gcc 5 is no longer included in debian unstable, but we need it to build
centos kernels, which are 3.x based and explicitly want a gcc version 3,
4, or 5 compiler.
So grab copies we've saved from debian snapshots with the prefix
https://snapshot.debian.org/archive/debian/20190122T000000Z. They're
stored at downloads.draios.com and installed in a dpkg -i step after the
main packages are installed, but before any other by-hand packages are
installed.
debian:unstable head contains binutils 2.31, which generates binaries
that are incompatible with kernels < 4.16.
To fix this, after installing everything, downgrade binutils to
2.30-22. This has to be done as the last step as it introduces conflicts
in other dependencies of the various gcc versions and some of the
packages already in the image.
If /lib/modules exists in the base image, the symlink will get created at
/lib/modules/modules. This removes any existing empty directory but will
fail if we try to remove a non-empty /lib/modules. (Punting on how to
handle non-empty base image dirs for now)
Start packaging (and building when necessary) a falco-specific kernel
module in falco releases. Previously, falco would depend on sysdig and
use its kernel module instead.
The kernel module was already templated to some degree in various
places, so we just had to change the templated name from
sysdig/sysdig-probe to falco/falco-probe.
In containers, run falco-probe-loader instead of
sysdig-probe-loader. This is actually a script in the sysdig repository
which is modified in https://github.com/draios/sysdig/pull/789, and uses
the filename to indicate what kernel module to build and/or load.
For the falco package itself, don't depend on sysdig any longer but instead
depend on dkms and its dependencies, using sysdig as a guide on the set
of required packages.
Additionally, for the package pre-install/post-install scripts start
running falco-probe-loader.
Finally, add a --version argument to falco so it can pass the desired
version string to falco-probe-loader.
