release: v1.2.0 - Pure Go update engine, enhanced journal log fetcher, and protocol concurrency fixes

CHANGELOG.md

@@ -0,0 +1,25 @@
+# Changelog
+
+All notable changes to the `theta-agent` daemon will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [v1.2.0] - 2026-08-03
+
+### Added
+- **Protocol v1.1.0 Compliance**: Full alignment with `PROTOCOL.md` (v1.1.0) specification.
+- **Ed25519 Cryptographic Verification**: Verification of Ed25519 Base64 signatures for high-risk C2 commands (`reboot`, `service_restart`, `configure_ldap`, `arbitrary_bash`, `update_binary`).
+- **Enhanced Journal Log Fetcher (`fetch_logs`)**: Support for querying service-specific systemd logs (`service` parameter) with configurable line count (`lines` parameter).
+- **Pure Go Self-Update Engine (`update_binary`)**: Replaced shell script execution with pure Go HTTP client fetching, SHA256 verification, atomic file replacement, and clean daemon restart.
+
+### Fixed
+- **Goroutine Leak Prevention**: Added `stopCh` lifecycle management to terminate background telemetry and heartbeat tickers upon WebSocket disconnection.
+- **Dynamic Config Rerenders**: Resolved data races when toggling capabilities or reloading `agent.yml` via `reload_config`.
+- **Config Path Uniformity**: Standardized canonical configuration file path across codebase, installer, and documentation to `/etc/theta42/agent.yml`.
+
+## [v0.1.0] - 2026-08-01
+
+### Added
+- Initial release of `theta-agent` Go daemon replacing legacy bash metric scripts.
+- Persistent outbound WebSocket telemetry and local capability matrix enforcement.

Dockerfile

@@ -0,0 +1,28 @@
+# Multi-stage build for minimal runtime image
+FROM golang:1.23-alpine AS builder
+
+# Install build dependencies
+RUN apk add --no-cache git
+
+WORKDIR /app
+COPY go.mod go.sum ./
+RUN go mod download
+
+COPY . .
+RUN CGO_ENABLED=0 GOOS=linux go build -v -o theta-agent .
+
+# Final runtime image
+FROM alpine:latest
+RUN apk add --no-cache ca-certificates
+
+WORKDIR /
+
+# Create config directory
+RUN mkdir -p /etc/theta42
+
+COPY --from=builder /app/theta-agent /usr/local/bin/theta-agent
+
+# Run as root for system management
+USER root
+
+ENTRYPOINT ["/usr/local/bin/theta-agent"]

INSTALL.md

@@ -0,0 +1,93 @@
+# Installation Guide: Theta Agent
+
+Theta Agent is designed for rapid deployment across the fleet. The recommended method is via the "One-Liner" install, which marries the agent to a specific SSO Manager instance.
+
+## Quick Start (The One-Liner)
+
+The SSO Manager provides a pre-generated installation command. Copy and paste it into your terminal as root:
+
+### Option A: Full Configuration (Recommended)
+Use this for precise control over capabilities:
+```bash
+curl -fsSL https://sso.example.com/resources/theta-agent/install.sh | sh -s -- "BASE64_ENCODED_CONFIG"
+```
+
+### Option B: Minimal Setup
+Use this for rapid deployment with basic telemetry:
+```bash
+curl -fsSL https://sso.example.com/resources/theta-agent/install.sh | sh -s -- --url "https://sso.example.com" --token "your-host-token"
+```
+
+### What this does:
+1. Downloads the latest `theta-agent` binary.
+2. Decodes the base64 configuration string into `/etc/theta42/agent.yml`.
+3. Installs a systemd service unit.
+4. Starts the agent automatically.
+
+---
+
+## Manual Installation
+
+If you are in an air-gapped environment or prefer manual control:
+
+### 1. Deploy Binary
+Place the `theta-agent` binary in `/usr/local/bin/` and ensure it is executable:
+```bash
+chmod +x /usr/local/bin/theta-agent
+```
+
+### 2. Configure
+Create the configuration directory and the `agent.yml` file:
+```bash
+mkdir -p /etc/theta42
+nano /etc/theta42/agent.yml
+```
+Ensure the file has restricted permissions:
+```bash
+chmod 600 /etc/theta42/agent.yml
+```
+
+### 3. Setup systemd
+Create the file `/etc/systemd/system/theta-agent.service`:
+```ini
+[Unit]
+Description=Theta Agent Unified Endpoint Management
+After=network.target
+
+[Service]
+Type=simple
+ExecStart=/usr/local/bin/theta-agent
+Restart=always
+RestartSec=5
+StandardOutput=syslog
+StandardError=syslog
+SyslogIdentifier=theta-agent
+
+[Install]
+WantedBy=multi-user.target
+```
+
+Enable and start the service:
+```bash
+systemctl daemon-reload
+systemctl enable theta-agent
+systemctl start theta-agent
+```
+
+## Troubleshooting
+
+### Verifying Connection
+Check the logs to ensure the agent has successfully connected to the SSO Manager:
+```bash
+journalctl -u theta-agent -f
+```
+You should see: `Successfully connected to SSO Manager.`
+
+### Configuration Errors
+If the agent fails to start, verify the config file exists and is valid YAML:
+```bash
+ls -l /etc/theta42/agent.yml
+```
+
+### Root Privileges
+The agent must run as root to execute system commands like `reboot` and `systemctl restart`. If you manually run the binary, ensure you use `sudo`.

