2019-06-07 08:00:41 +00:00
---
2020-05-29 18:08:26 +00:00
stage: Verify
group: Continuous Integration
2020-11-26 06:09:20 +00:00
info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments
2019-06-07 08:00:41 +00:00
type: howto
---
2018-08-16 14:32:15 +00:00
# Building images with kaniko and GitLab CI/CD
2020-05-21 03:08:00 +00:00
> [Introduced](https://gitlab.com/gitlab-org/gitlab-foss/-/issues/45512) in GitLab 11.2. Requires GitLab Runner 11.2 and above.
2018-08-16 14:32:15 +00:00
[kaniko ](https://github.com/GoogleContainerTools/kaniko ) is a tool to build
container images from a Dockerfile, inside a container or Kubernetes cluster.
kaniko solves two problems with using the
2020-05-27 09:08:30 +00:00
[Docker-in-Docker
2020-12-23 09:10:13 +00:00
build](using_docker_build.md#use-the-docker-executor-with-the-docker-image-docker-in-docker) method:
2018-08-16 14:32:15 +00:00
2020-05-27 09:08:30 +00:00
- Docker-in-Docker requires [privileged mode ](https://docs.docker.com/engine/reference/run/#runtime-privilege-and-linux-capabilities )
2020-10-08 06:08:35 +00:00
to function, which is a significant security concern.
2020-05-27 09:08:30 +00:00
- Docker-in-Docker generally incurs a performance penalty and can be quite slow.
2018-08-16 14:32:15 +00:00
## Requirements
2020-10-08 06:08:35 +00:00
To use kaniko with GitLab, [a runner ](https://docs.gitlab.com/runner/ ) with one
of the following executors is required:
2019-06-07 08:00:41 +00:00
- [Kubernetes ](https://docs.gitlab.com/runner/executors/kubernetes.html ).
- [Docker ](https://docs.gitlab.com/runner/executors/docker.html ).
- [Docker Machine ](https://docs.gitlab.com/runner/executors/docker_machine.html ).
2018-08-16 14:32:15 +00:00
## Building a Docker image with kaniko
When building an image with kaniko and GitLab CI/CD, you should be aware of a
few important details:
- The kaniko debug image is recommended (`gcr.io/kaniko-project/executor:debug`)
because it has a shell, and a shell is required for an image to be used with
GitLab CI/CD.
2020-11-18 15:09:08 +00:00
- The entrypoint needs to be [overridden ](using_docker_images.md#overriding-the-entrypoint-of-an-image ),
otherwise the build script doesn't run.
2018-08-16 14:32:15 +00:00
- A Docker `config.json` file needs to be created with the authentication
information for the desired container registry.
2019-06-07 08:00:41 +00:00
In the following example, kaniko is used to:
1. Build a Docker image.
2019-09-17 12:06:48 +00:00
1. Then push it to [GitLab Container Registry ](../../user/packages/container_registry/index.md ).
2018-08-16 14:32:15 +00:00
2020-11-18 15:09:08 +00:00
The job runs only when a tag is pushed. A `config.json` file is created under
2018-10-03 09:15:12 +00:00
`/kaniko/.docker` with the needed GitLab Container Registry credentials taken from the
2019-01-30 10:20:50 +00:00
[environment variables ](../variables/README.md#predefined-environment-variables )
2019-06-07 08:00:41 +00:00
GitLab CI/CD provides.
In the last step, kaniko uses the `Dockerfile` under the
2018-08-16 14:32:15 +00:00
root directory of the project, builds the Docker image and pushes it to the
project's Container Registry while tagging it with the Git tag:
```yaml
build:
stage: build
image:
name: gcr.io/kaniko-project/executor:debug
entrypoint: [""]
script:
2020-08-20 06:10:17 +00:00
- mkdir -p /kaniko/.docker
2018-10-03 09:15:12 +00:00
- echo "{\"auths\":{\"$CI_REGISTRY\":{\"username\":\"$CI_REGISTRY_USER\",\"password\":\"$CI_REGISTRY_PASSWORD\"}}}" > /kaniko/.docker/config.json
2018-08-16 14:32:15 +00:00
- /kaniko/executor --context $CI_PROJECT_DIR --dockerfile $CI_PROJECT_DIR/Dockerfile --destination $CI_REGISTRY_IMAGE:$CI_COMMIT_TAG
2020-12-10 09:09:32 +00:00
rules:
- if: $CI_COMMIT_TAG
2018-08-16 14:32:15 +00:00
```
2018-12-17 15:26:53 +00:00
2021-01-09 00:10:30 +00:00
### Building an image with kaniko behind a proxy
If you use a custom GitLab Runner behind an http(s) proxy, kaniko needs to be set
up accordingly. This means:
- Adding the proxy to `/kaniko/.docker/config.json`
2021-01-23 00:08:46 +00:00
- Passing the `http_proxy` environment variables as build arguments so the Dockerfile
2021-01-09 00:10:30 +00:00
instructions can use the proxy when building the image.
