Sandbox ports and SSH

PortsCopy Anchor Link

A server in a sandbox gets a URL for each port, for HTTPS and WebSockets. The server must listen on 0.0.0.0 or 127.0.0.1.

1. Start a server in the sandbox, for example on port 8080:

curl -sS --fail-with-body "https://api.munito.ai/sandboxes/v1/sandboxes/$SANDBOX/exec" \
  -H "Authorization: Bearer $MUNITO_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"command": "nohup python3 -m http.server 8080 >/dev/null 2>&1 &"}'

2. Get the url of the port and the token of the sandbox:

curl -sS --fail-with-body "https://api.munito.ai/sandboxes/v1/sandboxes/$SANDBOX/ports/8080" \
  -H "Authorization: Bearer $MUNITO_API_KEY"

3. Send the token in the header munito-sandbox-token:

curl -sS "$URL" -H "munito-sandbox-token: $TOKEN"

A port is private. These open it:

• The token opens all ports of the sandbox while the sandbox lives. Keep it secret.
• A signed URL opens one private port in a browser. Send {"expires_in": 3600} to POST /sandboxes/{sandbox_id}/ports/8080/url. The browser that opens the URL keeps access to that port for 24 hours.
• A public port opens for each person with its URL. Set "public_ports": [8080] in the create, or send {"public": true} to PUT /sandboxes/{sandbox_id}/ports/8080. To make it private again, send {"public": false}.

Connections:

• A connection can stay open for hours, so WebSockets and server-sent events work.
• A connection with no data for one hour closes.
• The server gets the address of the client in X-Forwarded-For.
• The munito-sandbox-token header and the cookie of a signed URL do not go to the server.
• A Munito API key in Authorization or x-api-key does not go to the server. Other values of these headers go to it.
• Each cookie that the server sets stays with the host of its port: the edge removes the Domain attribute from each Set-Cookie.

SSHCopy Anchor Link

1. Give the sandbox your public key. Set ssh_keys in the create, or use PUT /sandboxes/{sandbox_id}/ssh.
2. Get the SSH command with GET /sandboxes/{sandbox_id}/ssh.
3. Run the command. The user name is the id of the sandbox.

curl -sS --fail-with-body -X PUT "https://api.munito.ai/sandboxes/v1/sandboxes/$SANDBOX/ssh" \
  -H "Authorization: Bearer $MUNITO_API_KEY" \
  -H "Content-Type: application/json" \
  -d "{\"keys\": [\"$(cat ~/.ssh/id_ed25519.pub)\"]}"

curl -sS --fail-with-body "https://api.munito.ai/sandboxes/v1/sandboxes/$SANDBOX/ssh" \
  -H "Authorization: Bearer $MUNITO_API_KEY"

• Only the keys in ssh_keys open SSH. SSH accepts no password.
• The answer gives the host_key. Add the line <host> <host_key> to ~/.ssh/known_hosts. Then ssh trusts the host at once.
• A shell is bash as root, in /workspace. ssh <host> <command> runs one command. scp and sftp work.
• ssh -L 3000:localhost:3000 reaches port 3000 of the sandbox. A forward reaches only the ports of the sandbox.
• SSH refuses remote forwards (-R), agent forwarding and X11.
• A new list of keys replaces the old list. An open session stays open.