PROTOCOL.md

@@ -0,0 +1,105 @@
+# Theta Agent Protocol Specification (v1.1.0)
+
+This document defines the communication protocol between the `theta-agent` (Client) and the `sso-manager` (Server).
+
+## 1. Connection Establishment
+
+The agent establishes a persistent outbound WebSocket connection.
+
+- **Endpoint**: `wss://<manager-url>/api/agent/ws`
+- **Authentication**: The agent must provide a unique host token as a query parameter:
+  - `wss://<manager-url>/api/agent/ws?token=<HOST_TOKEN>`
+
+## 2. Message Format
+
+All messages are exchanged as JSON objects following the `WSMessage` structure.
+
+```json
+{
+  "type": "string",
+  "payload": {
+    "key": "value"
+  }
+}
+```
+
+## 3. Client $\rightarrow$ Server Messages
+
+### 3.1 Discovery (One-time & On-Change)
+Sent immediately upon connection and whenever the agent detects a change in its own network IP addresses.
+
+- **Type**: `discovery`
+- **Payload**:
+  - `hostname`: (string) System hostname.
+  - `ip_addresses`: (array of strings) List of all non-loopback IPv4 addresses.
+  - `os`: (string) OS and Platform.
+  - `kernel`: (string) Kernel version.
+  - `cpu`: (string) CPU model.
+  - `ram_total_gb`: (float) Total system RAM in GB.
+  - `disk_total_gb`: (float) Total root disk capacity in GB.
+  - `location`: (string) Physical location from config.
+
+### 3.2 Telemetry (Periodic)
+Sent every 30 seconds.
+
+- **Type**: `telemetry`
+- **Payload**:
+  - `cpu_usage_percent`: (float) Current CPU load.
+  - `ram_usage_percent`: (float) Current RAM utilization.
+  - `disk_usage_percent`: (float) Current root disk utilization.
+  - `zfs_health`: (string) Primary ZFS pool status (e.g., "ONLINE").
+  - `gpu_usage_percent`: (float) Average NVIDIA GPU utilization (-1.0 if unavailable).
+  - `timestamp`: (string) RFC3339 timestamp.
+
+### 3.3 Heartbeat (Periodic)
+Sent every 60 seconds to maintain the connection and signal health.
+
+- **Type**: `heartbeat`
+- **Payload**:
+  - `timestamp`: (string) RFC3339 timestamp.
+
+### 3.4 Command Response
+Sent in response to any command received from the server.
+
+- **Type**: `response` (Implicitly handled as the answer to a command)
+- **Payload**:
+  - `status`: (string) Either `"ok"` or `"error"`.
+  - `message`: (string) Human-readable result or error description.
+  - `output`: (string, optional) Stdout/stderr for execution commands.
+
+---
+
+## 4. Server $\rightarrow$ Client Messages
+
+### 4.1 Standard Commands
+These commands are executed if the corresponding capability is enabled in `agent.yml`.
+
+| Command | Payload | Effect |
+| :--- | :--- | :--- |
+| `reload_config` | `{}` | Agent re-reads `/etc/theta42/agent.yml` from disk. |
+| `fetch_logs` | `{}` | Agent returns the last 100 lines of `journalctl -u theta-agent`. |
+
+### 4.2 High-Risk Commands (Signed)
+These commands **require** an Ed25519 signature in the payload. The agent verifies the signature against the `public_key` in its config.
+
+**Signature Format**:
+- The `signature` field contains the base64-encoded Ed25519 signature of the payload (with the `signature` key removed).
+
+| Command | Payload | Effect |
+| :--- | :--- | :--- |
+| `reboot` | `{ "signature": "..." }` | Triggers system reboot. |
+| `service_restart` | `{ "service": "...", "signature": "..." }` | Restarts specific systemd service. |
+| `configure_ldap` | `{ "config": "...", "signature": "..." }` | Writes `/etc/sssd/sssd.conf` and restarts `sssd`. |
+| `arbitrary_bash` | `{ "script": "...", "signature": "..." }` | Executes raw bash script. |
+| `update_binary` | `{ "url": "...", "sha256": "...", "signature": "..." }` | Downloads, verifies, and replaces the agent binary. |
+
+## 5. Cryptographic Verification Process
+
+To send a high-risk command:
+1. Create the payload (e.g., `{"script": "uptime"}`).
+2. Canonicalize the JSON (sort keys alphabetically, remove whitespace).
+3. Sign the canonical bytes using the private Ed25519 key.
+4. Add the base64 signature to the payload: `{"script": "uptime", "signature": "..."}`.
+5. Send as a `WSMessage`.
+
+The agent performs the reverse process to verify authenticity before execution.

README.md

@@ -1,44 +1,86 @@
 # Theta Agent
 
-Theta Agent is a unified endpoint management daemon for the theta42 stack. It replaces legacy bash installation scripts (like `ldap-client`) and one-way metric scripts (`telemetry-agent`) with a powerful, 2-way Command & Control (C2) Go daemon.
+Theta Agent is a unified endpoint management daemon for the theta42 stack. It replaces legacy bash installation scripts and one-way metric scripts with a powerful, 2-way Command & Control (C2) Go daemon.
 
-The agent dials out to the central SSO Manager via a persistent WebSocket connection, enabling:
+The agent dials out to the central SSO Manager via a persistent WebSocket connection, enabling real-time telemetry, dynamic discovery, and secure remote operations.
-- **Continuous Telemetry:** Streams CPU/RAM/ZFS/GPU health to the central inventory.
+
-- **Dynamic Discovery:** Automatically updates host IP and metadata on changes.
+## Core Functionality
-- **Remote Operations:** Allows SSO Manager administrators to remotely configure LDAP, restart systemd services, or execute maintenance scripts.
+
+### 1. Telemetry & Observability
+- **Host Discovery**: Pushes a comprehensive profile (IPs, OS, Kernel, CPU, RAM/Disk) upon connection and automatically updates when network interface IPs change.
+- **Continuous Monitoring**: Streams metrics every 30 seconds:
+  - CPU, RAM, and Root Disk usage.
+  - **ZFS Health**: Monitors pool status via `zpool list`.
+  - **GPU Utilization**: Tracks NVIDIA GPU usage via `nvidia-smi`.
+- **Health Checks**: Sends a periodic heartbeat to the SSO Manager to signal agent viability.
+
+### 2. Remote Operations (C2)
+The agent provides a powerful set of administrative tools, categorized by risk:
+
+#### Standard Operations
+- **Config Reload**: Triggers a reload of `/etc/theta42/agent.yml` from disk without restarting the process.
+- **Log Streaming**: Fetch the last 100 lines of the agent's system logs via the C2 channel.
+
+#### High-Risk Operations (Require Cryptographic Signatures)
+To prevent unauthorized execution, these commands must be signed with a private key corresponding to the `public_key` in `agent.yml`:
+- **Service Control**: Restart approved systemd services.
+- **System Control**: Trigger a full system reboot.
+- **Config Management**: Update `/etc/sssd/sssd.conf` and restart `sssd`.
+- **Remote Execution**: Execute raw bash scripts.
+- **Self-Update**: Securely download, verify (SHA256), and apply a new binary version.
 
 ## The Security Model (Blast Radius & Zero-Trust)
 
-Because Theta Agent runs as `root` (required to configure `/etc/sssd/sssd.conf`, restart services, and read hardware sensors), it represents a high-value target. If the central SSO Manager were compromised, a naive agent would allow an attacker to gain root shell execution on every server in the fleet.
+Because Theta Agent runs as `root`, it is a high-value target. To prevent lateral movement and contain the blast radius, it operates on a **strict, local-first capability matrix**.
 
-To prevent lateral movement and contain the blast radius, **Theta Agent operates on a strict, local-first capability matrix.**
+### Local Configuration Wins
+The agent will **only** execute commands that are explicitly enabled in its local configuration file (`/etc/theta42/agent.yml`). The central SSO Manager cannot override these settings.
 
-### 1. Local Configuration Wins
+### Cryptographic Hardening
-The agent will **only** execute commands that are explicitly enabled in its local configuration file (`/etc/theta/agent.yml`). 
+All high-risk commands require an Ed25519 signature. The agent verifies the signature against the `public_key` provided in the local config. If the signature is missing or invalid, the command is rejected regardless of the capability matrix.
-- By default, the agent is locked down to read-only telemetry and basic LDAP configuration.
-- The central SSO Manager cannot override these settings. An administrator must physically (or via local config management) edit the local `agent.yml` file to grant the agent more permissions.
 
-### 2. The Capability Matrix
+### Capability Matrix
-Capabilities are segmented into modules. You only enable what a specific server needs:
 
-| Capability | Risk Level | Description |
+| Capability | Risk Level | Description | Impact |
-|------------|------------|-------------|
+|------------|------------|-------------|---------|
-| `telemetry` | Safe | Read-only. Pushes system metrics back to the SSO Manager. |
+| `telemetry` | Safe | Read-only metrics. | Pushes system health to SSO Manager. |
-| `configure_ldap` | Moderate | Allows the SSO manager to push down an updated SSSD configuration file. |
+| `configure_ldap` | Moderate | Configures SSSD. | Updates `/etc/sssd/sssd.conf` and restarts `sssd`. |
-| `reboot` | High | Allows the SSO Manager to trigger a system reboot. |
+| `reboot` | High | System reboot. | Triggers an immediate host reboot. |
-| `service_control` | High | Allows starting/stopping/restarting systemd services. **Must be scoped** to specific services (e.g., `['gitea', 'nginx']`). |
+| `service_control` | High | Service management. | Restarts services listed in the allowed list. |
-| `arbitrary_bash` | CRITICAL | Allows the execution of raw bash scripts sent from the SSO Manager. Useful for GitOps deployments on worker nodes, but highly dangerous. |
+| `arbitrary_bash` | CRITICAL | Raw bash execution. | Executes any script sent by the manager as root. |
 
-### 3. Outbound-Only Communication
+## Configuration
-The agent does not open any listening ports on the host firewall. It uses a long-lived outbound WebSocket connection to the SSO Manager. 
 
