The docker harness now detects and stages host CLI auth files
(~/.gemini/oauth_creds.json, ~/.claude/.credentials.json) into a
writable agent-home directory mounted at /home/agent. This lets
containerized agents reuse the host's Gemini Pro / Claude Pro OAuth
sessions without manual secret management or API keys.
Only auth files are copied — not the host's settings.json or MCP
configs (which contain stale localhost URLs that would hang Gemini CLI
inside containers). The staged dir is writable so CLIs can create
projects.json, history, etc. alongside the auth files.
Also sets GEMINI_DEFAULT_AUTH_TYPE=oauth-personal and
GEMINI_CLI_NO_RELAUNCH=true when OAuth creds are detected, writes
Claude's hasCompletedOnboarding flag, and simplifies the doc-gardener
example to use the harness-level credential staging instead of manual
HOME directory seeding.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
New `internal/harness/docker` package: per-run ephemeral container
backend that runs each agent in `docker run --rm`, bind-mounts the
materialized workdir at /workspace, and captures stdout/stderr/exit
code/result.json the same way the subprocess backend does.
Inspired by scion's pkg/runtime/docker.go: shell out to the docker
CLI (zero new Go deps, zero CGO), per-task ephemeral containers with
no warm pool, host-side scratch dir bind-mounted in.
Default security posture (overridable per agent):
--rm
--cap-drop=ALL
--security-opt=no-new-privileges
--read-only with tmpfs /tmp
--pids-limit=512
--user=<host uid:gid>
--network=bridge (configurable; --network=none for air-gap)
--memory / --cpus from agent config
--add-host host.docker.internal:host-gateway on Linux
The backend reuses subprocess.AgentConfig for gemini_md/claude_md/
mcp_servers/skills materialization so existing example configs work
unchanged. Per-agent docker tunables go under a new `docker` block
in harness_config_json: image, memory, cpus, network, extra_mounts,
cap_add, read_only_root, user, entrypoint, command, extra_args.
MCP host rewrite: `.gemini/settings.json` URLs of the form
http://127.0.0.1:<port>/mcp are rewritten to
http://host.docker.internal:<port>/mcp at materialization time so the
in-container Gemini CLI can reach the SynapBus MCP server on the host
without code changes in the example wrappers.
Wired into the reactor and Registry resolver:
- Registry.Resolve picks "docker" when harness_config_json contains a
`"docker"` block, taking precedence over local_command so explicit
isolation never silently downgrades.
- reactor.agentBackendKind() returns backendDocker for the same case.
- evaluateTrigger's harness-backend gate accepts backendDocker
alongside subprocess + webhook.
- main.go registers docker.Harness with the harness registry, passing
the SynapBus listen port so the URL rewrite uses the correct host
port.
Smoke tests in docker_test.go (skipped when no docker daemon):
- TestExecute_Hello: env injection + bind-mount writeback + message.json
+ result.json + stdout capture using alpine:3.20
- TestExecute_NoImage: rejects agents missing docker.image
- TestExecute_TimeoutCancel: wall-clock budget kills the container
New canonical agent image at image-build/synapbus-agent/:
- Debian bookworm-slim base
- Node 22 + @google/gemini-cli + @anthropic-ai/claude-code
- jq, sqlite3, curl, git, python3, tini (PID 1 for signal forwarding)
- Non-root agent user uid/gid 1000
- ENTRYPOINT tini, CMD /workspace/wrapper.sh
No SynapBus binary inside the image — agents reach the host MCP server
over the network at host.docker.internal:<port>.
Pre-existing reactor test failures (TestReactorNoK8sImage,
TestReactorDepthExceeded, TestReactorBudgetExhausted,
TestReactorCooldownSkipped, TestReactorSequentialExecution) verified
to exist on f319290 unchanged — not introduced by this commit.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
