docs: moved manual pages to docs repo, added link

Signed-off-by: David Karlsson <david.karlsson@docker.com>
This commit is contained in:
David Karlsson
2022-12-02 09:45:15 +01:00
parent e91d5326fe
commit 6c5168e1ec
22 changed files with 22 additions and 3131 deletions

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@@ -1,74 +1,3 @@
# Defining additional build contexts and linking targets
In addition to the main `context` key that defines the build context each target
can also define additional named contexts with a map defined with key `contexts`.
These values map to the `--build-context` flag in the [build command](https://docs.docker.com/engine/reference/commandline/buildx_build/#build-context).
Inside the Dockerfile these contexts can be used with the `FROM` instruction or `--from` flag.
The value can be a local source directory, container image (with `docker-image://` prefix),
Git URL, HTTP URL or a name of another target in the Bake file (with `target:` prefix).
## Pinning alpine image
```dockerfile
# syntax=docker/dockerfile:1
FROM alpine
RUN echo "Hello world"
```
```hcl
# docker-bake.hcl
target "app" {
contexts = {
alpine = "docker-image://alpine:3.13"
}
}
```
## Using a secondary source directory
```dockerfile
# syntax=docker/dockerfile:1
FROM scratch AS src
FROM golang
COPY --from=src . .
```
```hcl
# docker-bake.hcl
target "app" {
contexts = {
src = "../path/to/source"
}
}
```
## Using a result of one target as a base image in another target
To use a result of one target as a build context of another, specity the target
name with `target:` prefix.
```dockerfile
# syntax=docker/dockerfile:1
FROM baseapp
RUN echo "Hello world"
```
```hcl
# docker-bake.hcl
target "base" {
dockerfile = "baseapp.Dockerfile"
}
target "app" {
contexts = {
baseapp = "target:base"
}
}
```
Please note that in most cases you should just use a single multi-stage
Dockerfile with multiple targets for similar behavior. This case is recommended
when you have multiple Dockerfiles that can't be easily merged into one.
Moved to [docs.docker.com](https://docs.docker.com/build/customize/bake/build-contexts)

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# Building from Compose file
## Specification
Bake uses the [compose-spec](https://docs.docker.com/compose/compose-file/) to
parse a compose file and translate each service to a [target](file-definition.md#target).
```yaml
# docker-compose.yml
services:
webapp-dev:
build: &build-dev
dockerfile: Dockerfile.webapp
tags:
- docker.io/username/webapp:latest
cache_from:
- docker.io/username/webapp:cache
cache_to:
- docker.io/username/webapp:cache
webapp-release:
build:
<<: *build-dev
x-bake:
platforms:
- linux/amd64
- linux/arm64
db:
image: docker.io/username/db
build:
dockerfile: Dockerfile.db
```
```console
$ docker buildx bake --print
```
```json
{
"group": {
"default": {
"targets": [
"db",
"webapp-dev",
"webapp-release"
]
}
},
"target": {
"db": {
"context": ".",
"dockerfile": "Dockerfile.db",
"tags": [
"docker.io/username/db"
]
},
"webapp-dev": {
"context": ".",
"dockerfile": "Dockerfile.webapp",
"tags": [
"docker.io/username/webapp:latest"
],
"cache-from": [
"docker.io/username/webapp:cache"
],
"cache-to": [
"docker.io/username/webapp:cache"
]
},
"webapp-release": {
"context": ".",
"dockerfile": "Dockerfile.webapp",
"tags": [
"docker.io/username/webapp:latest"
],
"cache-from": [
"docker.io/username/webapp:cache"
],
"cache-to": [
"docker.io/username/webapp:cache"
],
"platforms": [
"linux/amd64",
"linux/arm64"
]
}
}
}
```
Unlike the [HCL format](file-definition.md#hcl-definition), there are some
limitations with the compose format:
* Specifying variables or global scope attributes is not yet supported
* `inherits` service field is not supported, but you can use [YAML anchors](https://docs.docker.com/compose/compose-file/#fragments) to reference other services like the example above
## `.env` file
You can declare default environment variables in an environment file named
`.env`. This file will be loaded from the current working directory,
where the command is executed and applied to compose definitions passed
with `-f`.
