Revert "Add stunnel container for Glance service"

This reverts commit 935adb5913.

It seems we cannot use stunnel on Ubuntu because
of no support for current OpenSSL. See [1].

We have some alternatives to replace stunnel:
- HAProxy (image ready; in progress)
- Apache2 (only embedded, no image)
- Nginx (possibly in the future)

[1] https://review.opendev.org/707131

Change-Id: If1140b293423ad3173cb3a4e1f19abbfecdaf2f6

doc/source/matrix_aarch64.csv

@@ -78,7 +78,6 @@ sensu (deprecated),C,C,N,N,N,N
 skydive,N,N,N,N,N,N
 solum,N,C,N,C,N,C
 storm,C,C,C,C,N,C
-stunnel,C,C,C,C,C,C
 swift,C,C,C,C,N,C
 tacker,C,C,N,C,N,C
 telegraf,N,N,N,N,N,N

doc/source/matrix_x86.csv

@@ -80,7 +80,6 @@ sensu (deprecated),C,C,C,C,N,N
 skydive,C,C,C,C,N,C
 solum,N,C,N,C,N,C
 storm,C,C,C,C,N,C
-stunnel,C,C,C,C,C,C
 swift,C,T,C,T,N,C
 tacker,C,T,N,C,N,C
 telegraf,C,C,C,C,N,N

docker/stunnel/Dockerfile.j2

@@ -1,15 +0,0 @@
-FROM {{ namespace }}/{{ image_prefix }}base:{{ tag }}
-{% block labels %}
-LABEL maintainer="{{ maintainer }}" name="{{ image_name }}" build-date="{{ build_date }}"
-{% endblock %}
-
-{% block stunnel_header %}{% endblock %}
-
-{% import "macros.j2" as macros with context %}
-
-{% set stunnel_packages = ['stunnel'] %}
-
-{{ macros.install_packages(stunnel_packages | customizable("packages")) }}
-
-{% block stunnel_footer %}{% endblock %}
-{% block footer %}{% endblock %}

releasenotes/notes/add-stunnel-54c00678cd8aba08.yaml

@@ -1,4 +0,0 @@
----
-features:
-  - Adds stunnel container image initially to provide ssl termination for
-    Glance (eventlet).