Updating Bigtable stub creation to work with emulator.

[dhermes]

System test will be updated soon, once some issues with the emulator are worked out.

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Message was previously:

Currently does not work as-is since most of the methods (most notable row.commit()) result in UNAVAILABLE from the backend.

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Towards #2242.

/cc @garye Could you check out this branch and run tox -e bigtable-emulator to see the failures?

NOTE: Has #2245 as diffbase.

[garye]

I'll take a look

[dhermes]

Thanks!

[dhermes]

@garye I should note that only the last commit is germane to this PR, the rest are for the two diffbase PRs.

[dhermes]

@garye I have found the start of a culprit. Some operations accidentally kill the server, causing all subsequent operations to fail. Also the example stack trace refers to a path not on my machine (/usr/local/google/home/garyelliott)

$ gcloud beta emulators bigtable start
Executing: /home/dhermes/google-cloud-sdk/platform/bigtable-emulator/cbtemulator --host=localhost --port=8645
[bigtable] Cloud Bigtable emulator running on 127.0.0.1:8645
[bigtable] panic: runtime error: invalid memory address or nil pointer dereference
[bigtable] [signal 0xb code=0x1 addr=0x48 pc=0x4888c8]
[bigtable] 
[bigtable] goroutine 16 [running]:
[bigtable] panic(0x9348a0, 0xc820010130)
[bigtable]      /usr/local/google/home/garyelliott/dl_go/go/src/runtime/panic.go:481 +0x3e6
[bigtable] cloud.google.com/go/bigtable/bttest.(*server).SampleRowKeys(0xc820013a00, 0xc8201b0c10, 0x7f4c92733130, 0xc8201b0c40, 0x0, 0x0)
[bigtable]      <autogenerated>:3 +0x78
[bigtable] google.golang.org/genproto/googleapis/bigtable/v2._Bigtable_SampleRowKeys_Handler(0x9c5360, 0xc820013a00, 0x7f4c92733098, 0xc8200842d0, 0x0, 0x0)
[bigtable]      /usr/local/google/home/garyelliott/go/src/google.golang.org/genproto/googleapis/bigtable/v2/bigtable.pb.go:817 +0x175
[bigtable] google.golang.org/grpc.(*Server).processStreamingRPC(0xc820017900, 0x7f4c926e7200, 0xc820084240, 0xc8201e23c0, 0xc8201754a0, 0xcf9d80, 0xc8201f68d0, 0x0, 0x0)
[bigtable]      /usr/local/google/home/garyelliott/go/src/google.golang.org/grpc/server.go:686 +0x489
[bigtable] google.golang.org/grpc.(*Server).handleStream(0xc820017900, 0x7f4c926e7200, 0xc820084240, 0xc8201e23c0, 0xc8201f68d0)
[bigtable]      /usr/local/google/home/garyelliott/go/src/google.golang.org/grpc/server.go:770 +0x1151
[bigtable] google.golang.org/grpc.(*Server).serveStreams.func1.1(0xc8201b0ac0, 0xc820017900, 0x7f4c926e7200, 0xc820084240, 0xc8201e23c0)
[bigtable]      /usr/local/google/home/garyelliott/go/src/google.golang.org/grpc/server.go:419 +0xa0
[bigtable] created by google.golang.org/grpc.(*Server).serveStreams.func1
[bigtable]      /usr/local/google/home/garyelliott/go/src/google.golang.org/grpc/server.go:420 +0x9a

[tseaver]

@dhermes needs rebasing.

[tseaver]

PEP8 failure

[tseaver]

Would it be simpler to wrap the instance admin / table admin testsuite classes in @unittest.skipIf(IN_EMULATOR)?

[dhermes]

Would it be simpler to wrap the instance admin / table admin testsuite classes in @unittest.skipIf(IN_EMULATOR)?

The problem is that IN_EMULATOR is not known at import time, since setting the env. var. happens in Python (via run_emulator.py).

[dhermes]

FWIW the AppVeyor check has been deleted (was created when messing around trying to create https://ci.appveyor.com/project/GoogleCloudPlatform/google-cloud-python/)

[dhermes]

@tseaver PTAL

[tseaver]

LGTM