413 lines
16 KiB
Markdown
413 lines
16 KiB
Markdown
<!--[metadata]>
|
|
+++
|
|
title = "build"
|
|
description = "The build command description and usage"
|
|
keywords = ["build, docker, image"]
|
|
[menu.main]
|
|
parent = "smn_cli"
|
|
+++
|
|
<![end-metadata]-->
|
|
|
|
# build
|
|
|
|
```markdown
|
|
Usage: docker build [OPTIONS] PATH | URL | -
|
|
|
|
Build an image from a Dockerfile
|
|
|
|
Options:
|
|
--build-arg value Set build-time variables (default [])
|
|
--cgroup-parent string Optional parent cgroup for the container
|
|
--cpu-period int Limit the CPU CFS (Completely Fair Scheduler) period
|
|
--cpu-quota int Limit the CPU CFS (Completely Fair Scheduler) quota
|
|
-c, --cpu-shares int CPU shares (relative weight)
|
|
--cpuset-cpus string CPUs in which to allow execution (0-3, 0,1)
|
|
--cpuset-mems string MEMs in which to allow execution (0-3, 0,1)
|
|
--disable-content-trust Skip image verification (default true)
|
|
-f, --file string Name of the Dockerfile (Default is 'PATH/Dockerfile')
|
|
--force-rm Always remove intermediate containers
|
|
--help Print usage
|
|
--isolation string Container isolation technology
|
|
--label value Set metadata for an image (default [])
|
|
-m, --memory string Memory limit
|
|
--memory-swap string Swap limit equal to memory plus swap: '-1' to enable unlimited swap
|
|
--no-cache Do not use cache when building the image
|
|
--pull Always attempt to pull a newer version of the image
|
|
-q, --quiet Suppress the build output and print image ID on success
|
|
--rm Remove intermediate containers after a successful build (default true)
|
|
--shm-size string Size of /dev/shm, default value is 64MB.
|
|
The format is `<number><unit>`. `number` must be greater than `0`.
|
|
Unit is optional and can be `b` (bytes), `k` (kilobytes), `m` (megabytes),
|
|
or `g` (gigabytes). If you omit the unit, the system uses bytes.
|
|
-t, --tag value Name and optionally a tag in the 'name:tag' format (default [])
|
|
--ulimit value Ulimit options (default [])
|
|
```
|
|
|
|
Builds Docker images from a Dockerfile and a "context". A build's context is
|
|
the files located in the specified `PATH` or `URL`. The build process can refer
|
|
to any of the files in the context. For example, your build can use an
|
|
[*ADD*](../builder.md#add) instruction to reference a file in the
|
|
context.
|
|
|
|
The `URL` parameter can refer to three kinds of resources: Git repositories,
|
|
pre-packaged tarball contexts and plain text files.
|
|
|
|
### Git repositories
|
|
|
|
When the `URL` parameter points to the location of a Git repository, the
|
|
repository acts as the build context. The system recursively clones the
|
|
repository and its submodules using a `git clone --depth 1 --recursive`
|
|
command. This command runs in a temporary directory on your local host. After
|
|
the command succeeds, the directory is sent to the Docker daemon as the
|
|
context. Local clones give you the ability to access private repositories using
|
|
local user credentials, VPN's, and so forth.
|
|
|
|
Git URLs accept context configuration in their fragment section, separated by a
|
|
colon `:`. The first part represents the reference that Git will check out,
|
|
this can be either a branch, a tag, or a commit SHA. The second part represents
|
|
a subdirectory inside the repository that will be used as a build context.