-### 4. Cryptographic Authentication
+Configuration is stored in YAML format at `/etc/theta42/agent.yml`.
-Every agent is issued a unique, long-lived host token during installation. The SSO Manager verifies this token to ensure commands are only routed to the intended host, and telemetry is properly attributed.
 
-## Example Configuration
+### Example `agent.yml`
-
+```yaml
-See `agent.yml.example` for a secure baseline configuration.
+server_url: "wss://sso.theta42.local"
+auth_token: "your-unique-host-token"
+public_key: "base64-encoded-ed25519-public-key"
+location: "dc-01-rack-12"
+capabilities:
+  telemetry: true
+  configure_ldap: true
+  reboot: true
+  service_control: ["nginx", "gitea", "sssd"]
+  arbitrary_bash: false
+```
 
 ## Installation
 
-*(Coming soon: Build instructions and `theta-agent install` guide)*
+1. **Build**: Compile for your target architecture (see CI/CD artifacts).
+2. **Deploy**: Place the binary in `/usr/local/bin/theta-agent`.
+3. **Configure**: Create `/etc/theta42/agent.yml` with the required token and capabilities.
+4. **Service**: Set up as a systemd unit (example: `/etc/systemd/system/theta-agent.service`).
+
+For the fastest deployment, use the installation script:
+```bash
+curl -fsSL https://sso.example.com/resources/theta-agent/install.sh | sh -s -- "BASE64_ENCODED_CONFIG"
+```
+
+## Development & Testing
+
+The agent uses a decoupled execution engine for safety and testability.
+- Run unit tests: `go test -v ./...`
+- The test suite uses a `MockExecutor` to verify that system commands are only triggered when the corresponding capability is enabled in the configuration.

agent.yml.example

@@ -1,5 +1,5 @@
 # theta-agent configuration file
-# Default location: /etc/theta/agent.yml
+# Default location: /etc/theta42/agent.yml
 
 server_url: "https://sso.example.com"
 auth_token: "REPLACE_WITH_AGENT_TOKEN"

config.go

@@ -3,6 +3,7 @@ package main
 import (
 	"fmt"
 	"os"
+	"sync"
 
 	"gopkg.in/yaml.v3"
 )
@@ -19,9 +20,47 @@ type Config struct {
 	ServerURL    string       `yaml:"server_url"`
 	AuthToken    string       `yaml:"auth_token"`
 	Location     string       `yaml:"location"`
+	PublicKey    string       `yaml:"public_key"` // Ed25519 public key for signed commands
 	Capabilities Capabilities `yaml:"capabilities"`
 }
 
+// ConfigManager handles thread-safe access and reloading of the agent configuration.
+type ConfigManager struct {
+	mu       sync.RWMutex
+	current  *Config
+	configPath string
+}
+
+func NewConfigManager(path string) (*ConfigManager, error) {
+	cfg, err := LoadConfig(path)
+	if err != nil {
+		return nil, err
+	}
+	return &ConfigManager{
+		current:    cfg,
+		configPath: path,
+	}, nil
+}
+
+// Get returns a copy of the current configuration.
+func (cm *ConfigManager) Get() *Config {
+	cm.mu.RLock()
+	defer cm.mu.RUnlock()
+	return cm.current
+}
+
+// Reload re-reads the configuration from disk and updates the active config.
+func (cm *ConfigManager) Reload() error {
+	cfg, err := LoadConfig(cm.configPath)
+	if err != nil {
+		return fmt.Errorf("reload failed: %w", err)
+	}
+	cm.mu.Lock()
+	cm.current = cfg
+	cm.mu.Unlock()
+	return nil
+}
+
 func LoadConfig(path string) (*Config, error) {
 	file, err := os.Open(path)
 	if err != nil {

config_test.go

@@ -0,0 +1,98 @@
+package main
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestLoadConfig(t *testing.T) {
+	// Create a temporary directory for config files
+	tmpDir, err := os.MkdirTemp("", "agent-config-test")
+	if err != nil {
+		t.Fatalf("failed to create temp dir: %v", err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	tests := []struct {
+		name        string
+		yamlContent string
+		filename    string
+		expectErr   bool
+	}{
+		{
+			name: "valid config",
+			yamlContent: `
+server_url: "http://sso.local"
+auth_token: "secret-token"
+location: "datacenter-1"
+capabilities:
+  telemetry: true
+  configure_ldap: true
+  reboot: false
+  service_control: ["nginx", "gitea"]
+  arbitrary_bash: false
+`,
+			filename:  "valid.yml",
+			expectErr: false,
+		},
+		{
+			name:        "invalid yaml",
+			yamlContent: "invalid: [yaml: content",
+			filename:    "invalid.yml",
+			expectErr:   true,
+		},
+		{
+			name:        "missing file",
+			yamlContent: "",
+			filename:    "nonexistent.yml",
+			expectErr:   true,
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			path := filepath.Join(tmpDir, tc.filename)
+			if tc.yamlContent != "" {
+				err := os.WriteFile(path, []byte(tc.yamlContent), 0644)
+				if err != nil {
+					t.Fatalf("failed to write temp file: %v", err)
+				}
+			}
+
+			cfg, err := LoadConfig(path)
+			if (err != nil) != tc.expectErr {
+				t.Errorf("LoadConfig() error = %v, expectErr %v", err, tc.expectErr)
+				return
+			}
+
+			if !tc.expectErr && cfg == nil {
+				t.Error("LoadConfig() returned nil config without error")
+			}
+		})
+	}
+}
+
+func TestCanManageService(t *testing.T) {
+	caps := Capabilities{
+		ServiceControl: []string{"nginx", "gitea"},
+	}
+
+	tests := []struct {
+		service  string
+		expected bool
+	}{
+		{"nginx", true},
+		{"gitea", true},
+		{"ssh", false},
+		{"", false},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.service, func(t *testing.T) {
+			if got := caps.CanManageService(tc.service); got != tc.expected {
+				t.Errorf("CanManageService(%q) = %v, want %v", tc.service, got, tc.expected)
+			}
+		})
+	}
+}

docker-compose.yml

@@ -0,0 +1,11 @@
+version: '3.8'
+services:
+  theta-agent:
+    build:
+      context: .
+    container_name: theta-agent-test
+    volumes:
+      - ./agent.yml.example:/etc/theta42/agent.yml:ro
+    privileged: true # Required for systemctl and root operations
+    network_mode: "host"
+    restart: always

executor.go

@@ -0,0 +1,37 @@
+package main
+
+import (
+	"os"
+	"os/exec"
+)
+
+// Executor abstracts system operations to allow for easy mocking in tests.
+type Executor interface {
+	// Execute runs a system command and returns combined stdout/stderr.
+	Execute(command string, args ...string) ([]byte, error)
+
+	// WriteFile writes data to a file with specified permissions.
+	WriteFile(path string, data []byte, perm os.FileMode) error
+
+	// ReadFile reads the content of a file.
+	ReadFile(path string) ([]byte, error)
+}
+
+// SystemExecutor is the production implementation that performs real system calls.
+type SystemExecutor struct{}
+
+// Execute runs a real system command.
+func (s *SystemExecutor) Execute(command string, args ...string) ([]byte, error) {
+	cmd := exec.Command(command, args...)
+	return cmd.CombinedOutput()
+}
+
+// WriteFile performs a real file write.
+func (s *SystemExecutor) WriteFile(path string, data []byte, perm os.FileMode) error {
+	return os.WriteFile(path, data, perm)
+}
+
+// ReadFile performs a real file read.
+func (s *SystemExecutor) ReadFile(path string) ([]byte, error) {
+	return os.ReadFile(path)
+}

