cluster: fix parsing of paths if there are redundant slashes in it

[AstroProfundis]

What problem does this PR solve?

If an imported cluster has deploy dir ending with /, and sub dirs as <deploy-dir>//sub, the result of CountDir() may not be accurate, and could results to delete wrong paths on scale-in.

One of the case is when:

• The deploy dir is /foo/, and
• The log dir is /foo//log, and
• There is and only is 1 instance with only 1 sub directory under deploy dir (e.g., tidb with log dir under deploy dir) deployed on host 1.2.3.4, and
• There are other instances without log dir and data dir (e.g., grafana) deployed on the same host

The deploy dir will be deleted when scale-in the grafana instance, so that the tidb instance is also broken.

What is changed and how it works?

1. Not deleting deploy dir for imported instance
2. Trim redundant slashes from the path when parsing meta file

Check List

Tests

• Unit test

Code changes

• Has exported function/method change
• Has persistent data change

Related changes

• Need to cherry-pick to the release branch

Release notes:

cluster: fix parsing of paths if there are redundant slashes in it

[codecov-io]

Codecov Report

Merging #1068 (1d270e0) into master (3b6ac73) will decrease coverage by 16.84%.
The diff coverage is 100.00%.

@@             Coverage Diff             @@
##           master    #1068       +/-   ##
===========================================
- Coverage   55.95%   39.10%   -16.85%     
===========================================
  Files         282      281        -1     
  Lines       19898    19898               
===========================================
- Hits        11133     7781     -3352     
- Misses       7040    10874     +3834     
+ Partials     1725     1243      -482     

Flag	Coverage Δ
cluster	?
dm	22.20% <100.00%> (-1.85%)	⬇️
integrate	30.23% <100.00%> (-20.02%)	⬇️
playground	20.29% <ø> (ø)
tiup	16.48% <0.00%> (-0.01%)	⬇️
unittest	22.27% <100.00%> (+<0.01%)	⬆️

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

Impacted Files	Coverage Δ
pkg/cluster/operation/destroy.go	26.44% <100.00%> (-30.17%)	⬇️
pkg/cluster/spec/util.go	33.33% <100.00%> (-48.07%)	⬇️
components/cluster/main.go	0.00% <0.00%> (-100.00%)	⬇️
pkg/cluster/template/config/config.go	0.00% <0.00%> (-100.00%)	⬇️
pkg/cluster/template/scripts/scripts.go	0.00% <0.00%> (-100.00%)	⬇️
pkg/cluster/spec/bindversion.go	0.00% <0.00%> (-83.34%)	⬇️
pkg/cluster/task/update_meta.go	0.00% <0.00%> (-80.00%)	⬇️
pkg/cluster/template/scripts/tiflash.go	0.00% <0.00%> (-79.60%)	⬇️
pkg/cluster/spec/cdc.go	3.44% <0.00%> (-79.32%)	⬇️
pkg/cluster/manager/reload.go	0.00% <0.00%> (-77.56%)	⬇️
... and 121 more

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[lucklove]

/lgtm

[lucklove]

/merge

[ti-chi-bot]

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

Commit hash: 3a42a5c

[ti-chi-bot]

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

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