docker-adlmflexnetserver

Unofficial, vendor-neutral container image for running a FlexNet license server (lmgrd + vendor daemon) for any vendor whose FlexNet package can be supplied as a download URL or a local file.

The repository provides a single Docker-based deployment pattern for environments that operate FlexNet network licenses as managed infrastructure. The vendor FlexNet package is selected at build time via FLEXNET_PACKAGE_URL in .env; license files stay outside the image and are mounted read-only at runtime.

This project is not affiliated with Autodesk, AMD/Xilinx, MathWorks or Flexera. It does not provide license entitlements. Vendor FlexNet binaries are redistribution-restricted: the CI workflow builds and validates images but does not publish them to a registry, and packages that require a vendor login are never committed to this repository.

Supported Vendors

Vendor	Package	Source	Status
Autodesk	NLM (nlm*.tar.gz, contains RPMs)	public download	tested
AMD/Xilinx	linux_flexlm__v*.zip	AMD account required, place in packages/	tested
MathWorks	MATLAB License Manager	MathWorks account	planned

Runtime Contract

Item	Value
License server manager	lmgrd (starts the vendor daemon from the license file's VENDOR line)
Default license path	/usr/local/flexlm/licenses/license.dat
Default log target	Docker stdout/stderr (docker compose logs)
License manager port	2100 (configurable via FLEXNET_PORT)
Vendor daemon port	dynamic; publish it only if your network setup requires it (pin with VENDOR <name> PORT=<port> in the license file)
Runtime user	lmadmin (uid/gid 10001)
Default Compose command	-z -datestamp
Compose health check	lmutil lmstat -c /usr/local/flexlm/licenses/license.dat

The container hostname and MAC address must match the values used when the vendor license file was generated. If the license file pins different ports, publish those ports instead of the default above.

Quick Start

git clone https://github.com/symrex/docker-adlmflexnetserver.git
cd docker-adlmflexnetserver

cp example.env .env
cp /path/to/license.lic licenses/latest.lic
chmod 0444 licenses/latest.lic

Edit .env:

FLEXNET_PACKAGE_URL=https://damassets.autodesk.net/content/dam/autodesk/www/files/linux/nlm11.19.9.0_ipv4_ipv6_linux64.tar.gz
FLEXNET_HOSTNAME=name_registered_with_vendor
FLEXNET_MAC_ADDRESS=XX:XX:XX:XX:XX:XX

Build and start:

docker compose up --build -d

Check status:

docker compose ps
docker compose logs --tail=100 flexnet
docker compose exec flexnet lmutil lmstat -a -c /usr/local/flexlm/licenses/license.dat

Vendor Packages

FLEXNET_PACKAGE_URL accepts two kinds of values:

1. Public HTTPS URL — the package is downloaded during the image build (Autodesk NLM works this way).
2. Local file reference — packages/<filename> for packages that are only downloadable behind a vendor login (AMD/Xilinx FlexLM, MATLAB). Place the file in ./packages/ before building; the directory is git-ignored.

The Dockerfile detects the archive layout automatically:

• tar.gz/tar.xz/tar.bz2 containing *.rpm → extracted with rpm2cpio (Autodesk NLM layout)
• zip containing an lnx64.o/ directory → binaries copied from there (AMD/Xilinx FlexLM layout)
• any other tar/zip → all contained files are used as-is

The build fails early if the package does not contain lmgrd and lmutil.

Configuration

The Compose file reads runtime values from .env.

Variable	Required	Purpose
FLEXNET_PACKAGE_URL	yes for builds	Vendor FlexNet package (HTTPS URL or packages/<file>).
FLEXNET_HOSTNAME	yes	Hostname used by the vendor license file.
FLEXNET_MAC_ADDRESS	yes	MAC address / host ID registered for the license server.
FLEXNET_PORT	optional	Host-side port published for lmgrd. Defaults to 2100.
FLEXNET_VENDOR_PORT	optional	Host-side port published for the vendor daemon (must match VENDOR <name> PORT= in the license file). Defaults to 27010.
FLEXNET_IMAGE	optional	Local image tag used by Docker Compose.
FLEXNET_PLATFORM	optional	Build and runtime platform. Defaults to linux/amd64, matching the vendor Linux packages.
FLEXNET_COMMAND	optional	Extra runtime arguments for lmgrd.

Treat license files and .env as sensitive operational material.

Build Targets

The Dockerfile uses a Debian bookworm builder stage to download and extract the vendor FlexNet package. The final stage is selected with TARGET_TYPE and defaults to debian:bookworm-slim, which keeps a shell available for operational tooling. A distroless final image (gcr.io/distroless/base-debian12:nonroot) remains available via build-arg.

