Unable to open Composer extension for a Plesk domain: Could not open input file: /usr/local/psa/var/modules/composer//composer.phar

Symptoms

• Opening Composer extension for a domain at Plesk > Domains > example.com fails with error:

  PLESK_ERROR: Could not open input file: /usr/local/psa/var/modules/composer//composer.phar

• In an attempt to update packages using the composer a similar error is shown:

  PLESK_ERROR: – Could not open input file: /opt/psa/var/modules/composer//composer.phar
  – Failed to retrieve paths for the installed packages: Could not open input file: /opt/psa/var/modules/composer//composer.phar

Cause

Incorrect permissions to the composer installation path.

Resolution

1. Connect to the server via SSH
2. Check the permissions via the following command:

   # namei -l /usr/local/psa/var/modules/composer//composer.phar

3. Compare permissions to the following list:

   namei -l /usr/local/psa/var/modules/composer//composer.phar
   f: /usr/local/psa/var/modules/composer//composer.phar
   dr-xr-xr-x root root /
   drwxr-xr-x root root usr
   drwxr-xr-x root root local
   drwxr-xr-x root root psa
   drwxr-xr-x psaadm psaadm var
   drwxr-xr-x psaadm root modules
   drwxr-xr-x psaadm psaadm composer
   -rwxr-xr-x root root composer.phar

4. Set correct permissions for files/folders to rwxr-xr-x via the following command:

   # chmod 755 file_name/directory_name