Root cause: the github-app-auth plugin injects GH_TOKEN + GITHUB_TOKEN
into each workspace container's env at provision time (EnvMutator). Those
are GitHub App installation tokens with a fixed ~60 min TTL. The plugin
has an in-process cache that proactively refreshes 5 min before expiry —
but the workspace env is set once at container start and never updated.
Any workspace alive >60 min ends up with an expired token.
Fix (Option B — on-demand endpoint):
pkg/provisionhook:
- Add TokenProvider interface: Token(ctx) (token, expiresAt, error)
Lives in pkg/ (public) so the github-app-auth plugin can implement it.
- Add Registry.FirstTokenProvider() — discovers the first mutator that
also satisfies TokenProvider via interface assertion. Safe under
concurrent reads (existing RWMutex).
platform/internal/handlers/github_token.go:
- New GitHubTokenHandler serving GET /admin/github-installation-token
- Delegates to the registered TokenProvider (plugin cache — always fresh)
- 404 if no GitHub App configured, 500 + [github] prefix log on error
- Never logs the token itself
platform/internal/handlers/workspace.go:
- Add TokenRegistry() getter so the router can wire the handler without
coupling to WorkspaceHandler internals
platform/internal/router/router.go:
- Register GET /admin/github-installation-token under AdminAuth
workspace-template/:
- scripts/molecule-git-token-helper.sh — git credential helper; calls
the platform endpoint on every push/fetch; falls through to next
helper (operator PAT) if platform unreachable
- entrypoint.sh — configure the credential helper at startup
Why Option B over Option A (background goroutine):
- The plugin already has its own cache refresh; nothing to refresh here.
- Pushing env updates into running containers requires docker exec, which
the architecture explicitly rejects (issue #547 "Alternatives").
- Pull-based is stateless, trivially testable, zero extra goroutines.
Closes#547
Co-authored-by: Molecule AI DevOps Engineer <devops-engineer@agents.moleculesai.app>
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
Add `provisionhook.EnvMutator` extension point so out-of-tree plugins
(e.g. github-app-auth, vault-secrets) can inject or override env vars
right before container Start, without forking core or piling more
provider-specific code into the handlers package.
WorkspaceHandler gains an optional `envMutators *provisionhook.Registry`
wired in via SetEnvMutators during boot. The hook fires after built-in
secret loads + per-agent git identity, so plugins can both read what's
already there and override anything they own (GIT_AUTHOR_*, GITHUB_TOKEN).
A nil registry is a no-op via Registry.Run's nil-receiver branch — keeps
the hot path a single nil compare and means existing flows stay green
even with zero plugins registered.
Mutator failure aborts provisioning and marks the workspace failed with
the wrapped error in last_sample_error. Failing fast surfaces the cause
to the operator instead of letting an agent boot into opaque "git push
401" loops it can never recover from on its own.
Tests cover ordered execution, chained env visibility, first-error abort,
nil-receiver no-op, nil-mutator drop, registration order, and concurrent
register-vs-run safety (-race clean).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
