traffic_ctl: Add config reset command

[brbzull0]

Adds traffic_ctl config reset to reset configuration records to their default values. Supports both record name format (proxy.config.) and YAML format (records.) for path matching.

There is no new ATS rpc handler needed, it just use the existing API and checks for differences between current value and default value. This can be used eventually to reset any config without changing the semantic, just use whatever config node you need(if able to) to change.

This includes Autests.

Examples:

  traffic_ctl config reset records
  traffic_ctl config reset proxy.config.diags.debug.enabled
  traffic_ctl config reset records.diags

[Copilot]

Pull request overview

This PR adds a new traffic_ctl config reset command that allows resetting configuration records to their default values. The implementation leverages existing RPC APIs by fetching records that match the provided path patterns, comparing current values against defaults, and using the existing set API to restore default values. The command supports both traditional record name format (proxy.config.*) and YAML format (records.*), with automatic conversion between the two.

Key changes:

• Implements config_reset() method that uses regex-based record lookup to identify modified records and resets them to defaults
• Adds helper function yaml_to_record_name() to convert YAML-style paths to record name format
• Refactors test utilities to use a cleaner inheritance model with shared _finish() method and adds new validation helpers

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/traffic_ctl/CtrlCommands.cc	Implements core reset logic: lookup matching records, filter modified ones, and reset to defaults via existing set API
src/traffic_ctl/CtrlCommands.h	Adds RESET_STR constant and config_reset() method declaration
src/traffic_ctl/traffic_ctl.cc	Registers new "reset" subcommand with CLI parser
src/mgmt/rpc/handlers/config/Configuration.cc	Adds blank line for formatting consistency
tests/gold_tests/traffic_ctl/traffic_ctl_test_utils.py	Refactors test utilities with cleaner inheritance, adds validate_contains_all() and exec() methods, updates validate_with_text() to handle empty output
tests/gold_tests/traffic_ctl/traffic_ctl_config_output.test.py	Adds comprehensive test coverage for reset command including single record, partial path, all records, and YAML-style path scenarios
doc/appendices/command-line/traffic_ctl.en.rst	Documents reset command with examples showing both record name and YAML format usage

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[serrislew]

It's not really a regex pattern right? It's just prefix of the config. Can users put a full regex expression in the argument?

[serrislew]

I like this idea but I wonder if it might be confusing that values return to default values as opposed to init values (what the user defined in files which got changed by traffic_ctl). When I think of reset, I think about returning values to the startup state, not the default state (as if I didn't configure anything). This might be a bit nitpicky, just wanted to share my thoughts.

[brbzull0]

I like this idea but I wonder if it might be confusing that values return to default values as opposed to init values (what the user defined in files which got changed by traffic_ctl). When I think of reset, I think about returning values to the startup state, not the default state (as if I didn't configure anything). This might be a bit nitpicky, just wanted to share my thoughts.

Let me add a bit of context:

$ traffic_ctl config diff --records
records:
  diags:
    debug:
      enabled: 1  # default: 0
      tags: rpc|http|ssl|config$|filem # default: http|dns
    show_location: 2  # default: 1
  exec_thread:
    autoconfig:
      enabled: 0  # default: 1
    limit: 1  # default: 2
  http:
    connect:
      down:
        policy: 0  # default: 2

note the # default X beside each value. This values are what is set at compile time and used as default if nothing set in the record.yaml.
So you have the running value(if changed) and the default value, the reset basically means, let's set what's changed in the records.yaml to it's default value.
This only affect records for now.

How this is useful? This actually came from a need I had when testing some cve bugs, a simple flow would be.

1 - I have a working ATS running, with my own config.
2 - A patch/use case/bug needs to be tested. More likely without all our local changes in the records.yaml.
3 (new)- Run traffic_ctl config reset and it will only change the values a runtime, once you restart ats, it will still use records.yaml.

Without this feature, you would need to copy/save/edit your records.yaml just to do the test, instead of just run reset.

Thanks.

NOTE: traffic_ctl config diff --records the --records option is misleading in this case as in this case it refers to the format of the output(legacy, backguard compatibility)... honestly should be --yaml or something else.

[serrislew]

Ah I see. Thank you for providing that context and explanation!