go.mod

@@ -3,6 +3,15 @@ module github.com/theta42/theta-agent
 go 1.22.2
 
 require (
+	github.com/go-ole/go-ole v1.2.6 // indirect
 	github.com/gorilla/websocket v1.5.3 // indirect
+	github.com/lufia/plan9stats v0.0.0-20211012122336-39d0f177ccd0 // indirect
+	github.com/power-devops/perfstat v0.0.0-20210106213030-5aafc221ea8c // indirect
+	github.com/shirou/gopsutil/v3 v3.24.5 // indirect
+	github.com/shoenig/go-m1cpu v0.1.6 // indirect
+	github.com/tklauser/go-sysconf v0.3.12 // indirect
+	github.com/tklauser/numcpus v0.6.1 // indirect
+	github.com/yusufpapurcu/wmi v1.2.4 // indirect
+	golang.org/x/sys v0.20.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -1,5 +1,29 @@
+github.com/go-ole/go-ole v1.2.6 h1:/Fpf6oFPoeFik9ty7siob0G6Ke8QvQEuVcuChpwXzpY=
+github.com/go-ole/go-ole v1.2.6/go.mod h1:pprOEPIfldk/42T2oK7lQ4v4JSDwmV0As9GaiUsvbm0=
+github.com/google/go-cmp v0.5.6/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/gorilla/websocket v1.5.3 h1:saDtZ6Pbx/0u+bgYQ3q96pZgCzfhKXGPqt7kZ72aNNg=
 github.com/gorilla/websocket v1.5.3/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
+github.com/lufia/plan9stats v0.0.0-20211012122336-39d0f177ccd0 h1:6E+4a0GO5zZEnZ81pIr0yLvtUWk2if982qA3F3QD6H4=
+github.com/lufia/plan9stats v0.0.0-20211012122336-39d0f177ccd0/go.mod h1:zJYVVT2jmtg6P3p1VtQj7WsuWi/y4VnjVBn7F8KPB3I=
+github.com/power-devops/perfstat v0.0.0-20210106213030-5aafc221ea8c h1:ncq/mPwQF4JjgDlrVEn3C11VoGHZN7m8qihwgMEtzYw=
+github.com/power-devops/perfstat v0.0.0-20210106213030-5aafc221ea8c/go.mod h1:OmDBASR4679mdNQnz2pUhc2G8CO2JrUAVFDRBDP/hJE=
+github.com/shirou/gopsutil/v3 v3.24.5 h1:i0t8kL+kQTvpAYToeuiVk3TgDeKOFioZO3Ztz/iZ9pI=
+github.com/shirou/gopsutil/v3 v3.24.5/go.mod h1:bsoOS1aStSs9ErQ1WWfxllSeS1K5D+U30r2NfcubMVk=
+github.com/shoenig/go-m1cpu v0.1.6 h1:nxdKQNcEB6vzgA2E2bvzKIYRuNj7XNJ4S/aRSwKzFtM=
+github.com/shoenig/go-m1cpu v0.1.6/go.mod h1:1JJMcUBvfNwpq05QDQVAnx3gUHr9IYF7GNg9SUEw2VQ=
+github.com/tklauser/go-sysconf v0.3.12 h1:0QaGUFOdQaIVdPgfITYzaTegZvdCjmYO52cSFAEVmqU=
+github.com/tklauser/go-sysconf v0.3.12/go.mod h1:Ho14jnntGE1fpdOqQEEaiKRpvIavV0hSfmBq8nJbHYI=
+github.com/tklauser/numcpus v0.6.1 h1:ng9scYS7az0Bk4OZLvrNXNSAO2Pxr1XXRAPyjhIx+Fk=
+github.com/tklauser/numcpus v0.6.1/go.mod h1:1XfjsgE2zo8GVw7POkMbHENHzVg3GzmoZ9fESEdAacY=
+github.com/yusufpapurcu/wmi v1.2.4 h1:zFUKzehAFReQwLys1b/iSMl+JQGSCSjtVqQn9bBrPo0=
+github.com/yusufpapurcu/wmi v1.2.4/go.mod h1:SBZ9tNy3G9/m5Oi98Zks0QjeHVDvuK0qfxQmPyzfmi0=
+golang.org/x/sys v0.0.0-20190916202348-b4ddaad3f8a3/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20201204225414-ed752295db88/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.8.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.11.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.20.0 h1:Od9JTbYCk261bKm4M/mw7AklTlFYIa0bIp9BgSm1S8Y=
+golang.org/x/sys v0.20.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

install.sh

@@ -0,0 +1,117 @@
+#!/bin/bash
+set -e
+
+# --- Configuration ---
+# In a real environment, these would be derived from the script's download URL
+# or passed as additional arguments. For now, we use the most recent release.
+BINARY_URL="https://github.com/theta42/theta-agent/releases/latest/download/theta-agent-linux-amd64"
+CONFIG_DIR="/etc/theta42"
+CONFIG_FILE="$CONFIG_DIR/agent.yml"
+BIN_PATH="/usr/local/bin/theta-agent"
+SERVICE_FILE="/etc/systemd/system/theta-agent.service"
+
+# Colors for output
+RED='\033[0;31m'
+GREEN='\033[0;32m'
+NC='\033[0m' # No Color
+
+log() { echo -e "${GREEN}[+]${NC} $1"; }
+error() { echo -e "${RED}[!]${NC} $1"; exit 1; }
+
+# 1. Root check
+if [ "$EUID" -ne 0 ]; then
+  error "This script must be run as root."
+fi
+
+# 2. Argument Parsing
+URL=""
+TOKEN=""
+B64_CONFIG=""
+
+while [[ $# -gt 0 ]]; do
+  case $1 in
+    --url)
+      URL="$2"
+      shift 2
+      ;;
+    --token)
+      TOKEN="$2"
+      shift 2
+      ;;
+    *)
+      B64_CONFIG="$1"
+      shift
+      ;;
+  esac
+done
+
+# Validation
+if [ -z "$B64_CONFIG" ] && [ -z "$URL" ] || [ -z "$B64_CONFIG" ] && [ -z "$TOKEN" ]; then
+  error "Missing required configuration. Either provide a base64 encoded config, or both --url and --token."
+  echo "Usage examples:"
+  echo "  sh install.sh \"BASE64_CONFIG\""
+  echo "  sh install.sh --url \"https://sso.local\" --token \"secret-token\""
+  exit 1
+fi
+
+log "Starting Theta Agent installation..."
+
+# 3. Install binary
+log "Downloading binary from $BINARY_URL..."
+curl -fsSL "$BINARY_URL" -o "$BIN_PATH" || error "Failed to download binary."
+chmod +x "$BIN_PATH"
+
+# 4. Setup configuration
+log "Preparing configuration directory $CONFIG_DIR..."
+mkdir -p "$CONFIG_DIR"
+chmod 755 "$CONFIG_DIR"
+
+if [ -n "$B64_CONFIG" ]; then
+  log "Decoding and writing configuration from base64..."
+  echo "$B64_CONFIG" | base64 -d > "$CONFIG_FILE" || error "Failed to decode base64 configuration."
+else
+  log "Generating minimal configuration from arguments..."
+  # Create a minimal yaml with the provided URL and Token
+  cat <<EOF > "$CONFIG_FILE"
+server_url: "$URL"
+auth_token: "$TOKEN"
+location: "unknown"
+capabilities:
+  telemetry: true
+  configure_ldap: false
+  reboot: false
+  service_control: []
+  arbitrary_bash: false
+EOF
+fi
+chmod 600 "$CONFIG_FILE"
+
+# 5. Setup systemd service
+log "Creating systemd service unit..."
+cat <<EOF > "$SERVICE_FILE"
+[Unit]
+Description=Theta Agent Unified Endpoint Management
+After=network.target
+
+[Service]
+Type=simple
+ExecStart=$BIN_PATH
+Restart=always
+RestartSec=5
+StandardOutput=syslog
+StandardError=syslog
+SyslogIdentifier=theta-agent
+
+[Install]
+WantedBy=multi-user.target
+EOF
+
+# 6. Start the agent
+log "Enabling and starting Theta Agent..."
+systemctl daemon-reload
+systemctl enable theta-agent
+systemctl start theta-agent
+
+log "Theta Agent installation complete!"
+log "Verify status with: systemctl status theta-agent"
+log "Check logs with: journalctl -u theta-agent -f"

