Add custom field in global options

[lucklove]

What problem does this PR solve?

Fix #571

What is changed and how it works?

This PR introduce a custom field in global of topology. By this way, the user can define his server specs in global level:

global:
  custom:
    tidb_spec: &tidb_spec
      deploy_dir: "test-deploy"
      log_dir: "test-deploy/log"

tidb_servers:
  - <<: *tidb_spec
    host: 172.16.5.138

The tidb_server of host 172.16.5.138 will be expanded as

tidb_servers:
  - host: 172.16.5.138
    deploy_dir: "test-deploy"
    log_dir: "test-deploy/log"

Check List

Tests

• Unit test

Code changes

• Has exported function/method change
• Has exported variable/fields change
• Has interface methods change
• Has persistent data change

Side effects

• Possible performance regression
• Increased code complexity
• Breaking backward compatibility

Related changes

• Need to cherry-pick to the release branch
• Need to update the documentation

Release notes:

NONE

[lonng]

It's not an elegant way.

[lucklove]

So do you have a better idea? We must define an extra field because we use yaml.UnmarshalStrict, which will report error when user define custom field outside the Custom

[codecov-io]

Codecov Report

Merging #1098 (158d825) into master (4d93059) will decrease coverage by 11.87%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           master    #1098       +/-   ##
===========================================
- Coverage   56.65%   44.77%   -11.88%     
===========================================
  Files         285      251       -34     
  Lines       20202    17345     -2857     
===========================================
- Hits        11445     7767     -3678     
- Misses       6996     8302     +1306     
+ Partials     1761     1276      -485     

Flag	Coverage Δ
cluster	42.43% <ø> (-2.61%)	⬇️
dm	25.23% <ø> (-0.26%)	⬇️
integrate	44.77% <ø> (-6.29%)	⬇️
playground	?
tiup	?
unittest	?

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
pkg/cluster/spec/spec.go	78.21% <ø> (-10.36%)	⬇️
pkg/repository/store/store.go	0.00% <0.00%> (-100.00%)	⬇️
components/dm/ansible/worker.go	0.00% <0.00%> (-100.00%)	⬇️
pkg/repository/utils/hash.go	0.00% <0.00%> (-81.82%)	⬇️
pkg/meta/err.go	0.00% <0.00%> (-81.25%)	⬇️
pkg/telemetry/meta.go	0.00% <0.00%> (-80.00%)	⬇️
pkg/telemetry/scrub.go	6.66% <0.00%> (-80.00%)	⬇️
pkg/cluster/api/error.go	0.00% <0.00%> (-80.00%)	⬇️
pkg/utils/freeport.go	0.00% <0.00%> (-77.28%)	⬇️
pkg/repository/store/local.go	0.00% <0.00%> (-76.48%)	⬇️
... and 107 more

---

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[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• AstroProfundis

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[AstroProfundis]

/merge

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: 8784485

[ti-chi-bot]

@lucklove: Your PR has out-of-dated, I have automatically updated it for you.

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