[pmg-devel] [PATCH http/common/manager/wt/backup/pmg v2] fix: #3971 Tasklog download button

[Daniel Tschlatscher <d.tschlatscher@proxmox.com>]

This patch series' aim is to add a download button in the tasklog-
viewer GUI so that users may access all parts of the tasklog more
easily (The tasklog-viewer only displays 50 lines at a time).

For this change in the GUI (proxmox-widget-toolkit) there were revised
implementations for all backends (PVE, PMG and PBS) needed.
Now, when the parameter 'limit' for the /log API call is set to '0',
the backends will stream the file rather than returning a JSON array
with the corresponding lines. (Beforehand, it would return 0 lines)

I initially included a number of patches aimed at refactoring
redundant implementations of downloading a file via a button click.
However, after talking with Sterzy, Dominik and Aaron a bit about
it, I decided to only send the "core" task log download patch series
now, because the refactoring depends on the changes made in widget-
toolkit, but is done in the same repositories as the backend patches.
This would make both reviewing and applying them more confusing, and
the refactoring patches are "a step removed" anyway from this patch
series. Therefore, I am going to send a separate patch series for them
later instead.


During the implementation of the file stream download I found a bug
concerning chromium browsers because of which downloads "randomly"
fail.
The problem was, when implementing the download through an html a tag
and setting its property "download" to anything, (even undefined)
with a not imported self-signed certificate, the download will fail
once the SSL connection is reset.
In my testing this was the case after about 5 seconds. This problem is
especially pronounced in the PMG as there are less background calls in
contrast to the PVE. The PBS, however, does not seem to suffer this
error at all, because the SSL handshake timeout seems to not run out.
 
Without the 'download' attribute you can't set the filename though.
The file will only have a proper name if the server adds the correct
'content-disposition' header. A few calls to the 'downloadAsFile'
function set the filename anyway, because in most cases the browser
frontend is making enough polling calls so that the SSL handshake
does not have to be executed for the download. (That is also why it
probably did not come up before)
This problem does not apply in Firefox as far as I could tell.

See https://bugs.chromium.org/p/chromium/issues/detail?id=993362 for
more information on this.

-- Changes from v1 --
* Rewrote commit messages and cover letter
* Got rid of some refactoring which were initially included
  (going to send as own patch series later)
* Rebased to current repository versions


Daniel Tschlatscher (1):
  make tasklog downloadable in the backup server backend

 src/api2/node/tasks.rs             | 159 ++++++++++++++++++-----------
 4 files changed, 107 insertions(+), 79 deletions(-)

Daniel Tschlatscher (1):
  stream file method for PMG and PVE

 src/PVE/Tools.pm | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)
 
Daniel Tschlatscher (1):
  acknowledge content-disposition header

 src/PVE/APIServer/AnyEvent.pm | 3 +++
 1 file changed, 3 insertions(+)
 
Daniel Tschlatscher (1):
  Revised task log API call when parameter 'limit' is 0

 PVE/API2/Tasks.pm                 | 13 ++++++++++---
 3 files changed, 15 insertions(+), 24 deletions(-)
 
Daniel Tschlatscher (1):
  revised task log download function in the PMG backend

 src/PMG/API2/Tasks.pm | 34 +++++++++++-----------------------
 1 file changed, 11 insertions(+), 23 deletions(-)

Daniel Tschlatscher (3):
  Source file download call in central function
  add task log download button in TaskViewer

 src/Utils.js              | 13 +++++++++++++
 src/window/TaskViewer.js  | 17 +++++++++++++++--
 src/window/FileBrowser.js | 11 +++++------
 3 files changed, 38 insertions(+), 8 deletions(-)

-- 
2.30.2