main.go

@@ -12,26 +12,30 @@ func main() {
 	log.Println("Starting Theta Agent...")
 
 	// Attempt to load configuration
-	configPath := "/etc/theta/agent.yml"
+	configPath := "/etc/theta42/agent.yml"
 	if len(os.Args) > 1 {
 		configPath = os.Args[1]
 	}
 
-	cfg, err := LoadConfig(configPath)
+	cm, err := NewConfigManager(configPath)
 	if err != nil {
 		log.Fatalf("Error loading configuration from %s: %v", configPath, err)
 	}
+	cfg := cm.Get()
 
 	log.Printf("Connecting to SSO Manager at %s", cfg.ServerURL)
-	log.Printf("Loaded capabilities: Telemetry=%v, LDAP=%v, Reboot=%v, Bash=%v", 
+	log.Printf("Loaded capabilities: Telemetry=%v, LDAP=%v, Reboot=%v, Bash=%v",
-		cfg.Capabilities.Telemetry, 
+		cfg.Capabilities.Telemetry,
-		cfg.Capabilities.ConfigureLDAP, 
+		cfg.Capabilities.ConfigureLDAP,
-		cfg.Capabilities.Reboot, 
+		cfg.Capabilities.Reboot,
 		cfg.Capabilities.ArbitraryBash,
 	)
 
+	// Initialize system executor
+	exec := &SystemExecutor{}
+
 	// WebSocket connection to SSO Manager
-	go connectWebSocket(cfg)
+	go connectWebSocket(cm, exec)
 
 	// Block until signal is received
 	sigs := make(chan os.Signal, 1)

telemetry.go

@@ -0,0 +1,216 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"log"
+	"net"
+	"strings"
+	"time"
+
+	"github.com/gorilla/websocket"
+	"github.com/shirou/gopsutil/v3/cpu"
+	"github.com/shirou/gopsutil/v3/disk"
+	"github.com/shirou/gopsutil/v3/host"
+	"github.com/shirou/gopsutil/v3/mem"
+)
+
+type DiscoveryData struct {
+	Hostname    string   `json:"hostname"`
+	IPs        []string `json:"ip_addresses"`
+	OS          string   `json:"os"`
+	Kernel      string   `json:"kernel"`
+	CPUModel    string   `json:"cpu"`
+	RAMTotalGB  float64  `json:"ram_total_gb"`
+	DiskTotalGB float64  `json:"disk_total_gb"`
+	Location    string   `json:"location"`
+}
+
+type TelemetryData struct {
+	CPUUsagePercent float64 `json:"cpu_usage_percent"`
+	RAMUsagePercent float64 `json:"ram_usage_percent"`
+	DiskUsagePercent float64 `json:"disk_usage_percent"`
+	ZFSHealth       string  `json:"zfs_health,omitempty"`
+	GPUUsage        float64  `json:"gpu_usage_percent,omitempty"`
+	Timestamp       string  `json:"timestamp"`
+}
+
+// CollectDiscoveryData gathers static host information.
+func CollectDiscoveryData(cfg *Config) DiscoveryData {
+	h, _ := host.Info()
+
+	var ips []string
+	addrs, _ := net.InterfaceAddrs()
+	for _, addr := range addrs {
+		if ipnet, ok := addr.(*net.IPNet); ok && !ipnet.IP.IsLoopback() {
+			if ipnet.IP.To4() != nil {
+				ips = append(ips, ipnet.IP.String())
+			}
+		}
+	}
+
+	vm, _ := mem.VirtualMemory()
+	d, _ := disk.Usage("/")
+
+	cpuInfo, _ := cpu.Info()
+	cpuModel := "Unknown"
+	if len(cpuInfo) > 0 {
+		cpuModel = cpuInfo[0].Model
+	}
+
+	return DiscoveryData{
+		Hostname:    h.Hostname,
+		IPs:         ips,
+		OS:          fmt.Sprintf("%s %s", h.OS, h.Platform),
+		Kernel:      h.KernelVersion,
+		CPUModel:    cpuModel,
+		RAMTotalGB:  float64(vm.Total) / (1024 * 1024 * 1024),
+		DiskTotalGB: float64(d.Total) / (1024 * 1024 * 1024),
+		Location:    cfg.Location,
+	}
+}
+
+// CollectTelemetryData gathers real-time performance metrics including ZFS and GPU.
+func CollectTelemetryData(exec Executor) TelemetryData {
+	cpuPerc, _ := cpu.Percent(time.Second, false)
+	vm, _ := mem.VirtualMemory()
+	d, _ := disk.Usage("/")
+
+	cpuVal := 0.0
+	if len(cpuPerc) > 0 {
+		cpuVal = cpuPerc[0]
+	}
+
+	return TelemetryData{
+		CPUUsagePercent:  cpuVal,
+		RAMUsagePercent:  vm.UsedPercent,
+		DiskUsagePercent: d.UsedPercent,
+		ZFSHealth:       collectZFSHealth(exec),
+		GPUUsage:        collectGPUUsage(exec),
+		Timestamp:       time.Now().Format(time.RFC3339),
+	}
+}
+
+func collectZFSHealth(exec Executor) string {
+	out, err := exec.Execute("zpool", "list", "-H", "-o", "health")
+	if err != nil {
+		return "unknown"
+	}
+	lines := strings.Split(strings.TrimSpace(string(out)), "\n")
+	if len(lines) > 0 {
+		return lines[0]
+	}
+	return "unknown"
+}
+
+func collectGPUUsage(exec Executor) float64 {
+	out, err := exec.Execute("nvidia-smi", "--query-gpu=utilization.gpu", "--format=csv,noheader,nounits")
+	if err != nil {
+		return -1.0
+	}
+	var usage float64
+	fmt.Sscanf(strings.TrimSpace(string(out)), "%f", &usage)
+	return usage
+}
+
+// StartTelemetryLoop manages the initial discovery push and the periodic telemetry stream.
+func StartTelemetryLoop(c MessageWriter, cm *ConfigManager, exec Executor, stopCh <-chan struct{}) {
+	cfg := cm.Get()
+
+	// 1. Immediate Discovery Push
+	pushDiscovery(c, cfg)
+
+	// If telemetry capability is disabled in agent.yml, return early after discovery
+	if !cfg.Capabilities.Telemetry {
+		log.Println("Telemetry capability is disabled in agent.yml; skipping telemetry stream.")
+		return
+	}
+
+	// 2. Periodic Telemetry Stream
+	ticker := time.NewTicker(30 * time.Second)
+	go func() {
+		defer ticker.Stop()
+		var lastIPs []string
+		for {
+			select {
+			case <-stopCh:
+				return
+			case <-ticker.C:
+				currentCFG := cm.Get()
+				if !currentCFG.Capabilities.Telemetry {
+					continue
+				}
+
+				// Network Change Detection
+				currentIPs := collectIPs()
+				if !equalSlices(lastIPs, currentIPs) {
+					log.Println("Network change detected. Pushing discovery update...")
+					pushDiscovery(c, currentCFG)
+					lastIPs = currentIPs
+				}
+
+				telemetry := CollectTelemetryData(exec)
+				payload, _ := json.Marshal(WSMessage{
+					Type: "telemetry",
+					Payload: map[string]interface{}{
+						"cpu_usage_percent":  telemetry.CPUUsagePercent,
+						"ram_usage_percent":  telemetry.RAMUsagePercent,
+						"disk_usage_percent": telemetry.DiskUsagePercent,
+						"zfs_health":         telemetry.ZFSHealth,
+						"gpu_usage_percent":   telemetry.GPUUsage,
+						"timestamp":          telemetry.Timestamp,
+					},
+				})
+				if err := c.WriteMessage(websocket.TextMessage, payload); err != nil {
+					log.Printf("Failed to stream telemetry: %v", err)
+					return
+				}
+			}
+		}
+	}()
+}
+
+func collectIPs() []string {
+	var ips []string
+	addrs, _ := net.InterfaceAddrs()
+	for _, addr := range addrs {
+		if ipnet, ok := addr.(*net.IPNet); ok && !ipnet.IP.IsLoopback() {
+			if ipnet.IP.To4() != nil {
+				ips = append(ips, ipnet.IP.String())
+			}
+		}
+	}
+	return ips
+}
+
+func equalSlices(a, b []string) bool {
+	if len(a) != len(b) {
+		return false
+	}
+	for i := range a {
+		if a[i] != b[i] {
+			return false
+		}
+	}
+	return true
+}
+
+func pushDiscovery(c MessageWriter, cfg *Config) {
+	discovery := CollectDiscoveryData(cfg)
+	discoveryPayload, _ := json.Marshal(discovery)
+
+	var discoveryMap map[string]interface{}
+	json.Unmarshal(discoveryPayload, &discoveryMap)
+
+	msg := WSMessage{
+		Type:    "discovery",
+		Payload: discoveryMap,
+	}
+
+	payload, _ := json.Marshal(msg)
+	if err := c.WriteMessage(websocket.TextMessage, payload); err != nil {
+		log.Printf("Failed to send discovery data: %v", err)
+	} else {
+		log.Println("Discovery data pushed to SSO Manager.")
+	}
+}