```yaml
# docker-compose.yml
services:
webapp:
image: docker.io/username/webapp:${TAG:-v1.0.0}
build:
dockerfile: Dockerfile
```
```
# .env
TAG=v1.1.0
```
```console
$ docker buildx bake --print
```
```json
{
"group": {
"default": {
"targets": [
"webapp"
]
}
},
"target": {
"webapp": {
"context": ".",
"dockerfile": "Dockerfile",
"tags": [
"docker.io/username/webapp:v1.1.0"
]
}
}
}
```
> **Note**
>
> System environment variables take precedence over environment variables
> in `.env` file.
## Extension field with `x-bake`
Even if some fields are not (yet) available in the compose specification, you
can use the [special extension](https://docs.docker.com/compose/compose-file/#extension)
field `x-bake` in your compose file to evaluate extra fields:
```yaml
# docker-compose.yml
services:
addon:
image: ct-addon:bar
build:
context: .
dockerfile: ./Dockerfile
args:
CT_ECR: foo
CT_TAG: bar
x-bake:
tags:
- ct-addon:foo
- ct-addon:alp
platforms:
- linux/amd64
- linux/arm64
cache-from:
- user/app:cache
- type=local,src=path/to/cache
cache-to:
- type=local,dest=path/to/cache
pull: true
aws:
image: ct-fake-aws:bar
build:
dockerfile: ./aws.Dockerfile
args:
CT_ECR: foo
CT_TAG: bar
x-bake:
secret:
- id=mysecret,src=./secret
- id=mysecret2,src=./secret2
platforms: linux/arm64
output: type=docker
no-cache: true
```
```console
$ docker buildx bake --print
```
```json
{
"group": {
"default": {
"targets": [
"aws",
"addon"
]
}
},
"target": {
"addon": {
"context": ".",
"dockerfile": "./Dockerfile",
"args": {
"CT_ECR": "foo",
"CT_TAG": "bar"
},
"tags": [
"ct-addon:foo",
"ct-addon:alp"
],
"cache-from": [
"user/app:cache",
"type=local,src=path/to/cache"
],
"cache-to": [
"type=local,dest=path/to/cache"
],
"platforms": [
"linux/amd64",
"linux/arm64"
],
"pull": true
},
"aws": {
"context": ".",
"dockerfile": "./aws.Dockerfile",
"args": {
"CT_ECR": "foo",
"CT_TAG": "bar"
},
"tags": [
"ct-fake-aws:bar"
],
"secret": [
"id=mysecret,src=./secret",
"id=mysecret2,src=./secret2"
],
"platforms": [
"linux/arm64"
],
"output": [
"type=docker"
],
"no-cache": true
}
}
}
```
Complete list of valid fields for `x-bake`:
* `cache-from`
* `cache-to`
* `contexts`
* `no-cache`
* `no-cache-filter`
* `output`
* `platforms`
* `pull`
* `secret`
* `ssh`
* `tags`
Moved to [docs.docker.com](https://docs.docker.com/build/customize/bake/compose-file)

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# Configuring builds
Bake supports loading build definition from files, but sometimes you need even
more flexibility to configure this definition.
For this use case, you can define variables inside the bake files that can be
set by the user with environment variables or by [attribute definitions](#global-scope-attributes)
in other bake files. If you wish to change a specific value for a single
invocation you can use the `--set` flag [from the command line](#from-command-line).
## Global scope attributes
You can define global scope attributes in HCL/JSON and use them for code reuse
and setting values for variables. This means you can do a "data-only" HCL file
with the values you want to set/override and use it in the list of regular
output files.
