3 files changed, 12 insertions, 19 deletions
diff --git a/doc/ci/docker/using_docker_build.md b/doc/ci/docker/using_docker_build.md
index d5adedc611c..9a4290ead4c 100644
--- a/doc/ci/docker/using_docker_build.md
+++ b/doc/ci/docker/using_docker_build.md
@@ -572,7 +572,7 @@ The configuration is picked up by the `dind` service.
 ## Authenticate with registry in Docker-in-Docker
 
 When you use Docker-in-Docker, the
-[standard authentication methods](using_docker_images.md#define-an-image-from-a-private-container-registry)
+[standard authentication methods](using_docker_images.md#access-an-image-from-a-private-container-registry)
 don't work because a fresh Docker daemon is started with the service.
 
 ### Option 1: Run `docker login`
diff --git a/doc/ci/docker/using_docker_images.md b/doc/ci/docker/using_docker_images.md
index c2991ce66f9..79c23d73a68 100644
--- a/doc/ci/docker/using_docker_images.md
+++ b/doc/ci/docker/using_docker_images.md
@@ -214,7 +214,7 @@ Look for the `[runners.docker]` section:
 The image and services defined this way are added to all jobs run by
 that runner.
 
-## Define an image from a private Container Registry
+## Access an image from a private Container Registry
 
 To access private container registries, the GitLab Runner process can use:
 
@@ -224,19 +224,12 @@ To access private container registries, the GitLab Runner process can use:
 
 To define which option should be used, the runner process reads the configuration in this order:
 
-- A `DOCKER_AUTH_CONFIG` variable provided as either:
-  - A [CI/CD variable](../variables/index.md) in the `.gitlab-ci.yml` file.
-  - A project's variables stored on the project's **Settings > CI/CD** page.
-- A `DOCKER_AUTH_CONFIG` variable provided as environment variable in the runner's `config.toml` file.
+- A `DOCKER_AUTH_CONFIG` [CI/CD variable](../variables/index.md).
+- A `DOCKER_AUTH_CONFIG` environment variable set in the runner's `config.toml` file.
 - A `config.json` file in `$HOME/.docker` directory of the user running the process.
   If the `--user` flag is provided to run the child processes as unprivileged user,
   the home directory of the main runner process user is used.
 
-The runner reads this configuration **only** from the `config.toml` file and ignores it if
-it's provided as a CI/CD variable. This is because the runner uses **only**
-`config.toml` configuration and does not interpolate **any** CI/CD variables at
-runtime.
-
 ### Requirements and limitations
 
 - Available for [Kubernetes executor](https://docs.gitlab.com/runner/executors/kubernetes.html)
@@ -253,9 +246,9 @@ private registry. Both require setting the CI/CD variable
 `DOCKER_AUTH_CONFIG` with appropriate authentication information.
 
 1. Per-job: To configure one job to access a private registry, add
-   `DOCKER_AUTH_CONFIG` as a job variable.
+   `DOCKER_AUTH_CONFIG` as a [CI/CD variable](../variables/index.md).
 1. Per-runner: To configure a runner so all its jobs can access a
-   private registry, add `DOCKER_AUTH_CONFIG` to the environment in the
+   private registry, add `DOCKER_AUTH_CONFIG` as an environment variable in the
    runner's configuration.
 
 See below for examples of each.
@@ -274,7 +267,7 @@ Let's also assume that these are the sign-in credentials:
 | username | `my_username`               |
 | password | `my_password`               |
 
-Use one of the following methods to determine the value of `DOCKER_AUTH_CONFIG`:
+Use one of the following methods to determine the value for `DOCKER_AUTH_CONFIG`:
 
 - Do a `docker login` on your local machine:
 
diff --git a/doc/ci/docker/using_kaniko.md b/doc/ci/docker/using_kaniko.md
index 6886899a54b..69c4557dcbe 100644
--- a/doc/ci/docker/using_kaniko.md
+++ b/doc/ci/docker/using_kaniko.md
@@ -13,8 +13,8 @@ type: howto
 container images from a Dockerfile, inside a container or Kubernetes cluster.
 
 kaniko solves two problems with using the
-[Docker-in-Docker
-build](using_docker_build.md#use-the-docker-executor-with-the-docker-image-docker-in-docker) method:
+[Docker-in-Docker build](using_docker_build.md#use-the-docker-executor-with-the-docker-image-docker-in-docker)
+method:
 
 - Docker-in-Docker requires [privileged mode](https://docs.docker.com/engine/reference/run/#runtime-privilege-and-linux-capabilities)
   to function, which is a significant security concern.
@@ -64,7 +64,7 @@ build:
     entrypoint: [""]
   script:
     - mkdir -p /kaniko/.docker
-    - echo "{\"auths\":{\"$CI_REGISTRY\":{\"auth\":\"$(echo -n ${CI_REGISTRY_USER}:${CI_REGISTRY_PASSWORD} | base64)\"}}}" > /kaniko/.docker/config.json
+    - echo "{\"auths\":{\"$CI_REGISTRY\":{\"auth\":\"$(echo -n ${CI_REGISTRY_USER}:${CI_REGISTRY_PASSWORD} | base64 | tr -d '\n')\"}}}" > /kaniko/.docker/config.json
     - /kaniko/executor --context $CI_PROJECT_DIR --dockerfile $CI_PROJECT_DIR/Dockerfile --destination $CI_REGISTRY_IMAGE:$CI_COMMIT_TAG
   rules:
     - if: $CI_COMMIT_TAG
@@ -91,7 +91,7 @@ build:
     - mkdir -p /kaniko/.docker
     - |-
        KANIKOPROXYBUILDARGS=""
-       KANIKOCFG="{\"auths\":{\"$CI_REGISTRY\":{\"auth\":\"$(echo -n ${CI_REGISTRY_USER}:${CI_REGISTRY_PASSWORD} | base64)\"}}}"
+       KANIKOCFG="{\"auths\":{\"$CI_REGISTRY\":{\"auth\":\"$(echo -n ${CI_REGISTRY_USER}:${CI_REGISTRY_PASSWORD} | base64 | tr -d '\n')\"}}}"
        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=${no_proxy}"
@@ -120,7 +120,7 @@ store:
 ```yaml
 before_script:
   - mkdir -p /kaniko/.docker
-  - echo "{\"auths\":{\"$CI_REGISTRY\":{\"auth\":\"$(echo -n ${CI_REGISTRY_USER}:${CI_REGISTRY_PASSWORD} | base64)\"}}}" > /kaniko/.docker/config.json
+  - echo "{\"auths\":{\"$CI_REGISTRY\":{\"auth\":\"$(echo -n ${CI_REGISTRY_USER}:${CI_REGISTRY_PASSWORD} | base64 | tr -d '\n')\"}}}" > /kaniko/.docker/config.json
   - |
     echo "-----BEGIN CERTIFICATE-----
     ...