forked from Docker/baseimage-docker
45facca75e
According to [the stock Ubuntu 16.04 config](https://github.com/hyperknot/baseimage16/blob/1.0.1/image/services/syslog-ng/syslog-ng.conf.original#L21), the default source driver is `system()`, that is documented in [the syslog-ng 3.5 official documentation](https://www.balabit.com/documents/syslog-ng-ose-3.5-guides/en/syslog-ng-ose-guide-admin/html-single/index.html#configuring-source-system) on Linux as `unix-dgram("/dev/log");` with some `/proc/kmsg` involvement if kernel "is version 3.5 or newer". `/proc/kmsg` causes trouble on Docker hence using syslog-ng 3.5 on Docker `unix-dgram("/dev/log")` shall be used (not `unix-stream("/dev/log");`). If using syslog-ng [3.6](https://www.balabit.com/documents/syslog-ng-ose-3.6-guides/en/syslog-ng-ose-guide-admin/html-single/index.html#configuring-source-system) or [newer](https://www.balabit.com/documents/syslog-ng-ose-3.9-guides/en/syslog-ng-ose-guide-admin/html-single/index.html#configuring-source-system) on Docker, `system()` shall be able to be used. But [Ubuntu 16.04 is at syslog-ng 3.5](http://packages.ubuntu.com/xenial/syslog-ng-core) so `system()` cannot be used. See also https://github.com/phusion/baseimage-docker/issues/277