# Updating Base Images in Dockerfiles

<p className="subtitle">
	Create a batch change to update Dockerfiles in each repository.
</p>

In this example, Batch Changes will allow you to update the base images used in your Dockerfiles across many repositories in just a few commands. First you will create [a batch spec](/batch-changes/create-a-batch-change) that:

-   Finds `Dockerfile` that make use of `google/dart:2.x` base images, and
-   Changes those `Dockerfiles` to use `google/dart:2.10`

The batch spec and instructions here can [easily be adapted to update other base images](#updating-other-base-images).

![update_base_images_in_dockerfiles_teaser](https://storage.googleapis.com/sourcegraph-assets/Docs/update_base_images_in_dockerfiles_teaser_latest.png)

## Prerequisites

<Callout type="tip">
	It's recommended to use the latest version of Sourcegraph when working with
	Batch Changes.
</Callout>

Before you start, it's better to read the following docs:

-   [Batch Changes Quickstart](/batch-changes/quickstart)
-   [How to create and run a Batch Spec?](/batch-changes/create-a-batch-change)

## Create the batch spec

Save the following batch spec YAML as `update-dart-base-images-2-10.batch.yaml`:

```yaml
name: update-dart-base-images-2-10
description: This batch change updates `google/dart:2.*` base images in Dockerfiles to `google/dart:2.10.2`.

on:
    # Find all repositories that contain Dockerfiles with `FROM google/dart:2.*` as base images.
    # The regexp used here matches images
    #
    #   google/dart:2.MINOR.PATCH
    #   google/dart:2.MINOR.PATCH-dev.DEVMINOR.DEVPATCH
    #
    #   google/dart-runtime:2.MINOR.PATCH
    #   google/dart-runtime:2.MINOR.PATCH-dev.DEVMINOR.DEVPATCH
    #
    # where the tag is < 2.10. Feel free to adjust it to your requirements.
    - repositoriesMatchingQuery: ^FROM google\/dart(-runtime)?:2\.[0-9]\.?\d?(-dev\.\d\.\d)? file:Dockerfile  patternType:regexp

# In each repository
steps:
    # find all Dockerfiles and replace the old image tags with our desired ones:
    - run: |
          find . -name Dockerfile -type f |\
          xargs sed\
            -i\
            --regexp-extended\
            's/FROM google\/dart(-runtime)?:2\.[[:digit:]]\.?[[:digit:]]?(-dev\.?[[:digit:]]?\.?[[:digit:]]?)?/FROM google\/dart:2\.10/g'
      container: alpine:3

# Describe the changeset (e.g., GitHub pull request) you want for each repository.
changesetTemplate:
    title: Update google/dart base images in Dockerfiles to 2.10.2
    body: This updates google/dart base images used in Dockerfiles to version 2.10.2
    branch: batch-changes/google-dart-2-10-2-base-images # Push the commit to this branch.
    commit:
        message: Update google/dart base images in Dockerfiles to 2.10.2
    published: false
```

## Create the batch change

-   In your terminal, run the following command:

```shell
src batch preview -f update-dart-base-images-2-10.batch.yaml
```

-   Wait for it to run and compute the changes for each repository

![update_base_images_in_dockerfiles_wait_run](https://sourcegraphstatic.com/docs/images/batch_changes/update_base_images_in_dockerfiles_wait_run.png)

-   Open the preview URL that the command printed out

![update_base_images_in_dockerfiles_click_url](https://sourcegraphstatic.com/docs/images/batch_changes/update_base_images_in_dockerfiles_click_url.png)

-   Examine the preview. Confirm that the changesets are the ones you intended to track. If not, edit the batch spec and then re-run the command above

![batch_changes/update_base_images_in_dockerfiles_preview](https://sourcegraphstatic.com/docs/images/batch_changes/update_base_images_in_dockerfiles_preview.png)

-   Click the **Apply** button to create the batch change
-   Feel free to then publish the changesets (i.e., create pull requests and merge requests) by [modifying the `published` attribute in the batch spec](/batch-changes/batch-spec-yaml-reference#changesettemplatepublished) and re-running the `src batch preview` command.

## Updating other base images

In order to update other base images in Dockerfiles you can either extend the batch spec or create another batch spec in which you change the `repositoriesMatchingQuery` and the `steps.run` properties.

You can keep using regexp-based search and `sed`, or you can use [structural search](/code-search/types/structural) combined with [comby](https://comby.dev) to update base images.

For example, here's how you would update `alpine` base images from `alpine:3.9`, `alpine:3.10`, `alpine:3.11` to `alpine:3.12`:

```yaml
# [...]

on:
    - repositoriesMatchingQuery: FROM alpine:3.:[minor~[91]+[0-1]?] file:Dockerfile patternType:structural
    - repositoriesMatchingQuery: FROM alpine:3.:[minor~[91]+[0-1]?]@sha256::[hash~[a-f0-9]+] file:Dockerfile patternType:structural

steps:
    - run: |
          comby \
            -in-place \
            'FROM alpine:3.:[minor~[91]+[0-1]?]@sha256::[hash~[a-f0-9]+]' \
            'FROM alpine:3.12@ sha256:c0e9560cda118f9ec63ddefb4a173a2b2a0347082d7dff7dc14272e7841a5b5a' \
            Dockerfile
      container: comby/comby
    - run: comby -in-place 'alpine:3.:[minor~[91]+[0-1]?]' 'FROM alpine:3.12' Dockerfile
      container: comby/comby
# [...]
```

And here's how you could update `golang` base images to use Go 1.15:

```yaml
# [...]
on:
    - repositoriesMatchingQuery: FROM golang:1.1:[minor~[0-4]]-alpine file:Dockerfile patternType:structural
    - repositoriesMatchingQuery: FROM golang:1.1:[minor~[0-4]]-alpine@sha256::[hash~[a-f0-9]+] file:Dockerfile patternType:structural

steps:
    - run: |
          comby \
            -in-place \
            'FROM golang::[version]-alpine@sha256::[hash~[a-f0-9]+]' \
            'FROM golang:1.15-alpine@sha256:df0119b970c8e5e9f0f5c40f6b55edddf616bab2b911927ebc3b361c469ea29c' \
            Dockerfile
      container: comby/comby
    - run: comby -in-place 'FROM golang::[version]-alpine' 'FROM golang:1.15-alpine' Dockerfile
      container: comby/comby
```