sha256:a9561eb1b190625c9adb5a9513e72c4dedafc1cb2d4c5236c9a6957ec7dfd5a9.
- Layers must be packed and unpacked reproducibly to avoid changing the
- layer ID, for example by using tar-split to save the tar headers. Note
- that the digest used as the layer ID is taken over an uncompressed
- version of the tar.
- ChainID. For a
- single layer (or the layer at the bottom of a stack), the
- ChainID is equal to the layer's DiffID.
- Otherwise the ChainID is given by the formula:
- ChainID(layerN) = SHA256hex(ChainID(layerN-1) + " " + DiffID(layerN)).
- sha256:a9561eb1b190625c9adb5a9513e72c4dedafc1cb2d4c5236c9a6957ec7dfd5a9.
- Since the configuration JSON that gets hashed references hashes of each
- layer in the image, this formulation of the ImageID makes images
- content-addressable.
- [a-zA-Z0-9_.-], except they may not start with a .
- or - character. Tags are limited to 128 characters.
- :). For example, in an image tagged with the name
- my-app:3.1.4, my-app is the Repository
- component of the name. A repository name is made up of slash-separated
- name components, optionally prefixed by a DNS hostname. The hostname
- must comply with standard DNS rules, but may not contain
- _ characters. If a hostname is present, it may optionally
- be followed by a port number in the format :8080.
- Name components may contain lowercase characters, digits, and
- separators. A separator is defined as a period, one or two underscores,
- or one or more dashes. A name component may not start or end with
- a separator.
- string
- string
- string
- string
- struct
- null, in
- which case any execution parameters should be specified at creation of
- the container.
- string
- The username or UID which the process in the container should - run as. This acts as a default value to use when the value is - not specified when creating a container.
-All of the following are valid:
-useruiduser:groupuid:giduid:groupuser:gidIf group/gid is not specified, the
- default group and supplementary groups of the given
- user/uid in /etc/passwd
- from the container are applied.
integer
- integer
- -1 to
- disable swap. This acts as a default value to use when the
- value is not specified when creating a container.
- integer
- struct
- map[string]struct{} and is represented in JSON as
- an object mapping its keys to an empty object. Here is an
- example:
-{
- "8080": {},
- "53/udp": {},
- "2356/tcp": {}
-}
- Its keys can be in the format of:
- "port/tcp"
- "port/udp"
- "port"
- "tcp" if not
- specified. These values act as defaults and are merged with
- any specified when creating a container.
- array of strings
- VARNAME="var value".
- These values act as defaults and are merged with any specified
- when creating a container.
- array of strings
- array of strings
- Entrypoint value is
- not specified, then the first entry of the Cmd
- array should be interpreted as the executable to run.
- boolean
- Entrypoint
- or Cmd or both, contain only a single element array
- that is a pre-escaped, and combined into a single string, **CommandLine**.
- If "true", the value in Entrypoint or CmdCmd
- should be used as-is to avoid double escaping.
- Note, the exact behavior of ArgsEscaped is complex
- and subject to implementation details.
- struct
- {
- "Test": [
- "CMD-SHELL",
- "/usr/bin/check-health localhost"
- ],
- "Interval": 30000000000,
- "Timeout": 10000000000,
- "Retries": 3,
- "StartInterval": 3000000000
-}
- The object has the following fields.
- array of strings
- [] : inherit healthcheck from base image["NONE"] : disable healthcheck["CMD", arg1, arg2, ...] : exec arguments directly["CMD-SHELL", command] : run command with system's default shellinteger
- integer
- integer
- integer
- struct
- map[string]struct{} and is represented in
- JSON as an object mapping its keys to an empty object. Here is
- an example:
-{
- "/var/my-app-data/": {},
- "/etc/some-config.d/": {},
-}
- string
- array of strings
- array of strings
- ["/bin/sh", "-c"], and ["cmd", "/S", "/C"]
- on Windows. This field is set by the SHELL
- instruction in a Dockerfile, and *must* be written in JSON
- form.
- struct
- type is usually set to layers.
- diff_ids is an array of layer content hashes (DiffIDs), in order from bottom-most to top-most.
- "rootfs": {
- "diff_ids": [
- "sha256:c6f988f4874bb0add23a778f753c65efe992244e148a1d2ec2a8b664fb66bbd1",
- "sha256:5f70bf18a086007016e948b04aed3b82103a36bea41755b6cddfaf10ace3c6ef",
- "sha256:13f53e08df5a220ab6d13c58b2bf83a59cbdc2e04d0a3f041ddf4b0ba4112d49"
- ],
- "type": "layers"
-}
- struct
- history is an array of objects describing the history of
- each layer. The array is ordered from bottom-most layer to top-most
- layer. The object has the following fields.
- created: Creation time, expressed as a ISO-8601 formatted
- combined date and time
- author: The author of the build point
- created_by: The command which created the layer
- comment: A custom message set when creating the layer
- empty_layer: This field is used to mark if the history
- item created a filesystem diff. It is set to true if this history
- item doesn't correspond to an actual layer in the rootfs section
- (for example, a command like ENV which results in no change to the
- filesystem).
- "history": [
- {
- "created": "2015-10-31T22:22:54.690851953Z",
- "created_by": "/bin/sh -c #(nop) ADD file:a3bc1e842b69636f9df5256c49c5374fb4eef1e281fe3f282c65fb853ee171c5 in /"
- },
- {
- "created": "2015-10-31T22:22:55.613815829Z",
- "created_by": "/bin/sh -c #(nop) CMD [\"sh\"]",
- "empty_layer": true
- }
-]
-