Before downloading a role using the ansible-galaxy install command, you will first need to find the role that you want to install. Often, this is done by searching the Ansible Galaxy website for the role you want to install. For example, here is the HTTPD role on the Ansible Galaxy website.
Or, you can use the ansible-galaxy search command to find the role you want to install, and then the ansible-galaxy info command to display more information on a role. For example, here is the output that would be produced when using the ansible-galaxy info bertvv.httpd command.
~]$ ansible-galaxy info bertvv.httpd Role: bertvv.httpd description: Installs the Apache web server on a RedHat based Linux distribution. active: True commit: e52068adaec7cb9c5d5d95597763bd9bd87269c1 commit_message: Bump Fedora version commit_url: https://api.github.com/repos/bertvv/ansible-role-httpd/git/commits/e52068adaec7cb9c5d5d95597763bd9bd87269c1 company: created: 2015-03-06T13:41:15.137765Z download_count: 2157 forks_count: 21 github_branch: master github_repo: ansible-role-httpd github_user: bertvv id: 3047 imported: 2018-10-07T19:04:51.987774-04:00 is_valid: True issue_tracker_url: https://github.com/bertvv/ansible-role-httpd/issues license: BSD min_ansible_version: 2.0 modified: 2018-10-07T23:04:51.987909Z open_issues_count: 0 path: ('/usr/local/ansible/roles',) role_type: ANS stargazers_count: 13 travis_status_url: