9

Background

  1. We use Ansible to provision and manage Azure infrastructure. At the moment we run Ansible "manually" i.e. we manually execute playbooks for various automated tasks. No CI infrastructure.
  2. Probably not relevant but we manage our inventory using dynamic script azure_rm.py.
  3. We are encouraged to be as secure as possible i.e.
    1. Don't store Vault passwords in ~/.vault_pass or in any local file
    2. Don't store Azure secrets in ~/.azure/credentials
    3. Don't store anything secure in .bashrc.

In such a scenario, I am having trouble coming up with a coherent strategy to ensure that my playbooks can access Azure secrets, while following the guidelines above.

Question

How can I avoid storing Ansible Vault and Azure credentials on files, while still ensuring my playbooks can access them?

What I've tried

So far I have come up with a wrapper script that

  1. asks the user for Vault password
  2. Uses that to decrypt a Vaulted Shell script
  3. Evaluates the script, which loads Azure environment variables into the environment;
  4. Runs the playbook on the environment that has been thus set.

Any better (more elegant, less complicated, more "Ansible") solutions out there?

  • What bothers you most in this workflow? – Konstantin Suvorov Apr 6 '18 at 12:48
  • @KonstantinSuvorov mainly it's the number of hoops I need to jump to achieve what seems (to me at least) a fairly common requirement in compliance-heavy enterprises. – Vish Apr 7 '18 at 3:41
4

Vault password

First of all, you should get familiar with the fact that vault password file can be executable script. In this case Ansible executes it and expects to receive password as its output.

For example you can use gpg-agent or keychain to store your actual password and unlock it when required. Read more in this blog post: https://benincosa.com/?p=3235

If you are a bit paranoid, you can add notification when your password script is called, like this:

#!/bin/bash
PARENT_PROCESS=$(ps -p $PPID -o args | tail -n 1)
osascript -e "display notification \"Vault password used by ${PARENT_PROCESS}\" with title \"Ansible\" sound name \"default\""
gpg --batch --use-agent --no-tty --decrypt key.gpg 2>/dev/null

This vault password script uses key.gpg as actual vault key and also shows popup notification (for MacOS) with parent process name when script is used. Gpg-agent caches unlock password for some time, so there is no need to enter password every time you start playbook.

Just set vault_password_file = ./vault_pass.sh in your ansible.cfg.

Environment

You said that you use azure_rm.py as dynamic inventory script. This means that you have to set credentials into your environment variables before you start ansible-playbook for it to be able to use them.

You can make two files:

secure_env (encrypted with vault):

export AZURE_SECRET=xxx;export AZURE_SUBSCRIPTION_ID=xxx;

set_env (plain text):

echo -n "Setting secure vars... "
eval $(ansible-vault view secure_env)
echo "done."

When you open new terminal to execute your automation tasks, you have to run:

source set_env

At this moment, bash evaluates set_env and secure_env (decrypted via ansible-vault). After this command you have Azure credentials defined for the current shell, so you can execute playbooks as usual:

ansible-playbook provision-my-azure-instances.yml

So using this two approaches, you can store key.gpg and secure_env in your repository; then in the new terminal call source set_env once, enter gpg password once (to unlock future use of key.gpg); then call ansible-playbook as many times as you like without any passwords.

  • Thank you for the reply. Let me try this out over the week. – Vish Apr 8 '18 at 4:15
  • So the main advantage over my original approach is that it uses GPG - which brings up caching benefits --- right? The environment approach is similar to what I came up with. – Vish Apr 10 '18 at 4:59
  • From your OP I understand that you use wrapper every time when you run playbook. With source approach you set environment once per terminal session and can use all range of tools separately: ansible-playbooks, inventory scripts, azure cli, without any wrappers. – Konstantin Suvorov Apr 10 '18 at 5:52
  • Ah, understood. Ill pitch this to my team. Accepting your reply as a more convenient solution. Thanks for the research and explanation! Also, I liked your blog :) – Vish Apr 11 '18 at 1:12
  • Main benefit of using GPG (or a keychain on macOS or Linux) is that each team member has their own authentication to unlock a private key unique to them. This key is then used to unlock the Ansible Vault password, which is a shared secret. You have to rotate all your secrets if someone leaves the team anyway, including the Ansible Vault password, but at least the GPG/keychain passwords don't have to change. – RichVel Jan 30 at 7:18
2

Please read https://docs.ansible.com/ansible/2.4/vault.html Since Ansible 2.4 one could use --vault-id @prompt.

Encrypt a file using ansible-vault:

ansible-vault encrypt /path/to/encrypted/file

Run the playbook and it will result in:

fatal: [localhost]: FAILED! => {"msg": "A vault password or secret must be
specified to decrypt /path/to/encrypted/file"}

There are multiple options to decrypt files, including @prompt:

ansible-playbook some-playbook --vault-id @prompt

will prompt:

Vault password (default):

Once the vault password has been entered, the playbook should succeed.

  • 1
    Reading the page it does look like there's a solution there, but unable to figure out using only the link. Could you please elaborate? – Vish Apr 6 '18 at 1:24
  • Extended the answer – 030 Apr 6 '18 at 17:49
  • Thank you for elaborating. I'm indeed requiring asking the user for a vault password - using the older --ask-vault-pass option. And I fail to understand how replacing it with --vault-id would answer the bigger question of a better workflow. – Vish Apr 7 '18 at 3:44
  • When you referred me to the link I did see one intriguing option: ansible-playbook --vault-id my-vault-password.py. I thought perhaps you had a solution around using a python script :) I'm also doing some thinking around this one. – Vish Apr 7 '18 at 3:45

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