Add unique hash to icon uenv (only on a100 so far) (#76)

* add(icon, balfrin): compute hash at post-install stage

recipes/wcp/icon/v1/a100/post-install

@@ -1,11 +1,23 @@
 #!/usr/bin/python3
 
 import yaml
+import hashlib
 
+
+# Add cuda_arch to packages.yaml
 with open("{{ env.mount }}/config/packages.yaml", mode='r') as file:
     packages = yaml.safe_load(file)
 
 packages['packages']['all'] = {'variants': 'cuda_arch=80'}
 
 with open("{{ env.mount }}/config/packages.yaml", mode='w') as file:
     yaml.dump(packages, file)
+
+
+# Generate a hash to make the uenv uniquely identifiable
+with open("{{ env.mount }}/meta/configure.json", mode='rb') as f:
+    sha = hashlib.sha256(f.read()).hexdigest()
+
+with open("{{ env.mount }}/meta/hash", mode='w') as f:
+    f.write(sha)
+