#!/usr/bin/env bash

gccversion=$(gcc --version | head -n1)
cppversion=$(g++ -dM -E -x c++ /dev/null | grep -F __cplusplus | cut -d' ' -f3)
cmakeversion=$(cmake --version | head -n1)
clangversion=$(clang --version | head -n1)

cat <<EOF
Hello, this is the Falco builder container.

How to use.

    The default commands for the Falco builder image reports usage and environment info.
    * docker run falcosecurity/falco-builder
    * docker run falcosecurity/falco-builder usage

    It supports bash.
    * docker run -ti falcosecurity/falco-builder bash

    To build Falco it needs:
    - a bind-mount on the source directory (ie., the directory containing the Falco source as sibling)

    Optionally, you can also bind-mount the build directory.
    So, you can execute it from the Falco root directory as follows.

    * docker run -v $PWD/..:/source -v $PWD/build:/build falcosecurity/falco-builder cmake
    * docker run -v $PWD/..:/source -v $PWD/build:/build falcosecurity/falco-builder [<cmake-target-x>, ..., <cmake-target-y>]

    Eg.,
    * docker run -v $PWD/..:/source -v $PWD/build:/build falcosecurity/falco-builder tests
    * docker run -v $PWD/..:/source -v $PWD/build:/build falcosecurity/falco-builder install

How to build.

    * cd docker/builder && DOCKER_BUILDKIT=1 docker build -t falcosecurity/falco-builder .

    In case you want to customise the builder at build time the following build arguments are provided:
    - BUILD_TYPE                whether you want a "release" or "debug" build (defaults to "release").
    - BUILD_DRIVER              whether to build the driver or not (defaults to "OFF")
    - BUILD_BPF                 whether to build the BPF driver or not (defaults to "OFF")
    - BUILD_WARNINGS_AS_ERRORS  whether to intend warnings as errors or not (defaults to "ON")
    - MAKE_JOBS                 the number of jobs to use during make (defaults to "4")
    - FALCO_VERSION             the version to label the build (built from git index in case it is missing)

    It is possible to change these at runtime (in the container) since environment variables with the same names are provided, too.

Environment.

    * ${gccversion}
    * cplusplus ${cppversion}
    * ${cmakeversion}
    * ${clangversion}
EOF