```hcl
# docker-bake.hcl
variable "FOO" {
default = "abc"
}
target "app" {
args = {
v1 = "pre-${FOO}"
}
}
```
You can use this file directly:
```console
$ docker buildx bake --print app
```
```json
{
"group": {
"default": {
"targets": [
"app"
]
}
},
"target": {
"app": {
"context": ".",
"dockerfile": "Dockerfile",
"args": {
"v1": "pre-abc"
}
}
}
}
```
Or create an override configuration file:
```hcl
# env.hcl
WHOAMI="myuser"
FOO="def-${WHOAMI}"
```
And invoke bake together with both of the files:
```console
$ docker buildx bake -f docker-bake.hcl -f env.hcl --print app
```
```json
{
"group": {
"default": {
"targets": [
"app"
]
}
},
"target": {
"app": {
"context": ".",
"dockerfile": "Dockerfile",
"args": {
"v1": "pre-def-myuser"
}
}
}
}
```
## From command line
You can also override target configurations from the command line with the
[`--set` flag](https://docs.docker.com/engine/reference/commandline/buildx_bake/#set):
```hcl
# docker-bake.hcl
target "app" {
args = {
mybuildarg = "foo"
}
}
```
```console
$ docker buildx bake --set app.args.mybuildarg=bar --set app.platform=linux/arm64 app --print
```
```json
{
"group": {
"default": {
"targets": [
"app"
]
}
},
"target": {
"app": {
"context": ".",
"dockerfile": "Dockerfile",
"args": {
"mybuildarg": "bar"
},
"platforms": [
"linux/arm64"
]
}
}
}
```
Pattern matching syntax defined in [https://golang.org/pkg/path/#Match](https://golang.org/pkg/path/#Match)
is also supported:
```console
$ docker buildx bake --set foo*.args.mybuildarg=value # overrides build arg for all targets starting with "foo"
$ docker buildx bake --set *.platform=linux/arm64 # overrides platform for all targets
$ docker buildx bake --set foo*.no-cache # bypass caching only for targets starting with "foo"
```
Complete list of overridable fields:
* `args`
* `cache-from`
* `cache-to`
* `context`
* `dockerfile`
* `labels`
* `no-cache`
* `output`
* `platform`
* `pull`
* `secrets`
* `ssh`
* `tags`
* `target`
## Using variables in variables across files
When multiple files are specified, one file can use variables defined in
another file.
```hcl
# docker-bake1.hcl
variable "FOO" {
default = upper("${BASE}def")
}
variable "BAR" {
default = "-${FOO}-"
}
target "app" {
args = {
v1 = "pre-${BAR}"
}
}
```
```hcl
# docker-bake2.hcl
variable "BASE" {
default = "abc"
}
target "app" {
args = {
v2 = "${FOO}-post"
}
}
```
```console
$ docker buildx bake -f docker-bake1.hcl -f docker-bake2.hcl --print app
```
```json
{
"group": {
"default": {
"targets": [
"app"
]
}
},
"target": {
"app": {
"context": ".",
"dockerfile": "Dockerfile",
"args": {
"v1": "pre--ABCDEF-",
"v2": "ABCDEF-post"
}
}
}
}
```
Moved to [docs.docker.com](https://docs.docker.com/build/customize/bake/configuring-build)

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# Bake file definition
`buildx bake` supports HCL, JSON and Compose file format for defining build
[groups](#group), [targets](#target) as well as [variables](#variable) and
[functions](#functions). It looks for build definition files in the current
directory in the following order:
* `docker-compose.yml`
* `docker-compose.yaml`
* `docker-bake.json`
* `docker-bake.override.json`
* `docker-bake.hcl`
* `docker-bake.override.hcl`
## Specification
Inside a bake file you can declare group, target and variable blocks to define
project specific reusable build flows.
