NE-2636: Add truncation and filtering to router tools by Thealisyed · Pull Request #304 · openshift/openshift-mcp-server

Thealisyed · 2026-05-11T12:16:15Z

Summary

Add tail_lines, section, and filter parameters to get_router_config to limit and filter HAProxy config output
Add limit and filter parameters to get_router_sessions to cap and filter session output
Both tools show truncation metadata so the AI can refine queries when output is limited

Test plan

Unit tests for truncateConfigOutput (12 cases: tail_lines, section filter, substring filter, combined, edge cases)
Unit tests for truncateSessionsOutput (8 cases: limit, filter, combined, edge cases)
make build && make test && make lint pass cleanly
CodeRabbit review passes with 0 findings

Summary by CodeRabbit

New Features
- Router configuration queries now support filtering by HAProxy section type and substring matching, with configurable output truncation.
- Router session queries now support substring filtering and configurable result limits.
- Enhanced output includes truncation status summaries and properly formatted code blocks.
Tests
- Added comprehensive test coverage for configuration and session output filtering and truncation.

Add output truncation and filtering to get_router_config and get_router_sessions to prevent large HAProxy outputs from flooding the AI context window or hitting MCP response size limits. get_router_config gains tail_lines (default 200), section (global/defaults/frontend/backend/listen), and filter parameters. get_router_sessions gains limit (default 50) and filter parameters. Both tools display truncation metadata so the AI knows how to refine. Handlers refactored to use WrapParams sticky-error pattern. Assisted with Claude

openshift-ci-robot · 2026-05-11T12:16:19Z

@Thealisyed: This pull request references NE-2636 which is a valid jira issue.

Warning: The referenced jira issue has an invalid target version for the target branch this PR targets: expected the story to target the "5.0.0" version, but no target version was set.

Details

In response to this:

Summary

Add tail_lines, section, and filter parameters to get_router_config to limit and filter HAProxy config output

Add limit and filter parameters to get_router_sessions to cap and filter session output

Both tools show truncation metadata so the AI can refine queries when output is limited

Test plan

Unit tests for truncateConfigOutput (12 cases: tail_lines, section filter, substring filter, combined, edge cases)

Unit tests for truncateSessionsOutput (8 cases: limit, filter, combined, edge cases)

make build && make test && make lint pass cleanly

CodeRabbit review passes with 0 findings

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coderabbitai · 2026-05-11T12:16:31Z

📝 Walkthrough

Walkthrough

The PR extends NetEdge router tools (get_router_config and get_router_sessions) with structured parameter validation, output filtering by HAProxy section type and substring matching, and configurable tail-line/session-count truncation, supported by new helper functions and comprehensive test coverage.

Changes

Router Output Filtering and Truncation

Layer / File(s)	Summary
Data & Configuration `pkg/toolsets/netedge/router.go` (lines 21–34)	Introduces `defaultConfigTailLines` and `defaultSessionLimit` constants, and module-level variables (`podGVR`, `haproxySectionKeywords`) used by truncation and filtering logic.
Tool Schema — Config `pkg/toolsets/netedge/router.go` (lines 35–61)	`get_router_config` schema is expanded with `tail_lines`, `section` (enum: `global`, `backend`, `frontend`), and `filter` (substring match) parameters with descriptions.
Tool Schema — Sessions `pkg/toolsets/netedge/router.go` (lines 98–115)	`get_router_sessions` schema is expanded with `limit` (default applied) and `filter` (substring match) parameters.
Handler: Config Execution & Truncation `pkg/toolsets/netedge/router.go` (lines 130–169)	`getRouterConfig` is rewritten to use `api.WrapParams` for validation, resolve router pod if unset, fetch HAProxy config via pod exec, and post-process output via `truncateConfigOutput` with truncation/filter summary messages.
Handler: Sessions Execution & Truncation `pkg/toolsets/netedge/router.go` (lines 205–246)	`getRouterSessions` is rewritten to use `api.WrapParams` for validation, resolve router pod if unset, fetch session data via pod exec, and post-process via `truncateSessionsOutput` with truncation/filter summary messages.
Helper Functions `pkg/toolsets/netedge/router.go` (lines 248–348)	New helpers added: `configSectionType` (HAProxy section header detection), `truncateConfigOutput` (section/filter-aware tail truncation), `truncateSessionsOutput` (block splitting and filtering), and `blockContainsSubstring` (case-insensitive substring matching).
Tests `pkg/toolsets/netedge/router_test.go` (lines 1–216)	`TestTruncateConfigOutput` and `TestTruncateSessionsOutput` verify truncation semantics, section/backend filtering (case-insensitive), edge cases (empty input, no-match filters), and large-data scenarios with expected line/session counts.

