Updated How to Install Falco from Source (markdown)

How-to-Install-Falco-from-Source.md

@@ -2,7 +2,33 @@
 
 Building falco requires having `cmake` and `g++` installed.
 
-## Check out source code
+## Build using docker-builder container
+
+One easy way to build falco is to run the [falco-builder](https://hub.docker.com/r/falcosecurity/falco/). It contains the reference toolchain we use to build packages.
+
+The image depends on the following parameters:
+
+* `FALCO_VERSION`: the version to give any built packages
+* `BUILD_TYPE`: Debug or Release
+* `BUILD_DRIVER`: whether or not to build the kernel module when
+building. This should usually be OFF, as the kernel module would be
+built for the files in the centos image, not the host.
+* `BUILD_BPF: Like `BUILD_DRIVER` but for the ebpf program.
+* `BUILD_WARNINGS_AS_ERRORS`: consider all build warnings fatal
+* `MAKE_JOBS`: passed to the -j argument of make
+
+A typical way to run this builder is the following. Assumes you have
+checked out falco and sysdig to directories below /home/user/src, and
+want to use a build directory of /home/user/build/falco:
+
+```
+$ docker run --user $(id -u):$(id -g) -v /etc/passwd:/etc/passwd:ro -e MAKE_JOBS=4 -it -v /home/user/src:/source -v /home/user/build/falco:/build falco-builder cmake
+$ docker run --user $(id -u):$(id -g) -v /etc/passwd:/etc/passwd:ro -e MAKE_JOBS=4 -it -v /home/user/src:/source -v /home/user/build/falco:/build falcosecurity/falco-builder package
+```
+
+## Build directly on host
+
+If you'd rather build directly on the host, you can use your local toolchain and cmake binaries.
 
 Clone this repo in a directory that also contains the sysdig source repo. The result should be something like: