Implement PICCOLO Settings Service with complete history management and version tracking

src/server/Cargo.toml

@@ -9,6 +9,7 @@ members = [
     "apiserver",
     "policymanager",
     "monitoringserver",
+    "settingsservice",
 ]
 
 [workspace.dependencies]

src/server/settingsservice/Cargo.toml

@@ -0,0 +1,68 @@
+[package]
+name = "settingsservice"
+version = "0.1.0"
+edition = "2021"
+license = "Apache-2.0"
+description = "PICCOLO Settings Service - Central configuration and metrics management service"
+
+[[bin]]
+name = "settingsservice"
+path = "src/main.rs"
+
+[[bin]]
+name = "settings-cli"
+path = "src/bin/settings-cli.rs"
+
+[dependencies]
+# Core async runtime
+tokio = { version = "1.43.1", features = ["full"] }
+futures = "0.3"
+
+# Web framework
+axum = "0.7.7"
+tower = "0.4"
+tower-http = { version = "0.6.1", features = ["cors", "trace"] }
+
+# Serialization
+serde = { version = "1.0.214", features = ["derive"] }
+serde_json = "1.0"
+serde_yaml = "0.9"
+
+# Validation
+jsonschema = "0.18"
+
+# Data storage
+etcd-client = "0.14"
+
+# CLI
+clap = { version = "4.0", features = ["derive", "env"] }
+rustyline = "14.0"
+
+# Logging and errors
+tracing = "0.1"
+tracing-subscriber = { version = "0.3", features = ["env-filter", "json"] }
+anyhow = "1.0"
+thiserror = "2.0"
+
+# Utilities
+uuid = { version = "1.0", features = ["v4", "serde"] }
+chrono = { version = "0.4", features = ["serde"] }
+toml = "0.8"
+url = "2.0"
+
+# HTTP client
+reqwest = { version = "0.12", features = ["json"] }
+
+# Async utilities
+async-trait = "0.1"
+
+# Configuration
+config = "0.14"
+
+# Common shared library
+common = { workspace = true }
+
+[dev-dependencies]
+tokio-test = "0.4"
+tempfile = "3.0"
+wiremock = "0.6"

src/server/settingsservice/Dockerfile

@@ -0,0 +1,48 @@
+# SPDX-FileCopyrightText: Copyright 2024 LG Electronics Inc.
+# SPDX-License-Identifier: Apache-2.0
+
+FROM rust:latest as builder
+
+# Install system dependencies
+RUN apt-get update && apt-get install -y \
+    protobuf-compiler \
+    libdbus-1-dev \
+    pkg-config \
+    && rm -rf /var/lib/apt/lists/*
+
+# Set working directory
+WORKDIR /app
+
+# Copy the entire project for build context
+COPY . .
+
+# Build the settings service
+RUN cd src/server && cargo build --release
+
+# Runtime stage
+FROM debian:bookworm-slim
+
+# Install runtime dependencies
+RUN apt-get update && apt-get install -y \
+    libdbus-1-3 \
+    ca-certificates \
+    && rm -rf /var/lib/apt/lists/*
+
+# Create non-root user
+RUN useradd -r -s /bin/false settingsservice
+
+# Copy binary from builder
+COPY --from=builder /app/src/server/target/release/settingsservice /usr/local/bin/
+COPY --from=builder /app/src/server/target/release/settings-cli /usr/local/bin/
+
+# Create configuration directory
+RUN mkdir -p /etc/piccolo && chown settingsservice:settingsservice /etc/piccolo
+
+# Switch to non-root user
+USER settingsservice
+
+# Expose the default port
+EXPOSE 8080
+
+# Set default command
+CMD ["settingsservice", "--bind-address", "0.0.0.0", "--bind-port", "8080"]

