forked from crahles/galera_watchdog
/
watchdog.go
76 lines (64 loc) · 1.7 KB
/
watchdog.go
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package main
import (
"database/sql"
"flag"
"fmt"
"log"
"net/http"
_ "github.com/go-sql-driver/mysql"
"github.com/vharitonsky/iniflags"
)
var (
DB *sql.DB
err error
httpHost = flag.String("HTTP_HOST", "localhost", "Connect to host")
httpPort = flag.String("HTTP_PORT", "9199", "Connect to host")
sqlHost = flag.String("MYSQL_HOST", "localhost", "Connect to host")
sqlPort = flag.String("MYSQL_PORT", "3306", "Connect to host")
sqlUser = flag.String("MYSQL_USER", "root", "User for login to MySQL")
sqlPass = flag.String("MYSQL_PASS", "", "Password for login to MySQL")
donorOk = flag.Bool("DONOR_OK", false, "treat donor as regular working node")
showVersion = flag.Bool("version", false, fmt.Sprint("Show current version: ", Commit))
Commit = "dev"
)
func main() {
iniflags.Parse()
if *showVersion {
fmt.Println(Commit)
return
}
DB, err = sql.Open(
"mysql",
fmt.Sprintf("%s:%s@tcp(%s:%s)/mysql", *sqlUser, *sqlPass, *sqlHost, *sqlPort),
)
if err != nil {
log.Fatal(err)
}
http.HandleFunc("/", statusHandler)
http.ListenAndServe(*httpHost+":"+*httpPort, nil)
}
func statusHandler(w http.ResponseWriter, r *http.Request) {
err = DB.Ping()
if err != nil {
http.Error(w, "Galera Node is *down*. ("+err.Error()+")", 503)
return
}
var key string
var value int64
err = DB.QueryRow("SHOW STATUS LIKE 'wsrep_local_state'").Scan(&key, &value)
if err != nil {
http.Error(w, "Galera Node is *down*. ("+err.Error()+")", 503)
return
}
switch {
case 4 == value:
fmt.Fprintf(w, "Galera Node is running.")
return
case 2 == value && *donorOk:
fmt.Fprintf(w, "Galera Node is running.")
return
default:
http.Error(w, "Galera Node is *down*. (State Mismatch)", 503)
return
}
}