Convert flake report from Python to Go (#9334)

## What changed?
* Convert the flake report we use to monitor functional test reliability
from invoking the `tringa` cli tool and a Python script to only a Go
script that fetches the artifacts, parses the JUnit, and creates the
report.
* This also fixes an issue where `tringa` only found the last 20 tests,
the Go script will iterate through all failures in the last `N` days

## Why?
Everything is in a single executable making it easier to test and
extend.

## How did you test it?
- [X] built
- [X] run locally and tested manually
- [ ] covered by existing tests
- [X] added new unit test(s)
- [ ] added new functional test(s)

## Potential risks
Minimal, this is only a tooling change.

Author: spkane31

.github/workflows/flaky-tests-report.yml

@@ -40,65 +40,33 @@ jobs:
           token: ${{ steps.generate_token.outputs.token }}
           fetch-depth: 0
 
-      - name: Set up Python
-        uses: actions/setup-python@v5
+      - name: Set up Go
+        uses: actions/setup-go@v5
         with:
-          python-version: '3.13'
+          go-version-file: 'go.mod'
 
-      - name: Install uv
-        uses: astral-sh/setup-uv@v4
-        with:
-          version: ">=0.8.0"
-
-      - name: Install Python dependencies
-        run: |
-          cd tools/flakes
-          uv sync
-
-      - name: Install tringa
-        run: |
-          uv tool install git+https://github.com/dandavison/tringa@main --force
-
-      - name: Run tringa
-        id: generate-output-file
-        env:
-          GH_TOKEN: ${{ steps.generate_token.outputs.token }}
-          DAYS_PARAM: ${{ github.event.inputs.days || '7' }}
-        run: |
-          set -euo pipefail
-
-          # Create output directory
-          mkdir -p tools/flakes/out
-
-          tringa --json --since-days "$DAYS_PARAM" repo sql \
-            'select classname, name, artifact from test where passed = false and skipped = false order by classname, name, artifact desc' \
-            --branch main \
-            --workflow-id 80591745 \
-            https://github.com/temporalio/temporal > tools/flakes/out/out.json
-
-          echo "✅ Tringa command completed"
-          echo "📊 Output file size: $(wc -c < tools/flakes/out/out.json) bytes"
-          echo "📄 Full output file:"
-          cat tools/flakes/out/out.json
-
-      - name: Run Python script to process flaky tests
+      - name: Generate flaky test report
         id: process-flaky-tests
         env:
+          GH_TOKEN: ${{ steps.generate_token.outputs.token }}
           SLACK_WEBHOOK: ${{ secrets.SLACK_WEBHOOK }}
+          DAYS_PARAM: ${{ github.event.inputs.days || '7' }}
+          MAX_LINKS_PARAM: ${{ github.event.inputs.max_links || '3' }}
           RUN_ID: ${{ github.run_id }}
           REF_NAME: ${{ github.ref_name }}
           SHA: ${{ github.sha }}
-          MAX_LINKS_PARAM: ${{ github.event.inputs.max_links || '3' }}
         run: |
-          set -x
-          cd tools/flakes && uv run main.py \
-            --file out/out.json \
+          set -euo pipefail
+
+          go run ./cmd/tools/flakereport generate \
+            --days "$DAYS_PARAM" \
+            --max-links "$MAX_LINKS_PARAM" \
+            --output-dir tools/flakes/out \
             --github-summary \
             --slack-webhook "$SLACK_WEBHOOK" \
             --run-id "$RUN_ID" \
             --ref-name "$REF_NAME" \
-            --sha "$SHA" \
-            --max-links "$MAX_LINKS_PARAM"
+            --sha "$SHA"
 
       - name: Upload generated reports
         uses: actions/upload-artifact@v4

cmd/tools/flakereport/main.go

@@ -0,0 +1,15 @@
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"go.temporal.io/server/tools/flakereport"
+)
+
+func main() {
+	if err := flakereport.NewCliApp().Run(os.Args); err != nil {
+		fmt.Fprintf(os.Stderr, "Error running flakereport: %v\n", err)
+		os.Exit(1)
+	}
+}