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Using QPacker

A packaging utility for deploying kdb+ applications to the cloud



jq (Linux JSON parser) Version 1.6+


Docker Compose


Docker should be able to run under your user account without using sudo:

Your host should have access to the internet to pull Docker images, or access should be configured to allow Docker through a proxy.

Docker must run on the target, not where the target is a container with Docker running on the host


Install QPacker

QPacker installers are delivered via Nexus:

└── qpacker
    ├── qpacker-2.0.14-4.0.0.deb
    └── qpacker-2.0.14-4.0.0.x86_64.rpm

To install using the shell installer run:


The installer will also prompt for an installation directory.

Installation Directory [default /home/user]

Set your Git username and email:

git config --global "John Smith"
git config --global ""

Uninstall QPacker

To uninstall using the shell installer run:

sh --uninstall

When uninstalling or replacing, the installer will check PATH for qp, along with default install directories. If not found a normal install will proceed.


QPacker requires that a valid kdb+ license file is present in the system.

Copy the license provided as part of the EAP to your ~/.qp.licenses folder. QPacker will look there to determine which license should be used.

Alternatively if you already have a license you wish to use it can be passed to QPacker via an environment variable containing a base64 encoding of the license file, e.g.

kx.lic style license

export KDB_KXLICENSE_B64=$(base64 -w0 kx.lic)

kc.lic style license

export KDB_LICENSE_B64=$(base64 -w0 kc.lic)

k4.lic style license

export KDB_K4LICENSE_B64=$(base64 -w0 k4.lic)


By default QPacker will build a Docker image for your application. This image can then be tagged and pushed to a Docker registry of your choice. The images created are set to run as non-root user (USER nobody), this means that you cannot modify the contents of the container when it is running. If you have code running inside the container which needs to write data, then the location being written to needs to be volume-mapped into the container at run time.

qp run

Once QPacker has successfully built a Docker image you can run the application using qp run. This will launch the new container using Docker. The configuration for the container will be passed in via the qpbuild/.env file, which contains a base64-encoded license for kdb+ and the SHA256 hash of the Docker container.

Running the containerized application in this way is useful to debug simple standalone applications. To run multiple images together, consider using Docker Compose or a more fully featured container orchestrator such as Kubernetes.

Docker Compose

To run several images which make up an application, consider using Docker Compose. The basic-tick-system example provides a sample docker-compose.yml which shows how volumes can be mapped into the containers and ports exposed to the base system.

To run any image you need to provide a license file as a base64-encoded string e.g.

      - KDB_KXLICENSE_B64="base64 encoded kx.lic string"
      - KDB_LICENSE_B64="base64 encoded kc.lic string"
      - KDB_K4LICENSE_B64="base64 encoded k4.lic string"


This usage is also included in the README folder.

qp command and options:

Options Description
build Build a project and all dependencies [default if no args provided]. qp build can support more than one arg at a time.
[target] Specific target(s) to build (e.g. "qp build tp" or "qp build tp gw") if omitted, will default to all.
[-binlinux] Build in-tree linux and qpk.
[-docker] Build docker images.
[-linux] Build linux installers e.g. rpm, deb, sh. Will default to -binlinux build if ui field is not set in qp.json.
[-rpm] Build rpm+sh.
[-deb] Build deb+sh.
[-sh] Build sh code only.
[-dedup] Enable dependency deduplication.
[-unlocked] Do not lock q code in qpks or images.
run Runs an entrypoint for the project, rebuilding if necessary.
[entrypoint] Specific entrypoint to run (e.g. "qp run tp") if omitted, will default to 'default'.
[ -- ] Pass args through to entrypoint (e.g. "qp run tp -- -p 1234").
doctor Analyses the project environment and provides recommendations.
clean Clean up any files created by qp that are in the tree.
tag Tag a docker image of a built target. Target must exist in qpbuild/.env (e.g. "qp tag 1.2.3") To tag all images omit the image name from the url and pass the -all argument (e.g. "qp tag 1.2.3 -all")
push Push a tagged docker image or a qpk file. image: (e.g. "qp push 1.2.3") qpk: (e.g. "qp push 0.0.1") NB qpk will be picked up from "./qpbuild/qpk/"
pull Pull a pre-built qpk to be used as a dependency in your project.(e.g. "qp pull 0.0.1") NB qpk will be placed in current directory

Contains KX license information as prompted for on your first run of QPacker. If a k[xc4].lic license file is here it will be used for all build or run targets.


