104 lines
1.9 KiB
Go
104 lines
1.9 KiB
Go
package main
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import (
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"crypto/sha1"
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"encoding/hex"
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"flag"
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"fmt"
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"io"
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"log"
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"net/http"
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"os"
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gopath "path"
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"path/filepath"
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"time"
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)
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var (
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upstreamURL = flag.String("upstream", "https://direktil.novit.nc/dist", "Upstream server for dist elements")
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)
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func (ctx *renderContext) distFetch(path ...string) (outPath string, err error) {
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outPath = ctx.distFilePath(path...)
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if _, err = os.Stat(outPath); err == nil {
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return
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} else if !os.IsNotExist(err) {
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return
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}
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subPath := gopath.Join(path...)
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log.Print("need to fetch ", subPath)
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if err = os.MkdirAll(filepath.Dir(outPath), 0755); err != nil {
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return
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}
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fullURL := *upstreamURL + "/" + subPath
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resp, err := http.Get(fullURL)
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if err != nil {
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return
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}
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defer resp.Body.Close()
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if resp.StatusCode != 200 {
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err = fmt.Errorf("wrong status: %s", resp.Status)
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return
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}
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fOut, err := os.Create(filepath.Join(filepath.Dir(outPath), "._part_"+filepath.Base(outPath)))
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if err != nil {
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return
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}
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hash := sha1.New()
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out := io.MultiWriter(fOut, hash)
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done := make(chan error, 1)
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go func() {
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_, err = io.Copy(out, resp.Body)
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fOut.Close()
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if err != nil {
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os.Remove(fOut.Name())
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}
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done <- err
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close(done)
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}()
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wait:
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select {
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case <-time.After(10 * time.Second):
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log.Print("still fetching ", subPath, "...")
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goto wait
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case err = <-done:
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if err != nil {
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log.Print("fetch of ", subPath, " failed: ", err)
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return
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}
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}
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hexSum := hex.EncodeToString(hash.Sum(nil))
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log.Printf("fetch of %s finished (SHA1 checksum: %s)", subPath, hexSum)
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if remoteSum := resp.Header.Get("X-Content-SHA1"); remoteSum != "" {
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log.Printf("fetch of %s: remote SHA1 checksum: %s", subPath, remoteSum)
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if remoteSum != hexSum {
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err = fmt.Errorf("wrong SHA1 checksum: server=%s local=%s", remoteSum, hexSum)
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log.Print("fetch of ", subPath, ": ", err)
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os.Remove(fOut.Name())
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return
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}
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}
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err = os.Rename(fOut.Name(), outPath)
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return
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}
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