github.com/cloud-foundations/dominator@v0.0.0-20221004181915-6e4fee580046/lib/url/urlutil/watchUrl.go (about)

     1  package urlutil
     2  
     3  import (
     4  	"errors"
     5  	"io"
     6  	"net/http"
     7  	"net/url"
     8  	"time"
     9  
    10  	"github.com/Cloud-Foundations/Dominator/lib/fsutil"
    11  	"github.com/Cloud-Foundations/Dominator/lib/log"
    12  )
    13  
    14  func watchUrl(rawurl string, checkInterval time.Duration,
    15  	logger log.Logger) (<-chan io.ReadCloser, error) {
    16  	u, err := url.Parse(rawurl)
    17  	if err != nil {
    18  		return nil, err
    19  	}
    20  	if u.Scheme == "file" {
    21  		return fsutil.WatchFile(u.Path, logger), nil
    22  	}
    23  	if u.Scheme == "http" || u.Scheme == "https" {
    24  		ch := make(chan io.ReadCloser, 1)
    25  		go watchUrlLoop(rawurl, checkInterval, ch, logger)
    26  		return ch, nil
    27  	}
    28  	return nil, errors.New("unknown scheme: " + u.Scheme)
    29  }
    30  
    31  func watchUrlLoop(rawurl string, checkInterval time.Duration,
    32  	ch chan<- io.ReadCloser, logger log.Logger) {
    33  	for ; ; time.Sleep(checkInterval) {
    34  		watchUrlOnce(rawurl, ch, logger)
    35  		if checkInterval <= 0 {
    36  			return
    37  		}
    38  	}
    39  }
    40  
    41  func watchUrlOnce(rawurl string, ch chan<- io.ReadCloser, logger log.Logger) {
    42  	resp, err := http.Get(rawurl)
    43  	if err != nil {
    44  		logger.Println(err)
    45  		return
    46  	}
    47  	if resp.StatusCode != http.StatusOK {
    48  		logger.Println(resp.Status)
    49  		return
    50  	}
    51  	ch <- resp.Body
    52  }