feat(microservice): TCP microservice over TLS

[nomaxg]

Builds off of @Flusinerd's work to add the option to connect to a TCP microservice over TLS.

PR Checklist

Please check if your PR fulfills the following requirements:

• [ x] The commit message follows our guidelines: https://github.com/nestjs/nest/blob/master/CONTRIBUTING.md
• [x ] Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

Adds the ability to pass through TLS options to both the client and the server by means of an optional tlsOptions property.

• Bugfix
• [ x] Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Other... Please describe:

What is the current behavior?

Issue Number: #6745

What is the new behavior?

If tlsOptions are specified, a tls server will be instantiated server-side, and a TLSSocket will be used to connect to the server client-side. Under the hood, options are passed down to the Node tls library.

Does this PR introduce a breaking change?

• Yes
• [ x] No

Other information

[coveralls]

Pull Request Test Coverage Report for Build ab5aa6c9-6cd1-41e3-99b5-fb1f16ae7606

• 12 of 13 (92.31%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.01%) to 93.414%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
packages/microservices/server/server-tcp.ts	4	5	80.0%

Totals
Change from base Build e91ba0bb-da30-4334-a0c2-615d1d5bb062:	0.01%
Covered Lines:	6212
Relevant Lines:	6650

---

💛 - Coveralls

[nomaxg]

I'm not sure how to address the samples failure, the failing sample appears to build and run fine for me locally. Any suggestions?

[Flusinerd]

Seems like you mixed ConnectionOptions and TlsOptions

[nomaxg]

Seems like you mixed ConnectionOptions and TlsOptions

thanks! updated

[nomaxg]

Seems like you mixed ConnectionOptions and TlsOptions

thanks! updated

Actually I believe that the configuration was correct before - ClientTCP should use ConnectionOptions in the call to tls.connect

[kamilmysliwiec]

samples workflow is now failing with the following error:

[kamilmysliwiec]

What was the reason for moving this up? We should also add an inline comment on why "connect" is not required for tls

[nomaxg]

Moved this back to its original location, added a comment

[nomaxg]

Thanks for the review, @kamilmysliwiec. Fixed the samples failure by using ConnectionOptions instead of TlsOptions in TcpOptions (@Flusinerd you were correct about this). Added an inline comment explaining why connecting twice isn't necessary for tls sockets.

[kamilmysliwiec]

LGTM

[kamilmysliwiec]

Would you like to create a PR to the docs (with an additional section about this feature) @nomaxg? This could be based off this PR nestjs/docs.nestjs.com#1961

[nomaxg]

Would you like to create a PR to the docs (with an additional section about this feature) @nomaxg? This could be based off this PR nestjs/docs.nestjs.com#1961

sure! I'll work on it