src/server/settingsservice/README.md

@@ -0,0 +1,186 @@
+# PICCOLO Settings Service
+
+The Settings Service is a core component of the PICCOLO framework that provides centralized configuration management and metrics filtering capabilities.
+
+## Features
+
+- **Configuration Management**: Create, read, update, and delete YAML/JSON configurations
+- **Schema Validation**: Validate configurations against JSON schemas
+- **Change History**: Track configuration changes with rollback capabilities
+- **Metrics Filtering**: Filter and serve monitoring metrics from ETCD
+- **Multiple Interfaces**: REST API and CLI interfaces
+- **ETCD Integration**: Uses ETCD as the backend storage
+
+## Architecture
+
+The Settings Service consists of the following modules:
+
+- `settings_core`: Service initialization and coordination
+- `settings_config`: Configuration management with YAML/JSON support
+- `settings_history`: Change history tracking and rollback
+- `settings_monitoring`: Metrics data filtering from ETCD
+- `settings_storage`: ETCD client for data persistence
+- `settings_api`: REST API server
+- `settings_cli`: Command-line interface
+- `settings_utils`: Common utilities
+
+## Building
+
+```bash
+# Build the settings service
+cd src/server/settingsservice
+cargo build
+
+# Or build the entire project
+make build
+```
+
+## Running
+
+### Server Mode
+
+```bash
+# Run the server with default settings
+./target/debug/settingsservice
+
+# Run with custom configuration
+./target/debug/settingsservice \
+  --etcd-endpoints localhost:2379,localhost:2380 \
+  --bind-address 0.0.0.0 \
+  --bind-port 8080 \
+  --log-level info
+```
+
+### CLI Mode
+
+```bash
+# Run the CLI
+./target/debug/settingsservice --cli
+
+# Or use the dedicated CLI binary
+./target/debug/settings-cli
+```
+
+## REST API
+
+The Settings Service provides a comprehensive REST API:
+
+### Configuration Management
+
+- `GET /api/v1/settings` - List all configurations
+- `GET /api/v1/settings/{path}` - Get specific configuration
+- `POST /api/v1/settings/{path}` - Create new configuration
+- `PUT /api/v1/settings/{path}` - Update configuration
+- `DELETE /api/v1/settings/{path}` - Delete configuration
+- `POST /api/v1/settings/validate` - Validate configuration
+
+### Metrics Management
+
+- `GET /api/v1/metrics` - Get filtered metrics
+- `GET /api/v1/metrics/{id}` - Get specific metric
+- `GET /api/v1/metrics/component/{component}` - Get metrics by component
+- `GET /api/v1/metrics/filters` - List metric filters
+- `POST /api/v1/metrics/filters` - Create metric filter
+
+### History Management
+
+- `GET /api/v1/history/{path}` - Get configuration history
+- `GET /api/v1/history/{path}/version/{version}` - Get specific version
+- `POST /api/v1/history/{path}/rollback/{version}` - Rollback to version
+
+### System Information
+
+- `GET /api/v1/system/status` - Get system status
+- `GET /api/v1/system/health` - Health check
+
+## CLI Commands
+
+The CLI provides an interactive shell with the following commands:
+
+### Configuration Commands
+
+```bash
+config list [prefix]           # List configurations
+config get <path>              # Get configuration
+config set <path> <value>      # Set configuration
+config delete <path>           # Delete configuration
+config validate <path>         # Validate configuration
+```
+
+### Metrics Commands
+
+```bash
+metrics list                   # List all metrics
+metrics get <id>               # Get specific metric
+metrics filter <component>     # Filter metrics by component
+metrics filters                # List all filters
+```
+
+### History Commands
+
+```bash
+history <path>                 # Show configuration history
+history rollback <path> <ver>  # Rollback to version
+```
+
+## Configuration
+
+The service can be configured using command-line arguments or environment variables:
+
+- `--config`: Configuration file path (default: `/etc/piccolo/settings.yaml`)
+- `--etcd-endpoints`: ETCD endpoints (default: `localhost:2379`)
+- `--bind-address`: HTTP server bind address (default: `0.0.0.0`)
+- `--bind-port`: HTTP server bind port (default: `8080`)
+- `--log-level`: Log level (default: `info`)
+
+## Testing
+
+```bash
+# Run tests
+cargo test
+
+# Run with output
+cargo test -- --nocapture
+```
+
+## Example Usage
+
+### Create a Configuration
+
+```bash
+curl -X POST http://localhost:8080/api/v1/settings/myapp/config \
+  -H "Content-Type: application/json" \
+  -d '{
+    "content": {
+      "database": {
+        "host": "localhost",
+        "port": 5432
+      }
+    },
+    "schema_type": "database-config",
+    "author": "admin",
+    "comment": "Initial database configuration"
+  }'
+```
+
+### Get Configuration
+
+```bash
+curl http://localhost:8080/api/v1/settings/myapp/config
+```
+
+### Filter Metrics
+
+```bash
+curl "http://localhost:8080/api/v1/metrics?component=nodeagent&metric_type=gauge"
+```
+
+## Dependencies
+
+- Rust 1.70+
+- ETCD 3.5+
+- Protocol Buffers compiler (protoc)
+
+## License
+
+Apache-2.0

src/server/settingsservice/docker-compose.yml

@@ -0,0 +1,55 @@
+# SPDX-FileCopyrightText: Copyright 2024 LG Electronics Inc.
+# SPDX-License-Identifier: Apache-2.0
+
+version: '3.8'
+
+services:
+  etcd:
+    image: quay.io/coreos/etcd:v3.5.10
+    command:
+      - /usr/local/bin/etcd
+      - --name=etcd0
+      - --data-dir=/etcd-data
+      - --listen-client-urls=http://0.0.0.0:2379
+      - --advertise-client-urls=http://0.0.0.0:2379
+      - --listen-peer-urls=http://0.0.0.0:2380
+      - --initial-advertise-peer-urls=http://0.0.0.0:2380
+      - --initial-cluster=etcd0=http://0.0.0.0:2380
+      - --initial-cluster-token=etcd-cluster-1
+      - --initial-cluster-state=new
+    ports:
+      - "2379:2379"
+      - "2380:2380"
+    volumes:
+      - etcd-data:/etcd-data
+    healthcheck:
+      test: ["CMD", "etcdctl", "endpoint", "health"]
+      interval: 10s
+      timeout: 5s
+      retries: 5
+
+  settingsservice:
+    build:
+      context: ../../../  # Build from project root
+      dockerfile: src/server/settingsservice/Dockerfile
+    ports:
+      - "8080:8080"
+    environment:
+      - RUST_LOG=settingsservice=info,warn
+    command:
+      - settingsservice
+      - --etcd-endpoints=etcd:2379
+      - --bind-address=0.0.0.0
+      - --bind-port=8080
+      - --log-level=info
+    depends_on:
+      etcd:
+        condition: service_healthy
+    healthcheck:
+      test: ["CMD", "curl", "-f", "http://localhost:8080/api/v1/system/health"]
+      interval: 30s
+      timeout: 10s
+      retries: 3
+
+volumes:
+  etcd-data: