feat(orchestration): introduce Interpret trait and refactor score application

Refactor the orchestration process to use an `Interpret` trait instead of directly applying scores. This change introduces a more flexible and extensible design for executing commands associated with different types of topologies. The `CommandScore` and `K8sResourceScore` now implement this trait, providing a clear separation between score definition and execution logic. Update the `Maestro::orchestrate` method to compile scores into interpreters before executing them against their respective topologies.
This commit is contained in:
Jean-Gabriel Gill-Couture 2025-03-26 16:39:11 -04:00
parent 3962238f0d
commit d7897f29c4

View File

@ -1,47 +1,31 @@
use rand::Rng;
use std::process::Command;
use rand::Rng; // Add rand dependency
// ===== Capability Traits =====
/// Base trait for all capabilities
pub trait Capability {}
/// Capability for executing shell commands on a host
pub trait CommandCapability: Capability {
fn execute_command(&self, command: &str, args: &[&str]) -> Result<String, String>;
}
/// Capability for interacting with a Kubernetes cluster
pub trait KubernetesCapability: Capability {
fn apply_manifest(&self, manifest: &str) -> Result<(), String>;
fn get_resource(&self, resource_type: &str, name: &str) -> Result<String, String>;
}
// ===== Topology Traits =====
/// Base trait for all topologies
pub trait Topology {
// Base topology methods that don't depend on capabilities
fn name(&self) -> &str;
}
// ===== Score Traits =====
/// Generic Score trait with an associated Capability type
pub trait Score<T: Topology> {
fn apply(&self, topology: &T) -> Result<(), String>;
fn compile(&self) -> Result<Box<dyn Interpret<T>>, String>;
fn name(&self) -> &str;
}
// ===== Concrete Topologies =====
/// A topology representing a Linux host
pub struct LinuxHostTopology {
name: String,
host: String,
}
// Implement the base Capability trait for LinuxHostTopology
impl Capability for LinuxHostTopology {}
impl LinuxHostTopology {
@ -64,7 +48,7 @@ impl CommandCapability for LinuxHostTopology {
.args(args)
.output()
.map_err(|e| e.to_string())?;
if output.status.success() {
Ok(String::from_utf8_lossy(&output.stdout).to_string())
} else {
@ -73,19 +57,17 @@ impl CommandCapability for LinuxHostTopology {
}
}
/// A topology representing a K3D Kubernetes cluster
pub struct K3DTopology {
name: String,
linux_host: LinuxHostTopology,
cluster_name: String,
}
// Implement the base Capability trait for K3DTopology
impl Capability for K3DTopology {}
impl K3DTopology {
pub fn new(name: String, linux_host: LinuxHostTopology, cluster_name: String) -> Self {
Self {
Self {
name,
linux_host,
cluster_name,
@ -101,7 +83,6 @@ impl Topology for K3DTopology {
impl CommandCapability for K3DTopology {
fn execute_command(&self, command: &str, args: &[&str]) -> Result<String, String> {
// Delegate to the underlying Linux host
self.linux_host.execute_command(command, args)
}
}
@ -112,39 +93,40 @@ impl KubernetesCapability for K3DTopology {
// Write manifest to a temporary file
//let temp_file = format!("/tmp/manifest-{}.yaml", rand::thread_rng().gen::<u32>());
let temp_file = format!("/tmp/manifest-TODO_RANDOM_NUMBER.yaml");
// Use the linux_host directly to avoid capability trait bounds
self.linux_host.execute_command("bash", &["-c", &format!("cat > {}", temp_file)])?;
self.linux_host
.execute_command("bash", &["-c", &format!("cat > {}", temp_file)])?;
// Apply with kubectl
self.linux_host.execute_command(
"kubectl",
&["--context", &format!("k3d-{}", self.cluster_name), "apply", "-f", &temp_file]
)?;
self.linux_host.execute_command("kubectl", &[
"--context",
&format!("k3d-{}", self.cluster_name),
"apply",
"-f",
&temp_file,
])?;
Ok(())
}
fn get_resource(&self, resource_type: &str, name: &str) -> Result<String, String> {
println!("Getting resource {}/{} from K3D cluster '{}'", resource_type, name, self.cluster_name);
self.linux_host.execute_command(
"kubectl",
&[
"--context",
&format!("k3d-{}", self.cluster_name),
"get",
resource_type,
name,
"-o",
"yaml",
]
)
println!(
"Getting resource {}/{} from K3D cluster '{}'",
resource_type, name, self.cluster_name
);
self.linux_host.execute_command("kubectl", &[
"--context",
&format!("k3d-{}", self.cluster_name),
"get",
resource_type,
name,
"-o",
"yaml",
])
}
}
// ===== Concrete Scores =====
/// A score that executes commands on a topology
pub struct CommandScore {
name: String,
command: String,
@ -153,19 +135,35 @@ pub struct CommandScore {
impl CommandScore {
pub fn new(name: String, command: String, args: Vec<String>) -> Self {
Self { name, command, args }
Self {
name,
command,
args,
}
}
}
impl<T> Score<T> for CommandScore
where
T: Topology + CommandCapability
pub trait Interpret<T: Topology> {
fn execute(&self, topology: &T) -> Result<String, String>;
}
struct CommandInterpret;
impl<T> Interpret<T> for CommandInterpret
where
T: Topology + CommandCapability,
{
fn apply(&self, topology: &T) -> Result<(), String> {
