From 4e65a41bea4b892ef7232bfe6b9b20ca35380368 Mon Sep 17 00:00:00 2001
From: Tom Clegg <tom@curii.com>
Date: Sun, 13 Jun 2021 10:00:45 -0400
Subject: [PATCH] 17803: Warn when config keys are ignored due to case
 mismatch.

Arvados-DCO-1.1-Signed-off-by: Tom Clegg <tom@curii.com>
---
 lib/config/load.go      | 16 ++++++++++------
 lib/config/load_test.go | 12 +++++++-----
 2 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/lib/config/load.go b/lib/config/load.go
index cc26cdaecc..73f0a24457 100644
--- a/lib/config/load.go
+++ b/lib/config/load.go
@@ -354,20 +354,24 @@ func (ldr *Loader) logExtraKeys(expected, supplied map[string]interface{}, prefi
 	if ldr.Logger == nil {
 		return
 	}
-	allowed := map[string]interface{}{}
-	for k, v := range expected {
-		allowed[strings.ToLower(k)] = v
-	}
 	for k, vsupp := range supplied {
 		if k == "SAMPLE" {
 			// entry will be dropped in removeSampleKeys anyway
 			continue
 		}
-		vexp, ok := allowed[strings.ToLower(k)]
+		vexp, ok := expected[k]
 		if expected["SAMPLE"] != nil {
 			vexp = expected["SAMPLE"]
 		} else if !ok {
-			ldr.Logger.Warnf("deprecated or unknown config entry: %s%s", prefix, k)
+			// check for a case-insensitive match
+			hint := ""
+			for ek := range expected {
+				if strings.EqualFold(k, ek) {
+					hint = " (perhaps you meant " + ek + "?)"
+					break
+				}
+			}
+			ldr.Logger.Warnf("deprecated or unknown config entry: %s%s%s", prefix, k, hint)
 			continue
 		}
 		if vsupp, ok := vsupp.(map[string]interface{}); !ok {
diff --git a/lib/config/load_test.go b/lib/config/load_test.go
index 6c11ee7803..9d3258c195 100644
--- a/lib/config/load_test.go
+++ b/lib/config/load_test.go
@@ -196,9 +196,10 @@ Clusters:
     SystemRootToken: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
     Collections:
      BlobSigningKey: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
-    postgresql: {}
+    PostgreSQL: {}
     BadKey: {}
-    Containers: {}
+    Containers:
+      RunTimeEngine: abc
     RemoteClusters:
       z2222:
         Host: z2222.arvadosapi.com
@@ -206,11 +207,12 @@ Clusters:
         BadKey: badValue
 `, &logbuf).Load()
 	c.Assert(err, check.IsNil)
+	c.Log(logbuf.String())
 	logs := strings.Split(strings.TrimSuffix(logbuf.String(), "\n"), "\n")
 	for _, log := range logs {
-		c.Check(log, check.Matches, `.*deprecated or unknown config entry:.*BadKey.*`)
+		c.Check(log, check.Matches, `.*deprecated or unknown config entry:.*(RunTimeEngine.*RuntimeEngine|BadKey).*`)
 	}
-	c.Check(logs, check.HasLen, 2)
+	c.Check(logs, check.HasLen, 3)
 }
 
 func (s *LoadSuite) checkSAMPLEKeys(c *check.C, path string, x interface{}) {
@@ -322,7 +324,7 @@ func (s *LoadSuite) TestPostgreSQLKeyConflict(c *check.C) {
 	_, err := testLoader(c, `
 Clusters:
  zzzzz:
-  postgresql:
+  PostgreSQL:
    connection:
      DBName: dbname
      Host: host
-- 
2.30.2