Rename few ENV vars and add CHECK_DONORS_ENABLED option and donor check

README.md

@@ -43,11 +43,11 @@ You can override any of the following values in configuration file:
 - `WEB_READ_TIMEOUT`: Web server request read timeout in milliseconds. Default: `30000`
 - `WEB_WRITE_TIMEOUT`: Web server request write timeout in milliseconds. Default: `30000`
 - `CHECK_RO_ENABLED`: Mark 'read_only' node as available. Default: `false`
-- `CHECK_FORCE_ENABLE`: Ignoring the status of the checks and always marking the node as available. Default: `false`
+- `CHECK_FORCE_ENABLED`: Ignoring the status of the checks and always marking the node as available. Default: `false`
+- `CHECK_DONORS_ENABLED`: Mark donors nodes as available. By default donor nodes marking as failed. Default: `false`
 - `CHECK_INTERVAL`: Mysql checks interval in milliseconds. Default: `500`
 - `CHECK_FAIL_TIMEOUT`: Mark the node inaccessible if for the specified time (in milliseconds) there were no successful checks. Default: `3000`
 - `MYSQL_HOST`: MySQL host address. Default: `127.0.0.1`
 - `MYSQL_PORT`: MySQL port. Default: `3306`
 - `MYSQL_USER`: MySQL username. Default: `pxc_checker`
 - `MYSQL_PASS`: Mysql password. Default: no password
-

checker.go

@@ -22,6 +22,7 @@ const (
 	reasonCheckTimeout      ReasonCode = 4
 	reasonRWDisabled        ReasonCode = 5
 	reasonNonPrimaryCluster ReasonCode = 6
+	reasonDonorsDisabled    ReasonCode = 7
 )
 
 type Response struct {
@@ -34,7 +35,7 @@ func checkerHandler(ctx *fasthttp.RequestCtx) {
 	response := Response{NodeStatus: status}
 	ctx.SetContentType("application/json")
 
-	if config.CheckForceEnable {
+	if config.CheckForceEnabled {
 		ctx.SetStatusCode(fasthttp.StatusOK)
 		response.ReasonText = "Force enabled"
 		response.ReasonCode = reasonForceEnabled
@@ -46,6 +47,10 @@ func checkerHandler(ctx *fasthttp.RequestCtx) {
 		ctx.SetStatusCode(fasthttp.StatusServiceUnavailable)
 		response.ReasonText = "Node in non-Primary cluster"
 		response.ReasonCode = reasonNonPrimaryCluster
+	} else if (status.WSRepStatus == 2) && !config.CheckDonorsEnabled {
+		ctx.SetStatusCode(fasthttp.StatusServiceUnavailable)
+		response.ReasonText = "Node currently is donor"
+		response.ReasonCode = reasonDonorsDisabled
 	} else if (status.WSRepStatus != 4) && (status.WSRepStatus != 2) {
 		ctx.SetStatusCode(fasthttp.StatusServiceUnavailable)
 		response.ReasonText = "WSRep failed"

config/example.conf

@@ -6,6 +6,6 @@ MYSQL_USER="monitor"
 MYSQL_PASS="monitorUserPassword"
 
 CHECK_RO_ENABLED=false
-CHECK_FORCE_ENABLE=false
+CHECK_FORCE_ENABLED=false
 CHECK_INTERVAL=500 # ms
 CHECK_FAIL_TIMEOUT=3000 # ms

main.go

@@ -19,17 +19,18 @@ type NodeStatus struct {
 }
 
 type Config struct {
-	WebListen        string
-	WebReadTimeout   int
-	WebWriteTimeout  int
-	CheckROEnabled   bool
-	CheckInterval    int64
-	CheckFailTimeout int64
-	CheckForceEnable bool
-	MysqlHost        string
-	MysqlPort        int
-	MysqlUser        string
-	MysqlPass        string
+	WebListen          string
+	WebReadTimeout     int
+	WebWriteTimeout    int
+	CheckROEnabled     bool
+	CheckForceEnabled  bool
+	CheckDonorsEnabled bool
+	CheckInterval      int64
+	CheckFailTimeout   int64
+	MysqlHost          string
+	MysqlPort          int
+	MysqlUser          string
+	MysqlPass          string
 }
 
 var (
@@ -75,7 +76,8 @@ func parseFlags() *Config {
 	flag.IntVar(&config.WebReadTimeout, "WEB_READ_TIMEOUT", 30000, "Web server request read timeout, ms")
 	flag.IntVar(&config.WebWriteTimeout, "WEB_WRITE_TIMEOUT", 30000, "Web server request write timeout, ms")
 	flag.BoolVar(&config.CheckROEnabled, "CHECK_RO_ENABLED", false, "Mark 'read_only' node as available")
-	flag.BoolVar(&config.CheckForceEnable, "CHECK_FORCE_ENABLE", false, "Ignoring the status of the checks and always marking the node as available")
+	flag.BoolVar(&config.CheckForceEnabled, "CHECK_FORCE_ENABLED", false, "Ignoring the status of the checks and always marking the node as available")
+	flag.BoolVar(&config.CheckDonorsEnabled, "CHECK_DONORS_ENABLED", false, "Mark donors nodes as available.")
 	flag.Int64Var(&config.CheckInterval, "CHECK_INTERVAL", 500, "Mysql checks interval, ms")
 	flag.Int64Var(&config.CheckFailTimeout, "CHECK_FAIL_TIMEOUT", 3000, "Mark the node inaccessible if for the specified time there were no successful checks, ms")
 	flag.StringVar(&config.MysqlHost, "MYSQL_HOST", "127.0.0.1", "MySQL host addr")