Harmony : Open Infrastructure Orchestration

Quick demo

cargo run -p example-tui

This will launch Harmony's minimalist terminal ui which embeds a few demo scores.

Usage instructions will be displayed at the bottom of the TUI.

cargo run --bin example-cli -- --help

This is the harmony CLI, a minimal implementation

The current help text:

Usage: example-cli [OPTIONS]

Options:
  -y, --yes              Run score(s) or not
  -f, --filter <FILTER>  Filter query
  -i, --interactive      Run interactive TUI or not
  -a, --all              Run all or nth, defaults to all
  -n, --number <NUMBER>  Run nth matching, zero indexed [default: 0]
  -l, --list             list scores, will also be affected by run filter
  -h, --help             Print help
  -V, --version          Print version```

## Core architecture

![Harmony Core Architecture](docs/diagrams/Harmony_Core_Architecture.drawio.svg)

Supporting a new field in OPNSense config.xml

Two steps:

• Supporting the field in opnsense-config-xml
• Enabling Harmony to control the field

We'll use the filename field in the dhcpcd section of the file as an example.

Supporting the field

As type checking if enforced, every field from config.xml must be known by the code. Each subsection of config.xml has its .rs file. For the dhcpcd section, we'll modify opnsense-config-xml/src/data/dhcpd.rs.

When a new field appears in the xml file, an error like this will be thrown and Harmony will panic :

     Running `/home/stremblay/nt/dir/harmony/target/debug/example-nanodc`
Found unauthorized element filename
thread 'main' panicked at opnsense-config-xml/src/data/opnsense.rs:54:14:
OPNSense received invalid string, should be full XML: ()

Define the missing field (filename) in the DhcpInterface struct of opnsense-config-xml/src/data/dhcpd.rs:

pub struct DhcpInterface {
    ...
    pub filename: Option<String>,

Harmony should now be fixed, build and run.

Controlling the field

Define the xml field setter in opnsense-config/src/modules/dhcpd.rs.

impl<'a> DhcpConfig<'a> {
    ...
    pub fn set_filename(&mut self, filename: &str) {
        self.enable_netboot();
        self.get_lan_dhcpd().filename = Some(filename.to_string());
    }
    ...

Define the value setter in the DhcpServer trait in domain/topology/network.rs

#[async_trait]
pub trait DhcpServer: Send + Sync {
    ...
    async fn set_filename(&self, filename: &str) -> Result<(), ExecutorError>;
    ...

Implement the value setter in each DhcpServer implementation. infra/opnsense/dhcp.rs:

#[async_trait]
impl DhcpServer for OPNSenseFirewall {
    ...
    async fn set_filename(&self, filename: &str) -> Result<(), ExecutorError> {
        {
            let mut writable_opnsense = self.opnsense_config.write().await;
            writable_opnsense.dhcp().set_filename(filename);
            debug!("OPNsense dhcp server set filename {filename}");
        }

        Ok(())
    }
    ...

domain/topology/ha_cluster.rs

#[async_trait]
impl DhcpServer for DummyInfra {
    ...
    async fn set_filename(&self, _filename: &str) -> Result<(), ExecutorError> {
        unimplemented!("{}", UNIMPLEMENTED_DUMMY_INFRA)
    }
    ...

Add the new field to the DhcpScore in modules/dhcp.rs

pub struct DhcpScore {
    ...
    pub filename: Option<String>,

Define it in its implementation in modules/okd/dhcp.rs

impl OKDDhcpScore {
        ...
        Self {
            dhcp_score: DhcpScore {
                ...
                filename: Some("undionly.kpxe".to_string()),

Define it in its implementation in modules/okd/bootstrap_dhcp.rs

impl OKDDhcpScore {
        ...
        Self {
            dhcp_score: DhcpScore::new(
                ...
                Some("undionly.kpxe".to_string()),

Update the interpret (function called by the execute fn of the interpret) so it now updates the filename field value in modules/dhcp.rs

impl DhcpInterpret {
        ...
        let filename_outcome = match &self.score.filename {
            Some(filename) => {
                let dhcp_server = Arc::new(topology.dhcp_server.clone());
                dhcp_server.set_filename(&filename).await?;
                Outcome::new(
                    InterpretStatus::SUCCESS,
                    format!("Dhcp Interpret Set filename to {filename}"),
                )
            }
            None => Outcome::noop(),
        };

        if next_server_outcome.status == InterpretStatus::NOOP
            && boot_filename_outcome.status == InterpretStatus::NOOP
            && filename_outcome.status == InterpretStatus::NOOP

            ...

            Ok(Outcome::new(
            InterpretStatus::SUCCESS,
            format!(
                "Dhcp Interpret Set next boot to [{:?}], boot_filename to [{:?}], filename to [{:?}]",
                self.score.boot_filename, self.score.boot_filename, self.score.filename
            )
            ...