ci: migrate to flint v2 for linting

.editorconfig

@@ -663,7 +663,7 @@ ij_groovy_while_brace_force = never
 ij_groovy_while_on_new_line = false
 ij_groovy_wrap_long_lines = false
 
-[{*.kt, *.kts}]
+[*.{kt,kts}]
 ij_continuation_indent_size = 2
 ij_kotlin_align_in_columns_case_branch = false
 ij_kotlin_align_multiline_binary_operation = false
@@ -761,3 +761,16 @@ ij_properties_spaces_around_key_value_delimiter = false
 [{*.yaml, *.yml}]
 ij_yaml_keep_indents_on_empty_lines = false
 ij_yaml_keep_line_breaks = true
+
+# ktlint overrides (mirrors otel.spotless-conventions.gradle.kts)
+[*.{kt,kts}]
+max_line_length = 160
+continuation_indent_size = 2
+ktlint_standard_no-wildcard-imports = disabled
+ktlint_standard_package-name = disabled
+ktlint_standard_max-line-length = disabled
+ktlint_standard_trailing-comma-on-call-site = disabled
+ktlint_standard_trailing-comma-on-declaration-site = disabled
+ktlint_standard_wrapping = disabled
+ktlint_standard_property-naming = disabled
+ktlint_standard_function-literal = disabled

.github/config/.rumdl.toml

@@ -0,0 +1,5 @@
+[MD013]
+enabled = true
+line-length = 120
+code-blocks = false
+tables = false

.github/config/.yamllint.yml

@@ -0,0 +1,6 @@
+extends: relaxed
+
+rules:
+  document-start: disable
+  line-length: disable
+  indentation: warning

.github/config/flint.toml

@@ -0,0 +1,15 @@
+[settings]
+exclude = [
+  "gradlew",
+  "buildscripts/spotless.license.java",
+  "CHANGELOG.md",
+  "licenses/licenses.md",
+]
+
+[checks.license-header]
+text = """
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */"""
+patterns = ["**/*.java", "**/*.kt"]

.github/renovate.json5

@@ -1,6 +1,7 @@
 {
   $schema: 'https://docs.renovatebot.com/renovate-schema.json',
   extends: [
+    "github>grafana/flint#v0.20.4",
     'config:best-practices',
     'helpers:pinGitHubActionDigestsToSemver',
     ':semanticCommits',

.github/workflows/build-daily.yml

@@ -25,11 +25,8 @@ jobs:
   muzzle:
     uses: ./.github/workflows/reusable-muzzle.yml
 
-  link-check:
-    uses: ./.github/workflows/reusable-link-check.yml
-
-  markdown-lint-check:
-    uses: ./.github/workflows/reusable-markdown-lint-check.yml
+  lint:
+    uses: ./.github/workflows/reusable-lint-check.yml
 
   publish-snapshots:
     environment: protected

.github/workflows/build-pull-request.yml

@@ -40,15 +40,11 @@ jobs:
     with:
       cache-read-only: true
 
-  # this is not a required check to avoid blocking pull requests if external links break
-  markdown-check:
+  lint:
     # release branches are excluded because the README.md javaagent download link has to be updated
     # on release branches before the release download has been published
     if: "!startsWith(github.ref_name, 'release/') && !startsWith(github.base_ref, 'release/')"
-    uses: ./.github/workflows/reusable-link-check.yml
-
-  markdown-lint-check:
-    uses: ./.github/workflows/reusable-markdown-lint-check.yml
+    uses: ./.github/workflows/reusable-lint-check.yml
 
   required-status-check:
     # test-latest-deps is not included in the required status checks
@@ -63,7 +59,7 @@ jobs:
     needs:
       - common
       - muzzle
-      - markdown-lint-check
+      - lint
     runs-on: ubuntu-latest
     if: always()
     steps:
@@ -73,7 +69,7 @@ jobs:
             !startsWith(github.base_ref, 'release/') &&
             (
               needs.muzzle.result != 'success' ||
-              needs.markdown-lint-check.result != 'success'
+              needs.lint.result != 'success'
             )
           )
         run: exit 1 # fail

.github/workflows/build.yml

@@ -34,14 +34,8 @@ jobs:
     if: "!startsWith(github.ref_name, 'release/')"
     uses: ./.github/workflows/reusable-muzzle.yml
 
