'su -c' como outro usuário não trabalha em um repositório Rails

Question

Em um script bash que tem muitos comandos executados como outro usuário, encontrei uma classe de comandos que parece não funcionar.

Em um repositório Rails como root:

> su -c 'whoami' at
  at
> su -c 'rake tmp:clear' at
  rake aborted!
  LoadError: cannot load such file -- bundler/setup
> login at
> rake tmp:clear
  (Success)

Com todos os tipos de comandos orientados ao Rails, como rails [something] , rake [something] , etc., o comando só funciona se eu estiver logado como em.

O que está acontecendo aqui?

    

Answer 1

Isso parece um problema de $PATH ou de ambiente. Quando você executa esses comandos via su , você os executa no contexto do ambiente de outro usuário. Para confirmar, tente fazer um su -c 'echo $PATH' at e compare isso com seu $PATH quando estiver logado como usuário at .

Shells, como o Bash, têm 2 maneiras de originar seus arquivos de configuração ... normalmente. Por bash há 2 $HOME/.bashrc e $HOME/.bash_profile que são muitas vezes os que estão em jogo. Esses dois métodos de configuração de sourcing são chamados de interativos e não interativos e são discutidos na página Bash man bash na seção INVOCATION.

INVOCATION
    A login shell is one whose first character of argument zero is a -, or
    one started with the --login option.

    An  interactive  shell is one started without non-option arguments and
    without the -c option whose standard input and error are both connected to
    terminals (as determined by isatty(3)), or one started with the -i option.  PS1
    is set and $- includes i if bash is interactive, allowing a shell script or a
    startup file to test this state.

    The following paragraphs describe how bash executes its startup files.
    If any of the files exist but cannot be read, bash reports an error.  Tildes are
    expanded in file  names  as  described  below  under Tilde Expansion in the
    EXPANSION section.

    When bash is invoked as an interactive login shell, or as a
    non-interactive shell with the --login option, it first reads and executes
    commands from the file /etc/profile, if that file exists.  After read‐ ing that
    file, it looks for ~/.bash_profile, ~/.bash_login, and ~/.profile, in that
    order, and reads and executes commands from the first one that exists and is
    readable.  The  --noprofile  option  may  be used when the shell is started to
    inhibit this behavior.

    When a login shell exits, bash reads and executes commands from the files
    ~/.bash_logout and /etc/bash.bash_logout, if the files exists.

    When  an  interactive shell that is not a login shell is started, bash
    reads and executes commands from ~/.bashrc, if that file exists.  This may be
    inhibited by using the --norc option.  The --rcfile file option will force bash
    to read and execute commands from file instead of ~/.bashrc.

    When bash is started non-interactively, to run a shell script, for
    example, it looks for the variable BASH_ENV in the environment, expands its
    value if it appears there, and uses the expanded value as  the name of a file to
    read and execute.  Bash behaves as if the following command were executed: if [
    -n "$BASH_ENV" ]; then . "$BASH_ENV"; fi but the value of the PATH variable is
    not used to search for the file name.