kolla-build: fix build-date LABEL invalidating Docker layer cache

The build-date label was rendered into a LABEL instruction on line
3 of every Dockerfile template, immediately after FROM.

Because Docker invalidates the cache for a changed instruction and
all subsequent layers, a date change caused a full rebuild of every
image on each new calendar day, even when nothing else had changed.

Fix this by removing build-date from the Dockerfile templates and
applying it as a --label argument at build time via image.labels.

Labels passed on the build command line are not part of the
Dockerfile cache key, so the date is still recorded in the image
metadata without affecting layer caching.

Change-Id: I8ef0d85bab1a999a4d09f7cbf0c088ca00fdcf77
Signed-off-by: Michal Nasiadka <mnasiadka@gmail.com>

5 files changed, 5 insertions, 5 deletions

diff --git a/docker/cinder/cinder-api/Dockerfile.j2 b/docker/cinder/cinder-api/Dockerfile.j2
index f64291d7e..b82fba6d3 100644
--- a/docker/cinder/cinder-api/Dockerfile.j2
+++ b/docker/cinder/cinder-api/Dockerfile.j2
@@ -1,6 +1,6 @@
 FROM {{ namespace }}/{{ image_prefix }}cinder-base:{{ tag }}
 {% block labels %}
-LABEL maintainer="{{ maintainer }}" name="{{ image_name }}" build-date="{{ build_date }}"
+LABEL maintainer="{{ maintainer }}" name="{{ image_name }}"
 {% endblock %}
 
 {% block cinder_api_header %}{% endblock %}
diff --git a/docker/cinder/cinder-backup/Dockerfile.j2 b/docker/cinder/cinder-backup/Dockerfile.j2
index aaa8a344f..15be355dd 100644
--- a/docker/cinder/cinder-backup/Dockerfile.j2
+++ b/docker/cinder/cinder-backup/Dockerfile.j2
@@ -1,6 +1,6 @@
 FROM {{ namespace }}/{{ image_prefix }}cinder-base:{{ tag }}
 {% block labels %}
-LABEL maintainer="{{ maintainer }}" name="{{ image_name }}" build-date="{{ build_date }}"
+LABEL maintainer="{{ maintainer }}" name="{{ image_name }}"
 {% endblock %}
 
 {% block cinder_backup_header %}{% endblock %}
diff --git a/docker/cinder/cinder-base/Dockerfile.j2 b/docker/cinder/cinder-base/Dockerfile.j2
index d1f42a18b..bd25d9b18 100644
--- a/docker/cinder/cinder-base/Dockerfile.j2
+++ b/docker/cinder/cinder-base/Dockerfile.j2
@@ -1,6 +1,6 @@
 FROM {{ namespace }}/{{ image_prefix }}openstack-base:{{ tag }}
 {% block labels %}
-LABEL maintainer="{{ maintainer }}" name="{{ image_name }}" build-date="{{ build_date }}"
+LABEL maintainer="{{ maintainer }}" name="{{ image_name }}"
 {% endblock %}
 
 {% block cinder_base_header %}{% endblock %}
diff --git a/docker/cinder/cinder-scheduler/Dockerfile.j2 b/docker/cinder/cinder-scheduler/Dockerfile.j2
index d1835092e..c43792dcc 100644
--- a/docker/cinder/cinder-scheduler/Dockerfile.j2
+++ b/docker/cinder/cinder-scheduler/Dockerfile.j2
@@ -1,6 +1,6 @@
 FROM {{ namespace }}/{{ image_prefix }}cinder-base:{{ tag }}
 {% block labels %}
-LABEL maintainer="{{ maintainer }}" name="{{ image_name }}" build-date="{{ build_date }}"
+LABEL maintainer="{{ maintainer }}" name="{{ image_name }}"
 {% endblock %}
 
 {% block cinder_scheduler_header %}{% endblock %}
diff --git a/docker/cinder/cinder-volume/Dockerfile.j2 b/docker/cinder/cinder-volume/Dockerfile.j2
index e55b05e44..0e4f38a6e 100644
--- a/docker/cinder/cinder-volume/Dockerfile.j2
+++ b/docker/cinder/cinder-volume/Dockerfile.j2
@@ -1,6 +1,6 @@
 FROM {{ namespace }}/{{ image_prefix }}cinder-base:{{ tag }}
 {% block labels %}
-LABEL maintainer="{{ maintainer }}" name="{{ image_name }}" build-date="{{ build_date }}"
+LABEL maintainer="{{ maintainer }}" name="{{ image_name }}"
 {% endblock %}
 
 {% block cinder_volume_header %}{% endblock %}