ensure-rust: verify cryptography build on Ubuntu

Just for sanity, ensure the cryptography build (that uses rust) works.

Change-Id: I2fc9dc1fd0f19191af1535dd660d2a5376139764

test-playbooks/rust/ensure-rust.yaml

@@ -19,3 +19,28 @@
 
     - name: Run hello world
       command: ./hello
+
+    - name: Test pyca/cryptography build
+      when: ansible_distribution == 'Ubuntu'
+      block:
+
+        - name: Ensure pip
+          include_role:
+            name: ensure-pip
+
+        - name: Install deps
+          package:
+            name: '{{ item }}'
+            state: present
+          loop:
+            - build-essential
+            - libssl-dev
+            - libffi-dev
+            - python3-dev
+          become: yes
+
+        - name: Check build
+          shell: |
+            python3 -m venv ./venv
+            ./venv/bin/pip install --upgrade pip
+            ./venv/bin/pip install cryptography --no-binary cryptography

zuul-tests.d/rust-jobs.yaml

@@ -6,6 +6,7 @@
     files:
       - playbooks/ensure-rust.yaml
       - roles/ensure-rust
+      - test-playbooks/rust/ensure-rust.yaml
       - zuul.d/rust-jobs.yaml
 
 # -* AUTOGENERATED *-