### Target
A target reflects a single docker build invocation with the same options that
you would specify for `docker build`:
```hcl
# docker-bake.hcl
target "webapp-dev" {
dockerfile = "Dockerfile.webapp"
tags = ["docker.io/username/webapp:latest"]
}
```
```console
$ docker buildx bake webapp-dev
```
> **Note**
>
> In the case of compose files, each service corresponds to a target.
> If compose service name contains a dot it will be replaced with an underscore.
Complete list of valid target fields available for [HCL](#hcl-definition) and
[JSON](#json-definition) definitions:
| Name | Type | Description |
|---------------------|--------|-------------------------------------------------------------------------------------------------------------------------------------------------|
| `inherits` | List | [Inherit build options](#merging-and-inheritance) from other targets |
| `args` | Map | Set build-time variables (same as [`--build-arg` flag](https://docs.docker.com/engine/reference/commandline/buildx_build/)) |
| `cache-from` | List | External cache sources (same as [`--cache-from` flag](https://docs.docker.com/engine/reference/commandline/buildx_build/)) |
| `cache-to` | List | Cache export destinations (same as [`--cache-to` flag](https://docs.docker.com/engine/reference/commandline/buildx_build/)) |
| `context` | String | Set of files located in the specified path or URL |
| `contexts` | Map | Additional build contexts (same as [`--build-context` flag](https://docs.docker.com/engine/reference/commandline/buildx_build/)) |
| `dockerfile` | String | Name of the Dockerfile (same as [`--file` flag](https://docs.docker.com/engine/reference/commandline/buildx_build/)) |
| `dockerfile-inline` | String | Inline Dockerfile content |
| `labels` | Map | Set metadata for an image (same as [`--label` flag](https://docs.docker.com/engine/reference/commandline/buildx_build/)) |
| `no-cache` | Bool | Do not use cache when building the image (same as [`--no-cache` flag](https://docs.docker.com/engine/reference/commandline/buildx_build/)) |
| `no-cache-filter` | List | Do not cache specified stages (same as [`--no-cache-filter` flag](https://docs.docker.com/engine/reference/commandline/buildx_build/)) |
| `output` | List | Output destination (same as [`--output` flag](https://docs.docker.com/engine/reference/commandline/buildx_build/)) |
| `platforms` | List | Set target platforms for build (same as [`--platform` flag](https://docs.docker.com/engine/reference/commandline/buildx_build/)) |
| `pull` | Bool | Always attempt to pull all referenced images (same as [`--pull` flag](https://docs.docker.com/engine/reference/commandline/buildx_build/)) |
| `secret` | List | Secret to expose to the build (same as [`--secret` flag](https://docs.docker.com/engine/reference/commandline/buildx_build/)) |
| `ssh` | List | SSH agent socket or keys to expose to the build (same as [`--ssh` flag](https://docs.docker.com/engine/reference/commandline/buildx_build/)) |
| `tags` | List | Name and optionally a tag in the format `name:tag` (same as [`--tag` flag](https://docs.docker.com/engine/reference/commandline/buildx_build/)) |
| `target` | String | Set the target build stage to build (same as [`--target` flag](https://docs.docker.com/engine/reference/commandline/buildx_build/)) |
### Group
A group is a grouping of targets:
```hcl
# docker-bake.hcl
group "build" {
targets = ["db", "webapp-dev"]
}
target "webapp-dev" {
dockerfile = "Dockerfile.webapp"
tags = ["docker.io/username/webapp:latest"]
}
target "db" {
dockerfile = "Dockerfile.db"
tags = ["docker.io/username/db"]
}
```
```console
$ docker buildx bake build
```
### Variable
Similar to how Terraform provides a way to [define variables](https://www.terraform.io/docs/configuration/variables.html#declaring-an-input-variable),
the HCL file format also supports variable block definitions. These can be used
to define variables with values provided by the current environment, or a
default value when unset:
```hcl
# docker-bake.hcl
variable "TAG" {
default = "latest"
}
target "webapp-dev" {
dockerfile = "Dockerfile.webapp"
tags = ["docker.io/username/webapp:${TAG}"]
}
```
```console
$ docker buildx bake webapp-dev # will use the default value "latest"
$ TAG=dev docker buildx bake webapp-dev # will use the TAG environment variable value
```
> **Tip**
>
> See also the [Configuring builds](configuring-build.md) page for advanced usage.
