// Performs heuristics to determine the hostname of the current host.
// Tries os.Hostname(), and if that isn't fully qualified (contains a '.'),
// Fails over to finding the first hostname for the first IP of the host
// that contains a '.'. If none do, fails back to the unqualified hostname.
func hostname() string {
h, err := os_hostname()
if err != nil {
log.Error("Couldn't get hostname for current host: %s", err.Error())
return "unknown"
}
if strings.ContainsRune(h, '.') {
return h
}
addrs, err := net_lookuphost(h)
if err != nil {
log.Warn("Couldn't resolve FQDN of host: %s", err.Error())
return h
}
if len(addrs) > 0 {
names, err := net_lookupaddr(addrs[0])
if err != nil {
log.Warn("Couldn't resolve FQDN of host: %s", err.Error())
return h
}
for _, name := range names {
if strings.ContainsRune(name, '.') {
return name
}
}
}
log.Warn("No FQDN resolvable, defaulting to unqualified hostname")
return h
}
// Called on running checks, to determine if they have finished
// running.
//
// If the Check has not finished executing, returns false.
//
// If the Check has been running for longer than its Timeout,
// a SIGTERM (and failing that a SIGKILL) is issued to forcibly
// terminate the rogue Check process. In either case, this returns
// as if the check has not yet finished, and Reap() will need to be
// called again to fully reap the Check
//
// If the Check has finished execution (on its own, or via forced
// termination), it will return true.
//
// Once complete, some additional meta-stats for the check execution
// are appended to the check output, to be submit up to bolo
func (self *Check) Reap() bool {
pid := self.process.Process.Pid
var ws syscall.WaitStatus
status, err := syscall.Wait4(pid, &ws, syscall.WNOHANG, nil)
if err != nil {
log.Error("Error waiting on check %s[%d]: %s", self.Name, pid, err.Error())
return false
}
if status == 0 {
// self to see if we need to sigkill due to failed sigterm
if time.Now().After(self.started_at.Add(time.Duration(self.Timeout+2) * time.Second)) {
log.Warn("Check %s[%d] has been running too long, sending SIGKILL", self.Name, pid)
if err := syscall.Kill(pid, syscall.SIGKILL); err != nil {
log.Error("Error sending SIGKILL to check %s[%d]: %s", self.Name, pid, err.Error())
}
self.sig_kill = true
}
// self to see if we need to sigterm due to self timeout expiry
if !self.sig_kill && time.Now().After(self.started_at.Add(time.Duration(self.Timeout)*time.Second)) {
log.Warn("Check %s[%d] has been running too long, sending SIGTERM", self.Name, pid)
if err := syscall.Kill(pid, syscall.SIGTERM); err != nil {
log.Error("Error sending SIGTERM to check %s[%d]: %s", self.Name, pid, err.Error())
}
self.sig_term = true
}
return false
}
self.ended_at = time.Now()
self.running = false
self.duration = time.Since(self.started_at)
self.latency = self.started_at.Sub(self.next_run)
self.output = string(self.stdout.Bytes())
self.err_msg = string(self.stderr.Bytes())
if ws.Exited() {
self.rc = ws.ExitStatus()
} else {
log.Debug("Check %s[%d] exited abnormally (signaled/stopped). Setting rc to UNKNOWN", self.Name, pid)
self.rc = UNKNOWN
}
if self.rc > UNKNOWN {
log.Debug("Check %s[%d] returned with an invalid exit code. Setting rc to UNKOWN", self.Name, pid)
self.rc = UNKNOWN
}
self.reschedule()
if self.ended_at.After(self.next_run) {
timeout_triggered := "not reached"
if self.sig_term || self.sig_kill {
timeout_triggered = "reached"
}
log.Warn("Check %s[%d] took %0.3f seconds to run, at interval %d (timeout of %d was %s)",
self.Name, pid, self.duration.Seconds(), self.Every, self.Timeout, timeout_triggered)
}
return true
}
// Disconnects from bolo (terminates the send_bolo process)
// If send_bolo is no longer running, does nothing.
func DisconnectFromBolo() {
if send2bolo == nil {
log.Warn("Bolo disconnect requested, but send_bolo is not running")
return
}
pid := send2bolo.Process.Pid
if err := syscall.Kill(pid, syscall.SIGTERM); err != nil {
log.Debug("send_bolo[%d] already terminated", pid)
}
send2bolo = nil
}
// Loads a YAML config file specified by cfg_file, and returns
// a Config object representing that config. Config reloads are
// auto-detected and handled seemlessly.
func LoadConfig(cfg_file string) (*Config, error) {
new_cfg := default_config()
source, err := ioutil.ReadFile(cfg_file)
if err != nil {
return cfg, err
}
err = goyaml.Unmarshal(source, &new_cfg)
if err != nil {
return cfg, err
}
if new_cfg.Include_dir != "" {
log.Debug("Loading auxillary configs from %s", new_cfg.Include_dir)
files, err := filepath.Glob(new_cfg.Include_dir + "/*.conf")
if err != nil {
log.Warn("Couldn't find include files: %s", err.Error())
} else {
for _, file := range files {
log.Debug("Loading auxillary config: %s", file)
source, err := ioutil.ReadFile(file)
if err != nil {
log.Warn("Couldn't read %q: %s", file, err.Error())
continue
}
checks := map[string]*Check{}
err = goyaml.Unmarshal(source, &checks)
if err != nil {
log.Warn("Could not parse yaml from %q: %s", file, err.Error())
continue
}
for name, check := range checks {
if _, exists := new_cfg.Checks[name]; exists {
log.Warn("Check %q defined in multiple config files, ignoring definition in %s", name, file)
continue
}
new_cfg.Checks[name] = check
}
}
}
}
for name, check := range new_cfg.Checks {
if err := initialize_check(name, check, new_cfg); err != nil {
log.Error("Invalid check config for %s: %s (skipping)", name, err.Error())
delete(new_cfg.Checks, name)
continue
}
if cfg != nil {
if val, ok := cfg.Checks[check.Name]; ok {
merge_checks(check, val)
}
}
log.Debug("Check %s defined as %#v", check.Name, check)
}
cfg = new_cfg
log.SetupLogging(cfg.Log)
log.Debug("Config successfully loaded as: %#v", cfg)
return cfg, nil
}