Patterns can be used to omit source code and other artefacts from the qpbuild tree. The .qpignore file should be placed in the project root directory as a sibling of qp.json. .qpignore also supports selectively ignoring files on a per app basis by using .qpignore.<appname>

The supported patterns are detailed in the table below:

Pattern Description Ignore at all levels in the tree
*.sh Ignore files with .sh suffix at all levels in the tree
docs/* Ignore docs directory at top level in the tree
**/docs Ignore docs at all levels in the tree

This environment variable controls the Linux distro QPacker uses for image artefacts. By default this is set to rockylinux:9. This can be changed before running qp by setting export QPDOCKER_BASE=ubuntu:20.04 or by setting the value in qp.json. The distros supported are Centos, Rockylinux and Ubuntu.

To build a specific dependency under a particular distro, set the following in the qp.json inside the dependency source tree

"docker_base_image": [ "rockylinux:9" ]

This environment variable can be set to 1 to skip OS package additions when using a custom base image.


This environment variable controls the Linux distro QPacker uses for the builder containers sobuilder/qpacker/pybuilder. This be changed before running qp by setting `export QPDOCKER_BUILD_BASE=ubuntu:20.04.


To turn off kurl auto registration in a QPacker built image set the following in your qp.json inside your app definition

"kurl_disable_auto_register": "1"

To produce debug logging (set -x), set environment variable QPDEBUG to 1.

You can then capture output to file and to screen via qp build 2>&1 | tee -a qp.out.

To turn off debug logging either unset QPDEBUG or export QPDEBUG=0. NB: with debug enabled, QPacker will not clean up files in /tmp created by the build process.


To pass a taskset value through to containers which run q, set the environment variable QPTASKSET to taskset value

The format should follow the -c mask which specifies a list of processors, e.g. export QPTASKSET=0-3 would result in q being run with the following taskset stanza taskset -c 0-3.

To turn off QPTASKSET use unset QPTASKSET.

When passed to a qp built application it will cause LD_PRELOAD to be exported to the value provided, just before the execution of kdb+.
e.g. QPPRELOAD=/lib/ will result in export LD_PRELOAD=/lib/

To turn on, set environment variable QPBUILD_PARALLEL to 1.

When set, build configurations with three or more application targets will run in parallel.

The first app target will setup the build environment and prime the docker cache for all resulting images.

Each subsequent build will then execute in parallel reducing the overall build time.



To enable dependency deduplication, pass -dedup to qp build or export QP_DEDUP=1.

The resulting qpks will skip loading any dependencies that were loaded before. The name of the dependency is the part after the last path separator. This mode only makes a difference if the dependencies were themselves built with deduplication and the same dependency appears in more than one place in the dependency tree, in which case the first one encountered gets loaded. This allows resolution of dependency conflicts by putting the desired version first in the dependency list.


To produce unlocked builds, pass -unlocked to qp build or export QP_UNLOCKED=1.

The resulting qpks and images will contain unlocked q code.

The qpk name will have -unlocked.qpk suffix and an additional text file unlocked will be added to the qpk.

Images will have an additional Docker label com.kx.qp.unlocked with a value of 1.


To set the timeout for the qp helper containers, qlocker and sobuiler, set the following before running qp, export QPHELPER_TIMEOUT=integer.

The default timeout is 1800 seconds and will result in the container staying up for at least 1800 seconds if there are no builds running.


In order to add custom content to beginning of Dockerfiles generated by QPacker you can set the environment variable QPDOCKER_INCLUDE_FILE which should point to a file which includes the Docker commands you wish to be inserted.

The commands will be inserted after the FROM, USER and LABELS sections.


In order to add custom build args to Dockerfiles generated by QPacker you can set the environment variable QPDOCKER_BUILD_ARGS which should be a space separated string in the format export QPDOCKER_BUILD_ARGS="ARG1=VALUE1 ARG2=VALUE2".

To pass build args to the package manager used in the final image build set QPDOCKER_BUILD_ARGS="QPPGKMR_OPTS=--option".


In order to add docker args to docker build commands executed by QPacker, you can set the environment variable QPDOCKER_OPTS. For example if you set export QPDOCKER_OPTS="--no-cache", this will cause all docker build steps executed by QPacker as part of qp build to build without a docker cache. NB build commands will apply to the building of qlocker and sobuilder images as well as the application image produced by QPacker.