Vendor Linux packages contain x86_64 binaries, so local builds default to linux/amd64. This is required on ARM64 hosts such as Apple Silicon Macs.

Build the default image:

docker compose build

For a distroless final image:

docker build \
  --platform linux/amd64 \
  --build-context build-context=./packages \
  --build-arg FLEXNET_PACKAGE_URL="$(sed -n 's/^FLEXNET_PACKAGE_URL=//p' .env)" \
  --build-arg TARGET_TYPE=gcr.io/distroless/base-debian12:nonroot \
  -t flexnetserver:distroless .

Operations

Docker Compose enables init: true for the service. This lets Docker run a tiny init process as PID 1, forward signals, and reap child processes created by lmgrd or vendor daemons without adding an init binary to the image.

Read Docker logs:

docker compose logs -f flexnet

Validate the license service from inside the container:

docker compose exec flexnet lmutil lmstat -a -c /usr/local/flexlm/licenses/license.dat

Apply an updated license file:

cp /path/to/new_server.lic licenses/latest.lic
chmod 0444 licenses/latest.lic
docker compose restart flexnet

Switch vendors: replace the package in packages/ (or the URL in .env), replace licenses/latest.lic, update FLEXNET_HOSTNAME / FLEXNET_MAC_ADDRESS, then rebuild:

docker compose build --no-cache && docker compose up -d

Legal Distribution Guard

Vendor FlexNet binaries (Autodesk NLM, AMD/Xilinx FlexLM, MATLAB) are redistribution-restricted by their respective license terms. Because this image embeds vendor binaries after build, redistribution through public registries such as GHCR is treated as not allowed for this repository.

The default workflow is configured accordingly:

• pull requests, pushes to main, monthly scheduled runs, and manual dispatch build and smoke-test the local image;
• no workflow step logs in to a registry, pushes an image, signs a remote image, or attaches a registry attestation;
• each user or organization must build the image locally, or inside their own private CI/CD environment, from the official vendor download;
• packages that require a vendor login are never committed to this repository (packages/ is git-ignored).

Troubleshooting

Symptom	Checks
Container exits immediately	Inspect docker compose logs flexnet and verify the license file mount.
xilinxd/adskflex exited with status 45	The vendor daemon binary is missing from the image — verify FLEXNET_PACKAGE_URL points to the complete vendor package (not only lmgrd).
Unrecognized command-line switch "d"	The vendor lmgrd does not support -datestamp (Xilinx FlexLM does not). Use FLEXNET_COMMAND=-z for Xilinx; -z -datestamp works for Autodesk.
The TCP port number in the license, <port>, is already in use	The license file pins the vendor daemon port (VENDOR <name> PORT=<port>) to the same port as lmgrd. Change the PORT= value to a free port (e.g. 27010) or remove it entirely for dynamic assignment.
Not a valid server hostname	The container hostname must match the SERVER line of the license file (FLEXNET_HOSTNAME).
No valid hostids, exiting	The container MAC address must match the host ID in the license file (FLEXNET_MAC_ADDRESS).
Health check fails	Run lmutil lmstat manually and inspect docker compose logs flexnet.
Clients cannot obtain licenses	Verify hostname, MAC address, firewall rules and license-file SERVER / VENDOR lines.
Port conflict	Change FLEXNET_PORT or stop the conflicting service.
Build download fails	Validate FLEXNET_PACKAGE_URL; vendor download URLs can change.

CI/CD

.github/workflows/build.yml is intentionally small. It runs hadolint, builds the image from the public Autodesk NLM URL, and runs lmutil lmhostid as a smoke test. It runs on pull requests, pushes to main, manual dispatch, and once per month as a prophylactic check.

Migration from pre-2026-10 versions

Environment variables were renamed from ADM_FLEXNET_* to FLEXNET_*:

Old	New
ADM_FLEXNET_HOSTNAME	FLEXNET_HOSTNAME
ADM_FLEXNET_MAC_ADDRESS	FLEXNET_MAC_ADDRESS
ADM_FLEXNET_NLM_URL	FLEXNET_PACKAGE_URL
ADM_FLEXNET_IMAGE	FLEXNET_IMAGE
ADM_FLEXNET_PLATFORM	FLEXNET_PLATFORM
ADM_FLEXNET_COMMAND	FLEXNET_COMMAND

The compose service was renamed from admflexnet to flexnet, the default published port from 27000 to 2100, and the EXPOSE statements were removed (port publishing is now handled exclusively by Compose).

License

This repository's source files are licensed under the MIT License. That license does not apply to vendor FlexNet binaries (Autodesk NLM, AMD/Xilinx FlexLM, MATLAB License Manager) or vendor documentation downloaded during the Docker build.

Based on the original work by @haysclark.