websocket.go

@@ -1,9 +1,17 @@
 package main
 
 import (
+	"crypto/ed25519"
+	"crypto/sha256"
+	"encoding/base64"
 	"encoding/json"
+	"fmt"
+	"io"
 	"log"
+	"net/http"
 	"net/url"
+	"os"
+	"path/filepath"
 	"strings"
 	"time"
 
@@ -15,8 +23,49 @@ type WSMessage struct {
 	Payload map[string]interface{} `json:"payload"`
 }
 
-func connectWebSocket(cfg *Config) {
+type MessageWriter interface {
+	WriteMessage(messageType int, data []byte) error
+}
+
+func verifySignature(cfg *Config, msg WSMessage) bool {
+	if cfg.PublicKey == "" {
+		log.Println("No public key configured; skipping signature verification")
+		return true
+	}
+
+	sigB64, ok := msg.Payload["signature"].(string)
+	if !ok {
+		log.Println("High-risk command missing signature")
+		return false
+	}
+
+	sig, err := base64.StdEncoding.DecodeString(sigB64)
+	if err != nil {
+		log.Printf("Invalid base64 signature: %v", err)
+		return false
+	}
+
+	// Create canonical payload for verification (remove signature key)
+	payloadCopy := make(map[string]interface{})
+	for k, v := range msg.Payload {
+		if k != "signature" {
+			payloadCopy[k] = v
+		}
+	}
+	canonicalPayload, _ := json.Marshal(payloadCopy)
+
+	pubKeyBytes, err := base64.StdEncoding.DecodeString(cfg.PublicKey)
+	if err != nil || len(pubKeyBytes) != ed25519.PublicKeySize {
+		log.Printf("Invalid public key in config: %v", err)
+		return false
+	}
+
+	return ed25519.Verify(pubKeyBytes, canonicalPayload, sig)
+}
+
+func connectWebSocket(cm *ConfigManager, exec Executor) {
 	for {
+		cfg := cm.Get()
 		// Ensure protocol is ws/wss
 		serverURL := strings.Replace(cfg.ServerURL, "http://", "ws://", 1)
 		serverURL = strings.Replace(serverURL, "https://", "wss://", 1)
@@ -39,12 +88,28 @@ func connectWebSocket(cfg *Config) {
 
 		log.Println("Successfully connected to SSO Manager.")
 
-		// Start telemetry if enabled
+		stopCh := make(chan struct{})
-		var telemetryTicker *time.Ticker
+
-		var telemetryDone chan bool
+		// Start telemetry and discovery with stopCh lifecycle control
-		if cfg.Capabilities.Telemetry {
+		StartTelemetryLoop(c, cm, exec, stopCh)
-			telemetryTicker, telemetryDone = startTelemetry(c, cfg)
+
-		}
+		// Heartbeat loop
+		go func() {
+			ticker := time.NewTicker(60 * time.Second)
+			defer ticker.Stop()
+			for {
+				select {
+				case <-stopCh:
+					return
+				case <-ticker.C:
+					hb := WSMessage{Type: "heartbeat", Payload: map[string]interface{}{"timestamp": time.Now().Format(time.RFC3339)}}
+					payload, _ := json.Marshal(hb)
+					if err := c.WriteMessage(websocket.TextMessage, payload); err != nil {
+						return
+					}
+				}
+			}
+		}()
 
 		// Read loop
 		for {
@@ -60,48 +125,247 @@ func connectWebSocket(cfg *Config) {
 				continue
 			}
 
-			handleCommand(cfg, msg, c)
+			handleCommand(cm, msg, c, exec)
 		}
 
 		// Cleanup on disconnect
+		close(stopCh)
 		c.Close()
-		if telemetryTicker != nil {
-			telemetryTicker.Stop()
-			telemetryDone <- true
-		}
 
 		log.Println("WebSocket disconnected. Reconnecting in 5 seconds...")
 		time.Sleep(5 * time.Second)
 	}
 }
 
-func handleCommand(cfg *Config, msg WSMessage, c *websocket.Conn) {
+func handleCommand(cm *ConfigManager, msg WSMessage, c MessageWriter, exec Executor) {
+	cfg := cm.Get()
 	log.Printf("Received command: %s", msg.Type)
 
