fix v1 handler: use create command when test against prevexistence

[xiang90]

No description provided.

[xiang90]

@benbjohnson This should fix the single node test.

[philips]

@xiangli-cmu Travis seems upset still

--- FAIL: TestRemoveNode (1.00 seconds)
panic: runtime error: index out of range [recovered]
    panic: runtime error: index out of range
goroutine 10 [running]:
testing.func·004()
    /home/travis/.gvm/gos/go1.1/src/pkg/testing/testing.go:348 +0xcd
_/home/travis/gopath/src/github.com/coreos/etcd/tests/functional.TestRemoveNode(0xc2000cc5a0)
    /home/travis/gopath/src/github.com/coreos/etcd/tests/functional/remove_node_test.go:34 +0xc24
testing.tRunner(0xc2000cc5a0, 0x891d98)
    /home/travis/.gvm/gos/go1.1/src/pkg/testing/testing.go:353 +0x8a
created by testing.RunTests
    /home/travis/.gvm/gos/go1.1/src/pkg/testing/testing.go:433 +0x86b
goroutine 1 [chan receive]:
testing.RunTests(0x74fdd8, 0x891d20, 0xa, 0xa, 0x7fff0f263b00, ...)
    /home/travis/.gvm/gos/go1.1/src/pkg/testing/testing.go:434 +0x88e
testing.Main(0x74fdd8, 0x891d20, 0xa, 0xa, 0x896da0, ...)
    /home/travis/.gvm/gos/go1.1/src/pkg/testing/testing.go:365 +0x8a
main.main()
    _/home/travis/gopath/src/github.com/coreos/etcd/tests/functional/_test/_testmain.go:61 +0x9a
goroutine 2 [syscall]:
exit status 2
FAIL    _/home/travis/gopath/src/github.com/coreos/etcd/tests/functional    1.023s
The command "./test.sh" exited with 1.
Done. Your build exited with 1.

[xiang90]

@philips That tests call exec. And seem like exec failed due to cannot find the binary.

[benbjohnson]

@xiangli-cmu The code is not compiling the binary. I'm getting this error when running build:

src/github.com/coreos/etcd/server/v1/set_key_handler.go:4: imported and not used: "fmt"

The build.sh script doesn't fail when a command fails. I'll add a set -e on the script in a separate pull request to fix that. Another option is to move to Makefiles.

http://stackoverflow.com/questions/2870992/automatic-exit-from-bash-shell-script-on-error/2871029#2871029

[benbjohnson]

@xiangli-cmu Added the -e flag in #248.

[benbjohnson]

@xiangli-cmu Is this set to testAndSet for backwards compatibility?

[xiang90]

Yes.
Create is test against prevValue="" in v1

[benbjohnson]

@xiangli-cmu Logically, it seems like there should just be a SetCommand and that CAS (by value and by existence) are simply properties of SetCommand. I think we're going to get a lot of duplicate code between the different commands down the road as we add features. That's a whole different discussion though.

Outside of the design question of SetCommand, the code in this PR looks good to me.

[xiang90]

@benbjohnson We do not have many operation inside the store. Command is just wrapper. But we can even cleanup the wrappers in the future.