fix: detect missing SECP384R1 early and fix community.crypto compatibility (#14970)

Add pre-flight check in main.yml that catches missing cryptography/SECP384R1
before deployment starts, replacing the cryptic error from community.crypto
internals with an actionable message pointing users to run ./algo or uv sync.

Root cause of the CI ipsec/both test failures: cryptography 46.0.5 wraps
the ec module with _ModuleWithDeprecations (for SECT curve deprecation),
which breaks community.crypto's ec.__dict__.get("SECP384R1") lookup.
The fix in community.crypto 3.1.1 uses getattr() instead.

Changes:
- Add SECP384R1 pre-flight check to main.yml (conditional on ipsec_enabled)
- Add cryptography>=42.0.0 as explicit dependency in pyproject.toml
- Upgrade community.crypto to >=3.1.1 (fixes __dict__ vs getattr bug)
- Add ansible-galaxy collection install step to CI
- Use venv Python interpreter for local deployments in add_host tasks

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: dguido

.github/workflows/integration-tests.yml

@@ -56,6 +56,9 @@ jobs:
       - name: Install Python dependencies
         run: uv sync
 
+      - name: Install Ansible collections
+        run: uv run ansible-galaxy collection install -r requirements.yml
+
       - name: Create test configuration
         run: |
           cat > integration-test.cfg << EOF

deploy_client.yml

@@ -13,7 +13,7 @@
         ansible_ssh_user: "{{ 'root' if client_ip == 'localhost' else ssh_user }}"
         vpn_user: "{{ vpn_user }}"
         IP_subject_alt_name: "{{ server_ip }}"
-        ansible_python_interpreter: /usr/bin/python3
+        ansible_python_interpreter: "{% if client_ip == 'localhost' %}{{ ansible_playbook_python }}{% else %}/usr/bin/python3{% endif %}"
 
 - name: Configure the client and install required software
   hosts: client-host

main.yml

@@ -60,6 +60,24 @@
           You must update the requirements to use this version of Algo.
           Try to run: uv sync
 
+    - name: Check cryptography library SECP384R1 support
+      command: >
+        {{ ansible_playbook_python }} -c
+        "from cryptography.hazmat.primitives.asymmetric.ec import SECP384R1"
+      changed_when: false
+      failed_when: false
+      register: _crypto_check
+      when: ipsec_enabled | default(true) | bool
+
+    - name: Verify cryptography library supports IPsec requirements
+      assert:
+        that: _crypto_check.rc == 0
+        msg: >
+          The Python cryptography library is missing or does not support SECP384R1.
+          IPsec/IKEv2 requires the cryptography package with elliptic curve support.
+          Fix: Run ./algo (manages dependencies automatically) or: uv sync && uv run ansible-playbook main.yml
+      when: ipsec_enabled | default(true) | bool
+
 - name: Include prompts playbook
   import_playbook: input.yml
 

playbooks/cloud-post.yml

@@ -10,7 +10,7 @@
     ansible_connection: "{% if cloud_instance_ip == 'localhost' %}local{% else %}ssh{% endif %}"
     ansible_ssh_user: "{{ ansible_ssh_user | default('root') }}"
     ansible_ssh_port: "{{ ansible_ssh_port | default(22) }}"
-    ansible_python_interpreter: /usr/bin/python3
+    ansible_python_interpreter: "{% if cloud_instance_ip == 'localhost' %}{{ ansible_playbook_python }}{% else %}/usr/bin/python3{% endif %}"
     algo_provider: "{{ algo_provider }}"
     algo_server_name: "{{ algo_server_name }}"
     algo_ondemand_cellular: "{{ algo_ondemand_cellular }}"

pyproject.toml

@@ -9,6 +9,7 @@ version = "2.0.0-beta"
 requires-python = ">=3.11"
 dependencies = [
     "ansible==12.3.0",
+    "cryptography>=42.0.0",
     "jinja2>=3.1.6",
     "netaddr==1.3.0",
     "pyyaml>=6.0.2",

requirements.yml

@@ -7,7 +7,7 @@ collections:
   - name: community.general
     version: "==11.1.0"
   - name: community.crypto
-    version: "==3.0.3"
+    version: ">=3.1.1"
   - name: openstack.cloud
     version: "==2.4.1"
   - name: linode.cloud

users.yml

@@ -142,7 +142,7 @@
             groups: vpn-host
             ansible_ssh_user: "{{ server_user | default('root') }}"
             ansible_connection: "{% if algo_server == 'localhost' %}local{% else %}ssh{% endif %}"
-            ansible_python_interpreter: /usr/bin/python3
+            ansible_python_interpreter: "{% if algo_server == 'localhost' %}{{ ansible_playbook_python }}{% else %}/usr/bin/python3{% endif %}"
             CA_password: "{{ CA_password | default(omit) }}"
       rescue:
         - include_tasks: playbooks/rescue.yml