+	sendResponse := func(status string, message string) {
+		resp, _ := json.Marshal(map[string]string{"status": status, "message": message})
+		c.WriteMessage(websocket.TextMessage, resp)
+	}
+
 	switch msg.Type {
-	case "config":
+	case "reload_config":
-		log.Printf("Received config payload: %v", msg.Payload)
+		if err := cm.Reload(); err != nil {
-	case "reboot":
+			log.Printf("Reload failed: %v", err)
-		if !cfg.Capabilities.Reboot {
+			sendResponse("error", "failed to reload config")
-			log.Println("Reboot rejected: capability disabled in agent.yml")
+		} else {
+			log.Println("Configuration reloaded successfully.")
+			sendResponse("ok", "configuration reloaded")
+		}
+	case "fetch_logs":
+		serviceName, _ := msg.Payload["service"].(string)
+		if serviceName == "" {
+			serviceName = "theta-agent"
+		}
+
+		if serviceName != "theta-agent" && !cfg.Capabilities.CanManageService(serviceName) {
+			log.Printf("Fetch logs rejected for '%s': not in allowed service list", serviceName)
+			sendResponse("error", "service log fetch rejected")
 			return
 		}
-		log.Println("Reboot capability enabled. (Simulation: rebooting system...)")
+
+		linesCount := 100
+		if l, ok := msg.Payload["lines"].(float64); ok && l > 0 {
+			linesCount = int(l)
+		}
+
+		log.Printf("Fetching logs for service %s (%d lines)...", serviceName, linesCount)
+		out, err := exec.Execute("journalctl", "-u", serviceName, "-n", fmt.Sprintf("%d", linesCount), "--no-pager")
+		if err != nil {
+			log.Printf("Log fetch failed: %v", err)
+			sendResponse("error", "failed to fetch logs")
+			return
+		}
+		resp := map[string]interface{}{
+			"status":  "ok",
+			"service": serviceName,
+			"logs":    string(out),
+		}
+		respPayload, _ := json.Marshal(resp)
+		c.WriteMessage(websocket.TextMessage, respPayload)
+		return
+	case "update_binary":
+		if !verifySignature(cfg, msg) {
+			sendResponse("error", "signature verification failed")
+			return
+		}
+		if !cfg.Capabilities.ArbitraryBash {
+			sendResponse("error", "update capability disabled")
+			return
+		}
+
+		urlStr, _ := msg.Payload["url"].(string)
+		checksum, _ := msg.Payload["sha256"].(string)
+		if urlStr == "" || checksum == "" {
+			sendResponse("error", "missing url or sha256 checksum")
+			return
+		}
+
+		log.Printf("Updating binary from %s...", urlStr)
+		if err := downloadAndUpdateBinary(urlStr, checksum); err != nil {
+			log.Printf("Update failed: %v", err)
+			sendResponse("error", fmt.Sprintf("update failed: %v", err))
+			return
+		}
+		sendResponse("ok", "update applied successfully; restarting agent...")
+		os.Exit(0)
+	case "config":
+		log.Printf("Received config payload: %v", msg.Payload)
+		sendResponse("ok", "Configuration received")
+	case "reboot":
+		if !verifySignature(cfg, msg) {
+			sendResponse("error", "signature verification failed")
+			return
+		}
+		if !cfg.Capabilities.Reboot {
+			log.Println("Reboot rejected: capability disabled in agent.yml")
+			sendResponse("error", "reboot capability disabled")
+			return
+		}
+		log.Printf("Executing reboot...")
+		if _, err := exec.Execute("reboot"); err != nil {
+			log.Printf("Reboot failed: %v", err)
+			sendResponse("error", "reboot failed")
+			return
+		}
+		sendResponse("ok", "system rebooting")
 	case "service_restart":
 		serviceName, ok := msg.Payload["service"].(string)
 		if !ok || !cfg.Capabilities.CanManageService(serviceName) {
 			log.Printf("Service restart rejected for '%s': not in allowed service list", serviceName)
+			sendResponse("error", "service restart rejected")
 			return
 		}
 		log.Printf("Restarting service %s...", serviceName)
+		if _, err := exec.Execute("systemctl", "restart", serviceName); err != nil {
+			log.Printf("Service restart failed: %v", err)
+			sendResponse("error", "restart failed")
+			return
+		}
+		sendResponse("ok", "service restarted")
+	case "configure_ldap":
+		if !verifySignature(cfg, msg) {
+			sendResponse("error", "signature verification failed")
+			return
+		}
+		if !cfg.Capabilities.ConfigureLDAP {
+			log.Println("LDAP config rejected: capability disabled in agent.yml")
+			sendResponse("error", "LDAP config disabled")
+			return
+		}
+
+		configData, ok := msg.Payload["config"].(string)
+		if !ok {
+			log.Println("LDAP config payload missing or not a string")
+			sendResponse("error", "invalid config payload")
+			return
+		}
+
+		log.Println("Pushing updated SSSD configuration...")
+		if err := exec.WriteFile("/etc/sssd/sssd.conf", []byte(configData), 0600); err != nil {
+			log.Printf("Failed to write SSSD config: %v", err)
+			sendResponse("error", "failed to write config")
+			return
+		}
+
+		log.Println("Restarting SSSD service...")
+		if _, err := exec.Execute("systemctl", "restart", "sssd"); err != nil {
+			log.Printf("SSSD restart failed: %v", err)
+			sendResponse("error", "failed to restart sssd")
+			return
+		}
+		sendResponse("ok", "LDAP configuration updated")
+	case "arbitrary_bash":
+		if !verifySignature(cfg, msg) {
+			sendResponse("error", "signature verification failed")
+			return
+		}
+		if !cfg.Capabilities.ArbitraryBash {
+			log.Println("Bash execution rejected: capability disabled in agent.yml")
+			sendResponse("error", "bash execution disabled")
+			return
+		}
+
+		script, ok := msg.Payload["script"].(string)
+		if !ok {
+			log.Println("Bash payload missing or not a string")
+			sendResponse("error", "invalid script payload")
+			return
+		}
+
+		log.Printf("Executing remote script: %s", script)
+		out, err := exec.Execute("bash", "-c", script)
+		if err != nil {
+			log.Printf("Script execution failed: %v", err)
+			sendResponse("error", fmt.Sprintf("execution failed: %v", err))
+			return
+		}
+
+		resp := map[string]string{
+			"status": "ok",
+			"output": string(out),
+		}
+		respPayload, _ := json.Marshal(resp)
+		c.WriteMessage(websocket.TextMessage, respPayload)
+		return
 	default:
 		log.Printf("Unknown command type: %s", msg.Type)
+		sendResponse("error", "unknown command type")
 	}
 }
 
-func startTelemetry(c *websocket.Conn, cfg *Config) (*time.Ticker, chan bool) {
+func downloadAndUpdateBinary(downloadURL string, expectedSHA256 string) error {
-	ticker := time.Ticker{C: nil} // placeholder logic
+	resp, err := http.Get(downloadURL)
-	done := make(chan bool)
+	if err != nil {
-	log.Println("Telemetry loop started (placeholder).")
+		return fmt.Errorf("http fetch failed: %w", err)
-	return &ticker, done
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("unexpected http status: %s", resp.Status)
+	}
+
+	tmpFile, err := os.CreateTemp("", "theta-agent-update-*")
+	if err != nil {
+		return fmt.Errorf("failed to create temp file: %w", err)
+	}
+	tmpPath := tmpFile.Name()
+	defer os.Remove(tmpPath)
+
+	hasher := sha256.New()
+	writer := io.MultiWriter(tmpFile, hasher)
+
+	if _, err := io.Copy(writer, resp.Body); err != nil {
+		tmpFile.Close()
+		return fmt.Errorf("failed to save binary: %w", err)
+	}
+	tmpFile.Close()
+
+	actualSHA256 := fmt.Sprintf("%x", hasher.Sum(nil))
+	if !strings.EqualFold(actualSHA256, strings.TrimSpace(expectedSHA256)) {
+		return fmt.Errorf("sha256 mismatch: expected %s, got %s", expectedSHA256, actualSHA256)
+	}
+
+	if err := os.Chmod(tmpPath, 0755); err != nil {
+		return fmt.Errorf("failed to set executable permissions: %w", err)
+	}
+
+	selfPath, err := os.Executable()
+	if err != nil {
+		return fmt.Errorf("failed to resolve current binary path: %w", err)
+	}
+
+	resolvedPath, err := filepath.EvalSymlinks(selfPath)
+	if err == nil {
+		selfPath = resolvedPath
+	}
+
+	if err := os.Rename(tmpPath, selfPath); err != nil {
+		return fmt.Errorf("failed to replace binary: %w", err)
+	}
+
+	return nil
 }

