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hexd Daemon

hexd is a service designed to run continuously, capturing essential data such as audit logs, metrics, etc.
Once collected, the data is securely transmitted to HexDroid for analysis and monitoring.

Features​

SELinux Monitoring​

hexd daemon provides real-time monitoring of SELinux violations, helping you detect and respond to security events quickly. When violations occur, hexd automatically captures the details and transmits them to the HexDroid for in-depth analysis and reporting.

Enable SELinux monitoring with --selinux=1 parameter when starting the daemon.

For a complete feature overview on SELinux visit the SELinux Monitoring Overview.

Metrics​

hexd daemon offers system metric collection.

By enabling metrics collection with the --metrics=1 parameter, you can capture range of system indicators, such as:

  • CPU usage and load averages
  • Memory consumption and swap utilization
  • Network interface traffic and performance metrics

Refer to Built-in Metrics for an overview what metrics are captured.

For a complete metrics feature overview (including visualizations) refer to the Metrics Overview

Setup​

Prebuild (Linux & Android) Package​

Prebuild hexd binary is available for Linux and Android,

You can download the HexDroid CLI packaged binary from: https://github.com/HexDroidApp/hexd/releases

note

If provided prebuild package does not meet your specific environment or requirements, please contact our support team for assistance. support@hexdroid.com

Run it​

Basic usage​

./hexd --edgeKey=AABBCC --metrics=1 --selinux=1
tip

On Android to run a native binary (for testing purposes) from adb shell:

  • adb push PATH_TO_DOWNLOADED_HEXD /data/local/tmp/
  • adb shell
  • (Optional) su (if running a userdebug build)
  • chmod +x /data/local/tmp/hexd
  • /data/local/tmp/hexd --edgeKey=AABBCC --metrics=1 --selinux=1

Authentication​

The hexd daemon needs to communicate with the HexDroid service to upload metrics, events, and other data. To do so, authentication is required.

Authentication is performed with Edge API Keys.
You can issue new edge keys or view current ones under: Project -> Project Settings -> Edge API Keys

Example: ./hexd --edgeKey=AABBCC

Alternatively, pass the Edge Key as an environment variable: HEX_edgeKey=AABBCC ./hexd

Configuration​

Pass parameters as env​

All parameters can be passed as environment variables by adding the prefix HEX_.
For example, to enable metrics collection using an environment variable: HEX_metrics=1.

Production Deployment​

Linux​

On Linux systems hexd can be run with systemd service.

To do so, create a new systemd service:

sudoedit /etc/systemd/system/hexd.service

with the following content:

[Unit]
Description=HexDroid Monitoring Daemon
After=network.target

[Service]
Type=simple
Restart=always
RestartSec=5
Environment="HEX_edgeKey=AABBCC"
ExecStart=/etc/hexd/hexd --selinux=1 --metrics=1

[Install]
WantedBy=multi-user.target
note

In this example, hexd binary is expected to be at /etc/hexd/hexd path.
Feel free to change the binary path based on your requirements.

Save the file, then start the service with:

sudo systemctl start hexd

To make sure service runs after reboot, run:

sudo systemctl enable hexd

You can check the status of the service with:

sudo systemctl status hexd

And service's logs with:

journalctl -u hexd -f

Android​

service hexd /apex/com.example.app/bin/hexd
    class main
    user root
    group system
    setenv EXTERNAL_STORAGE /data/misc/apexdata/com.example.app