packer-cn/website/content/docs/post-processors/docker-import.mdx

---
description: |
  The Packer Docker import post-processor takes an artifact from the docker
  builder and imports it with Docker locally. This allows you to apply a
  repository and tag to the image and lets you use the other Docker
  post-processors such as docker-push to push the image to a registry.
page_title: Docker Import - Post-Processors
sidebar_title: Docker Import
---

# Docker Import Post-Processor

Type: `docker-import`

The Packer Docker import post-processor takes an artifact from the [docker
builder](/docs/builders/docker) and imports it with Docker locally. This
allows you to apply a repository and tag to the image and lets you use the
other Docker post-processors such as
[docker-push](/docs/post-processors/docker-push) to push the image to a
registry.

## Basic Example

<Tabs>
<Tab heading="JSON">

```json
{
  "builders": [
    {
      "type": "docker",
      "image": "ubuntu:18.04",
      "export_path": "party_parrot.tar"
    }
  ],
  "post-processors": [
    {
      "type": "docker-import",
      "repository": "local/ubuntu",
      "tag": "latest"
    }
  ]
}
```

</Tab>
<Tab heading="HCL2">

```hcl
source "docker" "example" {
    image = "ubuntu:18.04"
    export_path = "party_parrot.tar"
}

build {
  sources = [
    "source.docker.example"
  ]

  post-processor "docker-import" {
    repository = "local/ubuntu"
    tag = "latest"
  }
}
```

</Tab>
</Tabs>

## Configuration

The configuration for this post-processor only requires a `repository`, a `tag`
is optional.

### Required:

- `repository` (string) - The repository of the imported image.

### Optional:

- `tag` (string) - The tag for the imported image. By default this is not
  set.

- `changes` (array of strings) - Dockerfile instructions to add to the
  commit. Example of instructions are `CMD`, `ENTRYPOINT`, `ENV`, and
  `EXPOSE`. Example: `[ "USER ubuntu", "WORKDIR /app", "EXPOSE 8080" ]`

- `keep_input_artifact` (boolean) - if true, do not delete the source tar
  after importing it to docker. Defaults to false.

## Example

An example is shown below, showing only the post-processor configuration:

<Tabs>
<Tab heading="JSON">

```json
{
  "type": "docker-import",
  "repository": "hashicorp/packer",
  "tag": "0.7"
}
```

</Tab>
<Tab heading="HCL2">

```hcl
post-processor "docker-import" {
  repository = "hashicorp/packer"
  tag = "0.7"
}
```

</Tab>
</Tabs>

This example would take the image created by the Docker builder and import it
into the local Docker process with a name of `hashicorp/packer:0.7`.

Following this, you can use the
[docker-push](/docs/post-processors/docker-push) post-processor to push it
to a registry, if you want.

## Changing Metadata

Below is an example using the changes argument of the post-processor. This
feature allows the tarball metadata to be changed when imported into the Docker
environment. It is derived from the `docker import --change` command line
[option to
Docker](https://docs.docker.com/engine/reference/commandline/import/).

Example uses of all of the options, assuming one is building an NGINX image
from ubuntu as an simple example:

<Tabs>
<Tab heading="JSON">

```json
{
  "type": "docker-import",
  "repository": "local/centos6",
  "tag": "latest",
  "changes": [
    "USER www-data",
    "WORKDIR /var/www",
    "ENV HOSTNAME www.example.com",
    "VOLUME /test1 /test2",
    "EXPOSE 80 443",
    "LABEL version=1.0",
    "ONBUILD RUN date",
    "CMD [\"nginx\", \"-g\", \"daemon off;\"]",
    "ENTRYPOINT /var/www/start.sh"
  ]
}
```

</Tab>
<Tab heading="HCL2">

```hcl
post-processor "docker-import" {
  repository = "local/centos6"
  tag = "latest"
  changes = [
    "USER www-data",
    "WORKDIR /var/www",
    "ENV HOSTNAME www.example.com",
    "VOLUME /test1 /test2",
    "EXPOSE 80 443",
    "LABEL version=1.0",
    "ONBUILD RUN date",
    "CMD [\"nginx\", \"-g\", \"daemon off;\"]",
    "ENTRYPOINT /var/www/start.sh",
  ]
}
```

</Tab>
</Tabs>

Allowed metadata fields that can be changed are:

- CMD
  - String, supports both array (escaped) and string form
  - EX: `"CMD [\"nginx\", \"-g\", \"daemon off;\"]"`
  - EX: `"CMD nginx -g daemon off;"`
- ENTRYPOINT
  - String
  - EX: `"ENTRYPOINT /var/www/start.sh"`
- ENV
  - String, note there is no equal sign:
  - EX: `"ENV HOSTNAME www.example.com"` not
    `"ENV HOSTNAME=www.example.com"`
- EXPOSE
  - String, space separated ports
  - EX: `"EXPOSE 80 443"`
- LABEL
  - String, space separated key=value pairs
  - EX: `"LABEL version=1.0"`
- ONBUILD
  - String
  - EX: `"ONBUILD RUN date"`
- MAINTAINER
  - String, deprecated in Docker version 1.13.0
  - EX: `"MAINTAINER NAME"`
- USER
  - String
  - EX: `"USER USERNAME"`
- VOLUME
  - String
  - EX: `"VOLUME FROM TO"`
- WORKDIR
  - String
  - EX: `"WORKDIR PATH"`