-  link-check:
-    # release branches are excluded to avoid unnecessary maintenance if external links break
-    # (and also because the README.md javaagent download link has to be updated on release branches
-    #  before the release download has been published)
+  lint:
+    # release branches are excluded because the README.md javaagent download link has to be updated
+    # on release branches before the release download has been published
     if: "!startsWith(github.ref_name, 'release/')"
-    uses: ./.github/workflows/reusable-link-check.yml
-
-  markdown-lint-check:
-    # release branches are excluded
-    if: "!startsWith(github.ref_name, 'release/')"
-    uses: ./.github/workflows/reusable-markdown-lint-check.yml
+    uses: ./.github/workflows/reusable-lint-check.yml

.github/workflows/lint.yml

@@ -0,0 +1,32 @@
+name: Lint
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+permissions:
+  contents: read
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          persist-credentials: false
+          fetch-depth: 0
+
+      - name: Setup mise
+        uses: jdx/mise-action@1648a7812b9aeae629881980618f079932869151 # v4.0.1
+        with:
+          version: v2026.4.18
+          sha256: 6ae2d5f0f23a2f2149bc5d9bf264fe0922a1da843f1903e453516c462b23cc1f
+
+      - name: Lint
+        env:
+          GITHUB_TOKEN: ${{ github.token }}
+          GITHUB_HEAD_SHA: ${{ github.event.pull_request.head.sha }}
+        run: mise run lint

.github/workflows/reusable-link-check.yml → .github/workflows/reusable-lint-check.yml

@@ -1,4 +1,4 @@
-name: Reusable - Link check
+name: Reusable - Lint check
 
 on:
   workflow_call:
@@ -7,7 +7,7 @@ permissions:
   contents: read
 
 jobs:
-  link-check:
+  lint-check:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
@@ -16,16 +16,16 @@ jobs:
 
       - uses: jdx/mise-action@1648a7812b9aeae629881980618f079932869151 # v4.0.1
 
-      - name: Link check for pull requests
+      - name: Lint for pull requests
         if: github.event_name == 'pull_request'
         env:
           GITHUB_TOKEN: ${{ github.token }}
           GITHUB_HEAD_SHA: ${{ github.event.pull_request.head.sha }}
           PR_HEAD_REPO: ${{ github.event.pull_request.head.repo.full_name }}
-        run: mise run lint:links
+        run: mise run lint
 
-      - name: Link check for pushes and scheduled workflows
+      - name: Lint for pushes and scheduled workflows
         if: github.event_name != 'pull_request'
         env:
           GITHUB_TOKEN: ${{ github.token }}
-        run: mise run lint:links --full
+        run: mise run lint

benchmark-overhead-jmh/build.gradle.kts

@@ -40,23 +40,27 @@ tasks {
   //  -Pjmh.startFlightRecording=settings=profile.jfc,delay=50s,duration=50s,filename=output.jfr
   // since each iteration is 10 seconds, the flight recording produced will approximately cover the
   // (post-warmup) benchmarking iterations
-  val jmhStartFlightRecording = gradle.startParameter.projectProperties.get("jmh.startFlightRecording")
+  val jmhStartFlightRecording =
+    gradle.startParameter.projectProperties.get(
+      "jmh.startFlightRecording",
+    )
 
   named<JMHTask>("jmh") {
     val shadowTask = project(":javaagent").tasks.named<Jar>("shadowJar").get()
     inputs.files(layout.files(shadowTask))
 
     // note: without an exporter, toSpanData() won't even be called
     // (which is good for benchmarking the instrumentation itself)
-    val args = mutableListOf(
-      "-javaagent:${shadowTask.archiveFile.get()}",
-      "-Dotel.traces.exporter=none",
-      "-Dotel.metrics.exporter=none",
-      "-Dotel.logs.exporter=none",
-      // avoid instrumenting HttpURLConnection for now since it is used to make the requests
-      // and this benchmark is focused on servlet overhead for now
-      "-Dotel.instrumentation.http-url-connection.enabled=false",
-    )
+    val args =
+      mutableListOf(
+        "-javaagent:${shadowTask.archiveFile.get()}",
+        "-Dotel.traces.exporter=none",
+        "-Dotel.metrics.exporter=none",
+        "-Dotel.logs.exporter=none",
+        // avoid instrumenting HttpURLConnection for now since it is used to make the requests
+        // and this benchmark is focused on servlet overhead for now
+        "-Dotel.instrumentation.http-url-connection.enabled=false",
+      )
     if (jmhStartFlightRecording != null) {
       args.addAll(
         listOf(

benchmark-overhead/build.gradle.kts

@@ -6,7 +6,10 @@ plugins {
 spotless {
   java {
     googleJavaFormat()
-    licenseHeaderFile(rootProject.file("../buildscripts/spotless.license.java"), "(package|import|public)")
+    licenseHeaderFile(
+      rootProject.file("../buildscripts/spotless.license.java"),
+      "(package|import|public)",
+    )
     target("src/**/*.java")
   }
 }

benchmark-overhead/settings.gradle.kts

@@ -1 +1 @@
-rootProject.name = "opentelemetry-agent-overhead-test"
+rootProject.name = "opentelemetry-agent-overhead-test"

benchmark-overhead/src/test/java/io/opentelemetry/OverheadTests.java

@@ -5,9 +5,8 @@
 
 package io.opentelemetry;
 
