http_client: fixed support of runtime tests

[mabrarov]

Summary

Fixed support of runtime tests in HTTP client. Refer to #11686 (comment).

The enabled tests were successfully executed on CI within 3c55b69 temporary commit using fluent/fluent-bit-ci#153 - refer to https://github.com/fluent/fluent-bit/actions/runs/24538459905?pr=11724.

---

Testing

• [N/A] Example configuration file for the change.
• [N/A] Debug log output from testing the change.
• Attached Valgrind output that shows no leaks or memory corruption was found - refer to flb_run_code_analysis.log for the output of command

  TEST_PRESET=valgrind ./run_code_analysis.sh

• [N/A] Run local packaging test showing all targets (including any new ones) build.
• [N/A] Set ok-package-test label to test for all targets (requires maintainer to do).

Documentation

• [N/A] Documentation required for this feature

Backporting

• [N/A] Backport to latest stable release.

---

Fluent Bit is licensed under Apache 2.0, by submitting this pull request I understand that this code will be released under the terms of that license.

Summary by CodeRabbit

• Bug Fixes

  • Added null pointer safety check in HTTP client connection setup.

• Tests

  • Elasticsearch and forward output components are now tested by default.

[coderabbitai]

📝 Walkthrough

Walkthrough

Two configuration and safety adjustments: the test skip list in the build script is updated to remove two elasticsearch and forward output components from default exclusion, and the HTTP client initialization adds a null-check guard before accessing union connection members.

Changes

Cohort / File(s)	Summary
Build Configuration run_code_analysis.sh	Removed flb-rt-out_elasticsearch and flb-rt-out_forward from the default SKIP_TESTS list, allowing these components to be included in default test runs.
HTTP Client Initialization src/flb_http_client.c	Added null-check guard for u_conn parameter before accessing its members in create_http_client(), preventing potential null pointer dereference.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Suggested reviewers

• edsiper
• cosmo0920

Poem

🐰 Hops through the code with careful care,
Null checks and guards now everywhere,
Skip lists trimmed with thoughtful paws,
Safety first—that's Fluent's cause! ✨

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title directly addresses the main fix in the HTTP client code, but the PR also includes script changes to enable runtime tests for two output plugins—the title only captures one aspect of the changeset.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[coderabbitai]

🧹 Nitpick comments (1)

src/flb_http_client.c (1)

1020-1032: LGTM — null-guard correctly protects u_conn access in test paths.

The added if (u_conn != NULL) wrapper correctly prevents the NPE on u_conn->net / u_conn->upstream when create_http_client() is invoked in runtime-test mode with a NULL connection, while preserving the original behavior for the non-NULL path. When u_conn == NULL, c->original_net_setup stays NULL (from flb_calloc), which is consistent with the NULL checks in http_client_clamp_connection_io_timeout (Line 1499), http_client_update_connection_io_timeout (Line 1524), and http_client_unbind_connection (Line 1592).

Optional: this block now duplicates the net-setup selection logic already centralized in http_client_bind_connection() (Lines 1567–1588). Consider replacing the body with a call to http_client_bind_connection(c, u_conn) after the c->u_conn = u_conn; assignment is removed from Line 1019 — the helper already sets c->u_conn, selects original_net_setup, copies request_net_setup, and repoints u_conn->net. The only behavioral difference is that the helper additionally invokes http_client_update_connection_io_timeout(), which is a no-op here since response_timeout/read_idle_timeout are still 0 at this point, so it should be safe. Feel free to defer if you prefer to keep this PR minimally scoped.

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@src/flb_http_client.c` around lines 1020 - 1032, The duplicated net-setup
logic in create_http_client (the if (u_conn != NULL) block that sets
c->original_net_setup, copies into c->request_net_setup and rewires u_conn->net)
should be replaced by a call to the existing helper
http_client_bind_connection(c, u_conn); remove the manual c->u_conn = u_conn
assignment that precedes it so the helper can set c->u_conn itself; keep in mind
http_client_bind_connection also calls http_client_update_connection_io_timeout
(which is harmless here because response_timeout/read_idle_timeout are 0), so
simply call http_client_bind_connection(c, u_conn) instead of duplicating the
selection and rewire code.

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Nitpick comments:
In `@src/flb_http_client.c`:
- Around line 1020-1032: The duplicated net-setup logic in create_http_client
(the if (u_conn != NULL) block that sets c->original_net_setup, copies into
c->request_net_setup and rewires u_conn->net) should be replaced by a call to
the existing helper http_client_bind_connection(c, u_conn); remove the manual
c->u_conn = u_conn assignment that precedes it so the helper can set c->u_conn
itself; keep in mind http_client_bind_connection also calls
http_client_update_connection_io_timeout (which is harmless here because
response_timeout/read_idle_timeout are 0), so simply call
http_client_bind_connection(c, u_conn) instead of duplicating the selection and
rewire code.

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: f71e2bd1-e11f-444f-bf3d-d8ce25282e9e

📥 Commits

Reviewing files that changed from the base of the PR and between 856d762 and 2ebb0e7.

📒 Files selected for processing (2)

• run_code_analysis.sh
• src/flb_http_client.c