Building Container Images - Revision history

Leo: /* Apt-based package managers */

2022-02-23T22:16:45Z

Apt-based package managers

← Older revision		Revision as of 22:16, 23 February 2022
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	Apt-based package managers are used on Ubuntu and Debian based distros.		Apt-based package managers are used on Ubuntu and Debian based distros.

	*~~Set~~ <code>DEBIAN_FRONTEND=noninteractive</code> to prevent some packages from prompting interactive input (<code>tzdata</code> for example), which leads to indefinite waiting for an user input		*Prepend your apt install command with <code>DEBIAN_FRONTEND=noninteractive</code> to prevent some packages from prompting interactive input (<code>tzdata</code> for example), which leads to indefinite waiting for an user input. Don't set this as an environment variable since it will linger after the container is built.
	At the end of the run, <code>rm -rf /var/lib/apt/lists/</code> to clean up.		At the end of the run, <code>rm -rf /var/lib/apt/lists/</code> to clean up.

Leo: Updated categories

2021-12-30T01:28:55Z

Updated categories

← Older revision		Revision as of 01:28, 30 December 2021
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	{{Navbox Linux}}		{{Navbox Linux}}
	[[Category:Linux]]		[[Category:Linux]]
	~~[[Category:LinuxUtilities]]~~

Leo: Added categories and navbox

2021-12-30T00:47:38Z

Added categories and navbox

← Older revision		Revision as of 00:47, 30 December 2021
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	*Create virtual groups for build dependencies using <code>apk add --virtual=build-deps make gcc</code>. These groups can later be removed with <code>apk del --purge build-deps</code>.		*Create virtual groups for build dependencies using <code>apk add --virtual=build-deps make gcc</code>. These groups can later be removed with <code>apk del --purge build-deps</code>.
	At the end of the run, <code>/var/cache/apk/</code> to clean up.		At the end of the run, <code>/var/cache/apk/</code> to clean up.

			{{Navbox Linux}}
			[[Category:Linux]]
			[[Category:LinuxUtilities]]

Leo at 06:21, 11 November 2021

2021-11-11T06:21:31Z

← Older revision		Revision as of 06:21, 11 November 2021
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	~~<br />~~		== Container build Tools ==
			The easiest way to build container images is to use Docker and a Dockerfile. However, since Docker isn't cool anymore, there are some other options that may be worth looking into which will be covered in the following subsections.

	==~~Tips~~==		=== Docker ===
			The tried and true method to build container images. However, Docker itself can be a bit resource heavy and requires a daemon to be running on the system.

			A container is defined in a Dockerfile and built with the <code>docker build</code> command.

			=== BuildKit ===
			BuildKit is a new code base for building containers that's been part of Docker since version 19.03. It supports some interesting features such as more efficient caching, concurrent dependency resolution, and distributed workers, among other things. A container build is typically faster because of these performance enhancements. Best of all, it uses the same Dockerfile format as Docker.

			A container build can be done right now by export the <code>DOCKER_BUILDKIT=1</code> environment variable while calling <code>docker build</code>.

			=== Buildah ===
			Buildah is the container building component of podman, Red Hat's replacement to Docker. Containers are built with Dockerfiles (though not all features are supported) using the the <code>podman build</code> command.

			==Container build tips==
	Review the Dockerfile best practices at https://docs.docker.com/develop/develop-images/dockerfile_best-practices/		Review the Dockerfile best practices at https://docs.docker.com/develop/develop-images/dockerfile_best-practices/

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	Remember to clean up at the end of each RUN to minimize the layer sizes. Things you can do include:		Remember to clean up at the end of each RUN to minimize the layer sizes. Things you can do include:
	* <code>rm -rf /tmp/* /var/cache/* /var/tmp/*</code>
	* Clean up package manager caches and remove unnecessary build-only packages		<code>rm -rf /tmp/ /var/cache/* /var/tmp/*</code>
			*Clean up package manager caches and remove unnecessary build-only packages

	Better yet, use multi-staged builds (https://docs.docker.com/develop/develop-images/multistage-build/) to bundle the results of multiple layers into one.		Better yet, use multi-staged builds (https://docs.docker.com/develop/develop-images/multistage-build/) to bundle the results of multiple layers into one.
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	Apt-based package managers are used on Ubuntu and Debian based distros.		Apt-based package managers are used on Ubuntu and Debian based distros.

	* Set <code>DEBIAN_FRONTEND=noninteractive</code> to prevent some packages from prompting interactive input (<code>tzdata</code> for example), which leads to indefinite waiting for an user input		*Set <code>DEBIAN_FRONTEND=noninteractive</code> to prevent some packages from prompting interactive input (<code>tzdata</code> for example), which leads to indefinite waiting for an user input
	At the end of the run, <code>rm -rf /var/lib/apt/lists/</code> to clean up.		At the end of the run, <code>rm -rf /var/lib/apt/lists/</code> to clean up.

	===apk-based package managers ===		===apk-based package managers===
	Alpine Linux uses the apk package manager. One neat feature with apk is the ability to group packages into virtual groups which we can uninstall with one command.		Alpine Linux uses the apk package manager. One neat feature with apk is the ability to group packages into virtual groups which we can uninstall with one command.

