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- Remove redundant chars and all errors caused by RST->MD conversion. e.g. [/#, /\, \<, />, etc.] - Fix broken inter-document links - Fix outbound links no-longer active or changed - Fix lists - Fix code blocks - Correct apostrophes - Replace redundant inline note marks for code with code marks - Fix broken image links - Remove non-functional title links - Correct broken cross-docs links - Improve readability Note: This PR does not try to fix/amend: - Grammatical errors - Lexical errors - Linguistic-logic errors etc. It just aims to fix main structural or conversion errors to serve as a base for further amendments that will cover others including but not limited to those mentioned above. Docker-DCO-1.1-Signed-off-by: O.S. Tezer <ostezer@gmail.com> (github: ostezer) Update: - Fix backtick issues Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@home.org.au> (github: SvenDowideit)
43 lines
1.7 KiB
Markdown
43 lines
1.7 KiB
Markdown
page_title: Container
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page_description: Definitions of a container
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page_keywords: containers, lxc, concepts, explanation, image, container
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# Container
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## Introduction
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Once you start a process in Docker from an [*Image*](image.md), Docker fetches
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the image and its [*Parent Image*](image.md), and repeats the process until it
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reaches the [*Base Image*](image.md/#base-image-def). Then the
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[*Union File System*](layer.md) adds a read-write layer on top. That read-write
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layer, plus the information about its [*Parent Image*](image.md) and some
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additional information like its unique id, networking configuration, and
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resource limits is called a **container**.
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## Container State
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Containers can change, and so they have state. A container may be **running** or
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**exited**.
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When a container is running, the idea of a "container" also includes a
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tree of processes running on the CPU, isolated from the other processes
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running on the host.
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When the container is exited, the state of the file system and its exit
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value is preserved. You can start, stop, and restart a container. The
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processes restart from scratch (their memory state is **not** preserved
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in a container), but the file system is just as it was when the
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container was stopped.
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You can promote a container to an [*Image*](image.md) with `docker commit`.
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Once a container is an image, you can use it as a parent for new containers.
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## Container IDs
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All containers are identified by a 64 hexadecimal digit string
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(internally a 256bit value). To simplify their use, a short ID of the
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first 12 characters can be used on the commandline. There is a small
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possibility of short id collisions, so the docker server will always
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return the long ID.
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