Release notes: v1.2.1
Trailer.dev is a self-hostable platform that enables seamless container-based development environments. It provides a modern, efficient way to manage development workspaces and container resources. Trailer.dev puts emphasis on Python and ML development for ease-of-use.
This is a bugfix release for the v1.2.0 tunnel transport. It fixes request failures on busy workspace URLs and restores reverse proxy routing on hosts running Docker Engine 29. There are no breaking changes; update the server and agents as usual.
Workspace URLs no longer fail under heavy traffic
Section titled “Workspace URLs no longer fail under heavy traffic”The agent-side proxy introduced in v1.2.0 opened a new connection to the workspace container for nearly every request. Under sustained load this exhausted the agent’s ephemeral ports and a fraction of requests failed with a 502 error. The proxy now keeps a pool of reusable connections per workspace, so high-traffic workspace URLs no longer produce these failures and skip the extra connection handshake on most requests.
Reverse proxy works again on Docker Engine 29
Section titled “Reverse proxy works again on Docker Engine 29”Docker Engine 28.4 and later reject the API version used by Traefik v3.4, which left the deployed reverse proxy unable to discover workspaces: every workspace URL routed through it returned a 404 error, while direct and agent-proxied access kept working. Hosts registered from this release on deploy Traefik v3.6.23, which is compatible with current Docker Engine releases.
Existing hosts keep the Traefik image stored in their settings. If your workspace URLs return 404 errors after a Docker Engine upgrade, change the host’s Traefik image to traefik:v3.6.23 and redeploy the reverse proxy to replace the running container.