I am downloading a Helm chart from https://kubernetes-charts.storage.googleapis.com/redis-0.5.1.tgz. (The fact that it is Redis or related to Helm or anything in particular is irrelevant to this question, which is just about things like Content-Encoding and so on.)
When I check its headers like this:
$ curl -H "Accept-Encoding: gzip" -I https://kubernetes-charts.storage.googleapis.com/redis-0.5.1.tgz
…I do not see a Content-Encoding header in the output, and the Content-Type is listed as being application/x-tar:
HTTP/1.1 200 OK
X-GUploader-UploadID: AEnB2UqBzSXfTToMAdMARXSjJeN0on3jaNY3u74eXcWfvqsOwRpi38Xc6T0XrrmY4otPeySaYRwXyHccHYtChoPAgFQwYZhQMhcpZRWtZURRANGdfRJoupI
Expires: Tue, 27 Jun 2017 00:21:59 GMT
Date: Mon, 26 Jun 2017 23:21:59 GMT
Cache-Control: public, max-age=3600
Last-Modified: Fri, 05 May 2017 03:03:41 GMT
ETag: "e4184c81a58fb731283847222a1f4005"
x-goog-generation: 1493953421241613
x-goog-metageneration: 1
x-goog-stored-content-encoding: identity
x-goog-stored-content-length: 3550
x-goog-meta-goog-reserved-file-mtime: 1493953414
Content-Type: application/x-tar
x-goog-hash: crc32c=bQHveg==
x-goog-hash: md5=5BhMgaWPtzEoOEciKh9ABQ==
x-goog-storage-class: STANDARD
Accept-Ranges: bytes
Content-Length: 3550
Server: UploadServer
Alt-Svc: quic=":443"; ma=2592000; v="39,38,37,36,35"
The resulting file, when downloaded, is a gzipped tar archive.
What is the proper way of programmatically detecting that the payload is in fact gzipped? Or is this a problem with the web server in question?
I think the server is misconfigured. Since .tgz is just abbreviation for .tar.gz it should get the content type application/gzip-