Singer/Meltano: Add example github-to-cratedb

It uses the `meltano-target-cratedb` Singer component.
https://github.com/crate-workbench/meltano-target-cratedb

Author: amotl

.github/workflows/test-singer-meltano.yml

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+name: Python SQLAlchemy
+
+on:
+  pull_request:
+    branches: ~
+    paths:
+    - '.github/workflows/test-singer-meltano.yml'
+    - 'framework/singer-meltano/**'
+    - 'requirements.txt'
+  push:
+    branches: [ main ]
+    paths:
+    - '.github/workflows/test-singer-meltano.yml'
+    - 'framework/singer-meltano/**'
+    - 'requirements.txt'
+
+  # Allow job to be triggered manually.
+  workflow_dispatch:
+
+  # Run job each night after CrateDB nightly has been published.
+  schedule:
+    - cron: '0 3 * * *'
+
+# Cancel in-progress jobs when pushing to the same branch.
+concurrency:
+  cancel-in-progress: true
+  group: ${{ github.workflow }}-${{ github.ref }}
+
+jobs:
+  test:
+    name: "
+     Python: ${{ matrix.python-version }}
+     CrateDB: ${{ matrix.cratedb-version }}
+     on ${{ matrix.os }}"
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ 'ubuntu-latest' ]
+        python-version: [ '3.10', '3.11' ]
+        cratedb-version: [ 'nightly' ]
+
+    services:
+      cratedb:
+        image: crate/crate:nightly
+        ports:
+          - 4200:4200
+          - 5432:5432
+
+    steps:
+
+      - name: Acquire sources
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python-version }}
+          architecture: x64
+          cache: 'pip'
+          cache-dependency-path: |
+            requirements.txt
+            framework/singer-meltano/requirements.txt
+            framework/singer-meltano/requirements-dev.txt
+
+      - name: Install utilities
+        run: |
+          pip install -r requirements.txt
+
+      - name: Validate framework/singer-meltano
+        run: |
+          ngr test --accept-no-venv framework/singer-meltano

.gitignore

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+.DS_Store
 .idea
+.env
 .venv*
 __pycache__
 .coverage
 coverage.xml
 mlruns/
 archive/
-logs.log

framework/singer-meltano/.gitignore

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+.meltano
+output

framework/singer-meltano/README.md

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+# Meltano Examples
+
+Concise examples about working with [CrateDB] and [Meltano], for conceiving and
+running flexible ELT tasks. All the recipes are using [meltano-target-cratedb]
+for reading and writing data from/to CrateDB.
+
+## What's inside
+
+- `singerfile-to-cratedb`: Acquire data from Singer File, and load it into
+  CrateDB database table.
+
+- `github-to-cratedb`: Acquire repository metadata from GitHub API, and load
+  it separated per entity into 32 CrateDB database tables.
+
+## Prerequisites
+
+Before running an examples within the subdirectories, make sure to install
+Meltano and its dependencies.
+
+```shell
+python3 -m venv .venv
+source .venv/bin/activate
+pip install -r requirements.txt
+```
+
+## Usage
+
+Then, explore the individual Meltano projects, either invoke them from within
+their directories, or by using the `--cwd` option from the root folder.
+
+```shell
+meltano --cwd github-to-cratedb install
+meltano --cwd github-to-cratedb run tap-github target-cratedb
+```
+
+## Software Tests
+```shell
+pip install -r requirements-dev.txt
+poe check
+```
+
+
+[CrateDB]: https://cratedb.com/product
+[Meltano]: https://meltano.com/
+[meltano-target-cratedb]: https://github.com/crate-workbench/meltano-target-cratedb

