feat: Otel TracingHook implementation and repo skeleton (#1)

**Requirements**

- [x] I have added test coverage for new or changed functionality
- [x] I have followed the repository's [pull request submission
guidelines](../blob/main/CONTRIBUTING.md#submitting-pull-requests)
- [x] I have validated my changes against all supported platform
versions

**Related issues**

236794

**Describe the solution you've provided**

Implementation of SDK Hook interface that records spans and events for
feature flag evaluations using the OpenTelemetry API.

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,5 @@
+blank_issues_enabled: false
+contact_links:
+  - name: Support request
+    url: https://support.launchdarkly.com/hc/en-us/requests/new
+    about: File your support requests with LaunchDarkly's support team

.github/ISSUE_TEMPLATE/package-ldotel--bug_report.md

@@ -0,0 +1,36 @@
+---
+name: 'Bug report for the java-server-sdk-otel package'
+about: Create a report to help us improve
+title: ''
+labels: 'package: java-server-sdk-otel, bug'
+assignees: ''
+---
+
+**Is this a support request?**
+This issue tracker is maintained by LaunchDarkly SDK developers and is intended for feedback on the code in this library. If you're not sure whether the problem you are having is specifically related to this library, or to the LaunchDarkly service overall, it may be more appropriate to contact the LaunchDarkly support team; they can help to investigate the problem and will consult the SDK team if necessary. You can submit a support request by going [here](https://support.launchdarkly.com/) and clicking "submit a request", or by emailing [email protected].
+
+Note that issues filed on this issue tracker are publicly accessible. Do not provide any private account information on your issues. If your problem is specific to your account, you should submit a support request as described above.
+
+**Describe the bug**
+A clear and concise description of what the bug is.
+
+**To reproduce**
+Steps to reproduce the behavior.
+
+**Expected behavior**
+A clear and concise description of what you expected to happen.
+
+**Logs**
+If applicable, add any log output related to your problem.
+
+**SDK version**
+The version of this SDK that you are using.
+
+**Language version, developer tools**
+For instance, Go 1.11 or Ruby 2.5.3. If you are using a language that requires a separate compiler, such as C, please include the name and version of the compiler too.
+
+**OS/platform**
+For instance, Ubuntu 16.04, Windows 10, or Android 4.0.3. If your code is running in a browser, please also include the browser type and version.
+
+**Additional context**
+Add any other context about the problem here.

.github/ISSUE_TEMPLATE/package-ldotel--feature_request.md

@@ -0,0 +1,20 @@
+---
+name: Feature request for the java-server-sdk-otel package
+about: Suggest an idea for this project
+title: ''
+labels: 'package: java-server-sdk-otel, enhancement'
+assignees: ''
+
+---
+
+**Is your feature request related to a problem? Please describe.**
+A clear and concise description of what the problem is. Ex. I would love to see the SDK [...does something new...]
+
+**Describe the solution you'd like**
+A clear and concise description of what you want to happen.
+
+**Describe alternatives you've considered**
+A clear and concise description of any alternative solutions or features you've considered.
+
+**Additional context**
+Add any other context about the feature request here.

.github/actions/ci/action.yml

@@ -0,0 +1,43 @@
+# This is a composite to allow sharing these steps into other workflows.
+# It isn't a shared workflow, because then it isn't convenient to add
+# additional package specific steps.
+name: Shared CI Workflow
+inputs:
+  workspace_path:
+    description: 'Path to the package.'
+    required: true
+  run_tests:
+    description: 'If true, run unit tests, otherwise skip them.'
+    required: false
+    default: 'true'
+  java_version:
+    description: 'The Java version to use.'
+    required: true
+  java_distribution:
+    description: 'The Java distribution to use.'
+    required: false
+    default: 'temurin'
+
+runs:
+  using: composite
+  steps:
+    - name: Setup Java
+      uses: actions/setup-java@v4
+      with:
+        distribution: ${{ inputs.java_distribution }}
+        java-version: ${{ inputs.java_version }}
+
+    - name: Restore dependencies
+      shell: bash
+      id: restore
+      run: ${{ inputs.workspace_path }}/gradlew dependencies -p ${{ inputs.workspace_path }}
+
+    - name: Build
+      shell: bash
+      id: build
+      run: ${{ inputs.workspace_path }}/gradlew jar -p ${{ inputs.workspace_path }}
+
+    - name: Run Tests
+      if: steps.build.outcome == 'success' && inputs.run_tests == 'true'
+      shell: bash
+      run: ${{ inputs.workspace_path }}/gradlew test -p ${{ inputs.workspace_path }}

