feat: Add Flaky MCP, Docker-in-Docker, and rotation-proof git auth to Codespaces (no-changelog) (#35950)

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

.devcontainer/codespaces/Dockerfile

@@ -16,8 +16,14 @@ RUN npx -y playwright@${PLAYWRIGHT_VERSION} install-deps chromium
 ENV DISABLE_AUTOUPDATER=1
 RUN npm install -g @anthropic-ai/claude-code opencode-ai
 
+COPY codespaces-env.sh /usr/local/lib/codespaces-env.sh
 COPY codespaces-secrets.sh /etc/profile.d/codespaces-secrets.sh
 
+# git and gh must survive token rotation: these read the token on each call
+COPY gitcredential-refresh.sh /usr/local/bin/gitcredential-refresh.sh
+COPY gh-shim.sh /usr/local/bin/gh
+RUN chmod +x /usr/local/bin/gitcredential-refresh.sh /usr/local/bin/gh
+
 RUN echo node ALL=\(root\) NOPASSWD:ALL > /etc/sudoers.d/node && chmod 0440 /etc/sudoers.d/node
 RUN mkdir -p /workspaces && chown node:node /workspaces
 RUN corepack enable

.devcontainer/codespaces/README.md

@@ -6,7 +6,8 @@ from anywhere with a terminal, resume tomorrow.
 
 This is a separate devcontainer config from the laptop one in
 `.devcontainer/` — it ships both agent CLIs, `tmux` for session persistence,
-and Playwright system deps, on the same Postgres sidecar setup.
+Playwright system deps, and Docker-in-Docker (for testcontainers and
+`pnpm --filter n8n-containers services`), on the same Postgres sidecar setup.
 
 ## One-time setup (~5 min)
 
@@ -38,6 +39,15 @@ pnpm session rm           # delete the codespace
 - First codespace creation takes ~20 min uncached (image + full build). After
   that, sessions attach instantly; new worktrees cost a `pnpm install` (~1–2 min).
 
+## Flaky tools (MCP)
+
+Claude sessions get the `flaky` MCP server automatically: Currents
+flaky/quarantine data, the `qa_*` BigQuery dataset, Sentry RCA, live Linear,
+and repo investigation. Login registers it from the repo-level
+`FLAKY_MCP_TOKEN` / `FLAKY_MCP_URL` secrets. Forks have no secrets and skip
+it. Tell the agent to call `get_flaky_context` first — it returns the rules
+the tools assume.
+
 ## Viewing the dev UI locally
 
 Two terminal windows:
@@ -84,6 +94,14 @@ After a stop, `pnpm session <name>` restarts the codespace (~30–60 s); run
   agent injects them into VS Code sessions only; they're delivered
   base64-encoded to `/workspaces/.codespaces/shared/.env-secrets`. The image's
   profile shim exports them for ssh/tmux sessions.
+- **`git push` / `gh` return 401 in tmux and long sessions** — same root
+  cause as the secrets gotcha, plus rotation: Codespaces refreshes the
+  on-disk `GITHUB_TOKEN` every few minutes, so a login-time snapshot goes
+  stale. The image fixes both: a credential helper reads the current token
+  on each `git push` (`gitcredential-refresh.sh`), and a shim at
+  `/usr/local/bin/gh` does the same for `gh`. The token is scoped to
+  `n8n-io/n8n`: fork-based flows do not work, push branches directly. Do
+  not add SSH keys as a workaround — they have no per-repo granularity.
 - Codespaces created by org members on this repo are **org-owned and
   org-billed** (organization ownership + a monthly Codespaces budget are
   enabled for n8n-io). Codespaces created before that change, or by

.devcontainer/codespaces/codespaces-env.sh

@@ -0,0 +1,9 @@
+# Codespaces delivers secrets base64-encoded in a shared env file. It injects
+# them into VS Code sessions only. Other shells must source this file to get
+# them. Tokens rotate every few minutes: read at time of use, not at login.
+if [ -f /workspaces/.codespaces/shared/.env-secrets ]; then
+	while IFS='=' read -r key val; do
+		case "$key" in '' | *[!A-Za-z0-9_]*) continue ;; esac
+		dec=$(printf %s "$val" | base64 -d 2>/dev/null) && export "$key=$dec"
+	done </workspaces/.codespaces/shared/.env-secrets
+fi