### Functions
A [set of generally useful functions](https://github.com/docker/buildx/blob/master/bake/hclparser/stdlib.go)
provided by [go-cty](https://github.com/zclconf/go-cty/tree/main/cty/function/stdlib)
are available for use in HCL files:
```hcl
# docker-bake.hcl
target "webapp-dev" {
dockerfile = "Dockerfile.webapp"
tags = ["docker.io/username/webapp:latest"]
args = {
buildno = "${add(123, 1)}"
}
}
```
In addition, [user defined functions](https://github.com/hashicorp/hcl/tree/main/ext/userfunc)
are also supported:
```hcl
# docker-bake.hcl
function "increment" {
params = [number]
result = number + 1
}
target "webapp-dev" {
dockerfile = "Dockerfile.webapp"
tags = ["docker.io/username/webapp:latest"]
args = {
buildno = "${increment(123)}"
}
}
```
> **Note**
>
> See [User defined HCL functions](hcl-funcs.md) page for more details.
## Built-in variables
* `BAKE_CMD_CONTEXT` can be used to access the main `context` for bake command
from a bake file that has been [imported remotely](file-definition.md#remote-definition).
* `BAKE_LOCAL_PLATFORM` returns the current platform's default platform
specification (e.g. `linux/amd64`).
## Merging and inheritance
Multiple files can include the same target and final build options will be
determined by merging them together:
```hcl
# docker-bake.hcl
target "webapp-dev" {
dockerfile = "Dockerfile.webapp"
tags = ["docker.io/username/webapp:latest"]
}
```
```hcl
# docker-bake2.hcl
target "webapp-dev" {
tags = ["docker.io/username/webapp:dev"]
}
```
```console
$ docker buildx bake -f docker-bake.hcl -f docker-bake2.hcl webapp-dev
```
A group can specify its list of targets with the `targets` option. A target can
inherit build options by setting the `inherits` option to the list of targets or
groups to inherit from:
```hcl
# docker-bake.hcl
target "webapp-dev" {
dockerfile = "Dockerfile.webapp"
tags = ["docker.io/username/webapp:${TAG}"]
}
target "webapp-release" {
inherits = ["webapp-dev"]
platforms = ["linux/amd64", "linux/arm64"]
}
```
## `default` target/group
When you invoke `bake` you specify what targets/groups you want to build. If no
arguments is specified, the group/target named `default` will be built:
```hcl
# docker-bake.hcl
target "default" {
dockerfile = "Dockerfile.webapp"
tags = ["docker.io/username/webapp:latest"]
}
```
```console
$ docker buildx bake
```
## Definitions
### HCL definition
HCL definition file is recommended as its experience is more aligned with buildx UX
and also allows better code reuse, different target groups and extended features.
```hcl
# docker-bake.hcl
variable "TAG" {
default = "latest"
}
group "default" {
targets = ["db", "webapp-dev"]
}
target "webapp-dev" {
dockerfile = "Dockerfile.webapp"
tags = ["docker.io/username/webapp:${TAG}"]
}
target "webapp-release" {
inherits = ["webapp-dev"]
platforms = ["linux/amd64", "linux/arm64"]
}
target "db" {
dockerfile = "Dockerfile.db"
tags = ["docker.io/username/db"]
}
```
### JSON definition
```json
{
"variable": {
"TAG": {
"default": "latest"
}
},
"group": {
"default": {
"targets": [
"db",
"webapp-dev"
]
}
},
"target": {
"webapp-dev": {
"dockerfile": "Dockerfile.webapp",
"tags": [
"docker.io/username/webapp:${TAG}"
]
},
"webapp-release": {
"inherits": [
"webapp-dev"
],
"platforms": [
"linux/amd64",
"linux/arm64"
]
},
"db": {
"dockerfile": "Dockerfile.db",
"tags": [
"docker.io/username/db"
]
}
}
}
```
### Compose file
```yaml
# docker-compose.yml
services:
webapp:
image: docker.io/username/webapp:latest
build:
dockerfile: Dockerfile.webapp
db:
image: docker.io/username/db
build:
dockerfile: Dockerfile.db
```
> **Note**
>
> See [Building from Compose file](compose-file.md) page for more details.
