camel_component_wasm/
lib.rs

1//! WebAssembly component for rust-camel — executes WASM modules as route processors via a Wasmtime runtime.
2//!
3//! Main types: `WasmComponent`, `WasmBundle`, `WasmConfig`, `WasmEndpoint`, `StateStore`.
4//! Main modules: `runtime`, `bindings`, `state_store`, `host_functions`.
5//!
6//! # Limitations
7//!
8//! - Only the [Wasmtime](https://wasmtime.dev) runtime is supported; other WASM runtimes
9//!   (Wasmer, WasmEdge, etc.) are not compatible.
10//! - WASM modules must export a specific interface defined by `camel_wasm_bindings`; arbitrary
11//!   WASM binaries cannot be dropped in without meeting this contract.
12//! - The WASM sandbox has no access to the host filesystem or network by default;
13//!   host functions are limited to what is explicitly exposed via `host_functions`.
14//! - Epoch-based fuel/interruption requires the `epoch` feature; long-running modules
15//!   without epoch support may block the async executor.
16
17pub mod authorization_policy;
18pub mod bean;
19pub mod bean_bindings;
20pub mod bindings;
21pub mod bundle;
22mod cancel_guard;
23pub mod capabilities;
24pub mod config;
25pub mod endpoint;
26pub mod epoch;
27pub mod error;
28pub mod health;
29pub mod host_functions;
30pub(crate) mod metadata;
31pub mod producer;
32mod return_stream;
33pub mod runtime;
34pub mod security_policy;
35pub mod security_policy_bindings;
36pub mod serde_bridge;
37pub mod source_bindings;
38pub mod source_consumer;
39pub mod source_host;
40pub mod state_store;
41pub mod stream_bridge;
42mod wasi_surface;
43pub mod wasm_plugin_context;
44
45pub use authorization_policy::{WasmAuthorizationPolicyEvaluator, build_permission_registry};
46pub use bundle::WasmBundle;
47pub use config::WasmConfig;
48pub use endpoint::WasmEndpoint;
49pub use epoch::EpochTicker;
50pub use error::{TrapReason, WasmError};
51pub use health::WasmHealthCheck;
52pub use security_policy::{WasmSecurityPolicy, build_security_policy_registry};
53pub use state_store::StateStore;
54
55use std::path::PathBuf;
56use std::sync::Arc;
57use std::sync::atomic::AtomicBool;
58
59use camel_api::CamelError;
60use camel_component_api::{Component, ComponentContext, ComponentMetadata, Endpoint};
61use metadata::WasmMetadataDescriptor;
62
63pub struct WasmComponent {
64    registry: Arc<dyn ComponentContext>,
65    base_dir: PathBuf,
66    engine_loaded: Arc<AtomicBool>,
67}
68
69impl WasmComponent {
70    pub fn new(registry: Arc<dyn ComponentContext>, base_dir: PathBuf) -> Self {
71        Self {
72            registry,
73            base_dir,
74            // TODO: set to true when WASM module is successfully loaded/instantiated
75            engine_loaded: Arc::new(AtomicBool::new(false)),
76        }
77    }
78
79    fn validate_and_resolve_path(&self, uri_path: &str) -> Result<PathBuf, CamelError> {
80        if PathBuf::from(uri_path).is_absolute() {
81            return Err(CamelError::InvalidUri(
82                "WASM path must be relative (not absolute)".to_string(),
83            ));
84        }
85
86        if PathBuf::from(uri_path)
87            .components()
88            .any(|c| matches!(c, std::path::Component::ParentDir))
89        {
90            return Err(CamelError::InvalidUri(
91                "WASM path must not contain '..'".to_string(),
92            ));
93        }
94
95        let resolved = self.base_dir.join(uri_path);
96        let canonical = resolved.canonicalize().map_err(|_| {
97            CamelError::ComponentNotFound(format!("WASM module not found: {}", resolved.display()))
98        })?;
99
100        let canonical_base = self.base_dir.canonicalize().map_err(|_| {
101            CamelError::EndpointCreationFailed(format!(
102                "failed to resolve base directory: {}",
103                self.base_dir.display()
104            ))
105        })?;
106
107        if !canonical.starts_with(&canonical_base) {
108            return Err(CamelError::InvalidUri(
109                "WASM path escapes project root".to_string(),
110            ));
111        }
112
113        Ok(canonical)
114    }
115}
116
117impl Component for WasmComponent {
118    fn scheme(&self) -> &str {
119        "wasm"
120    }
121
122    fn metadata(&self) -> ComponentMetadata {
123        WasmMetadataDescriptor::metadata()
124    }
125
126    fn create_endpoint(
127        &self,
128        uri: &str,
129        ctx: &dyn ComponentContext,
130    ) -> Result<Box<dyn Endpoint>, CamelError> {
131        let uri_without_scheme = uri.strip_prefix("wasm:").ok_or_else(|| {
132            CamelError::InvalidUri(format!("WASM URI must start with 'wasm:': {uri}"))
133        })?;
134
135        let (path_part, wasm_config) = crate::config::WasmConfig::from_uri(uri_without_scheme);
136        if path_part.is_empty() {
137            return Err(CamelError::InvalidUri(
138                "WASM URI must include a module path".to_string(),
139            ));
140        }
141
142        let module_path = self.validate_and_resolve_path(&path_part)?;
143
144        let health_check = WasmHealthCheck::new(Arc::clone(&self.engine_loaded));
145        ctx.register_current_route_health_check(Arc::new(health_check));
146
147        Ok(Box::new(WasmEndpoint::new(
148            uri.to_string(),
149            module_path,
150            self.registry.clone(),
151            wasm_config,
152        )))
153    }
154}
camel_component_wasm/lib.rs

camel_component_wasm/
lib.rs
