api: Added GET method for machine-config

api_server/src/http_service.rs

@@ -198,17 +198,22 @@ fn parse_request<'a>(
                 .map_err(|s| Error::Generic(StatusCode::BadRequest, s))?),
             _ => Err(Error::InvalidPathMethod(path, method)),
         },
-        "machine-config" => match v[1..].len() {
-            0 if is_get => Ok(ParsedRequest::Dummy),
-
-            0 if is_put => Ok(
-                serde_json::from_slice::<request::MachineConfigurationBody>(body)
-                    .map_err(Error::SerdeJson)?
-                    .into_parsed_request()
-                    .map_err(|s| Error::Generic(StatusCode::BadRequest, s))?,
-            ),
-            _ => Err(Error::InvalidPathMethod(path, method)),
-        },
+        "machine-config" => {
+            match v[1..].len() {
+                0 if is_get => Ok(serde_json::from_slice::<request::MachineConfigurationBody>(
+                    body,
+                ).map_err(Error::SerdeJson)?
+                    .into_parsed_request(Method::Get)
+                    .map_err(|s| Error::Generic(StatusCode::BadRequest, s))?),
+
+                0 if is_put => Ok(serde_json::from_slice::<request::MachineConfigurationBody>(
+                    body,
+                ).map_err(Error::SerdeJson)?
+                    .into_parsed_request(Method::Put)
+                    .map_err(|s| Error::Generic(StatusCode::BadRequest, s))?),
+                _ => Err(Error::InvalidPathMethod(path, method)),
+            }
+        }
         "network-interfaces" => match v[1..].len() {
             0 if is_get => Ok(ParsedRequest::Dummy),
 

api_server/src/lib.rs

@@ -11,7 +11,7 @@ extern crate fc_util;
 extern crate net_util;
 extern crate sys_util;
 
-mod http_service;
+pub mod http_service;
 pub mod request;
 
 use std::cell::RefCell;

api_server/src/request/sync/machine_configuration.rs

@@ -1,7 +1,7 @@
 use std::result;
 
 use futures::sync::oneshot;
-use hyper::{Response, StatusCode};
+use hyper::{Method, Response, StatusCode};
 
 use http_service::{empty_response, json_fault_message, json_response};
 use request::{ParsedRequest, SyncRequest};
@@ -56,11 +56,18 @@ impl GenerateResponse for PutMachineConfigurationOutcome {
 }
 
 impl MachineConfigurationBody {
-    pub fn into_parsed_request(self) -> result::Result<ParsedRequest, String> {
+    pub fn into_parsed_request(self, method: Method) -> result::Result<ParsedRequest, String> {
         let (sender, receiver) = oneshot::channel();
-        Ok(ParsedRequest::Sync(
-            SyncRequest::PutMachineConfiguration(self, sender),
-            receiver,
-        ))
+        match method {
+            Method::Get => Ok(ParsedRequest::Sync(
+                SyncRequest::GetMachineConfiguration(sender),
+                receiver,
+            )),
+            Method::Put => Ok(ParsedRequest::Sync(
+                SyncRequest::PutMachineConfiguration(self, sender),
+                receiver,
+            )),
+            _ => Ok(ParsedRequest::Dummy),
+        }
     }
 }

api_server/src/request/sync/mod.rs

@@ -53,6 +53,7 @@ pub enum DeviceState {
 // This enum contains messages for the VMM which represent sync requests. They each contain various
 // bits of information (ids, paths, etc.), together with an OutcomeSender, which is always present.
 pub enum SyncRequest {
+    GetMachineConfiguration(SyncOutcomeSender),
     PutBootSource(BootSourceBody, SyncOutcomeSender),
     PutDrive(DriveDescription, SyncOutcomeSender),
     PutMachineConfiguration(MachineConfigurationBody, SyncOutcomeSender),

vmm/Cargo.toml

@@ -4,6 +4,7 @@ version = "0.1.0"
 authors = ["Amazon firecracker team <[email protected]>"]
 
 [dependencies]
+hyper = "=0.11.16"
 libc = ">=0.2.39"
 epoll = "=2.1.0"
 scopeguard = "=0.3.3"

vmm/src/lib.rs

@@ -1,4 +1,5 @@
 extern crate epoll;
+extern crate hyper;
 extern crate libc;
 
 extern crate api_server;
@@ -27,6 +28,7 @@ use std::sync::{Arc, Barrier, RwLock};
 use std::thread;
 
 use api_server::ApiRequest;
+use api_server::http_service::json_response;
 use api_server::request::async::{AsyncOutcome, AsyncRequest};
 use api_server::request::instance_info::{InstanceInfo, InstanceState};
 use api_server::request::sync::{DriveError, Error as SyncError, GenerateResponse,
@@ -283,8 +285,7 @@ pub struct KernelConfig {
     pub cmdline_addr: GuestAddress,
 }
 
-// This structure should replace MachineCfg; For now it is safer to duplicate the work as the
-// net support is not fuully integrated.
+#[derive(Clone)]
 pub struct VirtualMachineConfig {
     vcpu_count: u8,
     mem_size_mib: usize,
@@ -299,6 +300,18 @@ impl Default for VirtualMachineConfig {
     }
 }
 
+impl GenerateResponse for VirtualMachineConfig {
+    fn generate_response(&self) -> hyper::Response {
+        json_response(
+            hyper::StatusCode::Ok,
+            format!(
+                "{{ \"vcpu_count\": {:?}, \"mem_size_mib\": {:?} }}",
+                self.vcpu_count, self.mem_size_mib
+            ),
+        )
+    }
+}
+
 pub struct Vmm {
     _kvm_fd: Kvm,
 
@@ -911,6 +924,12 @@ impl Vmm {
             }
             ApiRequest::Sync(req) => {
                 match req {
+                    SyncRequest::GetMachineConfiguration(sender) => {
+                        sender
+                            .send(Box::new(self.vm_config.clone()))
+                            .map_err(|_| ())
+                            .expect("one-shot channel closed");
+                    }
                     SyncRequest::PutDrive(drive_description, sender) => {
                         match self.put_block_device(BlockDeviceConfig::from(drive_description)) {
                             Ok(_) =>