--- title: Redistribute on Linux description: Bundle the SmartSpectra Linux C++ SDK tarball into your own .deb so end users install your app on stock Ubuntu without a Presage apt source. --- > SmartSpectra SDK developer docs for v3.4.0, the latest stable release. Web page: https://presagetech.com/docs/smartspectra-sdk/redistribute-smartspectra-on-linux > Index of all pages: https://presagetech.com/docs/smartspectra-sdk/llms.txt # Redistribute SmartSpectra on Linux Validated path for a developer to take the published SmartSpectra Linux C++ SDK release tarball, build their own application against it, and ship a self-contained `.deb` that installs on a stock Ubuntu / Mint / Debian host without configuring a Presage apt source. This is the **only** Linux redistribution shape currently supported. Other shapes are not currently validated. ## When to use this path You're a developer who: - Ships a desktop app to enterprise Linux end-users - Wants the end-user install to be one `sudo apt install ./your-app.deb` step - Cannot ask end-users to configure a Presage apt source - Targets Ubuntu 22.04 / 24.04 (Mint 21 / 22). Those are the supported distributions; nothing else is tested. arm64 redistribution remains a follow-up If your end-users run a non-Debian-family distro (Fedora, RHEL, openSUSE, Arch), you're in territory we don't currently validate. ## The example app The public GitHub mirror ships the example as [`cpp/samples/debian-app-example/README.md`](https://github.com/Presage-Security/SmartSpectra/blob/main/cpp/samples/debian-app-example/README.md) with its packaging logic in [`cpp/samples/debian-app-example/CMakeLists.txt`](https://github.com/Presage-Security/SmartSpectra/blob/main/cpp/samples/debian-app-example/CMakeLists.txt). It demonstrates every choice this page documents and is a suitable starting point to copy into your own repository when integrating the SDK into a redistributable `.deb`. Build it standalone against an extracted SDK release tarball: ```bash # 1. Extract the published SDK release tarball # Use the codename-qualified asset name: # - Ubuntu 22.04 / Mint 21 / Debian 11+: linux-jammy-amd64 # - Ubuntu 24.04 / Mint 22: linux-noble-amd64 mkdir -p /tmp/sdk tar -xzf smartspectra-sdk--linux--amd64.tar.gz -C /tmp/sdk # 2. Choose the example source path for your checkout: # - Public GitHub mirror: cpp/samples/debian-app-example cmake -S -B /tmp/dae-build \ -DCMAKE_PREFIX_PATH=/tmp/sdk \ -DCMAKE_BUILD_TYPE=Release cmake --build /tmp/dae-build -j$(nproc) # 3. Produce the .deb (per-codename revision suffix) cd /tmp/dae-build cpack -G DEB # Produces e.g. debian-app-example_0.1.0-noble1_amd64.deb on Ubuntu 24.04 # or debian-app-example_0.1.0-jammy1_amd64.deb on Ubuntu 22.04 — the # revision suffix tracks the build-host codename so the same .deb stream # never serves a mismatched stock-archive Depends set. # 4. Install on a clean Debian-family container sudo apt install -y ./debian-app-example_*.deb ``` Read the example [`CMakeLists.txt`](https://github.com/Presage-Security/SmartSpectra/blob/main/cpp/samples/debian-app-example/CMakeLists.txt) end-to-end — it's the canonical source for the install layout, CPack DEB config, Depends manifest reading, and maintainer-script wiring. ## Install layout The `.deb` installs entirely under `/opt/debian-app-example/` (an app-private prefix per [FHS 3.0 §3.12](https://refspecs.linuxfoundation.org/FHS_3.0/fhs/ch03s12.html)). Replace `debian-app-example` with your own app name when you adapt the example. ```text /opt// ├── bin/ │ └── (the executable) ├── lib/ │ ├── libsmartspectra.so (bundled from SDK tarball) │ └── smartspectra_manifest.json (written at install time) └── share/ └── smartspectra/ └── graph/ ├── models/ (bundled from SDK tarball) └── ... ``` Plus one file outside the app's prefix, written by `postinst`: ```text # /etc/ld.so.conf.d/.conf /opt//lib ``` `postrm` removes that fragment on `remove` / `purge`. ## RPATH and per-app ldconfig Two mechanisms place the bundled `libsmartspectra.so` on the loader's path when the end-user launches the binary. **RPATH on the binary.** The example binary is linked with `INSTALL_RPATH=$ORIGIN/../lib` and `INSTALL_RPATH_USE_LINK_PATH=FALSE` so the resulting `DT_RUNPATH` is exactly `$ORIGIN/../lib`. From `/opt//bin/` this walks to `/opt//lib/`, where `libsmartspectra.so` lives. **ldconfig fragment for `libsmartspectra.so`.** The SDK's shared library has no embedded `DT_RUNPATH` / `DT_RPATH`, and `/opt//lib` is not on the loader's default search path, so `postinst` also registers it with the system loader cache: ```text # /etc/ld.so.conf.d/.conf /opt//lib ``` and runs `ldconfig`, so `libsmartspectra.so` resolves at load time. `postrm` removes the ldconfig fragment on `remove` / `purge` so the cache no longer maps libraries to the now-removed prefix. ## Model-path resolution At runtime the SDK locates its own shared-library directory and reads `smartspectra_manifest.json` from that directory. The manifest contains a single absolute path: ```json { "resource_root_dir": "/opt//share/smartspectra" } ``` The SDK joins `resource_root_dir` with the relative model paths it ships internally, so model lookups land under `/opt//share/smartspectra/...` at runtime. The example's CMake writes this manifest at install time (not build time) so the recorded prefix matches the actual install location, not the build prefix. ## Depends: from SmartSpectraPackageManifest.json The example does **not** hard-code its `Depends:` list. Drift between the SDK's own apt-resolved dependencies and the example's list would silently produce a `.deb` that installs but fails to load the SDK on a stock container. Instead, the example reads `/share/smartspectra/package/SmartSpectraPackageManifest.json` at CMake-configure time and feeds its `debian_depends` field straight into `CPACK_DEBIAN_PACKAGE_DEPENDS`. The manifest is per-codename, so each codename produces its own Depends set from the same example source. A `FATAL_ERROR` guard in the example's CMake refuses to package if the manifest is missing or its `debian_depends` field is empty. The end-user therefore needs no Presage apt source — every transitive dependency resolves from the codename's stock archive at `apt install ./.deb` time on both **jammy** and **noble**. arm64 remains a follow-up. ## See also - Example README: [`cpp/samples/debian-app-example/README.md`](https://github.com/Presage-Security/SmartSpectra/blob/main/cpp/samples/debian-app-example/README.md) - Example packaging logic: [`cpp/samples/debian-app-example/CMakeLists.txt`](https://github.com/Presage-Security/SmartSpectra/blob/main/cpp/samples/debian-app-example/CMakeLists.txt)