Docker: switch to Alpine Linux

[virtualtam]

Closes #843

Changed:

• switch base image from Debian:Jessie to Alpine:3.6
• switch to PHP 7.1
• switch from supervisord to s6 to manage services

Done:

• production/master image
  • rewrite Dockerfile
  • Alpine 3.6 base + Nginx + PHP 7 + PHP-FPM + exts
  • S6 service manager
  • docker: add alpine,debian,ubuntu test images #909 check unit tests pass under Alpine / PHP 7

WIP:

• thorough testing of Shaarli pages and features

See:

• https://alpinelinux.org/
• https://wiki.alpinelinux.org/wiki/Nginx_with_PHP
• http://www.skarnet.org/software/s6/
  • http://www.skarnet.org/software/s6/s6-svscan.html
  • http://www.skarnet.org/software/s6/s6-svc.html
  • http://www.skarnet.org/software/s6/s6-svstat.html

[virtualtam]

The main image (docker/production) builds & works, feel free to give it a spin!

There are some quirks highlighted by UTs that I suspect are due to musl-libc behaving a bit differently from glibc, this concerns path concatenation and globbing so far.

[virtualtam]

Similar errors from Debian8, Debian9 and Alpine36 (Ubuntu16 is fine):

$ docker run --rm -v $PWD:/shaarli shaarli-test:alpine36 docker_all_tests

rsync -az /shaarli/ ~/shaarli/
cd ~/shaarli && make all_tests
make[1]: Entering directory '/root/shaarli'
-------
PHPUNIT
-------
PHPUnit 4.8.36 by Sebastian Bergmann and contributors.

....................................F.F.E..E...................  63 / 397 ( 15%)
............................................................... 126 / 397 ( 31%)
............................................................... 189 / 397 ( 47%)
........F...................................................... 252 / 397 ( 63%)
............................................................... 315 / 397 ( 79%)
............................................................... 378 / 397 ( 95%)
...................

Time: 5.45 seconds, Memory: 27.25MB

There were 2 errors:

1) FileUtilsTest::testReadNotReadable
gzinflate(): data error

/root/shaarli/application/FileUtils.php:70
/root/shaarli/tests/FileUtilsTest.php:105

2) HistoryTest::testConstructNotWritable
gzinflate(): data error

/root/shaarli/application/FileUtils.php:70
/root/shaarli/application/History.php:167
/root/shaarli/application/History.php:83
/root/shaarli/application/History.php:133
/root/shaarli/application/History.php:121
/root/shaarli/tests/HistoryTest.php:51

--

There were 3 failures:

1) FileUtilsTest::testWriteWithoutPermission
Failed asserting that exception of type "IOException" is thrown.

2) FileUtilsTest::testWriteFolderPermission
Failed asserting that exception of type "IOException" is thrown.

3) UpdaterTest::testWriteUpdatesFileNotWritable
Failed asserting that exception of type "Exception" is thrown.

FAILURES!
Tests: 397, Assertions: 1449, Errors: 2, Failures: 3.

Generating code coverage report in PHP format ... done
Makefile:134: recipe for target 'test' failed
make[1]: Leaving directory '/root/shaarli'
make[1]: *** [test] Error 2
Makefile:28: recipe for target 'docker_all_tests' failed
make: *** [docker_all_tests] Error 2

[virtualtam]

The gzinflate errors happen on some platforms when attempting to inflate (decompress) archives that are actually empty (as in "empty file"). I don't know why this behaviour differs from Debian to Ubuntu, though.

This can be avoided by improving the robustness of FileUtils by adding a preliminary check, I'll submit the corresponding PR :)

Related (?) resources:

• https://secure.php.net/manual/en/function.gzinflate.php
• https://bugs.php.net/bug.php?id=71395
• https://stackoverflow.com/questions/27692527/why-phps-gzuncompress-function-can-go-wrong

[virtualtam]

PR rebased and in review \o/

[nodiscc]

Looks good to me, will unable to test this in the coming days though. Did you notice a performance increase?

[virtualtam]

No hurry, I'd greatly appreciate usage feedback before merging!

Did you notice a performance increase?

Well, my, lemme check my Shaarli bookmark mining farm...

Images are shrinked to a minimal size, and the memory footprint is significantly smaller.

Here's a rough comparison, using :

• Docker 17.07.0-ce with the overlay2 storage driver
• images:
  • shaarli:stable: current image for stable
  • shaarli/shaarli:latest: current image for master
  • shaarli:master: local development image for master (this PR)
• setup:
  • each instance has ~2500 bookmarks loaded
  • some plugins are enabled: addlink_toolbar, archiveorg, qrcode, playvideos
  • ~500 thumbnails have been loaded by the picwall

Note: output truncated for readability

$ docker images

REPOSITORY       TAG     IMAGE ID      CREATED       SIZE
shaarli          stable  dd0b1834fa93  24 hours ago  318MB
shaarli/shaarli  latest  c3ffba699be1  24 hours ago  293MB
shaarli          master  d24339645fed  24 hours ago  69MB

$ docker ps

CONTAINER ID        IMAGE                    COMMAND
bd4df1fc76ca        shaarli/shaarli:latest   "/usr/bin/supervis..."
cb5a76b665f0        shaarli:stable           "/usr/bin/supervis..."
1a358ebff5cb        shaarli:master           "/bin/s6-svscan /e..."

$ docker stats --no-stream

 CONTAINER     CPU %  MEM USAGE / LIMIT    NET I/O          BLOCK I/O         PIDS
bd4df1fc76ca  0.03%  54.92MiB / 15.62GiB  704kB / 1.79MB   1.87MB / 30.8MB   9
cb5a76b665f0  0.03%  54.25MiB / 15.62GiB  714kB / 1.49MB   32.4MB / 438kB    9
1a358ebff5cb  0.00%  28.89MiB / 15.62GiB  41.8kB / 2.16MB  24.5MB / 69.6kB   11