## Remote definition
You can also build bake files directly from a remote Git repository or HTTPS URL:
```console
$ docker buildx bake "https://github.com/docker/cli.git#v20.10.11" --print
#1 [internal] load git source https://github.com/docker/cli.git#v20.10.11
#1 0.745 e8f1871b077b64bcb4a13334b7146492773769f7 refs/tags/v20.10.11
#1 2.022 From https://github.com/docker/cli
#1 2.022 * [new tag] v20.10.11 -> v20.10.11
#1 DONE 2.9s
```
```json
{
"group": {
"default": {
"targets": [
"binary"
]
}
},
"target": {
"binary": {
"context": "https://github.com/docker/cli.git#v20.10.11",
"dockerfile": "Dockerfile",
"args": {
"BASE_VARIANT": "alpine",
"GO_STRIP": "",
"VERSION": ""
},
"target": "binary",
"platforms": [
"local"
],
"output": [
"build"
]
}
}
}
```
As you can see the context is fixed to `https://github.com/docker/cli.git` even if
[no context is actually defined](https://github.com/docker/cli/blob/2776a6d694f988c0c1df61cad4bfac0f54e481c8/docker-bake.hcl#L17-L26)
in the definition.
If you want to access the main context for bake command from a bake file
that has been imported remotely, you can use the [`BAKE_CMD_CONTEXT` built-in var](#built-in-variables).
```console
$ cat https://raw.githubusercontent.com/tonistiigi/buildx/remote-test/docker-bake.hcl
```
```hcl
target "default" {
context = BAKE_CMD_CONTEXT
dockerfile-inline = <<EOT
FROM alpine
WORKDIR /src
COPY . .
RUN ls -l && stop
EOT
}
```
```console
$ docker buildx bake "https://github.com/tonistiigi/buildx.git#remote-test" --print
```
```json
{
"target": {
"default": {
"context": ".",
"dockerfile": "Dockerfile",
"dockerfile-inline": "FROM alpine\nWORKDIR /src\nCOPY . .\nRUN ls -l \u0026\u0026 stop\n"
}
}
}
```
```console
$ touch foo bar
$ docker buildx bake "https://github.com/tonistiigi/buildx.git#remote-test"
```
```text
...
> [4/4] RUN ls -l && stop:
#8 0.101 total 0
#8 0.102 -rw-r--r-- 1 root root 0 Jul 27 18:47 bar
#8 0.102 -rw-r--r-- 1 root root 0 Jul 27 18:47 foo
#8 0.102 /bin/sh: stop: not found
```
```console
$ docker buildx bake "https://github.com/tonistiigi/buildx.git#remote-test" "https://github.com/docker/cli.git#v20.10.11" --print
#1 [internal] load git source https://github.com/tonistiigi/buildx.git#remote-test
#1 0.429 577303add004dd7efeb13434d69ea030d35f7888 refs/heads/remote-test
#1 CACHED
```
```json
{
"target": {
"default": {
"context": "https://github.com/docker/cli.git#v20.10.11",
"dockerfile": "Dockerfile",
"dockerfile-inline": "FROM alpine\nWORKDIR /src\nCOPY . .\nRUN ls -l \u0026\u0026 stop\n"
}
}
}
```
```console
$ docker buildx bake "https://github.com/tonistiigi/buildx.git#remote-test" "https://github.com/docker/cli.git#v20.10.11"
```
```text
...
