Emulated vault

[nir-sopher]

What does this PR (Pull Request) do?

• This PR is not related to any issue

The PR introduces the emulated_vault module which supplies a HTTP server mimicking RIAK behavior for usage as Traffic Vault.
It may be used in order to replace RIAK-based Traffic Vault, as it is much more simple to install.
The server may use different type of persistent storage (e.g. file-system), using the proper adapter.
The resiliency of the stored keys is derived from the resiliency of the underlying storage.

Which Traffic Control components are affected by this PR?

None by default.
It introduces a module that may replace the RIAK-based Traffic Vault.

What is the best way to verify this PR?

Install the emulated vault as described below, and add it to a running Traffic Ops instance instead of the standard RIAK-based Traffic Vault.
Run url-signing and SSL based scenarios.
Note: you would probably want to work on a fresh TC deployment, or somehow copy the RIAK vault to the emulated one...

The following criteria are ALL met by this PR

• This PR contains tests or I have explained why tests are unnecessary
• This PR contains documentation or I have explained why tests are unnecessary
• This PR includes an update to CHANGELOG.md
• This PR includes any and all required license headers
• This PR does not include a database migration
• This PR DOES NOT FIX A SERIOUS SECURITY VULNERABILITY (see the Apache Software Foundation's security guidelines for details)

Tests are not included in the PR as it is still under experimental.
Would be a must if/when the code goes to production.

Additional Information - Installation

Basic requirements: Centos ver >= 7; Python >= 2.7

In order to install the module on a server please:

1. Copy the module files to the server's root
2. Add the certificate and key to your favorite path
3. Adjust /opt/emulated_vault/conf/cfg.json - pointing at your certificate and key
4. "systemctl enable" the service

Logs may be found under /opt/emulated_vault/var/log

Additional Information - Developer's Notes

If you just want to play around with the module, you may of course run the server script on its own.
Before doing that, you would probably need to adjust the opt/emulated_vault/conf/cfg.json:

1. Changing the db-path to one you have access to
2. Disable ssl (just to make it easier)

Additionally, the vault-cmd script is also available to work against the DB with command line.
It is mostly useful when developing a new adapter.

[asf-ci]

Can one of the admins verify this patch?

[ocket8888]

Missing license headers in all files.

[ocket8888]

Please fill out the Pull Request template to the best of your ability, and avoid deleting it entirely.

[ocket8888]

The vast majority of this Python code-base could use some type-hinting and docstrings

[ocket8888]

Also isn't compatible with modern Python

[nir-sopher]

@ocket8888
As far as I can see, there are 2 type of remarks left to be handled.

1. Coding style
2. Server behavior (response codes, encoding).
   For update README.md - JIRA link #1 I replied.
   For Updates website docs for 1.7 and revs documentation version to 1.8 #2 I prefer to open an issue and make a separate PR

[ocket8888]

That's certainly fine with me, especially since this is experimental. I'll try to be a bit lax about the contribution guidelines as well, with that fact that it is experimental in mind.

[ocket8888]

I made some comments about how to approve your linter score above 4/10, but that's not strictly necessary for experimental code if you're strongly opposed to it.

Your files vault-debug and vault-server both start with "shebang"s (#!s) and don't end with .py which seems to indicate that they should be executable, and I think your unit file expects that as well. However, the files themselves are not executable - should they be?

[ocket8888]

Looks good at a glance. I'll run it through the linter again after this one small fix. I don't think I'll test it, since it's experimental.

[nir-sopher]

@ocket8888 Any additional AIs on my side?
Thanks,
Nir

[ocket8888]

The linter found a couple of bugs

[ocket8888]

Looks fine, net positive linting score, untested but experimental.