pd-ctl: avoid initializing a new PD client for each cmd execution

[JmPotato]

What problem does this PR solve?

Issue Number: ref #7300.

What is changed and how does it work?

Avoid initializing a new PD client for each cmd execution. Now we will only initialize a new one when the cluster changes.

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)

./bin/pd-ctl -i
» tso 123
system:  1970-01-01 08:00:00 +0800 CST
logic:   123
» cluster
Usage:
  pd-ctl cluster [flags]
  pd-ctl cluster [command]

Available Commands:
  status      show the cluster status

Flags:
  -h, --help   help for cluster

Use "pd-ctl cluster [command] --help" for more information about a command.

Get "http://127.0.0.1:2379/pd/api/v1/cluster": dial tcp 127.0.0.1:2379: connect: connection refused
// Start the cluster
» cluster
{
  "id": 7332031263979491699,
  "max_peer_count": 3
}
// Start another cluster
» -u http://127.0.0.1:63039 cluster
{
  "id": 7332031352003469768,
  "max_peer_count": 3
}
» -u http://127.0.0.1:63 cluster
Usage:
  pd-ctl cluster [flags]
  pd-ctl cluster [command]

Available Commands:
  status      show the cluster status

Flags:
  -h, --help   help for cluster

Use "pd-ctl cluster [command] --help" for more information about a command.

Get "http://127.0.0.1:63/pd/api/v1/cluster": dial tcp 127.0.0.1:63: connect: connection refused
» store 1
{
  "store": {
    "id": 1,
    "address": "127.0.0.1:20160",
    "version": "8.0.0-alpha",
    "peer_address": "127.0.0.1:20160",
    "status_address": "127.0.0.1:20180",
    "git_hash": "04370e9ef47c2768d368cb62309631018be3eaa8",
    "start_timestamp": 1707121719,
    "deploy_path": "/Users/jmpotato/.tiup/components/tikv/v8.0.0-alpha-nightly",
    "last_heartbeat": 1707121729917357000,
    "node_state": 1,
    "state_name": "Up"
  },
  "status": {
    "capacity": "460.4GiB",
    "available": "145.2GiB",
    "used_size": "290.8MiB",
    "leader_count": 61,
    "leader_weight": 1,
    "leader_score": 61,
    "leader_size": 60,
    "region_count": 61,
    "region_weight": 1,
    "region_score": 140.93049047606394,
    "region_size": 60,
    "slow_score": 1,
    "slow_trend": {
      "cause_value": 250010.35204081633,
      "cause_rate": 0,
      "result_value": 0,
      "result_rate": 0
    },
    "is_busy": true,
    "start_ts": "2024-02-05T16:28:39+08:00",
    "last_heartbeat_ts": "2024-02-05T16:28:49.917357+08:00",
    "uptime": "10.917357s"
  }
}
» -u http://127.0.0.1:63693 store 1
{
  "store": {
    "id": 1,
    "address": "127.0.0.1:63694",
    "version": "8.0.0-alpha",
    "peer_address": "127.0.0.1:63694",
    "status_address": "127.0.0.1:63695",
    "git_hash": "04370e9ef47c2768d368cb62309631018be3eaa8",
    "start_timestamp": 1707121730,
    "deploy_path": "/Users/jmpotato/.tiup/components/tikv/v8.0.0-alpha-nightly",
    "last_heartbeat": 1707121760528419000,
    "node_state": 1,
    "state_name": "Up"
  },
  "status": {
    "capacity": "460.4GiB",
    "available": "145GiB",
    "used_size": "290.8MiB",
    "leader_count": 61,
    "leader_weight": 1,
    "leader_score": 61,
    "leader_size": 60,
    "region_count": 61,
    "region_weight": 1,
    "region_score": 141.0322261693217,
    "region_size": 60,
    "slow_score": 1,
    "slow_trend": {
      "cause_value": 250007.81016949154,
      "cause_rate": 0,
      "result_value": 19.5,
      "result_rate": 0
    },
    "is_busy": true,
    "start_ts": "2024-02-05T16:28:50+08:00",
    "last_heartbeat_ts": "2024-02-05T16:29:20.528419+08:00",
    "uptime": "30.528419s"
  }
}

Release note

None.

[ti-chi-bot]

[REVIEW NOTIFICATION]

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• CabinfeverB
• HuSharp

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[codecov]

Codecov Report

Merging #7804 (07eac54) into master (37be34e) will decrease coverage by 0.07%.
The diff coverage is n/a.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #7804      +/-   ##
==========================================
- Coverage   73.47%   73.40%   -0.07%     
==========================================
  Files         432      432              
  Lines       47842    47842              
==========================================
- Hits        35151    35119      -32     
- Misses       9648     9675      +27     
- Partials     3043     3048       +5     

Flag	Coverage Δ
unittests	73.40% <ø> (-0.07%)	⬇️

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

[HuSharp]

LGTM!

[HuSharp]

/merge

[ti-chi-bot]

@HuSharp: It seems you want to merge this PR, I will help you trigger all the tests:

/run-all-tests

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[ti-chi-bot]

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

Commit hash: e1c5dc0

[ti-chi-bot]

@JmPotato: Your PR was out of date, I have automatically updated it for you.

If the CI test fails, you just re-trigger the test that failed and the bot will merge the PR for you after the CI passes.

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