Automatically install setuptools-scm in script called from Makefile

tools/ansible/build.yml

@@ -5,15 +5,16 @@
   tasks:
     - name: Get version from SCM if not explicitly provided
       shell: |
-        python3 -m setuptools_scm | cut -d + -f -1
+        make print-VERSION | cut -d + -f -1
       args:
         chdir: '../../'
-      register: setup_py_version
+      register: scm_version
+      failed_when: not scm_version.stdout
       when: awx_version is not defined
 
     - name: Set awx_version
       set_fact:
-        awx_version: "{{ setup_py_version.stdout }}"
+        awx_version: "{{ scm_version.stdout }}"
       when: awx_version is not defined
 
     - include_role:

tools/ansible/roles/dockerfile/templates/Dockerfile.j2

@@ -43,7 +43,7 @@ RUN dnf -y update && dnf install -y 'dnf-command(config-manager)' && \
     xmlsec1-devel \
     xmlsec1-openssl-devel
 
-RUN pip3 install virtualenv setuptools_scm build
+RUN pip3 install virtualenv build
 
 
 # Install & build requirements

tools/scripts/scm_version.py

@@ -1,4 +1,18 @@
-from setuptools_scm import get_version
+import os
+import sys
+import subprocess
+import traceback
+
+try:
+    from setuptools_scm import get_version
+except ModuleNotFoundError:
+    sys.stderr.write("Unable to import setuptools-scm, attempting to install now...\n")
+
+    os.environ['PIP_DISABLE_PIP_VERSION_CHECK'] = '1'
+    subprocess.check_output([sys.executable, '-m', 'ensurepip'])
+    subprocess.check_output([sys.executable, '-m', 'pip', 'install', 'setuptools-scm'])
+
+    from setuptools_scm import get_version
 
 version = get_version(root='../..', relative_to=__file__)
 print(version)