Sequence Diagram

sequenceDiagram
    participant Client
    participant Handler as Router Config Handler
    participant API as WrapParams<br/>(Validation)
    participant Resolver as Pod Resolver
    participant Executor as Pod Executor
    participant Processor as Output Processor
    participant Response

    Client->>Handler: Call get_router_config<br/>(pod?, tail_lines, section?, filter?)
    Handler->>API: Validate parameters
    API-->>Handler: Validated params or error
    Handler->>Resolver: Resolve router pod<br/>(if pod unset)
    Resolver-->>Handler: Router pod reference
    Handler->>Executor: Exec pod for<br/>/var/lib/haproxy/conf/haproxy.config
    Executor-->>Handler: Raw config output
    Handler->>Processor: truncateConfigOutput<br/>(output, section, filter, tail_lines)
    Processor->>Processor: Filter by section type<br/>(if section set)
    Processor->>Processor: Filter by substring<br/>(if filter set)
    Processor->>Processor: Truncate to tail_lines
    Processor-->>Handler: Filtered & truncated output,<br/>summary (lines shown/total,<br/>truncation flag)
    Handler->>Response: Format as code block<br/>+ summary message
    Response-->>Client: Structured response

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Poem

A rabbit hops through HAProxy halls,
Now filtering configs, truncating calls,
With section-smart snips and substring delight,
The router output shines bright,
Tests hopping ahead—the truncation's just right! 🐰✨

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 11.11% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title 'NE-2636: Add truncation and filtering to router tools' clearly and concisely describes the main changes: adding truncation and filtering capabilities to router tools. It accurately reflects the core functionality additions in the changeset.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.

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✨ Finishing Touches

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openshift-ci · 2026-05-11T12:16:58Z

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: Thealisyed
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openshift-ci · 2026-05-11T12:29:13Z

@Thealisyed: all tests passed!

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Thealisyed · 2026-05-11T12:54:55Z

A follow up PR to add truncation and filtering to router tools. The PR we are following up from
cc: @bentito

bentito · 2026-05-11T15:13:11Z

/assign

jcmoraisjr · 2026-05-13T14:44:34Z

/assign

bentito · 2026-05-13T15:03:25Z

+
+func configSectionType(line string) string {
+	for _, kw := range haproxySectionKeywords {
+		if strings.HasPrefix(line, kw) && (len(line) == len(kw) || line[len(kw)] == ' ' || line[len(kw)] == '\t') {


This is a smart default for HAProxy where dynamic backends often appear at the end.

bentito · 2026-05-13T15:24:25Z

+	var current []string
+
+	for _, line := range lines {
+		if strings.HasPrefix(line, "0x") {


This should help group into logical blocks so the pagination breaks things less awkwardly

bentito · 2026-05-13T15:27:14Z

-// getRouterSessions requires a live cluster as it queries the HAProxy admin socket
-// via exec on a running router pod. It cannot work against offline data (must-gather).
 func getRouterSessions(params api.ToolHandlerParams) (*api.ToolCallResult, error) {
+	p := api.WrapParams(params)


I think getRouterInfo needs this same help with WrapParams

bentito · 2026-05-13T15:28:58Z

docs/openshift/NETEDGE.md
Needs update this to detail the new tail_lines, section, filter, and limit parameters so users and agents are aware of these capabilities.

bentito · 2026-05-13T16:27:20Z

/assign @bentito @jcmoraisjr

openshift-ci-robot added the jira/valid-reference Indicates that this PR references a valid Jira ticket of any type. label May 11, 2026

openshift-ci Bot requested review from Cali0707 and Kaustubh-pande May 11, 2026 12:16

openshift-ci Bot assigned bentito May 11, 2026

openshift-ci Bot assigned jcmoraisjr May 13, 2026

bentito reviewed May 13, 2026

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Summary

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Walkthrough

Changes

Sequence Diagram

Estimated code review effort

Poem

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