Add dry run option to DataflowRunner in python SDK

[vikkyrk]

Be sure to do all of the following to help us incorporate your contribution
quickly and easily:

• Make sure the PR title is formatted like:
  [BEAM-<Jira issue #>] Description of pull request
• Make sure tests pass via mvn clean verify.
• Replace <Jira issue #> in the title with the actual Jira issue
  number, if there is one.
• If this contribution is large, please file an Apache
  Individual Contributor License Agreement.

---

[vikkyrk]

R: @robertwb

[robertwb]

Could we perhaps add this as a pipeline option so p.run() (including called implicitly by being a context) would still work rather than having to store the runner and call runner.run(p)?

[vikkyrk]

Yes I think would be better. Where would option be defined under, TestOptions maybe?

[robertwb]

+1 to TestOptions.

…

On Fri, Jun 16, 2017 at 5:54 PM, Vikas Kedigehalli ***@***.***> wrote: Yes I think would be better. Where would option be defined under, TestOptions maybe? — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub, or mute the thread.

[vikkyrk]

Done

[coveralls]

Coverage decreased (-0.02%) to 70.672% when pulling 2f23c00 on vikkyrk:df_runner_dry_run into 0cabdf6 on apache:master.

[coveralls]

Coverage decreased (-0.01%) to 70.681% when pulling 2f23c00 on vikkyrk:df_runner_dry_run into 0cabdf6 on apache:master.

[vikkyrk]

Retest this please

[robertwb]

LGTM

[coveralls]

Coverage remained the same at 70.695% when pulling 2f23c00 on vikkyrk:df_runner_dry_run into 0cabdf6 on apache:master.