getstatus.go

package main

import (
	"fmt"
	"io/ioutil"
	"net/http"
	"strings"
)

const (
	OK  = 0
	ERR = 1
)

type Status struct {
	code int
	msg  string
}

type Scan struct {
	url    string
	body   string
	err    error
	status *Status
}

func NewScanSuccess(url string, body string) *Scan {
	return &Scan{url, body, nil, &Status{OK, "O.K."}}
}
func NewScanError(url string, err error) *Scan {
	return &Scan{url, "", err, &Status{ERR, "ERROR!"}}
}

// Convert list of URL(s) into a Buffered Channel that emit Scan struct
func getStatus(urls []string) <-chan Scan {
	out := make(chan Scan, len(urls))
	go func() {
		for _, url := range urls {
			// DO HTTP GET
			resp, err := http.Get(url)
			if err != nil {
				out <- *NewScanError(url, err)
			} else {
				// PROCESS RESPONSE
				defer resp.Body.Close()
				body, err := ioutil.ReadAll(resp.Body)
				if err != nil {
					out <- *NewScanError(url, err)
				} else {
					// HTTP GET RESPONSE HAS A BODY!
					// ENQUEUE BODY AS STRING IN OUT CHAN
					out <- *NewScanSuccess(url, string(body))
				}
			}
		}
		close(out)
	}()
	return out
}

func processStatus(in <-chan Scan) <-chan Scan {
	out := make(chan Scan)

	go func() {
		for scan := range in {
			scan.status = evalStatus(scan.body)
			out <- scan
		}
		close(out)
	}()
	return out
}

func evalStatus(body string) *Status {
	status := &Status{OK, "Status O.K."}
	lines := strings.Split(body, "\n")

	for _, line := range lines {
		minus := strings.Index(line, "-")
		if minus >= 0 {
			colon := strings.Index(line, ":")
			if colon >= 0 {
				attr := strings.Split(line[minus:colon], " ")[1]
				value := strings.Split(line[colon:], " ")[1]
				// fmt.Printf("ATTR NAME: %s VALUE VALUE: %s\n", attr, value)
				// PROCESS "VALID" ATTR/VALUE PAIR
				if value != "true" {
					status = &Status{ERR, "Attr: " + attr + " is false!"}
					break // ERR! SKIP REMAINING LINE(s).
				} else {
					// fmt.Printf("Status ATTR: %s is O.K.", attr)
				}
			}
		}
		// fmt.Printf("LINE: %s\n", line)
	}
	return status
}

func main() {
	urls := []string{

		"https://gist.githubusercontent.com/sineer/3effbc864988af67c181/raw/2d9ecb3c16fa63d52252e30c8b02c647d87d63df/test_valid.yml",
		"https://gist.githubusercontent.com/sineer/ebb12db17abfbf6288c4/raw/d34e707bd045fb3495fdb9d4c6b8da59980d13e6/test.yml",
	}
	scan := make(map[string]Scan, len(urls))

	// Setup Pipeline to launch Concurrent Scan(s):
	for res := range processStatus(getStatus(urls)) {
		if res.url == "" {
			fmt.Println("ERROR: Invalid Response!")
		} else {
			scan[res.url] = res
			if res.err != nil {
				// HTTP GET ERROR!
				fmt.Printf("SCAN[%s] ERROR: %s\n", res.url, scan[res.url].err)
			} else if res.status == nil {
				// NIL status error!
				fmt.Printf("NIL STATUS ERR! url: %s\n", res.url)
			} else if res.status.code != 0 {
				// STATUS ERROR!
				fmt.Printf("SCAN[%s] STATUS ERROR: %s\n", res.url, scan[res.url].status.msg)
			} else {
				// fmt.Prinltf("SCAN[%s] BODY: %s\n", url, scan[url].body)
				fmt.Printf("SCAN[%s] SUCCESS! STATUS: %s\n", res.url, scan[res.url].status.msg)
			}
		}
	}
}