> [4/4] RUN ls -l && stop:
#8 0.136 drwxrwxrwx 5 root root 4096 Jul 27 18:31 kubernetes
#8 0.136 drwxrwxrwx 3 root root 4096 Jul 27 18:31 man
#8 0.136 drwxrwxrwx 2 root root 4096 Jul 27 18:31 opts
#8 0.136 -rw-rw-rw- 1 root root 1893 Jul 27 18:31 poule.yml
#8 0.136 drwxrwxrwx 7 root root 4096 Jul 27 18:31 scripts
#8 0.136 drwxrwxrwx 3 root root 4096 Jul 27 18:31 service
#8 0.136 drwxrwxrwx 2 root root 4096 Jul 27 18:31 templates
#8 0.136 drwxrwxrwx 10 root root 4096 Jul 27 18:31 vendor
#8 0.136 -rwxrwxrwx 1 root root 9620 Jul 27 18:31 vendor.conf
#8 0.136 /bin/sh: stop: not found
```
Moved to [docs.docker.com](https://docs.docker.com/build/customize/bake/file-definition)

View File

@@ -1,327 +1,3 @@
# User defined HCL functions
## Using interpolation to tag an image with the git sha
As shown in the [File definition](file-definition.md#variable) page, `bake`
supports variable blocks which are assigned to matching environment variables
or default values:
```hcl
# docker-bake.hcl
variable "TAG" {
default = "latest"
}
group "default" {
targets = ["webapp"]
}
target "webapp" {
tags = ["docker.io/username/webapp:${TAG}"]
}
```
alternatively, in json format:
```json
{
"variable": {
"TAG": {
"default": "latest"
}
},
"group": {
"default": {
"targets": ["webapp"]
}
},
"target": {
"webapp": {
"tags": ["docker.io/username/webapp:${TAG}"]
}
}
}
```
```console
$ docker buildx bake --print webapp
```
```json
{
"group": {
"default": {
"targets": [
"webapp"
]
}
},
"target": {
"webapp": {
"context": ".",
"dockerfile": "Dockerfile",
"tags": [
"docker.io/username/webapp:latest"
]
}
}
}
```
```console
$ TAG=$(git rev-parse --short HEAD) docker buildx bake --print webapp
```
```json
{
"group": {
"default": {
"targets": [
"webapp"
]
}
},
"target": {
"webapp": {
"context": ".",
"dockerfile": "Dockerfile",
"tags": [
"docker.io/username/webapp:985e9e9"
]
}
}
}
```
## Using the `add` function
You can use [`go-cty` stdlib functions](https://github.com/zclconf/go-cty/tree/main/cty/function/stdlib).
Here we are using the `add` function.
```hcl
# docker-bake.hcl
variable "TAG" {
default = "latest"
}
group "default" {
targets = ["webapp"]
}
target "webapp" {
args = {
buildno = "${add(123, 1)}"
}
}
```
```console
$ docker buildx bake --print webapp
```
```json
{
"group": {
"default": {
"targets": [
"webapp"
]
}
},
"target": {
"webapp": {
"context": ".",
"dockerfile": "Dockerfile",
"args": {
"buildno": "124"
}
}
}
}
```
## Defining an `increment` function
It also supports [user defined functions](https://github.com/hashicorp/hcl/tree/main/ext/userfunc).
The following example defines a simple an `increment` function.
```hcl
# docker-bake.hcl
function "increment" {
params = [number]
result = number + 1
}
group "default" {
targets = ["webapp"]
}
target "webapp" {
args = {
buildno = "${increment(123)}"
}
}
```
```console
$ docker buildx bake --print webapp
```
```json
{
"group": {
"default": {
"targets": [
"webapp"
]
}
},
"target": {
"webapp": {
"context": ".",
"dockerfile": "Dockerfile",
"args": {
"buildno": "124"
}
}
}
}
```
## Only adding tags if a variable is not empty using an `notequal`
Here we are using the conditional `notequal` function which is just for
symmetry with the `equal` one.
