Dev Testing Vm

In-VM Testing

capsem-doctor

The diagnostic suite runs inside the guest VM via pytest. Tests live in guest/artifacts/diagnostics/ and are baked into the rootfs.

Running diagnostics

just exec "capsem-doctor"              # Full suite (~10s total)
just exec "capsem-doctor -k sandbox"   # Only sandbox tests
just exec "capsem-doctor -k network"   # Only network tests
just exec "capsem-doctor -x"           # Stop on first failure

Test categories

| File | What it verifies |

|------|------------------|

| test_sandbox.py | Read-only rootfs, binary permissions, setuid/setgid, kernel hardening (no modules, no debugfs, no IPv6, no swap), process integrity, network isolation (dummy0, fake DNS, iptables) |

| test_network.py | MITM CA in system store + certifi, curl without -k, Python urllib HTTPS, CA env vars, HTTP/80 blocked, non-443 blocked, direct IP blocked, multi-domain DNS, AI provider domains |

| test_environment.py | TERM/HOME/PATH env vars, bash shell, kernel version, aarch64 arch, mount points, tmpfs |

| test_runtimes.py | Python3, Node.js, npm, pip3, git version checks, Python/Node file I/O, git workflow |

| test_utilities.py | ~36 unix utilities (coreutils, text processing, network, system tools) |

| test_workflows.py | Text write/read, JSON roundtrip, shell pipes, large file (10MB) |

| test_ai_cli.py | claude/gemini/codex installed and executable |

| test_virtiofs.py | VirtioFS mount, ext4 loopback, workspace I/O, pip install, file delete+recreate |

Adding new in-VM tests

• Add test functions to the appropriate guest/artifacts/diagnostics/test_*.py or create test_<category>.py
• Use from conftest import run for shell commands, output_dir fixture for temp files
• Tests auto-skip outside the capsem VM (conftest checks for root + writable /root)
• Rebuild rootfs with just _build-assets to bake new test files into the image
• For fast iteration during development, tests in diagnostics/ are also repacked into the initrd by just exec, so just exec "capsem-doctor" picks up changes without a full rootfs rebuild
• Verify: just exec "capsem-doctor -k <your_test>"

Session inspection

After running a VM session, inspect the telemetry database:

python3 scripts/check_session.py              # Latest session
python3 scripts/check_session.py <session-id> # Specific session
python3 scripts/check_session.py --list       # List recent sessions
python3 scripts/check_session.py -n 10        # Show 10 preview rows per table

Checks: session ledgers exist (net_events, model_calls, tool_calls, tool_responses, fs_events, dns_events, security_rule_events), row counts, orphaned tool_calls, AI-provider consistency.

Verifying telemetry pipelines

Each pipeline can be tested with a targeted VM command:

• fs_events: just exec 'touch /root/test.txt && sleep 1' then python3 scripts/check_session.py
• net_events: just exec 'curl -s https://api.anthropic.com/ && sleep 1'
• model_calls/tool_calls: boot interactively, run claude -p "what is 2+2"
• MCP-origin tool_calls: boot interactively, run claude -p "use fetch to get https://example.com" and query tool_calls WHERE origin = 'mcp'

If events are missing: check boot logs for daemon startup, vsock connection acceptance, and whether the VM lived long enough for the debouncer to flush (add sleep 1).

Test fixture

The fixture (data/fixtures/test.db) is a real session DB shared by frontend mock mode and Rust roundtrip tests. No synthetic data.

Updating the fixture

# 1. Run integration test to generate a rich session
python3 scripts/integration_test.py --binary target/debug/capsem --assets assets

# 2. Inspect completeness
python3 scripts/check_session.py <session-id>

# 3. Fixture refresh has no Just convenience command. Copy, checkpoint, and
# scrub the selected DB using the procedure in /dev-session-debug.

# 4. Verify
cargo test --workspace

The fixture must contain: both allowed and denied net_events, created/modified/deleted fs_events, model_calls with cost > 0, tool_calls with origin populated.