hellodrkey example

[juagargi]

This change is 

[marcfrei]

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_examples/hellodrkey/hellodrkey.go, line 54 at r1 (raw file):

func NewClient(sciondPath string) Client {
  sciond, err := sciond.NewService(sciondPath).Connect(context.Background())

Remove this empty line or add one in NewServer for consistency?

[marcfrei]

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_examples/hellodrkey/hellodrkey.go, line 126 at r1 (raw file):

}

func (s Server) HostKey(meta drkey.Lvl2Meta) drkey.Lvl2Key {

Not used, right? Maybe remove this function to keep the example minimal?

[marcfrei]

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_examples/hellodrkey/hellodrkey.go, line 151 at r1 (raw file):

  clientKey = client.HostKey(metaClient)

  durationClient := time.Since(t0)

Move this statement before the empty line?

[marcfrei]

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_examples/hellodrkey/hellodrkey.go, line 29 at r1 (raw file):

)

var now = time.Now().UTC()

I didn't quite get why this is global var. Could we also keep it local to main and pass it around via function params?

[marcfrei]

a discussion (no related file): I like the example because it is really minimal.

I already know the DRKey system a little bit from Lightning Filter and had no problem to understand what is going on here. Users with no prior knowledge will obviously have a harder time to understand the motivation for this example. What would be the best reference to get them started?

• Does it make sense to maintain the new "invariant" (introduced during the SCIONLab update) that all examples have a README.md and that every example is also shortly referenced from the main README.md?

• Maybe it would be helpful to also add a quick note to this example's README on how to generate the topology this example is expecting.

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[marcfrei]

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_examples/hellodrkey/README.md, line 22 at r2 (raw file):

Both slow and fast paths should obtain the same key.
And both slow and fast path are measure for performance and their times displayed at the end.

"measured" instead of "measure"?

[marcfrei]

a discussion (no related file):

Previously, juagargi (Juan A. Garcia Pardo) wrote…

Thanks for the review. Indeed much more documentation was needed. I followed your advice and added the README with a description of what `hellodrkey` does, and how to configure the `gen` directory for it to run.

Thanks, Juan. I think the new README is very helpful.

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[marcfrei]

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_examples/hellodrkey/hellodrkey.go, line 34 at r2 (raw file):

)

// should return the same timestamp everytime that it's called, but for simplicity we just

Maybe "Should" instead of "should"?

[marcfrei]

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_examples/hellodrkey/README.md, line 30 at r3 (raw file):

1. Create a local topology with the `tiny.topo` description: `./scion.sh topology -c ./topology/tiny.topo`.
1. Edit the CS configuration for `ff00:0:111` under `gen/ff00_0_111/cs1-ff00_0_111-1.toml`

gen/ASff00_0_111/cs1-ff00_0_111-1.toml

[marcfrei]

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_examples/hellodrkey/README.md, line 48 at r3 (raw file):

   connection = "gen-cache/sd1-ff00_0_111.drkey.db"

1. Edit the configuration for the CS in gen/ff00_0_112/cs1-ff00_0_112-1.toml and add:

gen/ASff00_0_112/cs1-ff00_0_112-1.toml

[marcfrei]

[marcfrei]

I've tested the DRKey example with the configuration described in the new README: works perfectly -- just two small typos see below. Thank you very much!

[marcfrei]