|
|
|
|
For example, run this command to use a directory called `docker` in the branch
|
|
`container`:
|
|
|
|
```bash
|
|
$ docker build https://github.com/docker/rootfs.git#container:docker
|
|
```
|
|
|
|
The following table represents all the valid suffixes with their build
|
|
contexts:
|
|
|
|
Build Syntax Suffix | Commit Used | Build Context Used
|
|
--------------------------------|-----------------------|-------------------
|
|
`myrepo.git` | `refs/heads/master` | `/`
|
|
`myrepo.git#mytag` | `refs/tags/mytag` | `/`
|
|
`myrepo.git#mybranch` | `refs/heads/mybranch` | `/`
|
|
`myrepo.git#abcdef` | `sha1 = abcdef` | `/`
|
|
`myrepo.git#:myfolder` | `refs/heads/master` | `/myfolder`
|
|
`myrepo.git#master:myfolder` | `refs/heads/master` | `/myfolder`
|
|
`myrepo.git#mytag:myfolder` | `refs/tags/mytag` | `/myfolder`
|
|
`myrepo.git#mybranch:myfolder` | `refs/heads/mybranch` | `/myfolder`
|
|
`myrepo.git#abcdef:myfolder` | `sha1 = abcdef` | `/myfolder`
|
|
|
|
|
|
### Tarball contexts
|
|
|
|
If you pass an URL to a remote tarball, the URL itself is sent to the daemon:
|
|
|
|
Instead of specifying a context, you can pass a single Dockerfile in the `URL`
|
|
or pipe the file in via `STDIN`. To pipe a Dockerfile from `STDIN`:
|
|
|
|
```bash
|
|
$ docker build http://server/context.tar.gz
|
|
|
|
The download operation will be performed on the host the Docker daemon is
|
|
running on, which is not necessarily the same host from which the build command
|
|
is being issued. The Docker daemon will fetch `context.tar.gz` and use it as the
|
|
build context. Tarball contexts must be tar archives conforming to the standard
|
|
`tar` UNIX format and can be compressed with any one of the 'xz', 'bzip2',
|
|
'gzip' or 'identity' (no compression) formats.
|
|
|
|
### Text files
|
|
|
|
Instead of specifying a context, you can pass a single `Dockerfile` in the
|
|
`URL` or pipe the file in via `STDIN`. To pipe a `Dockerfile` from `STDIN`:
|
|
|
|
```bash
|
|
$ docker build - < Dockerfile
|
|
```
|
|
|
|
With Powershell on Windows, you can run:
|
|
|
|
```powershell
|
|
Get-Content Dockerfile | docker build -
|
|
```
|
|
|
|
If you use `STDIN` or specify a `URL` pointing to a plain text file, the system
|
|
places the contents into a file called `Dockerfile`, and any `-f`, `--file`
|
|
option is ignored. In this scenario, there is no context.
|
|
|
|
By default the `docker build` command will look for a `Dockerfile` at the root
|
|
of the build context. The `-f`, `--file`, option lets you specify the path to
|
|
an alternative file to use instead. This is useful in cases where the same set
|
|
of files are used for multiple builds. The path must be to a file within the
|
|
build context. If a relative path is specified then it is interpreted as
|
|
relative to the root of the context.
|
|
|
|
In most cases, it's best to put each Dockerfile in an empty directory. Then,
|
|
add to that directory only the files needed for building the Dockerfile. To
|
|
increase the build's performance, you can exclude files and directories by
|
|
adding a `.dockerignore` file to that directory as well. For information on
|
|
creating one, see the [.dockerignore file](../builder.md#dockerignore-file).
|
|
|
|
If the Docker client loses connection to the daemon, the build is canceled.
|
|
This happens if you interrupt the Docker client with `CTRL-c` or if the Docker
|
|
client is killed for any reason. If the build initiated a pull which is still
|
|
running at the time the build is cancelled, the pull is cancelled as well.
|
|
|
|
## Return code
|
|
|
|
On a successful build, a return code of success `0` will be returned. When the
|
|
build fails, a non-zero failure code will be returned.
|
|
|
|
There should be informational output of the reason for failure output to
|
|
`STDERR`:
|
|
|
|
```bash
|
|
$ docker build -t fail .
