lal

A strict, language-agnostic build system and dependency manager.

• Use existing tools: lal build only shells out to an executable BUILD script in a configured docker container. Install what you want in your build environments: cmake, autotools, cargo, go, python.
• Cache large builds: publish built libraries for later use down the dependency tree.
• Strict with environments and versions: lal verify enforces that all your dependencies are built in the same environment and use the same version down the tree (and it runs before your build).
• Builds on existing package manager ideas: versions in a manifest, fetch dependencies first, verify them, then build however you want, lal autogenerates lockfiles during build.
• Transparent use of docker for build environments with configurable mounts and direct view of the docker run commands used. lal shell or lal script provides additional easy ways to use the build environments.

Conception

We needed a simple dependency manager built around the idea of a storage backend and a build environment. Strict versioning and consistent build environments for our C++ codebases where the most important features needed, and we already had docker and artifactory for the rest, however other storage backends can be implemented in the future.

The command line specification contains a detailed overview of what lal does.

Showcases

A few short ascii shorts about how lal is typically used internally:

• build / fetch
• custom dependencies
• scripts

Setup

Needs a few pieces to be set up across a team at the moment. Grab a :coffee:

Prerequisites (devs)

You need docker (minimum version 1.12), logged into the group with access to your docker images in the relevant config file. Distros with Linux >= 4.4.0 is the primary target, but Mac is also getting there.

Prerequisites (ops)

A set of docker images as outlined in the relevant config file, all built to include a lal user and available to docker logged in devs (see below)

CI setup to build and upload releases of master as outlined further below.

A configured backend in same config file, distrubuted with lal to your devs. Currently, this only supports artifactory.

Building

Clone, install from source with rust, setup autocomplete, and select your site-config:

git clone git@github.com:lalbuild/lal.git && cd lal
cargo install
echo "source $PWD/lal.complete.sh" >> ~/.bash_completion
lal configure configs/demo.json

If you want to release static binaries of these to developers, you can build lal on CI via clux/muslrust. This takes away the need to install rust for developers, and if you use the upgrade feature, you can set up automatic upgrades.

Usage

Creating a new component

Create a git repo, lal init it, then update deps and verify it builds.

lal init xenial # create manifest for a xenial component
git add .lal/
git commit -m "init newcomponent"
# add some dependencies to manifest (if you have a storage backend)
lal update gtest --save-dev
lal update libwebsockets --save
# create source and iterate until `lal build` passes

# later..
git commit -a -m "inital working version"
git push -u origin master

Note that the first lal build will call lal env update to make sure you have the build environment.

Creating a new version

Designed to be handled by CI on each push to master (ideally through validated merge). CI should create your numeric tag and upload the build output to artifactory. See the spec for full info.

Docker Image

The build and shell commands will use docker run on a configured image. The only condition we require of docker images is that they have a lal user added.

Normally, this is sufficient in a docker image to satisfy constraints:

RUN useradd -ms /bin/bash lal -G sudo && \
    echo "%sudo ALL=(ALL) NOPASSWD: ALL" >> /etc/sudoers

VOLUME ["/home/lal/volume"]

Note that sudo is not necessary, but sometimes convenient.

We will use this user inside the container to run build scripts. By default this works best if the id of the host user is 1000:1000, but if it is not, then lal will create a slightly modified version of the image that matches the user id and group id for your host system.

This is a one time operation, and it is a more general solution for use than docker usernamespaces (which is currently incompatible with features like host networking).

Developing

Have the rust documentation for lal ready.

To hack on lal, follow normal install procedure, but build non-release builds iteratively. When developing we do not do --release. Thus you should for convenience link lal via ln -sf $PWD/target/debug/lal /usr/local/bin/lal.

When making changes:

cargo build
lal subcommand ..args # check that your thing is good
cargo test # write tests

Good practices before comitting (not mandatory):

cargo fmt # requires `cargo install rustfmt` and $HOME/.cargo/bin on $PATH
rustup run nighthly cargo clippy # requires nightly install of clippy

Note that if you have a rust environment set up in your lal config, you can actually lal build lal (which will use the provided manifest.json and BUILD file).

Build issues

If libraries cannot be built, then upgrade rustc by running rustup update stable.

• missing ssl: install distro equivalent of libssl-dev then cargo clean
• fatal error: 'openssl/hmac.h' file not found If you are on a GNU/Linux distribution (like Ubuntu), please install libssl-dev. If you are on OSX, please install openssl and check your OpenSSL configuration:

brew install openssl
export OPENSSL_INCLUDE_DIR=`brew --prefix openssl`/include
export OPENSSL_LIB_DIR=`brew --prefix openssl`/lib
export DEP_OPENSSL_INCLUDE=`brew --prefix openssl`/include

Runtime issues

SSL Certificates

The lookup of SSL certificates to do peer verification can fail if they are missing or in a non-standard location. The search is done via the openssl-probe crate.

Although this shouldn't be necessary anymore; you can also override the search yourself by pointing to the certificates explicitly:

# OSX
export SSL_CERT_FILE=/usr/local/etc/openssl/cert.pem
# CentOS
export SSL_CERT_FILE=/etc/ssl/certs/ca-bundle.crt

This should be put in your ~/.bashrc or ~/.bash_profile as lal reads it on every run. Note that the normal location is /etc/ssl/certs/ca-certificates.crt for most modern linux distros.

Docker permission denieds

You need to have performed docker login, and your user must have been added to the correct group on dockerhub by someone in charge before you can pull build environments.

Logging

Configurable via flags before the subcommand:

lal fetch # normal output
lal -v fetch # debug output
lal -vv fetch # all output

Influences

Main inspirations were cargo and npm. A useful reference for the terms used throughout: so you want to write a package manager (long read).