add v2 onion service deprecation warning

[sssoleileraaa]

Status

Ready for review

Description of Changes

Fixes #5302

• show the following eol warning for v2 onion services if the source_v3_url file is missing:

Update Required: Your SecureDrop servers are still running v2 Onion Services. In February 2021, v2 Onion Services will be disabled, and your SecureDrop servers may become unreachable.

• show the following eol warning for v2 onion services if the source_v2_url file exists along with the source_v3_url:

Update Required: Your SecureDrop servers are still running v2+v3 Onion Services. In February 2021, v2 Onion Services will be disabled, and your SecureDrop servers may become unreachable.

Feedback request

Would like review on language here. This is a WIP until we set up the More info redirects. Or perhaps we should create a separate information page in the JI?

Test Plan

1. Make sure no source_v2_url or source_v3_url files exist in /var/lib/securedrop
2. Log into the JI in a Tor Browser

• Verify that the correct v2 warning appears

3. Add a source_v3_url file in /var/lib/securedrop
4. Log into the JI in a Tor Browser

• Verify that no warning appears

5. Add source_v2_url files in /var/lib/securedrop
6. Log into the JI in a Tor Browser

• Verify that the correct v2+v3 warning appears

[eloquence]

A redirect on https://securedrop.org/v2-onion-eol to our current v2/v3 docs is now live. We can update that section of the docs with more info re: the deprecation timeline as part of 1.5.0.

[sssoleileraaa]

tis ready

[zenmonkeykstop]

Tested in staging env - test plan passed with no issues.

Change looks good to me, approving!