Validate Dockerfile indentation in pep8

Delegate code style validation to computers, they're better than human
at it :)

This commit adds a new `tools/validate-indentation.sh` script that
errors when it finds an indented Dockerfile instruction, and enables
the validation in the pep8 check.

Also adjust the logic of `tools/validate-all-dockerfiles.sh` so that it
doesn't stop on first errors but instead shows all of them.

Fixes the remaining indentations in Dockerfiles.

Change-Id: I53c0d38304cb4f6d64a5dfab67f70d69b3eae587

docker/helm-repository/Dockerfile.j2

@@ -46,12 +46,12 @@ RUN curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py \
 
 RUN {{ macros.install_pip(helm_repository_pip_packages | customizable("pip_packages"), constraints = false) }}
 
-ENV helm_arch={{ base_arch }}
-
 {% if base_arch == 'x86_64' %}
-    ENV helm_arch=amd64
+ENV helm_arch=amd64
 {% elif base_arch == 'aarch64' %}
-    ENV helm_arch=arm64
+ENV helm_arch=arm64
+{% else %}
+ENV helm_arch={{ base_arch }}
 {% endif %}
 
 {% block helm_repository_install_kubernetes_helm %}

docker/ironic/ironic-pxe/Dockerfile.j2

@@ -16,7 +16,7 @@ LABEL maintainer="{{ maintainer }}" name="{{ image_name }}" build-date="{{ build
     ] %}
 
     {% if base_arch == 'aarch64' %}
-        ENV ironic_arch=aarch64
+ENV ironic_arch=aarch64
         {% set ironic_pxe_packages = ironic_pxe_packages + [
             'grub2-efi',
             'grub2-efi-aa64-modules'
@@ -41,7 +41,7 @@ RUN sed -i -r 's,^(Listen 80),#\1,' /etc/httpd/conf/httpd.conf \
             'syslinux'
         ] %}
     {% elif base_arch == 'aarch64' %}
-        ENV ironic_arch=aarch64
+ENV ironic_arch=aarch64
         {% set ironic_pxe_packages = ironic_pxe_packages + [
             'grub-efi-arm64'
         ] %}

tools/validate-all-dockerfiles.sh

@@ -3,9 +3,15 @@
 REAL_PATH=$(python -c "import os,sys;print os.path.realpath('$0')")
 cd "$(dirname "$REAL_PATH")/.."
 
-find docker -name Dockerfile.j2 -print0 |
-    xargs -0 tools/validate-maintainer.sh || exit 1
+RES=0
 
 find docker -name Dockerfile.j2 -print0 |
-    xargs -0 tools/validate-install-command.sh || exit 1
+    xargs -0 tools/validate-maintainer.sh || RES=1
 
+find docker -name Dockerfile.j2 -print0 |
+    xargs -0 tools/validate-install-command.sh || RES=1
+
+find docker -name Dockerfile.j2 -print0 |
+    xargs -0 tools/validate-indentation.sh || RES=1
+
+exit $RES

tools/validate-indentation.sh

@@ -0,0 +1,12 @@
+#!/bin/bash
+
+RES=0
+
+for dockerfile in "$@"; do
+    if grep -qE '^\s+[A-Z]+\s' "$dockerfile"; then
+        echo "ERROR: $dockerfile has indented Dockerfile instruction" >&2
+        RES=1
+    fi
+done
+
+exit $RES