libs/types: support load Kata agent configuration from file

Add structures to load Kata agent configuration from configuration files.
Also define a mechanism for vendor to extend the Kata configuration
structure.

Signed-off-by: Liu Jiang <gerry@linux.alibaba.com>

src/libs/kata-types/src/config/agent.rs

@@ -0,0 +1,80 @@
+// Copyright (c) 2021 Alibaba Cloud
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+use std::io::Result;
+
+use crate::config::{ConfigOps, TomlConfig};
+
+pub use vendor::AgentVendor;
+
+/// Kata agent configuration information.
+#[derive(Debug, Default, Deserialize, Serialize)]
+pub struct Agent {
+    /// If enabled, the agent will log additional debug messages to the system log.
+    #[serde(default, rename = "enable_debug")]
+    pub debug: bool,
+
+    /// Enable agent tracing.
+    ///
+    /// If enabled, the agent will generate OpenTelemetry trace spans.
+    /// # Notes:
+    /// - If the runtime also has tracing enabled, the agent spans will be associated with the
+    ///   appropriate runtime parent span.
+    /// - If enabled, the runtime will wait for the container to shutdown, increasing the container
+    ///   shutdown time slightly.
+    #[serde(default)]
+    pub enable_tracing: bool,
+
+    /// Enable debug console.
+    /// If enabled, user can connect guest OS running inside hypervisor through
+    /// "kata-runtime exec <sandbox-id>" command
+    #[serde(default)]
+    pub debug_console_enabled: bool,
+
+    /// Agent connection dialing timeout value in seconds
+    #[serde(default)]
+    pub dial_timeout: u32,
+
+    /// Comma separated list of kernel modules and their parameters.
+    ///
+    /// These modules will be loaded in the guest kernel using modprobe(8).
+    /// The following example can be used to load two kernel modules with parameters:
+    ///  - kernel_modules=["e1000e InterruptThrottleRate=3000,3000,3000 EEE=1", "i915 enable_ppgtt=0"]
+    /// The first word is considered as the module name and the rest as its parameters.
+    /// Container will not be started when:
+    /// - A kernel module is specified and the modprobe command is not installed in the guest
+    ///   or it fails loading the module.
+    /// - The module is not available in the guest or it doesn't met the guest kernel
+    ///    requirements, like architecture and version.
+    #[serde(default)]
+    pub kernel_modules: Vec<String>,
+}
+
+impl ConfigOps for Agent {
+    fn adjust_configuration(conf: &mut TomlConfig) -> Result<()> {
+        AgentVendor::adjust_configuration(conf)?;
+        Ok(())
+    }
+
+    fn validate(conf: &TomlConfig) -> Result<()> {
+        AgentVendor::validate(conf)?;
+        Ok(())
+    }
+}
+
+#[cfg(not(feature = "enable-vendor"))]
+mod vendor {
+    use super::*;
+
+    /// Vendor customization agent configuration.
+    #[derive(Debug, Default, Deserialize, Serialize)]
+    pub struct AgentVendor {}
+
+    impl ConfigOps for AgentVendor {}
+}
+
+#[cfg(feature = "enable-vendor")]
+#[path = "agent_vendor.rs"]
+mod vendor;

src/libs/kata-types/src/config/agent_vendor.rs

@@ -0,0 +1,12 @@
+// Copyright (c) 2021 Alibaba Cloud
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+use super::*;
+
+/// Vendor customization agent configuration.
+#[derive(Debug, Default, Deserialize, Serialize)]
+pub struct AgentVendor {}
+
+impl ConfigOps for AgentVendor {}

src/libs/kata-types/src/config/default.rs

@@ -20,6 +20,8 @@ lazy_static! {
     ];
 }
 
+pub const DEFAULT_AGENT_NAME: &str = "kata";
+
 pub const DEFAULT_INTERNETWORKING_MODEL: &str = "tcfilter";
 
 pub const DEFAULT_BLOCK_DEVICE_TYPE: &str = "virtio-blk";

src/libs/kata-types/src/config/mod.rs

@@ -14,6 +14,9 @@ use crate::{eother, sl};
 /// Default configuration values.
 pub mod default;
 
+mod agent;
+pub use self::agent::{Agent, AgentVendor};
+
 mod hypervisor;
 pub use self::hypervisor::{
     BootInfo, DragonballConfig, Hypervisor, QemuConfig, HYPERVISOR_NAME_DRAGONBALL,
@@ -64,6 +67,9 @@ pub trait ConfigObjectOps {
 /// Kata configuration information.
 #[derive(Debug, Default, Deserialize, Serialize)]
 pub struct TomlConfig {
+    /// Configuration information for agents.
+    #[serde(default)]
+    pub agent: HashMap<String, Agent>,
     /// Configuration information for hypervisors.
     #[serde(default)]
     pub hypervisor: HashMap<String, Hypervisor>,
@@ -123,6 +129,7 @@ impl TomlConfig {
 
         Hypervisor::adjust_configuration(&mut config)?;
         Runtime::adjust_configuration(&mut config)?;
+        Agent::adjust_configuration(&mut config)?;
         info!(sl!(), "get kata config: {:?}", config);
 
         Ok(config)
@@ -132,6 +139,7 @@ impl TomlConfig {
     pub fn validate(&self) -> Result<()> {
         Hypervisor::validate(self)?;
         Runtime::validate(self)?;
+        Agent::validate(self)?;
 
         Ok(())
     }

src/libs/kata-types/src/config/runtime.rs

@@ -1,4 +1,4 @@
-// Copyright (c) 2019-2021 Alibaba Cloud
+// Copyright (c) 2021 Alibaba Cloud
 //
 // SPDX-License-Identifier: Apache-2.0
 //