tests: added golang tests to lib/tests to test image fetching #181
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| "github.com/appc/docker2aci/lib/internal/typesV2" | ||
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| type Layer map[*tar.Header][]byte |
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This will use tar.Header pointer values as keys, not the tar.Header values. If put two equal values of tar.Header, but with distinct memory locations, they will have a different key.
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When I make that change I get:
derek@proton ~/go/src/github.com/appc/docker2aci> go test -v github.com/appc/docker2aci/lib/tests
# github.com/appc/docker2aci/lib/tests
lib/tests/common.go:16: invalid map key type tar.Header
No clue why go doesn't allow this, but I don't think that using pointers will be an issue here. This is only used in the creation of tests, and test writers can avoid creating duplicate tar.Headers.
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Ah, I overlooked you're trying to use stdlib's tar.Header as the key type. http://godoc.org/archive/tar#Header contains Xattrs of type map[string]string and that is the problem.
Map key types must have the comparison operators == and != fully defined, hence your struct key type must not contain a function, map, or slice.
I agree that this is used only in tests, but if you'll ever put two equal header values, but with different memory locations, they won't be the same :-/
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Suggestion: can't you take the layer hashes as the map keys?
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What I'm doing here is trying to work around the fact that Go doesn't have tuples. I want to store a list of pairs, where each pair is a tar header and the file contents. Go's maps kinda let me do this, by being a way to define a set of pairs (where each key and its value is the pair).
I could specify a struct that holds a tar.Header and a []byte, and have a layer be a slice of these structs, but that also would allow duplicate tar headers, so there's no benefit there over the current approach.
I don't think using layer hashes as the map keys here makes sense, as I don't know the hashes at this point in time and the keys here represent a given file in the layer, not the layer itself.
To truly prevent duplicates perhaps I could go with the slice of structs approach and have a helper function to search the slice each time to make sure that I'm not adding duplicates, but that seems rather heavy handed for hardcoded tests.
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You are right about the layer hashes, it is too late to do reviews ;-) Let's leave it like this then.
If I'll come up with a better idea, I'll do a follow-up PR.
LGTM
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We should run these tests on Semaphore |
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or Jenkins? |
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not trolling :-( On 11 July 2016 at 18:12, Iago López Galeiras [email protected]
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What's the benefit of running this on several distros? |
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I don't think we need to do it on several different distros - but it would On 11 July 2016 at 18:14, Iago López Galeiras [email protected]
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I don't see a pressing need for this, I think Semaphore works fine for docker2aci's use case. |
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OK On 11 July 2016 at 18:48, Iago López Galeiras [email protected]
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Added these tests to |
lib/tests/common.go
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| func GenerateDocker22(destPath string, img Docker22Image) error { | ||
| tmpDir, err := ioutil.TempDir("", "docker2aci-test-") |
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The tests don't check whether the converted image has the right contents, right? I guess that's tested on the tests in |
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That's right, at this point these tests aim only to exercise the fetching logic. I'd like to move the checks under |
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OK. Please remove the unused code I pointed out above and I'll merge it :) |
This commit creates the directory lib/tests, which includes the following: - code for generating a manifest and layers conforming to docker v2.2 - code for emulating a docker registry that hosts these images (the docker daemon can successfully pull images from this) - a few tests that utilize these to test using the docker2aci library to pull/convert an image
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Removed. |
This commit creates the directory lib/tests, which includes the
following:
docker daemon can successfully pull images from this)
to pull/convert an image
These fetching tests triggered a panic in docker2aci, which this commit also fixes.
I intend to create a followup PR to also test the docker v2.1 logic and the logic for converting a file on disk, and to hopefully pull the logic under tests/ into these golang tests.