feat(conf): print log when overriding configuration with env

Signed-off-by: Jiyong Huang <huangjy@emqx.io>

go.sum

@@ -93,8 +93,6 @@ github.com/golang/protobuf v1.5.2 h1:ROPKBNFfQgOUMifHyP+KYbvpjbdoFNs+aK7DXlji0Tw
 github.com/golang/protobuf v1.5.2 h1:ROPKBNFfQgOUMifHyP+KYbvpjbdoFNs+aK7DXlji0Tw=
 github.com/golang/protobuf v1.5.2/go.mod h1:XVQd3VNwM+JqD3oG2Ue2ip4fOMUkwXdXDdiuN0vRsmY=
 github.com/golang/protobuf v1.5.2/go.mod h1:XVQd3VNwM+JqD3oG2Ue2ip4fOMUkwXdXDdiuN0vRsmY=
-github.com/gomodule/redigo v1.8.5 h1:nRAxCa+SVsyjSBrtZmG/cqb6VbTmuRzpg/PoTFlpumc=
-github.com/gomodule/redigo v1.8.5/go.mod h1:P9dn9mFrCBvWhGE1wpxx6fgq7BAeLBk+UUUzlpkBYO0=
 github.com/gomodule/redigo v2.0.0+incompatible h1:K/R+8tc58AaqLkqG2Ol3Qk+DR/TlNuhuh457pBFPtt0=
 github.com/gomodule/redigo v2.0.0+incompatible/go.mod h1:B4C85qUVwatsJoIUNIfCRsp7qO0iAmpGFZ4EELWSbC4=
 github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=

internal/conf/load.go

@@ -80,6 +80,12 @@ func process(configMap map[string]interface{}, variables []string) error {
 		}
 		keys := nameToKeys(trimPrefix(pair[0]))
 		handle(configMap, keys, pair[1])
+		printableK := strings.Join(keys, ".")
+		printableV := pair[1]
+		if strings.Contains(strings.ToLower(printableK), "password") {
+			printableV = "*"
+		}
+		Log.Infof("Set config '%s.%s' to '%s' by environment variable", Prefix, printableK, printableV)
 	}
 	return nil
 }