Running service with systemd as default user via ansible in ec2 (requests password)

amazon ec2ansiblesudosystemd

I'm trying to employ the following Ansible script (part of a playbook) to run unicorn via systemd for a rails app on EC2 (micro) instance:

---

- name: restart unicorn
  command: psql -h {{ db_host }} -U {{ db_user }} -d {{ db }} -c "SELECT true FROM pg_tables WHERE tablename = 'order_cycles';"
  register: table_exists
  ignore_errors: yes
  sudo: yes
  sudo_user: "{{ unicorn_user }}"
  notify: restart unicorn step 2

#TODO make sure both of these things run as one handler.
- name: restart unicorn step 2
  service:
    name: unicorn_{{ app }}
    state: restarted
  when: table_exists.stderr.find('does not exist') == -1
  # If unicorn isn't actually started yet we probably need this:
  notify: start unicorn

- name: start unicorn
  service:
    name: unicorn_{{ app }}
    state: started

The user configured in the playbook is ubuntu, the default (EC2) user and I'm hitting an Interactive authentication required error there, so I'm just trying to troubleshoot directly in the command line of the deploy-to server and have come upon this roadblock.

I can run it as sudo:

$ sudo systemctl start unicorn_myapp.service

Either directly via the server's command line, or by using Ansible's raw method, which succeeds.

But then the rails server, being run by user ubuntu can't access it (at least that's an avenue I'm exploring for cause of .sock failed (111: Connection refused error).

If I run it without sudo, a password is requested, but as far as I can tell, EC2 ubuntu user runs without a password.

I know that a workaround might be to create a new user with password and run rails and systemctl/unicorn as that user, but I don't think that's the actual answer to this problem, even more so since the playbook's developer recently removed the user_password from the playbook altogether for security reasons.

If I can figure out how to run systemd as a non-root user at all, maybe I can figure out how to make Ansible succeed at it.

Of course it's also not unlikely that I'm approaching it from the wrong angle in the first place, as I'm fairly new to pretty much everything this scenario involves.

Best Answer

If you have global sudo, add become: no to the two tasks that do not require sudo privs.

Related Solutions

Security – How to implement ansible with per-host passwords, securely

You've certainly done your research...

From all of my experience with ansible what you're looking to accomplish, isn't supported. As you mentioned, ansible states that it does not require passwordless sudo, and you are correct, it does not. But I have yet to see any method of using multiple sudo passwords within ansible, without of course running multiple configs.

So, I can't offer the exact solution you are looking for, but you did ask...

"So... how are people using Ansible in situations like these? Setting NOPASSWD in /etc/sudoers, reusing password across hosts or enabling root SSH login all seem rather drastic reductions in security."

I can give you one view on that. My use case is 1k nodes in multiple data centers supporting a global SaaS firm in which I have to design/implement some insanely tight security controls due to the nature of our business. Security is always balancing act, more usability less security, this process is no different if you are running 10 servers or 1,000 or 100,000.

You are absolutely correct not to use root logins either via password or ssh keys. In fact, root login should be disabled entirely if the servers have a network cable plugged into them.

Lets talk about password reuse, in a large enterprise, is it reasonable to ask sysadmins to have different passwords on each node? for a couple nodes, perhaps, but my admins/engineers would mutiny if they had to have different passwords on 1000 nodes. Implementing that would be near impossible as well, each user would have to store there own passwords somewhere, hopefully a keypass, not a spreadsheet. And every time you put a password in a location where it can be pulled out in plain text, you have greatly decreased your security. I would much rather them know, by heart, one or two really strong passwords than have to consult a keypass file every time they needed to log into or invoke sudo on a machine.

So password resuse and standardization is something that is completely acceptable and standard even in a secure environment. Otherwise ldap, keystone, and other directory services wouldn't need to exist.

When we move to automated users, ssh keys work great to get you in, but you still need to get through sudo. Your choices are a standardized password for the automated user (which is acceptable in many cases) or to enable NOPASSWD as you've pointed out. Most automated users only execute a few commands, so it's quite possible and certainly desirable to enable NOPASSWD, but only for pre-approved commands. I'd suggest using your configuration management (ansible in this case) to manage your sudoers file so that you can easily update the password-less commands list.

Now, there are some steps you can take once you start scaling to further isolate risk. While we have 1000 or so nodes, not all of them are 'production' servers, some are test environments, etc. Not all admins can access production servers, those than can though use their same SSO user/pass|key as they would elsewhere. But automated users are a bit more secure, for instance an automated tool that non-production admins can access has a user & credentials that cannot be used in production. If you want to launch ansible on all nodes, you'd have to do it in two batches, once for non-production and once for production.

We also use puppet though, since it's an enforcing configuration management tool, so most changes to all environments would get pushed out through it.

Obviously, if that feature request you cited gets reopened/completed, what you're looking to do would be entirely supported. Even then though, security is a process of risk assessment and compromise. If you only have a few nodes that you can remember the passwords for without resorting to a post-it note, separate passwords would be slightly more secure. But for most of us, it's not a feasible option.

Ubuntu – Can’t install PM2 services via Ansible on an Ubuntu EC2 instance

This playbook is not idempotent, the shell task is going to run every time the playbook is run, you need to supply a creates argument to that task.

In the current version of PM2:

var scriptFile = '/etc/init.d/pm2-init.sh',
  script = cst.UBUNTU_STARTUP_SCRIPT;

Also, the use of sudo is redundant, as it is already specified globally above, and the default is to sudo to root, so that's redundant as well.

Additionally, once there's an init script for the service, it would be better to use the service module to manage it.

Best Answer

Related Solutions

Security – How to implement ansible with per-host passwords, securely

Ubuntu – Can’t install PM2 services via Ansible on an Ubuntu EC2 instance

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