1. Installation¶

This section describes how to build and install Charliecloud. For some distributions, this can be done using your package manager; otherwise, both normal users and admins can build and install it manually.

Warning

If you are installing on a Cray and have not applied the patch for Cray case #188073, you must use the cray branch to avoid crashing nodes during job completion. This is a Cray bug that Charliecloud happens to tickle. There is a patch available from Cray for CLE6.0 UP04 and UP05. The fix is mainlined into Cray CLE6.0 UP06, released in March 2018. Versions of Cray CLE6.0 prior to UP04 are unpatched and affected by the bug. Non-Cray build boxes and others at the same site can still use the master branch.

Prequisites
Package manager install
Manual build and install
Docker tips
- Understand the security implications of Docker
- Configuring for a proxy

1.1. Prequisites ¶

Charliecloud is a simple system with limited prerequisites. If your system meets these prerequisites but Charliecloud doesn’t work, please report that as a bug.

1.1.1. Run time ¶

Systems used for running images need:

Recent Linux kernel with CONFIG_USER_NS=y. We recommend version 4.4 or higher.
C compiler and standard library
POSIX shell and utilities

Some distributions need configuration changes to enable user namespaces. For example:

Debian Stretch needs sysctl kernel.unprivileged_userns_clone=1.
RHEL/CentOS 7.4 and 7.5 need both a kernel command line option and a sysctl. Important note: Docker does not work with user namespaces, so skip step 4 of the Red Hat instructions, i.e., don’t add --userns-remap to the Docker configuration (see issue #97).

1.1.2. Build time ¶

Systems used for building images need the run-time prerequisites, plus:

Bash 4.1+

and optionally:

Docker 17.03+
internet access or Docker configured for a local Docker hub
root access using sudo

Older versions of Docker may work but are untested. We know that 1.7.1 does not work.

1.1.3. Test suite ¶

In order to run the test suite on a run or build system (you can test each mode independently), you also need:

Bash 4.1+
Python 2.6+
Bats 0.4.0
wget

Note that without Docker on the build system, some of the test suite will be skipped.

Bats can be installed at the system level or embedded in the Charliecloud source code. If it’s in both places, the latter is used.

To embed Bats, either:

Download Charliecloud using git clone --recursive, which will check out Bats as a submodule in test/bats.
Unpack the Bats zip file or tarball in test/bats.

To check an embedded Bats:

$ test/bats/bin/bats --version
Bats 0.4.0

1.2. Package manager install ¶

Charliecloud is available in some distribution package repositories, and packages can be built for additional distributions. (Note, however, that system-wide installation is not required — Charliecloud works fine when built by any user and run from one’s home directory or similar.)

This section describes how to obtain packages for the distributions we know about, and where to go for support on them.

If you’d like to build one of the packages, or if you’re a package maintainer, see packaging/README and packaging/*/README for additional documentation.

Pull requests and other collaboration to improve the packaging situation are particularly welcome!

1.2.1. Debian ¶

Charliecloud has been proposed for inclusion in Debian; see issue 95.

Distribution versions	proposed for Buster and Stretch backports
Maintainers	Lucas Nussbaum (`lucas@debian.org`) and Peter Wienemann (`wienemann@physik.uni-bonn.de`)
Bug reports to	Charliecloud’s GitHub issue tracker
Packaging source code	in Charliecloud: `packaging/debian`

1.2.2. Gentoo ¶

A native package for Gentoo is available.

Package name	sys-cluster/charliecloud
Maintainer	Oliver Freyermuth (`o.freyermuth@googlemail.com`)
Bug reports to	Gentoo Bugzilla
Packaging source code	Gentoo ebuild repository

To install:

$ emerge sys-cluster/charliecloud

If may necessary to accept keywords first, e.g.:

$ echo "=sys-cluster/charliecloud-0.2.3_pre20171121 ~amd64" >> /etc/portage/package.accept_keywords

A live ebuild is also available and can be keyworded via:

$ echo "~sys-cluster/charliecloud-9999 \*\*" >> /etc/portage/package.accept_keywords

1.2.3. RPM-based distributions ¶

An RPM .spec file is provided in the Charliecloud source code. We are actively seeking distribution packagers to adapt this into official packages!