|
|
|
|
Sending build context to Docker daemon 2.048 kB
|
|
Sending build context to Docker daemon
|
|
Step 1 : FROM busybox
|
|
---> 4986bf8c1536
|
|
Step 2 : RUN exit 13
|
|
---> Running in e26670ec7a0a
|
|
INFO[0000] The command [/bin/sh -c exit 13] returned a non-zero code: 13
|
|
$ echo $?
|
|
1
|
|
```
|
|
|
|
See also:
|
|
|
|
[*Dockerfile Reference*](../builder.md).
|
|
|
|
## Examples
|
|
|
|
### Build with PATH
|
|
|
|
```bash
|
|
$ docker build .
|
|
|
|
Uploading context 10240 bytes
|
|
Step 1 : FROM busybox
|
|
Pulling repository busybox
|
|
---> e9aa60c60128MB/2.284 MB (100%) endpoint: https://cdn-registry-1.docker.io/v1/
|
|
Step 2 : RUN ls -lh /
|
|
---> Running in 9c9e81692ae9
|
|
total 24
|
|
drwxr-xr-x 2 root root 4.0K Mar 12 2013 bin
|
|
drwxr-xr-x 5 root root 4.0K Oct 19 00:19 dev
|
|
drwxr-xr-x 2 root root 4.0K Oct 19 00:19 etc
|
|
drwxr-xr-x 2 root root 4.0K Nov 15 23:34 lib
|
|
lrwxrwxrwx 1 root root 3 Mar 12 2013 lib64 -> lib
|
|
dr-xr-xr-x 116 root root 0 Nov 15 23:34 proc
|
|
lrwxrwxrwx 1 root root 3 Mar 12 2013 sbin -> bin
|
|
dr-xr-xr-x 13 root root 0 Nov 15 23:34 sys
|
|
drwxr-xr-x 2 root root 4.0K Mar 12 2013 tmp
|
|
drwxr-xr-x 2 root root 4.0K Nov 15 23:34 usr
|
|
---> b35f4035db3f
|
|
Step 3 : CMD echo Hello world
|
|
---> Running in 02071fceb21b
|
|
---> f52f38b7823e
|
|
Successfully built f52f38b7823e
|
|
Removing intermediate container 9c9e81692ae9
|
|
Removing intermediate container 02071fceb21b
|
|
```
|
|
|
|
This example specifies that the `PATH` is `.`, and so all the files in the
|
|
local directory get `tar`d and sent to the Docker daemon. The `PATH` specifies
|
|
where to find the files for the "context" of the build on the Docker daemon.
|
|
Remember that the daemon could be running on a remote machine and that no
|
|
parsing of the Dockerfile happens at the client side (where you're running
|
|
`docker build`). That means that *all* the files at `PATH` get sent, not just
|
|
the ones listed to [*ADD*](../builder.md#add) in the Dockerfile.
|
|
|
|
The transfer of context from the local machine to the Docker daemon is what the
|
|
`docker` client means when you see the "Sending build context" message.
|
|
|
|
If you wish to keep the intermediate containers after the build is complete,
|
|
you must use `--rm=false`. This does not affect the build cache.
|
|
|
|
### Build with URL
|
|
|
|
```bash
|
|
$ docker build github.com/creack/docker-firefox
|
|
```
|
|
|
|
This will clone the GitHub repository and use the cloned repository as context.
|
|
The Dockerfile at the root of the repository is used as Dockerfile. You can
|
|
specify an arbitrary Git repository by using the `git://` or `git@` scheme.