.github/actions/publish/action.yml

@@ -0,0 +1,43 @@
+name: Publish Package
+description: 'Publish the package to Sonatype'
+inputs:
+  workspace_path:
+    description: 'Path to the workspace.'
+    required: true
+  dry_run:
+    description: 'Is this a dry run. If so no package will be published.'
+    required: true
+  prerelease:
+    description: 'Is this a prerelease. If so then it will be published to the staging repository only.'
+    required: true
+  signing_key_id:
+    description: 'Signing key ID'
+    required: true
+  signing_key_passphrase:
+    description: 'Signing key passphrase'
+    required: true
+  code_signing_keyring:
+    description: 'The path of the code signing keyring.'
+    required: true
+  sonatype_username:
+    description: 'Sonatype repo username.'
+    required: true
+  sonatype_password:
+    description: 'Sonatype repo password.'
+    required: true
+
+runs:
+  using: composite
+  steps:
+    - name: Publish Library
+      shell: bash
+      env:
+        WORKSPACE_PATH: ${{ inputs.workspace_path }}
+        LD_RELEASE_IS_PRERELEASE: ${{ inputs.prerelease }}
+        LD_RELEASE_IS_DRYRUN: ${{ inputs.dry_run }}
+        SIGNING_KEY_ID: ${{ inputs.signing_key_id }}
+        SIGNING_KEY_PASSPHRASE: ${{ inputs.signing_key_passphrase }}
+        SIGNING_SECRET_KEY_RING_FILE: ${{ inputs.code_signing_keyring }}
+        SONATYPE_USER_NAME: ${{ inputs.sonatype_username }}
+        SONATYPE_PASSWORD: ${{ inputs.sonatype_password }}
+      run: source $GITHUB_ACTION_PATH/publish.sh

.github/actions/publish/publish.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+
+set -ue
+
+if $LD_RELEASE_IS_DRYRUN ; then
+  echo "Doing a dry run of publishing."
+else
+    echo "Publishing to Sonatype"
+    if [ "${LD_RELEASE_IS_PRERELEASE}" == "true" ]; then
+        echo "PRERELEASE"
+        ${WORKSPACE_PATH}/gradlew publishToSonatype -p ${WORKSPACE_PATH} -Psigning.keyId="${SIGNING_KEY_ID}" -Psigning.password="${SIGNING_KEY_PASSPHRASE}" -Psigning.secretKeyRingFile="${SIGNING_SECRET_KEY_RING_FILE}" -PsonatypeUsername="${SONATYPE_USER_NAME}" -PsonatypePassword="${SONATYPE_PASSWORD}" || {
+            echo "Gradle publish/release failed" >&2
+            exit 1
+        }
+    else
+        echo "RELEASE"
+        ${WORKSPACE_PATH}/gradlew publishToSonatype closeAndReleaseSonatypeStagingRepository -p ${WORKSPACE_PATH} -Psigning.keyId="${SIGNING_KEY_ID}" -Psigning.password="${SIGNING_KEY_PASSPHRASE}" -Psigning.secretKeyRingFile="${SIGNING_SECRET_KEY_RING_FILE}" -PsonatypeUsername="${SONATYPE_USER_NAME}" -PsonatypePassword="${SONATYPE_PASSWORD}" || {
+            echo "Gradle publish/release failed" >&2
+            exit 1
+        }
+    fi
+fi

.github/pull_request_template.md

@@ -0,0 +1,21 @@
+**Requirements**
+
+- [ ] I have added test coverage for new or changed functionality
+- [ ] I have followed the repository's [pull request submission guidelines](../blob/main/CONTRIBUTING.md#submitting-pull-requests)
+- [ ] I have validated my changes against all supported platform versions
+
+**Related issues**
+
+Provide links to any issues in this repository or elsewhere relating to this pull request.
+
+**Describe the solution you've provided**
+
+Provide a clear and concise description of what you expect to happen.
+
+**Describe alternatives you've considered**
+
+Provide a clear and concise description of any alternative solutions or features you've considered.
+
+**Additional context**
+
+Add any other context about the pull request here.

.github/workflows/java-server-sdk-otel.yml

@@ -0,0 +1,23 @@
+name: java-server-sdk-otel
+
+on:
+  push:
+    branches: [main, 'feat/**']
+    paths-ignore:
+      - '**.md' #Do not need to run CI for markdown changes.
+  pull_request:
+    branches: [main, 'feat/**']
+    paths-ignore:
+      - '**.md'
+
+jobs:
+  build-test-java-server-sdk-otel:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Shared CI Steps
+        uses: ./.github/actions/ci
+        with:
+          workspace_path: 'lib/java-server-sdk-otel'
+          java_version: 8