.devcontainer/codespaces/codespaces-secrets.sh

@@ -1,8 +1,19 @@
-# Codespaces delivers user secrets base64-encoded to a shared env file and only
-# injects them into VS Code sessions; ssh/tmux login shells must source them here.
-if [ -f /workspaces/.codespaces/shared/.env-secrets ]; then
-	while IFS='=' read -r key val; do
-		case "$key" in '' | *[!A-Za-z0-9_]*) continue ;; esac
-		dec=$(printf %s "$val" | base64 -d 2>/dev/null) && export "$key=$dec"
-	done </workspaces/.codespaces/shared/.env-secrets
+# Login-shell setup for ssh/tmux sessions: export secrets, then do the
+# one-time registrations.
+. /usr/local/lib/codespaces-env.sh
+
+# Register the Flaky MCP server for Claude Code. The config keeps a literal
+# ${FLAKY_MCP_TOKEN}; Claude Code expands it at connect time, so the token is
+# not written to disk. Forks have no repo secrets and skip this.
+if [ -n "$FLAKY_MCP_URL" ] && ! grep -qs '"flaky"' "$HOME/.claude.json" && command -v claude >/dev/null 2>&1; then
+	claude mcp add --scope user --transport http flaky "$FLAKY_MCP_URL" \
+		--header 'Authorization: Bearer ${FLAKY_MCP_TOKEN}' >/dev/null 2>&1 || true
+fi
+
+# Register the credential helper in the user config, because Codespaces
+# regenerates the managed /etc/gitconfig. When the env token is missing, the
+# system helper exits 0 without output, and git falls through to ours.
+if command -v git >/dev/null 2>&1 &&
+	! git config --global --get-all credential.helper 2>/dev/null | grep -qs gitcredential-refresh; then
+	git config --global --add credential.helper /usr/local/bin/gitcredential-refresh.sh
 fi

.devcontainer/codespaces/devcontainer.json

@@ -12,7 +12,10 @@
 	"features": {
 		"ghcr.io/devcontainers/features/github-cli:1": {},
 		// gh codespace ssh needs an SSH server inside the container
-		"ghcr.io/devcontainers/features/sshd:1": {}
+		"ghcr.io/devcontainers/features/sshd:1": {},
+		// Docker for testcontainers and `pnpm --filter n8n-containers services`;
+		// needs `privileged: true` on the n8n service (compose-based config)
+		"ghcr.io/devcontainers/features/docker-in-docker:2": {}
 	},
 	"forwardPorts": [8080, 5678],
 	// Runs in prebuilds, so a fresh codespace starts with deps installed and the build warm
@@ -23,6 +26,13 @@
 		},
 		"CLAUDE_CODE_OAUTH_TOKEN": {
 			"description": "Alternative to an API key: token from `claude setup-token` (Max subscription)"
+		},
+		// Both set at the repository level — team members get them automatically
+		"FLAKY_MCP_TOKEN": {
+			"description": "Bearer token for the Flaky (QA assistant) MCP endpoint"
+		},
+		"FLAKY_MCP_URL": {
+			"description": "URL of the Flaky MCP endpoint on the internal n8n instance"
 		}
 	}
 }

.devcontainer/codespaces/docker-compose.yml

@@ -15,6 +15,8 @@ services:
     build:
       context: .
       dockerfile: Dockerfile
+    # Required by the docker-in-docker devcontainer feature
+    privileged: true
     volumes:
       - ../..:/workspaces:cached
     command: sleep infinity

.devcontainer/codespaces/gh-shim.sh

@@ -0,0 +1,7 @@
+#!/bin/sh
+# gh reads its token from the env only. Long sessions hold a stale snapshot of
+# the rotated token. Read the current token on each call, then run the real gh
+# (the github-cli feature installs it at /usr/bin/gh).
+. /usr/local/lib/codespaces-env.sh
+[ -n "$GITHUB_TOKEN" ] && export GH_TOKEN="$GITHUB_TOKEN"
+exec /usr/bin/gh "$@"

.devcontainer/codespaces/gitcredential-refresh.sh

@@ -0,0 +1,6 @@
+#!/bin/sh
+# The stock helper reads $GITHUB_TOKEN from the env. Non-login shells do not
+# have it, and the token rotates. Read the current token, then delegate.
+[ "$1" = get ] || exit 0
+. /usr/local/lib/codespaces-env.sh
+exec /.codespaces/bin/gitcredential_github.sh "$@"