In order to add docker args to docker run commands executed by QPacker, you can set the environment variable QPDOCKER_RUN_OPTS. For example if you set export QPDOCKER_RUN_OPTS="--cpuset-cpus 2", this will cause all docker run steps executed by QPacker to run on 2 CPU cores. NB run commands will apply to the running of qlocker and sobuilder images as well as the application image produced by QPacker.

QPK artefact


The qp build command creates a QPK artefact as an output. It is a ZIP file and can be distributed. QPacker can use it in lieu of a dependency in the qp.json file. The QPK can be found in the qpbuild/qpk folder of your repository after building. To reset the folder in preparation for a clean build, use qp clean.

The QPK contains all of the files, but any dependency can also have a .qpignore file with patterns (much like .gitignore might have) used to omit source code and other artefacts from the build tree. Files can also be ignored on a per app in qp.json basis by using .qpignore.<appname>


The root directory of every QP project contains a qp.json file, with metadata for the package: what is it called, dependencies and the location for entrypoints for the qp run command.

The base level of the qp.json will be each component name, under which are properties. Properties QPacker parses are:

property value
entry location of the entrypoint for the qp run command (string array)
depends dependencies of the application (string array).
dynamic_depends These dependencies are added to the artefact but not automatically loaded.
docker_base_image base image to build the Docker containers sobuilder/qlocker, default: rockylinux:9 (single element string array)
docker_build_image base image used for image artefacts. By default this is set to rockylinux:9 (single element string array)

For example, a project has a dependency on kurl.qpk. QPacker searches for the dependency in

  1. folders relative to the current project directory; failing that
  2. relative to the directories listed in the QPPATH environment variable; failing that
  3. relative to the installation directory of QPacker itself.

For example, a project has a dependency on bq.qpk. QP searches for the dependency in folders relative to the current project directory; failing that, relative to the directories listed in the QPPATH environment variable; failing that, relative to the installation directory of QP itself. The qp.json file for this application would be

  "default": {
    "depends": [ "bq" ],
    "entry": [ "myapp.q" ]

A qp.json can contain multiple applications, for example

    "entry": [ "rdb.q"]
    "entry": [ "tp.q" ]

QPPATH separators vary by operating system

QPPATH items are separated by colon : on Linux and macOS, but by semicolon ; on Windows.

It is designed for use by CI/CD tools, and not for ordinary development.


Substitute for Google Cloud, or dkr.ecr.{region} for Amazon, or whatever registry you use.

Software is often built by disparate teams, who may individually have remit over a particular component, and package that component for consumption by others. QPacker will store all artefacts for a project in a QPK file. While this file is intended for binary dependencies, it is also intended to be portable across environments. The QPK artefact can be published to the package registry on Git using

qp push 0.1.0

This could also be added to your CI pipeline as a post-commit hook.


Once the QPK artefact has been published to a registry, other projects can pull it for inclusion in their applications. Starting a new project based on QPacker and using the REST library can be as simple as:

mkdir my-app
cd my-app
echo '{ "default": { "entry": [ "app.q" ], } }' > qp.json
qp pull 0.1.0


Container registry

By default, QPacker generates a Docker image for each application it builds. The images can be pushed to Docker Hub-compatible container repositories, including private repositories such as Google Cloud or GitLab. You can use:

qp tag 0.1.0
qp push 0.1.0

Docker directory permissions

By default qp build runs Docker images as the root user and generates output (often to ./qpbuild) which will be owned by root but the permissions will be altered via chmod -R 777.

For all QPacker-related output to be generated as your own user, configure Docker with userns-remap:

  1. Get your user id $ id -u e.g. 1000
  2. Get your users gid $ id -g e.g. 1000
  3. Edit /etc/subuid and add username:1000:65536
  4. Edit /etc/subgid and add username:1000:65536
  5. Create or edit /etc/docker/daemon.json
  6. Add (optional for Docker-on-Windows and Docker-on-Mac)

        "userns-remap": "username"

  7. Restart the Docker daemon using systemctl or similar

This change will make your current Docker containers inaccessible

Using QPacker in air-gapped environments

To use QPacker in air-gapped environments where there is no access to the internet, prebuild the all builder Docker images qlocker, sobuilder, rpmbuilder, debbuilder.

The environment used to prepare these images will require access to the internet to pull down their dependencies

Once built, the images should be made available to QPacker via an internal Docker registry. For QPacker to pick them up automatically, tag them with the version number returned by qp version.

