watch.go

package main

import (
  "fmt"
  "strings"

  "github.com/dynport/gocloud/aws/cloudformation"
  "github.com/vito/cloudformer/aws/deployer"
  "github.com/hotei/ansiterm"
  "github.com/mgutz/ansi"
)

func watch(name string) {
  deployer := deployer.New(cloudformation.NewFromEnv())

  events := make(chan *cloudformation.StackEvent)

  go deployer.Watch(events, name)

  ok := streamEvents(events)
  if !ok {
    fmt.Println()
    fatal(ansi.Color("formation failed and was rolled back", "yellow"))
  }
}

func streamEvents(events <-chan *cloudformation.StackEvent) bool {
  ok := true

  inFlight := make(map[string]Process)

  printedLines := 0

  for ev := range events {
    status := ev.ResourceStatus

    for i := 0; i < printedLines; i++ {
      fmt.Print("\x1b[1A")
      ansiterm.ClearLine()
    }

    process, progress := parseStatus(status)

    if progress == PendingProgress {
      inFlight[ev.LogicalResourceId] = process
    } else {
      delete(inFlight, ev.LogicalResourceId)

      label := process.CompletedLabel()

      if progress == FailedProgress {
        ok = false
        fmt.Printf(ansi.Color("%s: %s (%s)\n", "red"), label, ev.LogicalResourceId, ev.ResourceStatusReason)
      } else {
        fmt.Printf(ansi.Color("%s: %s (%s)\n", "green"), label, ev.LogicalResourceId, ev.PhysicalResourceId)
      }
    }

    printedLines = renderInFlight(inFlight)
  }

  return ok
}

func renderInFlight(inFlight map[string]Process) int {
  byProcess := make(map[Process][]string)

  for id, process := range inFlight {
    byProcess[process] = append(byProcess[process], id)
  }

  printedLines := 0

  for process, ids := range byProcess {
    prefix := process.ActiveLabel() + ": "

    for i, id := range ids {
      if i == 0 {
        fmt.Print(prefix)
      } else {
        fmt.Print(strings.Repeat(" ", len(prefix)))
      }

      fmt.Println(id)

      printedLines++
    }
  }

  return printedLines
}

func parseStatus(status string) (Process, Progress) {
  var process Process
  var progress Progress

  if strings.Contains(status, "ROLLBACK") {
    process = RollbackProcess
  } else if strings.Contains(status, "UPDATE") {
    process = UpdateProcess
  } else if strings.Contains(status, "DELETE") {
    process = DeleteProcess
  } else if strings.Contains(status, "CREATE") {
    process = CreateProcess
  }

  if strings.HasSuffix(status, "FAILED") {
    progress = FailedProgress
  } else if strings.HasSuffix(status, "COMPLETED") {
    progress = CompletedProgress
  } else if strings.HasSuffix(status, "IN_PROGRESS") {
    progress = PendingProgress
  }

  return process, progress
}