open-consul/command/monitor/monitor.go
Frank Schroeder efab66e616 commands: cleanup help and synopsis.
* move Help and Synopsis to bottom
* make help and synopsis constants
* make sure help output is formatted
2017-10-18 00:08:45 +02:00

116 lines
2.3 KiB
Go

package monitor
import (
"flag"
"fmt"
"sync"
"github.com/hashicorp/consul/command/flags"
"github.com/mitchellh/cli"
)
// cmd is a Command implementation that queries a running
// Consul agent what members are part of the cluster currently.
type cmd struct {
UI cli.Ui
help string
flags *flag.FlagSet
http *flags.HTTPFlags
shutdownCh <-chan struct{}
lock sync.Mutex
quitting bool
// flags
logLevel string
}
func New(ui cli.Ui, shutdownCh <-chan struct{}) *cmd {
c := &cmd{UI: ui, shutdownCh: shutdownCh}
c.init()
return c
}
func (c *cmd) init() {
c.flags = flag.NewFlagSet("", flag.ContinueOnError)
c.http = &flags.HTTPFlags{}
flags.Merge(c.flags, c.http.ClientFlags())
c.flags.StringVar(&c.logLevel, "log-level", "INFO",
"Log level of the agent.")
c.help = flags.Usage(help, c.flags, c.http.ClientFlags(), nil)
}
func (c *cmd) Run(args []string) int {
if err := c.flags.Parse(args); err != nil {
return 1
}
client, err := c.http.APIClient()
if err != nil {
c.UI.Error(fmt.Sprintf("Error connecting to Consul agent: %s", err))
return 1
}
eventDoneCh := make(chan struct{})
logCh, err := client.Agent().Monitor(c.logLevel, eventDoneCh, nil)
if err != nil {
c.UI.Error(fmt.Sprintf("Error starting monitor: %s", err))
return 1
}
go func() {
defer close(eventDoneCh)
OUTER:
for {
select {
case log := <-logCh:
if log == "" {
break OUTER
}
c.UI.Info(log)
}
}
c.lock.Lock()
defer c.lock.Unlock()
if !c.quitting {
c.UI.Info("")
c.UI.Output("Remote side ended the monitor! This usually means that the\n" +
"remote side has exited or crashed.")
}
}()
select {
case <-eventDoneCh:
return 1
case <-c.shutdownCh:
c.lock.Lock()
c.quitting = true
c.lock.Unlock()
}
return 0
}
func (c *cmd) Synopsis() string {
return synopsis
}
func (c *cmd) Help() string {
return c.help
}
const synopsis = "Stream logs from a Consul agent"
const help = `
Usage: consul monitor [options]
Shows recent log messages of a Consul agent, and attaches to the agent,
outputting log messages as they occur in real time. The monitor lets you
listen for log levels that may be filtered out of the Consul agent. For
example your agent may only be logging at INFO level, but with the monitor
you can see the DEBUG level logs.
`