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>
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