SPKI: Generate templates from topology file

[oncilla]

This PR enables templating the isd.ini and as.ini from .topo files.
To template the config files for the Default.topo run
scion-pki v2 tmpl topo topology/Default.topo.

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This change is 

[lukedirtwalker]

Reviewed 9 of 9 files at r1.
Reviewable status: all files reviewed, 3 unresolved discussions (waiting on @oncilla)

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go/tools/scion-pki/internal/tmpl/topo.go, line 139 at r1 (raw file):

		m[ia.I] = struct{}{}
	}
	var isds []addr.ISD

Why does this function return a slice, when the return value is just used to iterate over?

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go/tools/scion-pki/internal/v2/tmpl/topo.go, line 122 at r1 (raw file):

}

// topoFile is used to parse the topology description.

We should probably have this in a shared library somewhere at some point. (certainly not for this PR)

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go/tools/scion-pki/internal/v2/tmpl/topo.go, line 132 at r1 (raw file):

		m[ia.I] = struct{}{}
	}
	var isds []addr.ISD

ditto

[oncilla]

Reviewable status: all files reviewed, 3 unresolved discussions (waiting on @lukedirtwalker)

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go/tools/scion-pki/internal/tmpl/topo.go, line 139 at r1 (raw file):

Previously, lukedirtwalker (Lukas Vogel) wrote…

Why does this function return a slice, when the return value is just used to iterate over?

Done.

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go/tools/scion-pki/internal/v2/tmpl/topo.go, line 122 at r1 (raw file):

Previously, lukedirtwalker (Lukas Vogel) wrote…

We should probably have this in a shared library somewhere at some point. (certainly not for this PR)

Sure. If/when we write the generator in go.

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go/tools/scion-pki/internal/v2/tmpl/topo.go, line 132 at r1 (raw file):

Previously, lukedirtwalker (Lukas Vogel) wrote…

ditto

Done.

[lukedirtwalker]

Reviewed 2 of 2 files at r2.
Reviewable status: complete! all files reviewed, all discussions resolved