To simplify this process a qpacker-images TGZ is available for download, along with each release of QPacker. It contains all the files required to build the three builder images, and an example runtime image for the resulting QPacker Docker artefacts.

Package contents

The qpacker-images release tgz expands into the following layout:

├── py/
├── q/
├── run/
└── so/

Build environment

The host used to build the images should be a Linux platform with Docker installed and access to the following sites: 

Build preparation

Prepare the build environment by unpacking the qpacker-images TGZ and changing to the resulting directory.

tar -xvzf qpacker-images-X.Y.Z-X.Y.Z.tgz
cd qpacker-images-X.Y.Z-X.Y.Z

Custom content

How custom content, such as environment variables, can be added to the beginning of the Dockerfiles used to build the images

Create a file called docker.include.txt inside the qpacker-images-X.Y.Z-X.Y.Z directory. The contents of this file will be appended to each of the Dockerfiles (directly below the FROM) used to build qlocker, sobuilder, rpmbuilder, debbuilder and the runtime image.

For example:

$ cat docker.include.txt
ENV http_proxy=
ENV http_proxy=

This will have the following included in each Dockerfile

$ cat q/
FROM rockylinux:9
ENV http_proxy=
ENV http_proxy=


To build the images:


NB sobuilder image will be tagged with the value of QPDOCKER_BUILD_BASE (default rockylinux:9) which can be overwritten by passing the flag --docker-build-base ubuntu:20.04.


On successful execution of the build script there should be a new dist directory in the tree, containing Docker images saved (via docker save) as .tar.gz files:

$ ls -1 dist/

The images contain the appropriate tag (2.0.29) from the version of QPacker the qpacker-images TGZ was shipped with.

Each tarball contains an image, used by QPacker:

image description
kxbase Base runtime image: can be used as the base image for the Docker image artefact produced by QPacker
qlocker General-purpose container for QPacker build stages, to obfuscate q code and assemble contents for QPacker’s QPK artefacts
sobuilder Multi-purpose shared-object builder: can build C/C++ shared objects and understands make, cmake, configure etc.
rpmbuilder Container for building rpm installers
debbuilder Containers for building debian installers

Loading images

Each of the images above can be loaded via docker load and published to an internal Docker registry for use with QPacker.

For QPacker to pick up the image it must be present on the host machine (via docker pull) and it must also be tagged with the version number from the image .tar.gz file.

The images are loaded as follows:

docker load < kxbase_2.0.29.tar.gz
docker load < qlocker_2.0.29.tar.gz
docker load < sobuilder_rockylinux-9_9.9.9.tar.gz
docker load < rpmbuilder_2.0.29.tar.gz
docker load < debbuilder_2.0.29.tar.gz

This results in the following entries in the local Docker images cache:

$ docker images
REPOSITORY                           TAG      IMAGE ID       CREATED          SIZE
kxbase                               2.0.29   f81c9b14aa78   16 minutes ago   62.7MB
sobuilder-rockylinux-9               2.0.29   09a66bbdde41   16 minutes ago   255MB
qlocker                              2.0.29   718b7c994724   19 minutes ago   222MB
rpmbuilder                           2.0.29   9aff5fb10b3b   16 minutes ago   526MB
debbuilder                           2.0.29   09a66bbdde41   16 minutes ago   139MB

These images can then be retagged and pushed into another Docker registry, and QPacker can use them provided the TAG matches the version returned via qp version.

For example, for a registry the tag and push commands would be:

docker tag kxbase:2.0.29 \
docker push

docker tag sobuilder-rockylinux-9:2.0.29 \
docker push

docker tag qlocker:2.0.29 \
docker push

docker tag rpmbuilder:2.0.29 \
docker push

docker tag debbuilder:2.0.29 \
docker push

This image is then picked up by QPacker on any host that has pulled the image into its image cache:

$ docker pull
$ docker pull
$ docker pull
$ docker pull
$ docker pull
$ qp build
... [output trimmed]
INFO  | Build   | Using pre-built image qlocker:2.0.29
INFO  | Build   | Using pre-built image sobuilder-rockylinux-9:2.0.29
INFO  | Build   | Using pre-built image rpmbuilder:2.0.29
INFO  | Build   | Using pre-built image debbuilder:2.0.29

To use the pre-built kxbase image, set:


The resulting image should be built on top of the kxbase image.