Add support for decompression of HTTP responses #764

mem · 2021-03-16T20:22:59Z

If the module configuration specifies the "compression" option
blackbox_exporter will try to decompress the response using the
specified algorithm. If the response is not compressed using that
algorithm, the probe will fail.

It validates that the "Accept-Encoding" header is either absent, or that
it specifies the same algorithm as the "compression" option. If the
"Accept-Encoding" header is present but it specifies a different
algorithm, the probe will fail.

If the compression option is not used, probe_http_content_length and
probe_http_uncompressed_body_length will have the same value
corresponding to the original content length. If the compression option
is used and the content can be decompressed, probe_http_content_length
will report the original content length as it currently does, and
probe_http_uncompressed_body_length will report the length of the body
after decompression as expected.

Fixes #684

Signed-off-by: Marcelo E. Magallon marcelo.magallon@grafana.com

prober/http.go

roidelapluie · 2021-03-27T17:12:11Z

Thanks for this! I have left a few comments.

prober/http.go

roidelapluie · 2021-04-01T12:28:24Z

Thanks, I have added one last comment.

mem · 2021-04-16T15:10:32Z

Thanks, I have added one last comment.

Thank you! I think I have addressed everything. Can you take another look?

prober/http.go

roidelapluie

LGTM. I do not even think we should check the params like you did because there may be non-standard servers implementations that would use other formats, but for which users might still want to use with this exporter, but let's keep them and gather users feedback.

I have added a minor comment.

If the module configuration specifies the "compression" option blackbox_exporter will try to decompress the response using the specified algorithm. If the response is not compressed using that algorithm, the probe will fail. It validates that the "Accept-Encoding" header is either absent, or that it specifies the same algorithm as the "compression" option. If the "Accept-Encoding" header is present but it specifies a different algorithm, the probe will fail. If the compression option is *not* used, probe_http_content_length and probe_http_uncompressed_body_length will have the same value corresponding to the original content length. If the compression option is used and the content can be decompressed, probe_http_content_length will report the original content length as it currently does, and probe_http_uncompressed_body_length will report the length of the body after decompression as expected. Fixes #684 Signed-off-by: Marcelo E. Magallon <marcelo.magallon@grafana.com>

mem · 2021-04-19T22:10:15Z

LGTM. I do not even think we should check the params like you did because there may be non-standard servers implementations that would use other formats, but for which users might still want to use with this exporter, but let's keep them and gather users feedback.

I have added a minor comment.

Cool, thank you!

mem force-pushed the handle_compressed_payload branch 2 times, most recently from 605beb8 to 0dc0058 Compare March 16, 2021 20:27

mem requested a review from roidelapluie March 16, 2021 20:34

roidelapluie reviewed Mar 27, 2021

View reviewed changes