[PR #21747] [MERGED] feat: add LOG_FORMAT=json for structured JSON logging #41889

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GiteaMirror · 2026-04-25T13:59:01-05:00

GiteaMirror commented

2026-04-25 13:59:01 -05:00

📋 Pull Request Information

Original PR: https://github.com/open-webui/open-webui/pull/21747
Author: @goto1134
Created: 2/22/2026
Status: ✅ Merged
Merged: 2/22/2026
Merged by: @tjbck

Base: dev ← Head: feat/json-logging

📝 Commits (3)

39b8c94 feat: add LOG_FORMAT env var with JSON formatter for early logging
eea1130 feat: add JSON sink for Loguru when LOG_FORMAT=json
922f854 feat: suppress ASCII banner and fix alembic logging in JSON mode

📊 Changes

4 files changed (+101 additions, -11 deletions)

View changed files

📝 backend/open_webui/env.py (+46 -1)
📝 backend/open_webui/main.py (+3 -1)
📝 backend/open_webui/migrations/env.py (+9 -1)
📝 backend/open_webui/utils/logger.py (+43 -8)

📄 Description

Changelog Entry

Description

Add LOG_FORMAT environment variable — set to json to switch all stdout logging to single-line JSON objects suitable for log aggregators (Loki, Fluentd, CloudWatch, Datadog)

Added

LOG_FORMAT environment variable (json to enable, unset or any other value for default plain-text)
JSONFormatter class in env.py for early stdlib logging (covers module imports, alembic migrations)
_json_sink() Loguru sink in logger.py for runtime logging

Changed

start_logger() conditionally uses JSON sink or plain-text format based on LOG_FORMAT
migrations/env.py re-applies JSONFormatter after alembic's fileConfig() to preserve JSON logging during migrations
ASCII banner is suppressed when LOG_FORMAT=json to keep log stream parseable

JSON log fields

Field	Description
`ts`	ISO 8601 timestamp with milliseconds (UTC)
`level`	`debug`, `info`, `warn`, `error`, `fatal`
`msg`	Log message
`caller`	Logger name (early) or `module:function:line` (Loguru)
`extra`	Loguru extra context (when present)
`error`	Exception traceback (when present)
`stacktrace`	Stack info (when present)

Example output

{"ts": "2026-02-22T20:14:53.386+00:00", "level": "info", "msg": "GLOBAL_LOG_LEVEL: INFO", "caller": "open_webui.env"}
{"ts": "2026-02-22T20:15:02.245+00:00", "level": "info", "msg": "Context impl SQLiteImpl.", "caller": "alembic.runtime.migration"}

Additional Information

Default behavior (no LOG_FORMAT set) is completely unchanged
Two-phase approach: stdlib JSONFormatter handles early startup logs before Loguru is initialized, then _json_sink takes over after start_logger() runs

Contributor License Agreement

By submitting this pull request, I confirm that I have read and fully agree to the Contributor License Agreement (CLA), and I am providing my contributions under its terms.

_{🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.}

## 📋 Pull Request Information **Original PR:** https://github.com/open-webui/open-webui/pull/21747 **Author:** [@goto1134](https://github.com/goto1134) **Created:** 2/22/2026 **Status:** ✅ Merged **Merged:** 2/22/2026 **Merged by:** [@tjbck](https://github.com/tjbck) **Base:** `dev` ← **Head:** `feat/json-logging` --- ### 📝 Commits (3) - [`39b8c94`](https://github.com/open-webui/open-webui/commit/39b8c945f41d586df7e83d78e2c10843e064b746) feat: add LOG_FORMAT env var with JSON formatter for early logging - [`eea1130`](https://github.com/open-webui/open-webui/commit/eea11303d44c62f7683c49b9b6e4f48c9ad36e85) feat: add JSON sink for Loguru when LOG_FORMAT=json - [`922f854`](https://github.com/open-webui/open-webui/commit/922f8547bd1c3c00754c9571526b5e6adfe4a7a8) feat: suppress ASCII banner and fix alembic logging in JSON mode ### 📊 Changes **4 files changed** (+101 additions, -11 deletions) <details> <summary>View changed files</summary> 📝 `backend/open_webui/env.py` (+46 -1) 📝 `backend/open_webui/main.py` (+3 -1) 📝 `backend/open_webui/migrations/env.py` (+9 -1) 📝 `backend/open_webui/utils/logger.py` (+43 -8) </details> ### 📄 Description # Changelog Entry ### Description - Add `LOG_FORMAT` environment variable — set to `json` to switch all stdout logging to single-line JSON objects suitable for log aggregators (Loki, Fluentd, CloudWatch, Datadog) ### Added - `LOG_FORMAT` environment variable (`json` to enable, unset or any other value for default plain-text) - `JSONFormatter` class in `env.py` for early stdlib logging (covers module imports, alembic migrations) - `_json_sink()` Loguru sink in `logger.py` for runtime logging ### Changed - `start_logger()` conditionally uses JSON sink or plain-text format based on `LOG_FORMAT` - `migrations/env.py` re-applies `JSONFormatter` after alembic's `fileConfig()` to preserve JSON logging during migrations - ASCII banner is suppressed when `LOG_FORMAT=json` to keep log stream parseable ### JSON log fields | Field | Description | |---|---| | `ts` | ISO 8601 timestamp with milliseconds (UTC) | | `level` | `debug`, `info`, `warn`, `error`, `fatal` | | `msg` | Log message | | `caller` | Logger name (early) or `module:function:line` (Loguru) | | `extra` | Loguru extra context (when present) | | `error` | Exception traceback (when present) | | `stacktrace` | Stack info (when present) | ### Example output ```json {"ts": "2026-02-22T20:14:53.386+00:00", "level": "info", "msg": "GLOBAL_LOG_LEVEL: INFO", "caller": "open_webui.env"} {"ts": "2026-02-22T20:15:02.245+00:00", "level": "info", "msg": "Context impl SQLiteImpl.", "caller": "alembic.runtime.migration"} ``` --- ### Additional Information - Default behavior (no `LOG_FORMAT` set) is completely unchanged - Two-phase approach: stdlib `JSONFormatter` handles early startup logs before Loguru is initialized, then `_json_sink` takes over after `start_logger()` runs ### Contributor License Agreement By submitting this pull request, I confirm that I have read and fully agree to the [Contributor License Agreement (CLA)](https://github.com/open-webui/open-webui/blob/main/CONTRIBUTOR_LICENSE_AGREEMENT), and I am providing my contributions under its terms. --- <sub>🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.</sub>

GiteaMirror added the pull-request label 2026-04-25 13:59:01 -05:00

GiteaMirror closed this issue

2026-04-25 13:59:02 -05:00

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Reference: github-starred/open-webui#41889