Fix snapcraft build issues

The latest version of snapcraft fails to build microstack. Chasing
it down is due to multiple staged parts which have conflicting
information. Fixing that bit causes the uwsgi services not to run
correctly.

This patch fixes the uwsgi services by no longer overriding the python
home directory, since python3 is staged into the snap we can use the
default python home.

This patch also removes the libc6 staging into the package, which should
generally be avoided.

Change-Id: I8c176689083831a0b8b56a192a9fbdfb50edbb66

snap-overlay/templates/cinder-api.ini.j2

@@ -7,5 +7,4 @@ enable-threads = true
 processes = 4
 thunder-lock = true
 lazy-apps = true
-home = {{ snap }}/usr
 pyargv = {{ pyargv }}

snap-overlay/templates/cluster-api.ini.j2

@@ -7,5 +7,4 @@ enable-threads = true
 processes = 2
 thunder-lock = true
 lazy-apps = true
-home = {{ snap }}/usr
 pyargv = {{ pyargv }}

snap-overlay/templates/horizon.ini.j2

@@ -7,5 +7,4 @@ enable-threads = true
 processes = 4
 thunder-lock = true
 lazy-apps = true
-home = {{ snap }}/usr
 pyargv = {{ pyargv }}

snap-overlay/templates/keystone-api.ini.j2

@@ -7,5 +7,4 @@ enable-threads = true
 processes = 4
 thunder-lock = true
 lazy-apps = true
-home = {{ snap }}/usr
 pyargv = {{ pyargv }}

snap-overlay/templates/placement-api.ini.j2

@@ -7,5 +7,4 @@ enable-threads = true
 processes = 4
 thunder-lock = true
 lazy-apps = true
-home = {{ snap }}/usr
 pyargv = {{ pyargv }}

snapcraft.yaml

@@ -658,7 +658,6 @@ parts:
   # OpenStack Python Projects, keyed off Keystone
   openstack-projects:
     plugin: python
-    # python-version: python3
     after:
       - uca-sources
       - libvirt
@@ -682,9 +681,11 @@ parts:
       - haproxy
       - libglib2.0-0
       - libmagic1
-      - petname
-      - libsystemd0
       - libpython3.8
+      - libssl-dev
+      - libsystemd0
+      - petname
+      - python3
       - spice-html5
       - sg3-utils
       # LIO userspace dependencies
@@ -1423,9 +1424,6 @@ parts:
       - ${SNAPCRAFT_STAGE}/patches/upper-constraints.txt
     source: tools/init
     stage-packages:
-      # note(dmitriis) in order to avoid conflicts about lib64/ld-linux-x86-64.so.2
-      # with other parts.
-      - libc6
       - rsync
     python-packages:
       - pip==20.0.2
@@ -1454,10 +1452,6 @@ parts:
     constraints:
       - ${SNAPCRAFT_STAGE}/patches/upper-constraints.txt
     source: tools/launch
-    stage-packages:
-      # note(dmitriis) in order to avoid conflicts about lib64/ld-linux-x86-64.so.2
-      # with other parts.
-      - libc6
     python-packages:
       - pip==20.0.2
       - setuptools==44.0.0
@@ -1477,10 +1471,6 @@ parts:
   microstack:
     plugin: python
     source: tools/microstack
-    stage-packages:
-      # note(dmitriis) in order to avoid conflicts about lib64/ld-linux-x86-64.so.2
-      # with other parts.
-      - libc6
     python-packages:
       - pip==20.0.2
       - setuptools==44.0.0
@@ -1505,10 +1495,6 @@ parts:
     constraints:
       - ${SNAPCRAFT_STAGE}/patches/upper-constraints.txt
     source: tools/cluster
-    # note(dmitriis) in order to avoid conflicts about lib64/ld-linux-x86-64.so.2
-    # with other parts.
-    stage-packages:
-      - libc6
     python-packages:
       - pip==20.0.2
       - setuptools==44.0.0
@@ -1534,9 +1520,6 @@ parts:
     organize:
       setup-lvm-loopdev: bin/setup-lvm-loopdev
     stage-packages:
-      # note(dmitriis) in order to avoid conflicts about lib64/ld-linux-x86-64.so.2
-      # with other parts.
-      - libc6
       # fallocate
       - util-linux
       # losetup