	* Create virtual groups for build dependencies using <code>apk add --virtual=build-deps make gcc</code>. These groups can later be removed with <code>apk del --purge build-deps</code>.		*Create virtual groups for build dependencies using <code>apk add --virtual=build-deps make gcc</code>. These groups can later be removed with <code>apk del --purge build-deps</code>.
	* At the end of the run, <code>/var/cache/apk/*</code> to clean up.		At the end of the run, <code>/var/cache/apk/</code> to clean up.

Leo at 05:35, 8 November 2021

2021-11-08T05:35:31Z

← Older revision		Revision as of 05:35, 8 November 2021
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	<br />		<br />

	== Tips ==		==Tips==
			Review the Dockerfile best practices at https://docs.docker.com/develop/develop-images/dockerfile_best-practices/

	=== RUN commands ===		===RUN commands===
	Try to bundle multiple RUN commands together to reduce the number of container image layers and their overall size. Concatenating multiple commands with <code>&&</code> or <code>;</code> (with <code>set-x,</code> which stops the script when a non zero exit code is returned).		Try to bundle multiple RUN commands together to reduce the number of container image layers and their overall size. Concatenating multiple commands with <code>&&</code> or <code>;</code> (with <code>set-x,</code> which stops the script when a non zero exit code is returned).
	{{Highlight		{{Highlight
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	\| lang = text		\| lang = text
	}}		}}
	~~Alternatively, use multi-staged builds (https://docs.docker.com/develop/develop-images/multistage-build/) to bundle the results of multiple layers into one.~~

	~~=== Yum~~/~~dnf-based package managers ===~~		Remember to clean up at the end of each RUN to minimize the layer sizes. Things you can do include:
	~~Yum or dnf~~ package ~~managers are used on Red Hat based distros.~~		* <code>rm -rf /tmp/* /var/cache/* /var/tmp/*</code>
			* Clean up package manager caches and remove unnecessary build-only packages

	* Install packages with <code>yum -~~y install<~~/~~code> to avoid prompts~~		Better yet, use multi-staged builds (https://docs.docker.com/develop/develop-images/multistage-build/) to bundle the results of multiple layers into one.
	* <code>yum -y clean all</~~code>, and clean up caches <code>rm -rf~~ /~~var~~/~~cache<~~/~~code>~~
	* Apt-~~based package managers~~

			{{highlight\|lang=text\|code=
			FROM centos:8 as build
			RUN yum -y update
			RUN yum -y install vim

			FROM centos:8
			## We can copy specific artifacts from the build container. Eg:
			COPY --from=build /usr/bin/vim /usr/bin/vim
			}}


			===Yum/dnf-based package managers===
			Yum or dnf package managers are used on Red Hat based distros.

			*Install packages with <code>yum -y install</code> to avoid prompts
			*At the end of the run, <code>yum -y clean all</code>, and clean up caches <code>rm -rf /var/cache</code> afterwards

			===Apt-based package managers===
	Apt-based package managers are used on Ubuntu and Debian based distros.		Apt-based package managers are used on Ubuntu and Debian based distros.

	* Set <code>DEBIAN_FRONTEND=noninteractive</code> to prevent some packages from prompting interactive input (<code>tzdata</code> for example), which leads to indefinite waiting for an user input		* Set <code>DEBIAN_FRONTEND=noninteractive</code> to prevent some packages from prompting interactive input (<code>tzdata</code> for example), which leads to indefinite waiting for an user input
	* <code>rm -rf /var/lib/apt/lists/*</code> ~~afterwards~~		At the end of the run, <code>rm -rf /var/lib/apt/lists/</code> to clean up.

			===apk-based package managers ===
			Alpine Linux uses the apk package manager. One neat feature with apk is the ability to group packages into virtual groups which we can uninstall with one command.

	<br />		* Create virtual groups for build dependencies using <code>apk add --virtual=build-deps make gcc</code>. These groups can later be removed with <code>apk del --purge build-deps</code>.
			* At the end of the run, <code>/var/cache/apk/*</code> to clean up.

Leo: Created page with "
== Tips == === RUN commands === Try to bundle multiple RUN commands together to reduce the number of container image layers and their overall size. Concatenating mult..."

2021-11-08T05:25:59Z

Created page with "<br /> == Tips == === RUN commands === Try to bundle multiple RUN commands together to reduce the number of container image layers and their overall size. Concatenating mult..."

New page

<br />

== Tips ==

=== RUN commands ===
Try to bundle multiple RUN commands together to reduce the number of container image layers and their overall size. Concatenating multiple commands with <code>&&</code> or <code>;</code> (with <code>set-x,</code> which stops the script when a non zero exit code is returned).
{{Highlight
| code = RUN set -ex; \
yum -y install vim; \
yum clean all

## or,
RUN yum -y install vim && yum clean all
| lang = text
}}
Alternatively, use multi-staged builds (https://docs.docker.com/develop/develop-images/multistage-build/) to bundle the results of multiple layers into one.

=== Yum/dnf-based package managers ===
Yum or dnf package managers are used on Red Hat based distros.

* Install packages with <code>yum -y install</code> to avoid prompts
* <code>yum -y clean all</code>, and clean up caches <code>rm -rf /var/cache</code>
* Apt-based package managers

Apt-based package managers are used on Ubuntu and Debian based distros.

* Set <code>DEBIAN_FRONTEND=noninteractive</code> to prevent some packages from prompting interactive input (<code>tzdata</code> for example), which leads to indefinite waiting for an user input
* <code>rm -rf /var/lib/apt/lists/*</code> afterwards

<br />