println!("Applying CommandScore '{}' to topology '{}'", self.name, topology.name());
let args_refs: Vec<&str> = self.args.iter().map(|s| s.as_str()).collect();
topology.execute_command(&self.command, &args_refs)?;
Ok(())
fn execute(&self, topology: &T) -> Result<String, String> {
todo!()
}
}
impl<T> Score<T> for CommandScore
where
T: Topology + CommandCapability,
{
fn compile(&self) -> Result<Box<dyn Interpret<T>>, String> {
Ok(Box::new(CommandInterpret {}))
}
fn name(&self) -> &str {
@ -173,7 +171,8 @@ where
}
}
/// A score that applies Kubernetes resources to a topology
#[derive(Clone)]
pub struct K8sResourceScore {
name: String,
manifest: String,
@ -185,13 +184,24 @@ impl K8sResourceScore {
}
}
impl<T> Score<T> for K8sResourceScore
where
T: Topology + KubernetesCapability
struct K8sResourceInterpret {
score: K8sResourceScore,
}
impl<T: Topology + KubernetesCapability> Interpret<T> for K8sResourceInterpret {
fn execute(&self, topology: &T) -> Result<String, String> {
todo!()
}
}
impl<T> Score<T> for K8sResourceScore
where
T: Topology + KubernetesCapability,
{
fn apply(&self, topology: &T) -> Result<(), String> {
println!("Applying K8sResourceScore '{}' to topology '{}'", self.name, topology.name());
topology.apply_manifest(&self.manifest)
fn compile(&self) -> Result<Box<(dyn Interpret<T> + 'static)>, String> {
Ok(Box::new(K8sResourceInterpret {
score: self.clone(),
}))
}
fn name(&self) -> &str {
@ -199,35 +209,11 @@ where
}
}
// ===== Maestro Orchestrator =====
/// Type-safe orchestrator that enforces capability requirements at compile time
pub struct Maestro<T: Topology> {
topology: T,
scores: Vec<Box<dyn ScoreWrapper<T>>>,
scores: Vec<Box<dyn Score<T>>>,
}
/// A trait object wrapper that hides the specific Score type but preserves its
/// capability requirements
trait ScoreWrapper<T: Topology> {
fn apply(&self, topology: &T) -> Result<(), String>;
fn name(&self) -> &str;
}
/// Implementation of ScoreWrapper for any Score that works with topology T
impl<T, S> ScoreWrapper<T> for S
where
T: Topology,
S: Score<T> + 'static
{
fn apply(&self, topology: &T) -> Result<(), String> {
<S as Score<T>>::apply(self, topology)
}
fn name(&self) -> &str {
<S as Score<T>>::name(self)
}
}
impl<T: Topology> Maestro<T> {
pub fn new(topology: T) -> Self {
@ -237,70 +223,66 @@ impl<T: Topology> Maestro<T> {
}
}
/// Register a score that is compatible with this topology's capabilities
pub fn register_score<S>(&mut self, score: S)
where
S: Score<T> + 'static
pub fn register_score<S>(&mut self, score: S)
where
S: Score<T> + 'static,
{
println!("Registering score '{}' for topology '{}'", score.name(), self.topology.name());
println!(
"Registering score '{}' for topology '{}'",
score.name(),
self.topology.name()
);
self.scores.push(Box::new(score));
}
/// Apply all registered scores to the topology
pub fn orchestrate(&self) -> Result<(), String> {
println!("Orchestrating topology '{}'", self.topology.name());
for score in &self.scores {
score.apply(&self.topology)?;
let interpret = score.compile()?;
interpret.execute(&self.topology)?;
}
Ok(())
}
}
// ===== Example Usage =====
fn main() {
// Create a Linux host topology
let linux_host = LinuxHostTopology::new(
"dev-machine".to_string(),
"localhost".to_string()
);
// Create a maestro for the Linux host
let linux_host = LinuxHostTopology::new("dev-machine".to_string(), "localhost".to_string());
let mut linux_maestro = Maestro::new(linux_host);
// Register a command score that works with any topology having CommandCapability
linux_maestro.register_score(CommandScore::new(
"check-disk".to_string(),
"df".to_string(),
vec!["-h".to_string()]
vec!["-h".to_string()],
));
linux_maestro.orchestrate().unwrap();
// This would fail to compile if we tried to register a K8sResourceScore
// because LinuxHostTopology doesn't implement KubernetesCapability
// linux_maestro.register_score(K8sResourceScore::new(...));
//linux_maestro.register_score(K8sResourceScore::new(
// "...".to_string(),
// "...".to_string(),
//));
// Create a K3D topology which has both Command and Kubernetes capabilities
let k3d_host = LinuxHostTopology::new(
"k3d-host".to_string(),
"localhost".to_string()
);
let k3d_host = LinuxHostTopology::new("k3d-host".to_string(), "localhost".to_string());
let k3d_topology = K3DTopology::new(
"dev-cluster".to_string(),
k3d_host,
"devcluster".to_string()
"devcluster".to_string(),
);
// Create a maestro for the K3D topology
let mut k3d_maestro = Maestro::new(k3d_topology);
// We can register both command scores and kubernetes scores
k3d_maestro.register_score(CommandScore::new(
"check-nodes".to_string(),
"kubectl".to_string(),
vec!["get".to_string(), "nodes".to_string()]
vec!["get".to_string(), "nodes".to_string()],
));
k3d_maestro.register_score(K8sResourceScore::new(
"deploy-nginx".to_string(),
r#"
@ -323,9 +305,10 @@ fn main() {
image: nginx:latest
ports:
- containerPort: 80
"#.to_string()
"#
.to_string(),
));
// Orchestrate both topologies
linux_maestro.orchestrate().unwrap();
k3d_maestro.orchestrate().unwrap();