Repositories	none yet
Maintainer	Oliver Freyermuth (`o.freyermuth@googlemail.com`)
Bug reports to	Charliecloud’s GitHub issue tracker
Packaging source code	in Charliecloud: `packaging/redhat`

1.3. Manual build and install ¶

1.3.1. Download ¶

See our GitHub project: https://github.com/hpc/charliecloud

The recommended download method is git clone --recursive.

1.3.2. Build ¶

To build, simply:

$ make

To build the documentation, see the contributor’s guide.

1.3.3. Install (optional)¶

You can run Charliecloud from the source directory, and it’s recommended you at least run the test suite before installation to establish that your system will work.

To install (FHS-compliant):

$ make install PREFIX=/foo/bar

Note that PREFIX is required. It does not default to /usr/local like many packages.

1.4. Docker tips ¶

Docker is a convenient way to build Charliecloud images. While installing Docker is beyond the scope of this documentation, here are a few tips.

1.4.1. Understand the security implications of Docker ¶

Because Docker (a) makes installing random crap from the internet really easy and (b) is easy to deploy insecurely, you should take care. Some of the implications are below. This list should not be considered comprehensive nor a substitute for appropriate expertise; adhere to your moral and institutional responsibilities.

1.4.1.1. `docker` equals root¶

Anyone who can run the docker command or interact with the Docker daemon can trivially escalate to root. This is considered a feature.

For this reason, don’t create the docker group, as this will allow passwordless, unlogged escalation for anyone in the group.

1.4.1.2. Images can contain bad stuff¶

Standard hygiene for “installing stuff from the internet” applies. Only work with images you trust. The official Docker Hub repositories can help.

1.4.1.3. Containers run as root¶

By default, Docker runs container processes as root. In addition to being poor hygiene, this can be an escalation path, e.g. if you bind-mount host directories.

1.4.1.4. Docker alters your network configuration¶

To see what it did:

$ ifconfig    # note docker0 interface
$ brctl show  # note docker0 bridge
$ route -n

1.4.1.5. Docker installs services¶

If you don’t want the service starting automatically at boot, e.g.:

$ systemctl is-enabled docker
enabled
$ systemctl disable docker
$ systemctl is-enabled docker
disabled

1.4.2. Configuring for a proxy ¶

By default, Docker does not work if you have a proxy, and it fails in two different ways.

The first problem is that Docker itself must be told to use a proxy. This manifests as:

$ sudo docker run hello-world
Unable to find image 'hello-world:latest' locally
Pulling repository hello-world
Get https://index.docker.io/v1/repositories/library/hello-world/images: dial tcp 54.152.161.54:443: connection refused

If you have a systemd system, the Docker documentation explains how to configure this. If you don’t have a systemd system, then /etc/default/docker might be the place to go?

The second problem is that Docker containers need to know about the proxy as well. This manifests as images failing to build because they can’t download stuff from the internet.

The fix is to set the proxy variables in your environment, e.g.:

export HTTP_PROXY=http://proxy.example.com:8088
export http_proxy=$HTTP_PROXY
export HTTPS_PROXY=$HTTP_PROXY
export https_proxy=$HTTP_PROXY
export ALL_PROXY=$HTTP_PROXY
export all_proxy=$HTTP_PROXY
export NO_PROXY='localhost,127.0.0.1,.example.com'
export no_proxy=$NO_PROXY

You also need to teach sudo to retain them. Add the following to /etc/sudoers:

Defaults env_keep+="HTTP_PROXY http_proxy HTTPS_PROXY https_proxy ALL_PROXY all_proxy NO_PROXY no_proxy"

Because different programs use different subsets of these variables, and to avoid a situation where some things work and others don’t, the Charliecloud test suite (see below) includes a test that fails if some but not all of the above variables are set.