Provided by: charliecloud_0.9.1-1_amd64
ch-build - Wrapper for "docker build" that works around some of its annoying behaviors
$ ch-build -t TAG [ARGS ...] CONTEXT
Build a Docker image named TAG described by Dockerfile ./Dockerfile or as specified. This is a wrapper for docker build with various enhancements. Sudo privileges are required to run the docker command. Arguments: --file Dockerfile to use (default: ./Dockerfile) -t name (tag) of Docker image to build --help print help and exit --version print version and exit Additional arguments are accepted and passed unchanged to docker build.
IMPROVEMENTS OVER PLAIN DOCKER BUILD
ch-build adds the following features to docker build: · If there is a file Dockerfile in the current working directory and -f is not already specified, add -f $PWD/Dockerfile. · Pass the HTTP proxy environment variables through with --build-arg. NOTE: The suffix :latest is somewhat misleading, as neither ch-build nor bare docker build will notice if the base FROM image has been updated. Use --no-cache to make sure you have the latest base image, at the cost of rebuilding every layer.
Create a Docker image tagged foo and specified by the file Dockerfile located in the current working directory. Use /bar as the Docker context directory: $ ch-build -t foo /bar Equivalent to above: $ ch-build -t foo --file=./Dockerfile /bar Instead, use the Dockerfile /baz/qux.docker: $ ch-build -t foo --file=/baz/qux.docker /bar Note that calling your Dockerfile anything other than Dockerfile will confuse people.
If Charliecloud was obtained from your Linux distribution, use your distribution’s bug reporting procedures. Otherwise, report bugs to: <https://github.com/hpc/charliecloud/issues>
charliecloud(1) Full documentation at: <https://hpc.github.io/charliecloud>
Docker is a convenient way to build Charliecloud images. While installing Docker is beyond the scope of this documentation, here are a few tips. 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. 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. 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. 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. Docker alters your network configuration To see what it did: $ ifconfig # note docker0 interface $ brctl show # note docker0 bridge $ route -n 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 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 220.127.116.11:443: 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.
Reid Priedhorsky, Tim Randles, and others
2014–2018, Los Alamos National Security, LLC 2018-08-11 20:22 GMT+00:00 CH-BUILD(1)