|
|
|
|
```bash
|
|
$ docker build -f ctx/Dockerfile http://server/ctx.tar.gz
|
|
|
|
Downloading context: http://server/ctx.tar.gz [===================>] 240 B/240 B
|
|
Step 0 : FROM busybox
|
|
---> 8c2e06607696
|
|
Step 1 : ADD ctx/container.cfg /
|
|
---> e7829950cee3
|
|
Removing intermediate container b35224abf821
|
|
Step 2 : CMD /bin/ls
|
|
---> Running in fbc63d321d73
|
|
---> 3286931702ad
|
|
Removing intermediate container fbc63d321d73
|
|
Successfully built 377c409b35e4
|
|
```
|
|
|
|
This sends the URL `http://server/ctx.tar.gz` to the Docker daemon, which
|
|
downloads and extracts the referenced tarball. The `-f ctx/Dockerfile`
|
|
parameter specifies a path inside `ctx.tar.gz` to the `Dockerfile` that is used
|
|
to build the image. Any `ADD` commands in that `Dockerfile` that refer to local
|
|
paths must be relative to the root of the contents inside `ctx.tar.gz`. In the
|
|
example above, the tarball contains a directory `ctx/`, so the `ADD
|
|
ctx/container.cfg /` operation works as expected.
|
|
|
|
### Build with -
|
|
|
|
```bash
|
|
$ docker build - < Dockerfile
|
|
```
|
|
|
|
This will read a Dockerfile from `STDIN` without context. Due to the lack of a
|
|
context, no contents of any local directory will be sent to the Docker daemon.
|
|
Since there is no context, a Dockerfile `ADD` only works if it refers to a
|
|
remote URL.
|
|
|
|
```bash
|
|
$ docker build - < context.tar.gz
|
|
```
|
|
|
|
This will build an image for a compressed context read from `STDIN`. Supported
|
|
formats are: bzip2, gzip and xz.
|
|
|
|
### Usage of .dockerignore
|
|
|
|
```bash
|
|
$ docker build .
|
|
|
|
Uploading context 18.829 MB
|
|
Uploading context
|
|
Step 1 : FROM busybox
|
|
---> 769b9341d937
|
|
Step 2 : CMD echo Hello world
|
|
---> Using cache
|
|
---> 99cc1ad10469
|
|
Successfully built 99cc1ad10469
|
|
$ echo ".git" > .dockerignore
|
|
$ docker build .
|
|
Uploading context 6.76 MB
|
|
Uploading context
|
|
Step 1 : FROM busybox
|
|
---> 769b9341d937
|
|
Step 2 : CMD echo Hello world
|
|
---> Using cache
|
|
---> 99cc1ad10469
|
|
Successfully built 99cc1ad10469
|
|
```
|
|
|
|
This example shows the use of the `.dockerignore` file to exclude the `.git`
|
|
directory from the context. Its effect can be seen in the changed size of the
|
|
uploaded context. The builder reference contains detailed information on
|
|
[creating a .dockerignore file](../builder.md#dockerignore-file)
|
|
|
|
### Tag image (-t)
|
|
|
|
```bash
|
|
$ docker build -t vieux/apache:2.0 .
|
|
```
|
|
|
|
This will build like the previous example, but it will then tag the resulting
|
|
image. The repository name will be `vieux/apache` and the tag will be `2.0`.
|
|
[Read more about valid tags](tag.md).
|
|
|
|
You can apply multiple tags to an image. For example, you can apply the `latest`
|
|
tag to a newly built image and add another tag that references a specific
|
|
version.
|
|
For example, to tag an image both as `whenry/fedora-jboss:latest` and
|
|
`whenry/fedora-jboss:v2.1`, use the following:
|
|
|
|
```bash
|
|
$ docker build -t whenry/fedora-jboss:latest -t whenry/fedora-jboss:v2.1 .
|
|
```
|
|
### Specify Dockerfile (-f)
|
|
|
|
```bash
|
|
$ docker build -f Dockerfile.debug .
|
|
```
|
|
|
|
This will use a file called `Dockerfile.debug` for the build instructions
|
|
instead of `Dockerfile`.
|
|
|
|
```bash
|
|
$ docker build -f dockerfiles/Dockerfile.debug -t myapp_debug .
|
|
$ docker build -f dockerfiles/Dockerfile.prod -t myapp_prod .
