-    enableManual   <- o .:? "enable_manual" .!= False
-    retryConf      <- o .:? "retry_conf"
-    webhook        <- o .:? "webhook"
-    webhookFromEnv <- o .:? "webhook_from_env"
-    headers        <- o .:? "headers"
-    replace        <- o .:? "replace" .!= False
+    name            <- o .:  "name"
+    table           <- o .:  "table"
+    insert          <- o .:? "insert"
+    update          <- o .:? "update"
+    delete          <- o .:? "delete"
+    enableManual    <- o .:? "enable_manual" .!= False
+    retryConf       <- o .:? "retry_conf"
+    webhook         <- o .:? "webhook"
+    webhookFromEnv  <- o .:? "webhook_from_env"
+    headers         <- o .:? "headers"
+    replace         <- o .:? "replace" .!= False
     let regex = "^[A-Za-z]+[A-Za-z0-9_\\-]*$" :: LBS.ByteString
         compiledRegex = TDFA.makeRegex regex :: TDFA.Regex
         isMatch = TDFA.match compiledRegex . T.unpack $ triggerNameToTxt name
-    if isMatch then return ()
-      else fail "only alphanumeric and underscore and hyphens allowed for name"
-    if any isJust [insert, update, delete] || enableManual then
-      return ()
-      else
+    unless isMatch $
+      fail "only alphanumeric and underscore and hyphens allowed for name"
+    unless (T.length (triggerNameToTxt name) <= maxTriggerNameLength) $
+      fail "event trigger name can be at most 42 characters"
+    unless (any isJust [insert, update, delete] || enableManual) $
       fail "atleast one amongst insert/update/delete/enable_manual spec must be provided"
     case (webhook, webhookFromEnv) of
       (Just _, Nothing) -> return ()
@@ -195,10 +203,8 @@ instance NFData TriggerOpsDef
 instance Cacheable TriggerOpsDef
 $(deriveJSON (aesonDrop 2 snakeCase){omitNothingFields=True} ''TriggerOpsDef)
 
-data DeleteEventTriggerQuery
-  = DeleteEventTriggerQuery
-  { detqName :: !TriggerName
-  } deriving (Show, Eq, Lift)
+newtype DeleteEventTriggerQuery = DeleteEventTriggerQuery { detqName :: TriggerName }
+  deriving (Show, Eq, Lift)
 
 $(deriveJSON (aesonDrop 4 snakeCase){omitNothingFields=True} ''DeleteEventTriggerQuery)
 

server/src-lib/Hasura/Server/API/PGDump.hs

@@ -65,7 +65,7 @@ execPGDump b ci = do
         -- delete front matter
         || line `elem` preambleLines
         -- delete notify triggers
-        || notifyTriggerRegex `TDFA.match` line
+        || eventTriggerRegex `TDFA.match` line
 
     preambleLines =
       [ "SET statement_timeout = 0;"
@@ -85,8 +85,10 @@ execPGDump b ci = do
       , "COMMENT ON SCHEMA public IS 'standard public schema';"
       ]
 
-    notifyTriggerRegex =
+    eventTriggerRegex =
       let regexStr :: String =
+        -- pg functions created by hasura for event triggers used "notify_hasura"
+        -- These changes are also documented on the method pgIdenTrigger
             "^CREATE TRIGGER \"?notify_hasura_.+\"? AFTER [[:alnum:]]+ "
               <> "ON .+ FOR EACH ROW EXECUTE (FUNCTION|PROCEDURE) "
               <> "\"?hdb_views\"?\\.\"?notify_hasura_.+\"?\\(\\);$"