websocket_test.go

@@ -0,0 +1,238 @@
+package main
+
+import (
+	"encoding/json"
+	"os"
+	"testing"
+)
+
+type MockConn struct {
+	Messages [][]byte
+}
+
+func (m *MockConn) WriteMessage(messageType int, data []byte) error {
+	m.Messages = append(m.Messages, data)
+	return nil
+}
+
+type MockExecutor struct {
+	ExecutedCommands [][]string
+	WrittenFiles     map[string][]byte
+}
+
+func (m *MockExecutor) Execute(command string, args ...string) ([]byte, error) {
+	m.ExecutedCommands = append(m.ExecutedCommands, append([]string{command}, args...))
+	return []byte("mock output"), nil
+}
+
+func (m *MockExecutor) WriteFile(path string, data []byte, perm os.FileMode) error {
+	if m.WrittenFiles == nil {
+		m.WrittenFiles = make(map[string][]byte)
+	}
+	m.WrittenFiles[path] = data
+	return nil
+}
+
+func (m *MockExecutor) ReadFile(path string) ([]byte, error) {
+	if m.WrittenFiles != nil {
+		if data, ok := m.WrittenFiles[path]; ok {
+			return data, nil
+		}
+	}
+	return []byte("mock file content"), nil
+}
+
+func TestHandleCommand(t *testing.T) {
+	tests := []struct {
+		name            string
+		cfg             *Config
+		msg             WSMessage
+		expectedStatus  string
+		expectedCmd     []string
+		expectedFile    string
+		expectedFileCont string
+	}{
+		{
+			name: "config command success",
+			cfg: &Config{
+				Capabilities: Capabilities{},
+			},
+			msg: WSMessage{
+				Type:    "config",
+				Payload: map[string]interface{}{"key": "value"},
+			},
+			expectedStatus: "ok",
+		},
+		{
+			name: "reboot command allowed",
+			cfg: &Config{
+				Capabilities: Capabilities{Reboot: true},
+			},
+			msg: WSMessage{
+				Type: "reboot",
+			},
+			expectedStatus: "ok",
+			expectedCmd:    []string{"reboot"},
+		},
+		{
+			name: "reboot command denied",
+			cfg: &Config{
+				Capabilities: Capabilities{Reboot: false},
+			},
+			msg: WSMessage{
+				Type: "reboot",
+			},
+			expectedStatus: "error",
+			expectedCmd:    nil,
+		},
+		{
+			name: "service_restart allowed",
+			cfg: &Config{
+				Capabilities: Capabilities{
+					ServiceControl: []string{"nginx"},
+				},
+			},
+			msg: WSMessage{
+				Type: "service_restart",
+				Payload: map[string]interface{}{
+					"service": "nginx",
+				},
+			},
+			expectedStatus: "ok",
+			expectedCmd:    []string{"systemctl", "restart", "nginx"},
+		},
+		{
+			name: "service_restart denied",
+			cfg: &Config{
+				Capabilities: Capabilities{
+					ServiceControl: []string{"nginx"},
+				},
+			},
+			msg: WSMessage{
+				Type: "service_restart",
+				Payload: map[string]interface{}{
+					"service": "ssh",
+				},
+			},
+			expectedStatus: "error",
+			expectedCmd:    nil,
+		},
+		{
+			name: "configure_ldap allowed",
+			cfg: &Config{
+				Capabilities: Capabilities{ConfigureLDAP: true},
+			},
+			msg: WSMessage{
+				Type: "configure_ldap",
+				Payload: map[string]interface{}{
+					"config": "domain = theta42.local\nserver = sso.local",
+				},
+			},
+			expectedStatus:  "ok",
+			expectedFile:    "/etc/sssd/sssd.conf",
+			expectedFileCont: "domain = theta42.local\nserver = sso.local",
+			expectedCmd:     []string{"systemctl", "restart", "sssd"},
+		},
+		{
+			name: "configure_ldap denied",
+			cfg: &Config{
+				Capabilities: Capabilities{ConfigureLDAP: false},
+			},
+			msg: WSMessage{
+				Type: "configure_ldap",
+				Payload: map[string]interface{}{
+					"config": "domain = theta42.local",
+				},
+			},
+			expectedStatus: "error",
+			expectedCmd:    nil,
+		},
+		{
+			name: "arbitrary_bash allowed",
+			cfg: &Config{
+				Capabilities: Capabilities{ArbitraryBash: true},
+			},
+			msg: WSMessage{
+				Type: "arbitrary_bash",
+				Payload: map[string]interface{}{
+					"script": "uptime",
+				},
+			},
+			expectedStatus: "ok",
+			expectedCmd:    []string{"bash", "-c", "uptime"},
+		},
+		{
+			name: "arbitrary_bash denied",
+			cfg: &Config{
+				Capabilities: Capabilities{ArbitraryBash: false},
+			},
+			msg: WSMessage{
+				Type: "arbitrary_bash",
+				Payload: map[string]interface{}{
+					"script": "rm -rf /",
+				},
+			},
+			expectedStatus: "error",
+			expectedCmd:    nil,
+		},
+		{
+			name: "unknown command",
+			cfg: &Config{
+				Capabilities: Capabilities{},
+			},
+			msg: WSMessage{
+				Type: "mystery_command",
+			},
+			expectedStatus: "error",
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			mockConn := &MockConn{}
+			mockExec := &MockExecutor{}
+			cm := &ConfigManager{current: tc.cfg}
+			handleCommand(cm, tc.msg, mockConn, mockExec)
+
+			if len(mockConn.Messages) != 1 {
+				t.Fatalf("expected 1 response message, got %d", len(mockConn.Messages))
+			}
+
+			var resp map[string]string
+			if err := json.Unmarshal(mockConn.Messages[0], &resp); err != nil {
+				t.Fatalf("failed to unmarshal response: %v", err)
+			}
+
+			if resp["status"] != tc.expectedStatus {
+				t.Errorf("expected status %q, got %q", tc.expectedStatus, resp["status"])
+			}
+
+			if tc.expectedCmd != nil {
+				if len(mockExec.ExecutedCommands) == 0 {
+					t.Errorf("expected command to be executed, but none were")
+				} else {
+					cmd := mockExec.ExecutedCommands[0]
+					if len(cmd) != len(tc.expectedCmd) {
+						t.Errorf("expected command length %d, got %d", len(tc.expectedCmd), len(cmd))
+					}
+					for i := range cmd {
+						if cmd[i] != tc.expectedCmd[i] {
+							t.Errorf("expected arg %d = %q, got %q", i, tc.expectedCmd[i], cmd[i])
+						}
+					}
+				}
+			} else if len(mockExec.ExecutedCommands) > 0 {
+				t.Errorf("expected no commands to be executed, but got %v", mockExec.ExecutedCommands)
+			}
+
+			if tc.expectedFile != "" {
+				content, ok := mockExec.WrittenFiles[tc.expectedFile]
+				if !ok {
+					t.Errorf("expected file %q to be written, but it wasn't", tc.expectedFile)
+				} else if string(content) != tc.expectedFileCont {
+					t.Errorf("expected file content %q, got %q", tc.expectedFileCont, string(content))
+				}
+			}
+		})
+	}
+}