update(config): Improve http output, add compression and keep_alive

[sgaist]

What type of PR is this?

Uncomment one (or more) /kind <> lines:

/kind bug

/kind cleanup

/kind design

/kind documentation

/kind failing-test

/kind feature

/kind release

Any specific area of the project related to this PR?

Uncomment one (or more) /area <> lines:

/area build

/area engine

/area tests

/area proposals

/area CI

What this PR does / why we need it:

This PR adds two new configuration options for the http output:

• Post compression
• Connection keep alive
• Batching

Which issue(s) this PR fixes:

Fixes #2955

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

feat(userspace/falco): falco administrators can now configure the http output to compress the data sent as well as enable keep alive for the connection. Two new fields (compress_uploads and keep_alive) in the http_output block of the `falco.yaml` file can be used for that purpose. Both are disabled by default.

[incertum]

Thanks a bunch @sgaist 🚀 !

Recommend not marking this as feat and instead as new feature that doesn't break the old default behavior. More thoughts?

CC @leogr @Issif

/milestone 0.37.0

[FedeDP]

Recommend not marking this as feat and instead as new feature that doesn't break the old default behavior. More thoughts?

What do you mean?
A feat does not necessarily impose a breaking change. In this case, no breaking change in the default behavior is to be expected, right?
I think we are already ok with this one.

[FedeDP]

/approve

[poiana]

LGTM label has been added.

Git tree hash: 1c103b6386c1efb7bbb25b90049771303ae62101

[incertum]

/hold I think @sgaist is still looking into possibly adding batching 🙃

[sgaist]

@incertum I am currently waiting on an answer with regard to the batching part which will likely require a bit more work and design discussions.

What could be done is to split things and implement said batching in a follow up patch so the benefits of compression and keep alive are already made available. This would only require a bit of rewording of the pull request message.

[incertum]

/approve

/unhold

Yes let's split PRs!

[poiana]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: FedeDP, incertum, sgaist

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[Issif]

Don't know if the batching will be really useful, very few targets accept that. On the other hands, having more control on the http output would be a really nice thing:

• allow to set the User-Agent
• allow to set the Headers (really useful for Authentications either)
• allow to set the Http Method (PUT/POST)
• allow to use mTLS for the authentication

[sgaist]

@Issif based on the current code of the http output, the following are already available:

• User agent setting
• mTLS configuration

When you say authentication, are you thinking about setting a username/password or a token in the authorization header or something more involved like oauth ?