Filesystem

Three paths the server opens into the container’s filesystem: the tree, watched; one file read; one file written.

Three paths carry the server’s access to the filesystem of the container. The server opens each path as often as it chooses. Every opening is its own exchange, and no state is shared between openings.

Path	Carries
`/filesystem/tree`	the paths to leave out; the tree as a snapshot and every change, or the reason there is none
`/filesystem/read`	the name of one file; its bytes, or the reason there are none
`/filesystem/write`	the name of one file and its content; ok or an error

Paths are components. A file is named as a JSON array of path components from the root of the container.
What the tree leaves out. The server names the paths the tree leaves out in the message that opens the watch.
No repetition. An exchange whose path ended abruptly has failed. No party retries it.

In this section

/filesystem/tree — The filesystem of the container, watched: the server sends exactly one message naming the paths to leave out; the proxy sends a snapshot, one message per change, a snapshot again after lost events, or one error as its last message.
/filesystem/read — One file out of the container: the server sends exactly one message naming the file; the proxy sends the bytes of the file in one or more messages and closes the connection, or sends an error as its last message.
/filesystem/write — One file into the container: the server sends the name of the file, its content in one or more pieces, and one empty message; the proxy sends exactly one answer, ok or an error, and closes the connection.