Functional Options¶

Each of these options has context specific help and sub commands

-r, –run

Start new containers.

–build, –duebuild

Execute container’s /usr/local/bin/duebuild script in current directory. See the –run section for more.

–create

Make and configure new Docker images.

–delete

Delete existing Docker images that match the term.

-m, –manage

Manipulate and query existing images.

-h, –help

Usage information.

-v, –version

Print DUE’s version number.

–run options¶

These options are available after the –run argument, and relate to starting and logging in to containers.

Starting an image¶

-i, –run-image [filter]

Allows the user to reduce the number of images shown to run by restricting them to entries that contain [filter]. If only one image matches the filter, it will be invoked without asking the user to choose it.

-a, –all

Show all containers on the system. DUE can be used to log in to containers that it did not create, but the user may have to supply a default –username and –userid (usually –username root and –userid 0. See below )

–ignore-type

 When accessing the container, do not attempt to create a user
    

-c, –command [cmd]

Run [cmd] in the container using the –login-shell. This must be the last command parsed, as [cmd] is handed off to be run in the container. The primary use of this would be using the container to build without having to interactively log in to it. Note: when issuing multiple commands, remember to "" your arguments, and backslash () any semicolons (;) used to split up the commands. Otherwise the shell where the commands are invoked will take anything after the first ;, and treat it as a command to be run locally. This can obfuscate things if the command can work inside or out of the container.

Example: look at /proc and the password file in a container: ./due –run –command “ls -lrt /proc” ; “cat /etc/passwd”

–build | –duebuild

If there is a /usr/local/bin/duebuild script in the container, this option will run it with a default configuration, or take additional passed arguments if present. Those arguments will vary depending on the nature of the target being built by the container’s duebuild script. For more information, check the template/README.md for the image type, or use: due –duebuild –help to select a container and get its duebuild script’s help options directly.

–duebuild

Same behavior as –build, but a bit clearer that it is working with the selected container’s duebuild script. One notable difference is that due –duebuild –help will select a container and execute duebuild –help to see the options provided by that particular script.

–dockerarg [arg]

Put [arg] in the docker run invocation. For multiple arguments, use multiple invocations of –dockerarg. This allows for things like running containers with –privileged

–debug

Sets defaults of –username root –userid 0 and the –any option to show images that were not created by DUE. Helpful for internal debug if image creation dies running internal configuration scripts.

–container-name name

Change the name of the running container. This can provide clarity in a build automation environment, where containers may be automatically spun up. Note that if the new name does not have `due' in it, it will be filtered out from DUE’s –login option unless –all is also provided. This may or may not be desirable behavior.

–home-dir [host path]

Absolute path to a directory to use as the home directory when the user logs in. Defaults to the user’s home directory unless overridden with this argument, or set otherwise in /etc/due/due.conf, or ~/config/due/due.conf

–mount-dir [hp:cp]

Mount absolute path on host system (hp) at absolute path in container. The colon (:) is necessary to separate the two. Multiple –mount-dir commands can be used in a single invocation. Example: mount host /tmp dir in container /var/build: –mount-dir /tmp/:var/build

Logging in to a running container¶

-l, –login

Choose an existing container to log in to.

–username [username]

Name to use when logging in.

–userid [id#]

User ID to use when logging in.

–groupname [groupname]

Container user’s default group

–groupid [id#]

ID of container user’s group

–login-shell [path]

Program to use as login

–help-runtime

Invoke runtime help

–help-runtime-examples

Show examples of use

–create options¶

These options are accessed after the –create argument, and, predictably enough, relate to creating new images.

Creation Overview¶

Containers created by DUE will always have files from ./templates/common-templates in every image. The primary example of this is the container-create-user.sh script that sets up an account for the user in the container, and allows commands to be run in the container as if it was the user invoking them.

The order of creation is as follows, using the debian-package template as an example, where the resulting image will be named `debian-package-10'

1 - The contents of common-templates are copied to a debian-package-10-template-merge directory under ./due-build-merge/

2 - The contents of the debian-package template directory copied in to the debian-package-10-template-merge directory and will overwrite any files with identical names.

3 - Any REPLACE_ fields in the template files are replaced with values supplied from the command line (such as the starting container image) and all files are copied to ./due-build-merge/debian-package-10

4 - The ./due-build-merge/debian-package-10/Dockerfile.create file is used to create the image from this build directory.

Creation tips¶

Quick image changes can be made by editing the build directory ( ./due-build-merge/debian-package-10 ) and re running ./due –create –build-dir ./due-build-merge/debian-package-10

The final image will hold a /due-configuration directory, which holds everything that went into the image. This is very useful for install script debug inside the container.

A list of available default configurations is provided by running: due –create –help This will parse the README.md files under the ./templates directory looking for specific strings. This output can be filtered by using wildcard syntax as follows: due –create –help –filter

Advanced image creation¶

DUE 3.0.0 introduced hierarchical template parsing, where a template could be a combination of files provided by `sub-type' directories, to reduce file duplication. With this, files with identical names and paths will overwrite the ones provided by higher directories.

Example: Given directory structure: due/templates/foo/sub-type/bar/sub-type/baz

Image creation using the `baz' template will be: 1 - files from templates/common-templates 2 - plus files from foo overwriting any files with the same relative path from common-templates 3 - plus files from bar overwriting foo files the same way 4 - plus files from baz overwriting bar files the same way.

While not normally needed, this may be useful for supporting a number of Images with minor but important differences. See templates/README.md for more information.

Creation example¶

1 - Configure an image build directory under due-build-merge named from –name Mandatory:

–from [name:tag]

Pull name:tag from registry to use as starting point for the image.

–use-template [role]

Use files from templates/[role] to generate the config directory.

–description “desc”

Quoted string to describe the container on login.

–name name

Name for resulting image and config directory. Ex: debian-stretch-build, ubuntu-18.04-build, etc

Optional:

–prompt [prompt]

Set in container prompt to [prompt] to provide user context

–no-image

With –create, allow directories to be created, but do not try to build the image. Effectively stops use of –dir. Useful for debugging directory configuration issues.

–filter [term]

With –create –help, filter examples to contain [term].

2 - Build a Docker image from the image build directory.

–dir [dirname]

Build using an existing configuration directory.

–clean

Delete the due-build-merge staging directories.

–manage options¶

These options are accessed after the –manage argument, and can make working with containers/images easier.

-l, –list-images

List images created by DUE.

–stop

Use the menu interface to stop a running container. Works with –all to show containers not started by the user. If is supplied, it will match all the user’s containers to that pattern and produce a script that can be edited and run to delete the listed containers. NOTE: –all –stop can be used to do some serious damage. NOTE: since all DUE containers are started with -rm, stopping a container deletes it and all the data in it from memory.

–export-container name

Export a running container to disk as a Docker image named name. Note that to run the saved image it must be added back to the system with –import.

–export-image name

Save an existing Docker image as a file that can be copied elsewhere. If name is not supplied, the user can choose from a menu.

–import-image name

Import a docker image stored on disk as tar file

–copy-config

Create a personal DUE configuration file in ~/.config/due/due.config

–make-dev-dir [dir]

Populate a local directory for DUE container development.

–list-templates

List available templates.

–delete-matched [term]

Delete containers that contain this term. USE WITH CAUTION!

–docker-clean

Run `docker system prune ; docker image prune' to reclaim disk space.

–help-examples

Examples of using management options.