lt2http

What it is

lt2http is a libtorrent-to-http application.

It is a web-server, responding with json, which uses libtorrent torrent library inside, to download and manage torrents, and can stream downloaded files via http and download files to memory (without using hard disks).

It has built-in Swagger.

By default, runs on port 65225, so application can be accessed on http://localhost:65225.

Swagger is accessible on http://localhost:65225/swagger/ui

Checkout

You can clone this repository with downloading all the submodules, in one command:

$ git clone --recursive https://github.com/ElementumOrg/lt2http.git

Submodules

lt2http uses several external projects (header-only), so you need to download them first, if needed (if you did not clone repository with a --recursive key)

$ git submodule update --init --recursive --remote --no-fetch --depth=1

Dependencies

lt2http has these dependencies:

• Boost (at least version 1.66.0)
• OpenSSL (at least version 1.1.1)
• Libtorrent (at least version 1.2.1)
• Oatpp (at least version 1.2.5)
• Oatpp-swagger (at least version 1.2.5)
• MiMalloc (at least version 2.0.0)
• Libbacktrace (latest master)

Build dependencies

You can look at build commands at scripts/build-local.sh script.

By default everything is built with Release profile, meaning all the default optimizations and lack of debug symbols.

Default installation directory: ./local-env/.

To use custom directory run:

sudo CROSS_ROOT=/usr/ CROSS_TRIPLE=x86_64-linux-gnu ./scripts/build-local.sh

Some notes regarding dependencies and build-local.sh:

• We force use of gcc-6, because cross-build docker image has gcc-6 (for non-Android targets). That is because building on a newer OS will require newer libc, so users with old Kernels will not be able to run it. You can use any compiler.
• All dependencies are compiled as static libraries to avoid having library dependencies in a lt2http binary.
• We force use of C++17 to have same standard for all dependencies.
• Oatpp is compiled always in a Release profile, because we usually do not need to debug it.
• Boost installation makes a file ~/user-config.jam, so if you don't want it to be overwritten - comment that in build.sh.
• MiMalloc is not used by default.

Build lt2http

lt2http notes:

• Libtorrent RC1_2 is used.
• C++17 is required from the compiler.
• Cmake requires minimum version of 3.15.0.
• If you use profile RelWithDebInfo - Cmake will enable sanitizers for the binary: -fsanitize=leak -fsanitize=undefined -fsanitize=bounds -fsanitize=bounds-strict
• If you use profile Debug or RelWithDebInfo Cmake will add debug symbols in the binary, useful to find cause of a segmentation fault or some error.

Build locally process:

$ mkdir -p build && cd build
$ cmake -DCMAKE_BUILD_TYPE=Release .. && make -j$(nproc)

Build using Docker: There is a simple way, pull docker image and compile lt12http there.

$ make pull PLATFORM=linux-x64 # Pull Docker image for platform linux-x64 from Docker Hub
$ make linux-x64 # Run in linux-x64 Docker image

Build process helper:

For easy of building there is test_build.sh with 3 options:

test_build.sh local # Run compilation on a local system, without Docker
test_build.sh sanitize # Run compilation with CMake build type RelWithDebInfo, which includes sanitizers.
test_build.sh docker # Run compilation in a Docker.

Prepare new target OS:

• To build for specific OS, you need to create Dockerfile for that system.
• Add it into Makefile's list of platforms.
• Run Docker build with PLATFORM=linux-x64 make env, replace linux-x64 with name of your Dockerfile.