func main() {
var (
conf client.Configuration
cli client.Client
err error
op mig.Operation
a mig.Action
migrc, show, render, target, expiration, afile string
verbose bool
modargs []string
run interface{}
)
defer func() {
if e := recover(); e != nil {
fmt.Fprintf(os.Stderr, "%v\n", e)
}
}()
homedir := client.FindHomedir()
fs := flag.NewFlagSet("mig flag", flag.ContinueOnError)
fs.Usage = continueOnFlagError
fs.StringVar(&migrc, "c", homedir+"/.migrc", "alternative configuration file")
fs.StringVar(&show, "show", "found", "type of results to show")
fs.StringVar(&render, "render", "text", "results rendering mode")
fs.StringVar(&target, "t", fmt.Sprintf("status='%s' AND mode='daemon'", mig.AgtStatusOnline), "action target")
fs.StringVar(&expiration, "e", "300s", "expiration")
fs.StringVar(&afile, "i", "/path/to/file", "Load action from file")
fs.BoolVar(&verbose, "v", false, "Enable verbose output")
// if first argument is missing, or is help, print help
// otherwise, pass the remainder of the arguments to the module for parsing
// this client is agnostic to module parameters
if len(os.Args) < 2 || os.Args[1] == "help" || os.Args[1] == "-h" || os.Args[1] == "--help" {
usage()
}
if len(os.Args) < 2 || os.Args[1] == "-V" {
fmt.Println(version)
os.Exit(0)
}
// when reading the action from a file, go directly to launch
if os.Args[1] == "-i" {
err = fs.Parse(os.Args[1:])
if err != nil {
panic(err)
}
if afile == "/path/to/file" {
panic("-i flag must take an action file path as argument")
}
a, err = mig.ActionFromFile(afile)
if err != nil {
panic(err)
}
fmt.Fprintf(os.Stderr, "[info] launching action from file, all flags are ignored\n")
goto readytolaunch
}
// arguments parsing works as follow:
// * os.Args[1] must contain the name of the module to launch. we first verify
// that a module exist for this name and then continue parsing
// * os.Args[2:] contains both global options and module parameters. We parse the
// whole []string to extract global options, and module parameters will be left
// unparsed in fs.Args()
// * fs.Args() with the module parameters is passed as a string to the module parser
// which will return a module operation to store in the action
op.Module = os.Args[1]
if _, ok := modules.Available[op.Module]; !ok {
panic("Unknown module " + op.Module)
}
// -- Ugly hack Warning --
// Parse() will fail on the first flag that is not defined, but in our case module flags
// are defined in the module packages and not in this program. Therefore, the flag parse error
// is expected. Unfortunately, Parse() writes directly to stderr and displays the error to
// the user, which confuses them. The right fix would be to prevent Parse() from writing to
// stderr, since that's really the job of the calling program, but in the meantime we work around
// it by redirecting stderr to null before calling Parse(), and put it back to normal afterward.
// for ref, issue is at https://github.com/golang/go/blob/master/src/flag/flag.go#L793
fs.SetOutput(os.NewFile(uintptr(87592), os.DevNull))
err = fs.Parse(os.Args[2:])
fs.SetOutput(nil)
if err != nil {
// ignore the flag not defined error, which is expected because
// module parameters are defined in modules and not in main
if len(err.Error()) > 30 && err.Error()[0:29] == "flag provided but not defined" {
// requeue the parameter that failed
modargs = append(modargs, err.Error()[31:])
} else {
// if it's another error, panic
panic(err)
}
}
for _, arg := range fs.Args() {
modargs = append(modargs, arg)
}
run = modules.Available[op.Module].NewRun()
if _, ok := run.(modules.HasParamsParser); !ok {
fmt.Fprintf(os.Stderr, "[error] module '%s' does not support command line invocation\n", op.Module)
os.Exit(2)
}
op.Parameters, err = run.(modules.HasParamsParser).ParamsParser(modargs)
if err != nil || op.Parameters == nil {
panic(err)
}
// If running against the local target, don't post the action to the MIG API
// but run it locally instead.
if target == "local" {
msg, err := modules.MakeMessage(modules.MsgClassParameters, op.Parameters)
if err != nil {
panic(err)
}
out := run.(modules.Runner).Run(bytes.NewBuffer(msg))
if len(out) == 0 {
panic("got empty results, run failed")
}
if _, ok := run.(modules.HasResultsPrinter); ok {
var modres modules.Result
err := json.Unmarshal([]byte(out), &modres)
if err != nil {
panic(err)
}
outRes, err := run.(modules.HasResultsPrinter).PrintResults(modres, true)
if err != nil {
panic(err)
}
for _, resLine := range outRes {
fmt.Println(resLine)
}
} else {
out = fmt.Sprintf("%s\n", out)
}
os.Exit(0)
}
a.Operations = append(a.Operations, op)
for _, arg := range os.Args[1:] {
a.Name += arg + " "
}
a.Target = target
readytolaunch:
// instanciate an API client
conf, err = client.ReadConfiguration(migrc)
if err != nil {
panic(err)
}
cli, err = client.NewClient(conf, "cmd-"+version)
if err != nil {
panic(err)
}
if verbose {
cli.EnableDebug()
}
// set the validity 60 second in the past to deal with clock skew
a.ValidFrom = time.Now().Add(-60 * time.Second).UTC()
period, err := time.ParseDuration(expiration)
if err != nil {
panic(err)
}
a.ExpireAfter = a.ValidFrom.Add(period)
// add extra 60 seconds taken for clock skew
a.ExpireAfter = a.ExpireAfter.Add(60 * time.Second).UTC()
asig, err := cli.SignAction(a)
if err != nil {
panic(err)
}
a = asig
// evaluate target before launch, give a change to cancel before going out to agents
agents, err := cli.EvaluateAgentTarget(a.Target)
if err != nil {
panic(err)
}
fmt.Fprintf(os.Stderr, "\x1b[33m%d agents will be targeted. ctrl+c to cancel. launching in \x1b[0m", len(agents))
for i := 5; i > 0; i-- {
time.Sleep(1 * time.Second)
fmt.Fprintf(os.Stderr, "\x1b[33m%d\x1b[0m ", i)
}
fmt.Fprintf(os.Stderr, "\x1b[33mGO\n\x1b[0m")
// launch and follow
a, err = cli.PostAction(a)
if err != nil {
panic(err)
}
c := make(chan os.Signal, 1)
done := make(chan bool, 1)
signal.Notify(c, os.Interrupt)
go func() {
err = cli.FollowAction(a)
if err != nil {
panic(err)
}
done <- true
}()
select {
case <-c:
fmt.Fprintf(os.Stderr, "stop following action. agents may still be running. printing available results:\n")
goto printresults
case <-done:
goto printresults
}
printresults:
err = cli.PrintActionResults(a, show, render)
if err != nil {
panic(err)
}
}