framework/singer-meltano/github-to-cratedb/README.md

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+# Meltano GitHub -> CrateDB example
+
+## About
+
+Acquire repository metadata from GitHub API, and insert into CrateDB database
+tables, using [meltano-target-cratedb].
+
+It follows the canonical example demonstrated at the [Meltano Getting Started Tutorial].
+
+## Configuration
+
+### tap-github
+
+For accessing the GitHub API, you will need an authentication token. It
+can be acquired at [GitHub Developer Settings » Tokens].
+
+To configure the recipe, please store it into the `TAP_GITHUB_AUTH_TOKEN`
+environment variable, either interactively, or by creating a dotenv
+configuration file `.env`.
+
+```shell
+TAP_GITHUB_AUTH_TOKEN='ghp_hmQR3XTFWkfIcuyjRTBuVrRt6mnL1j2mMPT8'
+```
+
+Then, in `meltano.yml`, identify the `tap-github` section in `plugins.extractors`,
+and adjust the value of `config.repositories` to correspond to the repository
+you intend to scrape.
+
+### target-cratedb
+
+Within `loaders` section `target-cratedb`, adjust `config.sqlalchemy_url` to
+match your database connectivity settings.
+
+
+## Usage
+
+Install dependencies.
+```shell
+meltano install
+```
+
+Invoke data transfer to JSONL files.
+```shell
+meltano run tap-github target-jsonl
+cat github-to-cratedb/output/commits.jsonl
+```
+
+Invoke data transfer to CrateDB database.
+```shell
+meltano run tap-github target-cratedb
+```
+
+## Screenshot
+
+Enjoy the release notes.
+```sql
+SELECT repo, tag_name, body FROM melty.releases ORDER BY tag_name DESC;
+```
+
+![image](https://github.com/crate-workbench/cratedb-toolkit/assets/453543/ac37c9cc-8e42-4c7c-84aa-64498bf48f4d)
+
+## Troubleshooting
+
+If you see such errors on stdout, please verify your GitHub authentication
+token stored within the `TAP_GITHUB_AUTH_TOKEN` environment variable.
+```python
+singer_sdk.exceptions.RetriableAPIError: 401 Client Error: b'{"message":"This endpoint requires you to be authenticated.","documentation_url":"https://docs.github.com/graphql/guides/forming-calls-with-graphql#authenticating-with-graphql"}' (Reason: Unauthorized) for path: /graphql cmd_type=elb consumer=False name=tap-github producer=True stdio=stderr string_id=tap-github
+```
+
+## Development
+In order to link the sandbox to a development installation of [meltano-target-cratedb],
+configure the `pip_url` of the component like this:
+```yaml
+pip_url: --editable=/path/to/sources/meltano-target-cratedb
+```
+
+
+[GitHub Developer Settings » Tokens]: https://github.com/settings/tokens
+[Meltano Getting Started Tutorial]: https://docs.meltano.com/getting-started/part1
+[meltano-target-cratedb]: https://github.com/crate-workbench/meltano-target-cratedb
+[tap-github]: https://hub.meltano.com/extractors/tap-github/
+[target-jsonl]: https://hub.meltano.com/loaders/target-jsonl/

framework/singer-meltano/github-to-cratedb/meltano.yml

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+# A Meltano project is just a directory on your filesystem containing text-based files.
+# At a minimum, a Meltano project must contain a project file named `meltano.yml`,
+# which contains your project configuration, and tells Meltano that a particular
+# directory is a Meltano project.
+---
+version: 1
+default_environment: dev
+send_anonymous_usage_stats: false
+project_id: f14797b9-9d1c-414c-851c-c91e08ddbc2e
+
+environments:
+- name: dev
+- name: staging
+- name: prod
+
+plugins:
+
+  # Configure data source.
+  # In Singer jargon, it is an "extractor", wrapped into a "tap".
+  extractors:
+
+  - name: tap-github
+    variant: cratedb
+    namespace: cratedb
+    pip_url: git+https://github.com/crate-workbench/tap-github.git@cratedb
+    # Note: Configure your GitHub repository here.
+    config:
+      start_date: '2023-12-01'
+      repositories:
+      - crate-workbench/cratedb-toolkit
+
+  # Configure data sinks.
+  # In Singer jargon, it is a "loader", wrapped into a "target".
+  loaders:
+
+  - name: target-jsonl
+    variant: andyh1203
+    pip_url: target-jsonl
+
+  - name: target-cratedb
+    namespace: cratedb
+    variant: cratedb
+    # Acquire from PyPI.
+    pip_url: meltano-target-cratedb
+    # Acquire from GitHub.
+    # pip_url: git+https://github.com/crate-workbench/meltano-target-cratedb.git
+
+    # Note: Configure your database server and credentials here.
+    config:
+      sqlalchemy_url: crate://crate@localhost/
+      add_record_metadata: true