Documentation: Fix/Prettify kankiko example

doc/ci/docker/using_kaniko.md

@@ -64,8 +64,12 @@ build:
     entrypoint: [""]
   script:
     - mkdir -p /kaniko/.docker
-    - 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
+    - echo "{\"auths\":{\"${CI_REGISTRY}\":{\"auth\":\"$(printf "%s:%s" "${CI_REGISTRY_USER}" "${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: $CI_COMMIT_TAG
 ```
@@ -91,14 +95,19 @@ build:
     - mkdir -p /kaniko/.docker
     - |-
        KANIKOPROXYBUILDARGS=""
-       KANIKOCFG="{\"auths\":{\"$CI_REGISTRY\":{\"auth\":\"$(echo -n ${CI_REGISTRY_USER}:${CI_REGISTRY_PASSWORD} | base64 | tr -d '\n')\"}}}"
+       KANIKOCFG="{\"auths\":{\"${CI_REGISTRY}\":{\"auth\":\"$(printf "%s:%s" "${CI_REGISTRY_USER}" "${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=${no_proxy}"
        fi
        KANIKOCFG="${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
+    - >-
+      /kaniko/executor
+      --context "${CI_PROJECT_DIR}"
+      --dockerfile "${CI_PROJECT_DIR}/Dockerfile"
+      "${KANIKOPROXYBUILDARGS}"
+      --destination "${CI_REGISTRY_IMAGE}:${CI_COMMIT_TAG}"
   rules:
     - if: $CI_COMMIT_TAG
 ```
@@ -120,7 +129,7 @@ store:
 ```yaml
 before_script:
   - mkdir -p /kaniko/.docker
-  - echo "{\"auths\":{\"$CI_REGISTRY\":{\"auth\":\"$(echo -n ${CI_REGISTRY_USER}:${CI_REGISTRY_PASSWORD} | base64 | tr -d '\n')\"}}}" > /kaniko/.docker/config.json
+  - echo "{\"auths\":{\"${CI_REGISTRY}\":{\"auth\":\"$(printf "%s:%s" "${CI_REGISTRY_USER}" "${CI_REGISTRY_PASSWORD}" | base64 | tr -d '\n')\"}}}" > /kaniko/.docker/config.json
   - |
     echo "-----BEGIN CERTIFICATE-----
     ...