Permission error: Gemfile.production.lock

I run fluent in OpenShift.

```bash
`/` is not writable.
Bundler will use `/tmp/bundler20211227-7-1rry4sg7' as your home directory temporarily.
`/` is not writable.
Bundler will use `/tmp/bundler20211227-7-hpxmfc7' as your home directory temporarily.
bundler: failed to load command: rackup (/usr/local/bundle/bin/rackup)
Bundler::PermissionError: There was an error while trying to write to `/usr/local/bundle/gems/fluentd-ui-1.2.1/Gemfile.production.lock`. It is likely that you need to grant write permissions for that path.
/usr/local/lib/ruby/2.7.0/bundler/shared_helpers.rb:105:in `rescue in filesystem_access'
/usr/local/lib/ruby/2.7.0/bundler/shared_helpers.rb:102:in `filesystem_access'
/usr/local/lib/ruby/2.7.0/bundler/definition.rb:353:in `lock'
/usr/local/lib/ruby/2.7.0/bundler/runtime.rb:114:in `lock'
/usr/local/lib/ruby/2.7.0/bundler/runtime.rb:41:in `setup'
/usr/local/lib/ruby/2.7.0/bundler.rb:149:in `setup'
/usr/local/lib/ruby/2.7.0/bundler/setup.rb:20:in `block in '
/usr/local/lib/ruby/2.7.0/bundler/ui/shell.rb:136:in `with_level'
/usr/local/lib/ruby/2.7.0/bundler/ui/shell.rb:88:in `silence'
/usr/local/lib/ruby/2.7.0/bundler/setup.rb:20:in `'
```