tino 0.1.20

Features

Installation

# Install locally with Cargo
cargo install tino

# Build a static binary (e.g. for PID 1 in Docker)
cargo build --release --target x86_64-unknown-linux-musl

# Docker image (includes /sbin/tino)
docker pull lvillis/tino

Binary Releases

GitHub Releases publish stable, versioned archives with a single top-level directory:

tino-<version>-<os>-<arch>-<abi>/
├── tino
├── LICENSE
└── README.md

Supported platform matrix and asset mapping:

Every release also includes:

• SHA256SUMS covering all published assets
• per-asset *.spdx.json SBOM files in SPDX JSON format
• GitHub artifact attestations for the archives and attached SBOMs

Quick Start

# Replace tini in your Dockerfile
ENTRYPOINT ["/sbin/tino", "-g", "-s", "--"]

# Run locally
tino -- echo "hello from child"

Runtime Notes

• -g/--pgroup-kill logs a warning and falls back to single-process signalling when process-group creation fails (for example inside constrained PID namespaces).
• tino's internal signalfd is opened with CLOEXEC, ensuring child workloads do not inherit extra file descriptors.
• Logging setup is idempotent: repeated initialisation (tests, embedding) no longer panics.
• TINI_* env vars only apply when the corresponding CLI flag is not set (CLI wins).
• --expand-env expands child command arguments before execvp; supported forms are ${VAR}, ${VAR:-default}, and $$ for a literal dollar sign. Unbraced $VAR is left unchanged. This is not a shell.
• --explain prints the effective configuration, resolved child argv, and write allowlist, then exits without spawning the child. It is an explanation mode, not a dry-run simulator.
• Write restriction (optional, Linux): --write-restrict --write-allow /path (repeatable) denies filesystem writes outside allowlisted directories; default is strict (use --write-warn-only to continue).
• --write-preset tmp expands to /tmp and /var/tmp; --write-preset runtime adds /run. Missing standard directories are skipped, and presets can be combined with --write-allow.
• Write restriction keeps /dev writable for TTY/stdout by default (disable with --write-no-dev).
• TCP restriction (optional, Linux): --bind-tcp-allow 8900 limits which local TCP ports the child may bind; --connect-tcp-allow 443 limits outbound TCP connections by remote port. These options require Landlock ABI v4+.
• IPC scope restriction (optional, Linux): --scope-signals restricts signal delivery to processes in the same or a nested Landlock domain; --scope-abstract-unix restricts abstract UNIX socket connects to the same domain. These options require Landlock ABI v6+.
• Exec restriction (optional, Linux): --exec-allow /path restricts which executables the child may launch after startup. Allow entries that point to files automatically include direct shebang interpreters and ELF loaders; directory-based allow entries do not.
• Device ioctl restriction (optional, Linux): --device-ioctl-allow /dev/pts/0 restricts ioctl(2) to explicit device nodes or directories. This option requires Landlock ABI v5+.
• When any Landlock feature is requested, --write-warn-only switches startup failures to warnings and continues without applying the requested restriction.
• Docker: if Landlock syscalls are blocked, use --security-opt seccomp=./seccomp-landlock.json (or seccomp=unconfined for testing).

Landlock + Docker (seccomp)

Docker's default seccomp profile often blocks landlock_* syscalls. This repo includes seccomp-landlock.json, based on moby/profiles (see seccomp-landlock.upstream.sha).

docker run --rm -it \
  --security-opt seccomp=./seccomp-landlock.json \
  <image> \
  /sbin/tino --write-restrict --write-allow /data -- <cmd> ...

For scratch/distroless workloads that need simple parameter expansion without a shell:

/sbin/tino --expand-env -- /opt/app/collectord -port=${SERVICE_PORT:-8900}

For common runtime layouts, presets reduce boilerplate:

/sbin/tino --write-preset runtime --write-allow /data/logs -- /opt/app/collectord

To restrict a service to a known listen port without a full firewall layer:

/sbin/tino --bind-tcp-allow 8900 -- /opt/app/collectord --port=8900

To keep plugin-like child processes from signalling or connecting to IPC resources outside their own Landlock domain:

/sbin/tino --scope-signals --scope-abstract-unix -- /opt/app/untrusted-worker

To prevent a managed service from spawning helper commands except for an explicit allowlist:

/sbin/tino --exec-allow /opt/app/collectord -- /opt/app/collectord

To only permit device ioctl calls on a known PTY or device subtree:

/sbin/tino --device-ioctl-allow /dev/pts -- /opt/app/interactive-worker

To inspect the final argv and effective security settings without executing the child:

/sbin/tino --expand-env --write-preset runtime --write-allow /data/logs --bind-tcp-allow 8900 --scope-signals --exec-allow /opt/app/collectord --explain -- \
  /opt/app/collectord -port=${SERVICE_PORT:-8900}

To make this the default for all containers, set Docker's daemon config:

{
  "seccomp-profile": "/etc/docker/seccomp-landlock.json"
}

Refresh the profile with python scripts/update-seccomp-landlock.py.

Testing

cargo fmt --all -- --check
cargo clippy --all-targets --all-features -- -D warnings
cargo test --all --verbose

On Unix targets an integration suite in tests/unix_behaviour.rs covers the CLI licence output, missing-command error path, and exit-code remapping flow.