-import static java.util.concurrent.TimeUnit.SECONDS;
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
-
+import static java.util.concurrent.TimeUnit.SECONDS;
 import static org.assertj.core.api.Assertions.fail;
 import static org.junit.jupiter.api.DynamicTest.dynamicTest;
 
@@ -29,7 +28,6 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.concurrent.TimeUnit;
 import java.util.stream.Stream;
 import org.junit.jupiter.api.AfterAll;
 import org.junit.jupiter.api.BeforeAll;
@@ -145,15 +143,15 @@ private void doWarmupPhase(TestConfig testConfig, GenericContainer<?> petclinic)
     };
     petclinic.execInContainer(startCommand);
 
-    long deadline =
-        System.currentTimeMillis() + SECONDS.toMillis(testConfig.getWarmupSeconds());
+    long deadline = System.currentTimeMillis() + SECONDS.toMillis(testConfig.getWarmupSeconds());
     while (System.currentTimeMillis() < deadline) {
       GenericContainer<?> k6 =
           new GenericContainer<>(DockerImageName.parse("grafana/k6"))
               .withNetwork(NETWORK)
               .withCopyFileToContainer(MountableFile.forHostPath("./k6"), "/app")
               .withCommand("run", "-u", "5", "-i", "200", "/app/basic.js")
-              .withStartupCheckStrategy(new OneShotStartupCheckStrategy().withTimeout(Duration.ofMinutes(5)));
+              .withStartupCheckStrategy(
+                  new OneShotStartupCheckStrategy().withTimeout(Duration.ofMinutes(5)));
       k6.start();
     }
 

benchmark-overhead/src/test/java/io/opentelemetry/agents/LatestAgentSnapshotResolver.java

@@ -22,7 +22,9 @@ Optional<Path> resolve() throws IOException {
     Path localJavaagentPath = findLocalJavaagentJar();
 
     if (localJavaagentPath == null || !Files.exists(localJavaagentPath)) {
-      throw new IOException("Local javaagent JAR not found. Please run './gradlew :javaagent:assemble' from the project root first.");
+      throw new IOException(
+          "Local javaagent JAR not found. Please run './gradlew :javaagent:assemble' from the"
+              + " project root first.");
     }
 
     logger.info("Using local javaagent JAR: {}", localJavaagentPath);
@@ -66,13 +68,16 @@ private Path findJavaagentJarInDirectory(Path directory) {
 
     try {
       return Files.list(directory)
-          .filter(path -> {
-            String filename = path.getFileName().toString();
-            // Look for the main jar: opentelemetry-javaagent-VERSION.jar (no additional suffixes)
-            return filename.startsWith("opentelemetry-javaagent-") &&
-                   filename.endsWith(".jar") &&
-                   !filename.matches(".*-[a-z]+\\.jar"); // excludes anything with -word.jar pattern
-          })
+          .filter(
+              path -> {
+                String filename = path.getFileName().toString();
+                // Look for the main jar: opentelemetry-javaagent-VERSION.jar (no additional
+                // suffixes)
+                return filename.startsWith("opentelemetry-javaagent-")
+                    && filename.endsWith(".jar")
+                    && !filename.matches(
+                        ".*-[a-z]+\\.jar"); // excludes anything with -word.jar pattern
+              })
           .findFirst()
           .orElse(null);
     } catch (IOException e) {
@@ -81,4 +86,3 @@ private Path findJavaagentJarInDirectory(Path directory) {
     }
   }
 }
-

benchmark-overhead/src/test/java/io/opentelemetry/results/CsvPersister.java

@@ -5,8 +5,8 @@
 
 package io.opentelemetry.results;
 
-import static java.util.stream.Collectors.toList;
 import static java.util.concurrent.TimeUnit.NANOSECONDS;
+import static java.util.stream.Collectors.toList;
 
 import java.io.IOException;
 import java.nio.file.Files;