Adding testing phase to Skaffold run

[PriyaModali]

Fixes: #5593

Description
Adding testing phase to the Skaffold run

Skaffold run currently has just build & deploy. We need to add test.

PR includes integration tests.

Testing notes

Here are some sample outputs:

skaffold run - Before the fix. Note that the output has just build & deploy phases of Skaffold - test is missing.

Generating tags...
 - custom-test-example -> custom-test-example:v1.19.0-110-g7a4fc3a50
Checking cache...
 - custom-test-example: Found Locally
Tags used in deployment:
 - custom-test-example -> custom-test-example:5f9781c26f44e942c9217bdef8011a940faca385b03e53887b517e23bf80048e
Starting deploy...
 - pod/custom-test configured
Waiting for deployments to stabilize...
Deployments stabilized in 28.286087ms

skaffold run - After the fix. Note that the output has all three phases of Skaffold - build, test, & deploy.

Generating tags...
 - custom-test-example -> custom-test-example:v1.19.0-109-gb5e3d0b5d
Checking cache...
 - custom-test-example: Found. Tagging
Starting test...
Testing images...
Running custom test command: "./test.sh" with timeout 60 s
go custom test 
ok      github.com/GoogleContainerTools/skaffold/integration/examples/custom-tests      (cached)
Command finished successfully.
Running custom test command: "echo Hello world!!"
Hello world!!
Command finished successfully.
Tags used in deployment:
 - custom-test-example -> custom-test-example:eaa0bc790ed3196db41335a4ab03f5cf06abdd60951bc82f1181a579d5808833
Starting deploy...
 - pod/custom-test configured
Waiting for deployments to stabilize...
Deployments stabilized in 27.561713ms

skaffold run --skip-tests=true - After the fix. Note that the output has just build and deploy phases of Skaffold as the user decided to skip running tests.

Generating tags...
 - custom-test-example -> custom-test-example:v1.19.0-110-g7a4fc3a50
Checking cache...
 - custom-test-example: Found Locally
Tags used in deployment:
 - custom-test-example -> custom-test-example:5f9781c26f44e942c9217bdef8011a940faca385b03e53887b517e23bf80048e
Starting deploy...
 - pod/custom-test configured
Waiting for deployments to stabilize...
Deployments stabilized in 23.717865ms

[codecov]

Codecov Report

Merging #5594 (0da7793) into master (189a03b) will decrease coverage by 0.01%.
The diff coverage is 50.00%.

❗ Current head 0da7793 differs from pull request most recent head dbcfcb8. Consider uploading reports for the commit dbcfcb8 to get more accurate results

@@            Coverage Diff             @@
##           master    #5594      +/-   ##
==========================================
- Coverage   70.79%   70.78%   -0.02%     
==========================================
  Files         406      406              
  Lines       15461    15466       +5     
==========================================
+ Hits        10946    10947       +1     
- Misses       3711     3713       +2     
- Partials      804      806       +2     

Impacted Files	Coverage Δ
cmd/skaffold/app/cmd/run.go	71.42% <50.00%> (-16.08%)	⬇️

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[tejal29]

Does this respect the --skip-tests flag?

[PriyaModali]

Does this respect the --skip-tests flag?

Not now. But can add if the needed.

[PriyaModali]

Does this respect the --skip-tests flag?

Not now. But can add if the needed.

Added support for skip-tests.

[briandealwis]

Please simplify the defer; otherwise this looks good to go.