```hcl
# docker-bake.hcl
variable "TAG" {default="" }
group "default" {
targets = [
"webapp",
]
}
target "webapp" {
context="."
dockerfile="Dockerfile"
tags = [
"my-image:latest",
notequal("",TAG) ? "my-image:${TAG}": "",
]
}
```
```console
$ docker buildx bake --print webapp
```
```json
{
"group": {
"default": {
"targets": [
"webapp"
]
}
},
"target": {
"webapp": {
"context": ".",
"dockerfile": "Dockerfile",
"tags": [
"my-image:latest"
]
}
}
}
```
## Using variables in functions
You can refer variables to other variables like the target blocks can. Stdlib
functions can also be called but user functions can't at the moment.
```hcl
# docker-bake.hcl
variable "REPO" {
default = "user/repo"
}
function "tag" {
params = [tag]
result = ["${REPO}:${tag}"]
}
target "webapp" {
tags = tag("v1")
}
```
```console
$ docker buildx bake --print webapp
```
```json
{
"group": {
"default": {
"targets": [
"webapp"
]
}
},
"target": {
"webapp": {
"context": ".",
"dockerfile": "Dockerfile",
"tags": [
"user/repo:v1"
]
}
}
}
```
## Using typed variables
Non-string variables are also accepted. The value passed with env is parsed
into suitable type first.
```hcl
# docker-bake.hcl
variable "FOO" {
default = 3
}
variable "IS_FOO" {
default = true
}
target "app" {
args = {
v1 = FOO > 5 ? "higher" : "lower"
v2 = IS_FOO ? "yes" : "no"
}
}
```
```console
$ docker buildx bake --print app
```
```json
{
"group": {
"default": {
"targets": [
"app"
]
}
},
"target": {
"app": {
"context": ".",
"dockerfile": "Dockerfile",
"args": {
"v1": "lower",
"v2": "yes"
}
}
}
}
```
Moved to [docs.docker.com](https://docs.docker.com/build/customize/bake/hcl-funcs)

View File

@@ -1,36 +1,3 @@
# High-level build options with Bake
> This command is experimental.
>
> The design of bake is in early stages, and we are looking for [feedback from users](https://github.com/docker/buildx/issues).
{: .experimental }
Buildx also aims to provide support for high-level build concepts that go beyond
invoking a single build command. We want to support building all the images in
your application together and let the users define project specific reusable
build flows that can then be easily invoked by anyone.
[BuildKit](https://github.com/moby/buildkit) efficiently handles multiple
concurrent build requests and de-duplicating work. The build commands can be
combined with general-purpose command runners (for example, `make`). However,
these tools generally invoke builds in sequence and therefore cannot leverage
the full potential of BuildKit parallelization, or combine BuildKit's output
for the user. For this use case, we have added a command called
[`docker buildx bake`](https://docs.docker.com/engine/reference/commandline/buildx_bake/).
The `bake` command supports building images from HCL, JSON and Compose files.
This is similar to [`docker compose build`](https://docs.docker.com/compose/reference/build/),
but allowing all the services to be built concurrently as part of a single
request. If multiple files are specified they are all read and configurations are
combined.
We recommend using HCL files as its experience is more aligned with buildx UX
and also allows better code reuse, different target groups and extended features.
## Next steps
* [File definition](file-definition.md)
* [Configuring builds](configuring-build.md)
* [User defined HCL functions](hcl-funcs.md)
* [Defining additional build contexts and linking targets](build-contexts.md)
* [Building from Compose file](compose-file.md)
Moved to [docs.docker.com](https://docs.docker.com/build/customize/bake)