The previous example can be extended as follows:
```yaml
build:
stage: build
image:
name: gcr.io/kaniko-project/executor:debug
entrypoint: [""]
script:
- mkdir -p /kaniko/.docker
- |-
KANIKOPROXYBUILDARGS=""
KANIKOCFG="{ \"auths\":{\"$CI_REGISTRY\":{\"username\":\"$CI_REGISTRY_USER\",\"password\":\"$CI_REGISTRY_PASSWORD\"}}"
if [ "x${http_proxy}" != "x" -o "x${https_proxy}" != "x" ]; then
KANIKOCFG="${KANIKOCFG}, \"proxies\": { \"default\": { \"httpProxy\": \"${http_proxy}\", \"httpsProxy\": \"${https_proxy}\", \"noProxy\": \"${no_proxy}\"}}"
KANIKOPROXYBUILDARGS="--build-arg http_proxy=${http_proxy} --build-arg https_proxy=${https_proxy} --build-arg no_proxy=${no_proxy}"
fi
KANIKOCFG="${KANIKOCFG} }"
echo "${KANIKOCFG}" > /kaniko/.docker/config.json
- /kaniko/executor --context $CI_PROJECT_DIR --dockerfile $CI_PROJECT_DIR/Dockerfile $KANIKOPROXYBUILDARGS --destination $CI_REGISTRY_IMAGE:$CI_COMMIT_TAG
only:
- tags
```
2018-12-17 15:26:53 +00:00
## Using a registry with a custom certificate
When trying to push to a Docker registry that uses a certificate that is signed
by a custom CA, you might get the following error:
2020-01-30 15:09:15 +00:00
```shell
2018-12-17 15:26:53 +00:00
$ /kaniko/executor --context $CI_PROJECT_DIR --dockerfile $CI_PROJECT_DIR/Dockerfile --no-push
INFO[0000] Downloading base image registry.gitlab.example.com/group/docker-image
error building image: getting stage builder for stage 0: Get https://registry.gitlab.example.com/v2/: x509: certificate signed by unknown authority
```
This can be solved by adding your CA's certificate to the kaniko certificate
store:
```yaml
2020-09-08 18:08:48 +00:00
before_script:
- mkdir -p /kaniko/.docker
- echo "{\"auths\":{\"$CI_REGISTRY\":{\"username\":\"$CI_REGISTRY_USER\",\"password\":\"$CI_REGISTRY_PASSWORD\"}}}" > /kaniko/.docker/config.json
- |
echo "-----BEGIN CERTIFICATE-----
...
-----END CERTIFICATE-----" >> /kaniko/ssl/certs/additional-ca-cert-bundle.crt
2018-12-17 15:26:53 +00:00
```
2019-06-07 08:00:41 +00:00
2020-04-23 03:09:51 +00:00
## Video walkthrough of a working example
The [Least Privilege Container Builds with Kaniko on GitLab ](https://www.youtube.com/watch?v=d96ybcELpFs )
video is a walkthrough of the [Kaniko Docker Build ](https://gitlab.com/guided-explorations/containers/kaniko-docker-build )
Guided Exploration project pipeline. It was tested on:
2020-08-21 03:10:16 +00:00
- [GitLab.com shared runners ](../../user/gitlab_com/index.md#shared-runners )
- [The Kubernetes runner executor ](https://docs.gitlab.com/runner/executors/kubernetes.html )
2020-04-23 03:09:51 +00:00
The example can be copied to your own group or instance for testing. More details
on what other GitLab CI patterns are demonstrated are available at the project page.
2020-12-11 06:10:17 +00:00
## Troubleshooting
2019-06-07 08:00:41 +00:00
2020-12-11 06:10:17 +00:00
### 403 error: "error checking push permissions"
2019-06-07 08:00:41 +00:00
2020-12-11 06:10:17 +00:00
If you receive this error, it might be due to an outside proxy. Setting the `http_proxy`
and `https_proxy` [environment variables ](../../administration/packages/container_registry.md#running-the-docker-daemon-with-a-proxy )
can fix the problem.