.github/workflows/lint-pr-title.yml

@@ -0,0 +1,17 @@
+name: Lint PR title
+
+on:
+  pull_request_target:
+    types:
+      - opened
+      - edited
+      - synchronize
+
+jobs:
+  main:
+    name: Verify the PR title matches conventional commit spec.
+    runs-on: ubuntu-latest
+    steps:
+      - uses: amannn/action-semantic-pull-request@v5
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/manual-publish.yml

@@ -0,0 +1,55 @@
+name: Publish Package
+on:
+  workflow_dispatch:
+    inputs:
+      workspace_path:
+        description: 'The workspace to publish'
+        required: true
+        type: choice
+        options:
+          - lib/libotel
+      prerelease:
+        description: 'Is this a prerelease.'
+        type: boolean
+        required: true
+      dry_run:
+        description: 'Is this a dry run. If so no package will be published.'
+        type: boolean
+        required: true
+      run_tests:
+        description: 'If true, run unit tests, otherwise skip them.'
+        type: boolean
+        default: true
+
+jobs:
+  build-and-publish:
+    runs-on: ubuntu-latest
+    permissions:
+      id-token: write
+      contents: read
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Shared CI Steps
+        uses: ./.github/actions/ci
+        with:
+          workspace_path: ${{ inputs.workspace_path }}
+          java_version: 8
+
+      - uses: launchdarkly/gh-actions/actions/[email protected]
+        name: Get secrets
+        with:
+          aws_assume_role: ${{ vars.AWS_ROLE_ARN }}
+          ssm_parameter_pairs: '/production/common/releasing/sonatype/username = SONATYPE_USER_NAME,
+          /production/common/releasing/sonatype/password = SONATYPE_PASSWORD,
+          /production/common/releasing/android_code_signing/private_key_id = SIGNING_KEY_ID,
+          /production/common/releasing/android_code_signing/private_key_passphrase = SIGNING_KEY_PASSPHRASE'
+          s3_path_pairs: 'launchdarkly-releaser/android/code-signing-keyring.gpg = code-signing-keyring.gpg'
+
+      - name: Publish
+        uses: ./.github/actions/publish
+        with:
+          workspace_path: ${{ inputs.workspace_path }}
+          dry_run: ${{ inputs.dry_run }}
+          prerelease: ${{ inputs.prerelease }}
+          code_signing_keyring: 'code-signing-keyring.gpg'

.github/workflows/stale.yml

@@ -0,0 +1,14 @@
+name: 'Close stale issues and PRs'
+on:
+  schedule:
+    - cron: '30 1 * * *'
+
+jobs:
+  stale:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/stale@v7
+        with:
+          stale-issue-message: 'This issue is stale because it has been open for 90 days without activity. Remove the stale label or comment, or this will be closed in 14 days.'
+          days-before-stale: 90
+          days-before-close: 14

.gitignore

@@ -0,0 +1,2 @@
+.idea/*
+.vscode

CODEOWNERS

@@ -0,0 +1,2 @@
+# Repository Maintainers
+* @launchdarkly/team-sdk-java

CONTRIBUTING.md

@@ -0,0 +1,41 @@
+# Contributing to the LaunchDarkly monorepo for Java SDKs
+
+LaunchDarkly has published an [SDK contributor's guide](https://docs.launchdarkly.com/sdk/concepts/contributors-guide) that provides a detailed explanation of how our SDKs work. See below for additional information on how to contribute to this SDK.
+
+## Submitting bug reports and feature requests
+
+The LaunchDarkly SDK team monitors the [issue tracker](https://github.com/launchdarkly/java-core/issues) in the SDK repository. Bug reports and feature requests specific to this repository's packages should be filed in this issue tracker. The SDK team will make best effort to respond to all newly filed issues within two business days.
+
+## Submitting pull requests
+
+We encourage pull requests and other contributions from the community. Before submitting pull requests, ensure that all temporary or unintended code is removed. Don't worry about adding reviewers to the pull request; the LaunchDarkly SDK team will add themselves. The SDK team will acknowledge all pull requests within two business days.
+
+## Build instructions
+
+### Prerequisites
+
+The majority of packages in this repo are built with [Gradle](https://gradle.org/) and should be built against Java 8.
+
+### Building
+
+To build a package without running any tests:
+```
+<package_path>/gradlew jar -p <package_path>
+```
+
+If you wish to clean your working directory between builds, you can clean it by running:
+```
+<package_path>/gradlew clean -p <package_path>
+```
+
+If you wish to use your generated package artifact by another Maven/Gradle project, you will likely want to publish the artifact to your local Maven repository so that your other project can access it.
+```
+<package_path>/gradlew publishToMavenLocal  -p <package_path> -PskipSigning=true
+```
+
+### Testing
+
+To build the package and run all unit tests:
+```
+<package_path>/gradlew test -p <package_path>
+```

LICENSE

@@ -0,0 +1,13 @@
+Copyright 2024 Catamorphic, Co.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.