|
|
```
|
|
|
|
The above commands will build the current build context (as specified by the
|
|
`.`) twice, once using a debug version of a `Dockerfile` and once using a
|
|
production version.
|
|
|
|
```bash
|
|
$ cd /home/me/myapp/some/dir/really/deep
|
|
$ docker build -f /home/me/myapp/dockerfiles/debug /home/me/myapp
|
|
$ docker build -f ../../../../dockerfiles/debug /home/me/myapp
|
|
```
|
|
|
|
These two `docker build` commands do the exact same thing. They both use the
|
|
contents of the `debug` file instead of looking for a `Dockerfile` and will use
|
|
`/home/me/myapp` as the root of the build context. Note that `debug` is in the
|
|
directory structure of the build context, regardless of how you refer to it on
|
|
the command line.
|
|
|
|
> **Note:**
|
|
> `docker build` will return a `no such file or directory` error if the
|
|
> file or directory does not exist in the uploaded context. This may
|
|
> happen if there is no context, or if you specify a file that is
|
|
> elsewhere on the Host system. The context is limited to the current
|
|
> directory (and its children) for security reasons, and to ensure
|
|
> repeatable builds on remote Docker hosts. This is also the reason why
|
|
> `ADD ../file` will not work.
|
|
|
|
### Optional parent cgroup (--cgroup-parent)
|
|
|
|
When `docker build` is run with the `--cgroup-parent` option the containers
|
|
used in the build will be run with the [corresponding `docker run`
|
|
flag](../run.md#specifying-custom-cgroups).
|
|
|
|
### Set ulimits in container (--ulimit)
|
|
|
|
Using the `--ulimit` option with `docker build` will cause each build step's
|
|
container to be started using those [`--ulimit`
|
|
flag values](./run.md#set-ulimits-in-container-ulimit).
|
|
|
|
### Set build-time variables (--build-arg)
|
|
|
|
You can use `ENV` instructions in a Dockerfile to define variable
|
|
values. These values persist in the built image. However, often
|
|
persistence is not what you want. Users want to specify variables differently
|
|
depending on which host they build an image on.
|
|
|
|
A good example is `http_proxy` or source versions for pulling intermediate
|
|
files. The `ARG` instruction lets Dockerfile authors define values that users
|
|
can set at build-time using the `--build-arg` flag:
|
|
|
|
```bash
|
|
$ docker build --build-arg HTTP_PROXY=http://10.20.30.2:1234 .
|
|
```
|
|
|
|
This flag allows you to pass the build-time variables that are
|
|
accessed like regular environment variables in the `RUN` instruction of the
|
|
Dockerfile. Also, these values don't persist in the intermediate or final images
|
|
like `ENV` values do.
|
|
|
|
Using this flag will not alter the output you see when the `ARG` lines from the
|
|
Dockerfile are echoed during the build process.
|
|
|
|
For detailed information on using `ARG` and `ENV` instructions, see the
|
|
[Dockerfile reference](../builder.md).
|
|
|
|
### Specify isolation technology for container (--isolation)
|
|
|
|
This option is useful in situations where you are running Docker containers on
|
|
Windows. The `--isolation=<value>` option sets a container's isolation
|
|
technology. On Linux, the only supported is the `default` option which uses
|
|
Linux namespaces. On Microsoft Windows, you can specify these values:
|
|
|
|
|
|
| Value | Description |
|
|
|-----------|---------------------------------------------------------------------------------------------------------------------------------------------------------------|
|
|
| `default` | Use the value specified by the Docker daemon's `--exec-opt` . If the `daemon` does not specify an isolation technology, Microsoft Windows uses `process` as its default value. |
|
|
| `process` | Namespace isolation only. |
|
|
| `hyperv` | Hyper-V hypervisor partition-based isolation. |
|
|
|
|
Specifying the `--isolation` flag without a value is the same as setting `--isolation="default"`.
|