class Unicorn::Worker - unicorn-5.3.0 Documentation

# class Unicorn::Worker

This class and its members can be considered a stable interface and will not change in a backwards-incompatible fashion between releases of unicorn. Knowledge of this class is generally not not needed for most users of unicorn.

Some users may want to access it in the before_fork/after_fork hooks. See the Unicorn::Configurator RDoc for examples.

### Public Instance Methods

user(user, group = nil, chroot = false) click to toggle source

In most cases, you should be using the Unicorn::Configurator#user directive instead. This method should only be used if you need fine-grained control of exactly when you want to change permissions in your after_fork or after_worker_ready hooks, or if you want to use the chroot support.

Changes the worker process to the specified `user` and `group`, and chroots to the current working directory if `chroot` is set. This is only intended to be called from within the worker process from the `after_fork` hook. This should be called in the `after_fork` hook after any privileged functions need to be run (e.g. to set per-worker CPU affinity, niceness, etc)

Any and all errors raised within this method will be propagated directly back to the caller (usually the `after_fork` hook. These errors commonly include ArgumentError for specifying an invalid user/group and Errno::EPERM for insufficient privileges.

chroot support is only available in unicorn 5.3.0+ user and group switching appeared in unicorn 0.94.0 (2009-11-05)

    # File lib/unicorn/worker.rb, line 131
    def user(user, group = nil, chroot = false)
      # we do not protect the caller, checking Process.euid == 0 is
      # insufficient because modern systems have fine-grained
      # capabilities.  Let the caller handle any and all errors.
      uid = Etc.getpwnam(user).uid
      gid = Etc.getgrnam(group).gid if group
      Unicorn::Util.chown_logs(uid, gid)
      if gid && Process.egid != gid
        Process.initgroups(user, gid)
        Process::GID.change_privilege(gid)
      end
      if chroot
        chroot = Dir.pwd if chroot == true
        Dir.chroot(chroot)
        Dir.chdir('/')
      end
      Process.euid != uid and Process::UID.change_privilege(uid)
      @switched = true
    end