OS X Overseer

Simple, lightweight userspace process manager for OS X.

Requirements

• Run as a server overseerd
  • Persist its state somewhere
  • Bind a port to take triggers from
• Be triggered by re-running overseer
  • Detect new jobs
  • Detect jobs with changed configurations
  • Re-run tests for all jobs
  • Kill and kickoff processes for jobs with different state
  • Re-persist state
• Config in $XDG_CONFIG_HOME/overseer, default $HOME/.config/overseer/
• Runtime data in $XDG_DATA_HOME/overseer, default $HOME/.local/share/overseer
• Kick off process and restart them if they go down
• Check if process should be running with arbitrary test

Architecture

Daemon State Machine

• Start
  • -> InitHomes
• InitHomes
  • Success -> OpenSocket(Homes)
• OpenSocket(Homes)
  • Success -> ReceiveRequest(Socket)
  • Failure -> Exit(Err(SocketOpenError))
• ReceiveRequest(Socket)
  • Success -> ProcessRequest(Socket, Request)
  • Failure -> Exit(Err(SocketReadError))
• ProcessRequest(Socket, Request)
  • "DIE" -> Exit(Ok(()))
  • other -> SendResponse(Socket)
• SendResponse(Socket)
  • Success -> ReceiveRequest(Socket)
  • Failure -> Exit(Err(SocketWriteError))
• Exit(Result<(), Error>)
  • -> Done
• Done

Client State Machine

• Start
  • -> InitHomes
• InitHomes
  • Success -> CheckSocketExists(Homes)
  • Failure -> Exit(Err(InitHomesError))
• CheckSocketExists(Homes)
  • Success -> OpenSocket(Homes)
  • Failure -> LaunchDaemon
• OpenSocket(Homes)
  • Success -> SendRequest(Socket)
  • Failure -> DeleteSocketFile(Homes)
• SendRequest(Socket)
  • Success -> ReadResponse(Socket)
  • Failure -> CloseSocket(Socket, Exit(Err(SocketSendError)))
• CloseSocket(Socket, State)
  • -> param state
• DeleteSocketFile(Homes)
  • -> LaunchDaemon(Homes)
• LaunchDaemon(Homes)
  • Success -> OpenSocket(Homes)
  • Failure -> Exit(Err(DaemonLaunchError))
• ReadResponse(Socket)
  • Success -> CloseSocket(Socket, PrintResponse(Response))
  • Failure -> CloseSocket(Socket, Exit(Err(SocketReadError)))
• PrintResponse(Response)
  • -> Exit(Ok(()))
• Exit(Result<(), Error>)
  • -> Done
• Done

Types

struct Command {
  exe: String,
  args: Vec<String>,
};

struct Job { 
  name: String,
  job_command: Command,
  test_command: Option<Command>,
};

struct Config {
  jobs: Vec<Job>,
}