Add support for starting VMs with passt network

This required adding another field to the config. This is done by
migrating the old config to a newer version.
We are backwards compatible on configuration but not forwards compatible
(older versions of krunvm will not be able to use the config from
this version)
If we want forward compatibility, I feel like we need to ditch the confy
crate.

Signed-off-by: Matej Hrica <[email protected]>

Cargo.toml

@@ -16,3 +16,4 @@ serde = "1.0.120"
 serde_derive = "1.0.120"
 text_io = "0.1.8"
 nix = {version = "0.27.1", features = ["socket", "fs"]}
+rand="0.8.5"

src/bindings.rs

@@ -13,6 +13,7 @@ extern "C" {
     pub fn krun_set_mapped_volumes(ctx: u32, mapped_volumes: *const *const c_char) -> i32;
     pub fn krun_set_port_map(ctx: u32, port_map: *const *const c_char) -> i32;
     pub fn krun_set_workdir(ctx: u32, workdir_path: *const c_char) -> i32;
+    pub fn krun_set_passt_fd(ctx: u32, fd: c_int) -> i32;
     pub fn krun_set_exec(
         ctx: u32,
         exec_path: *const c_char,

src/commands/changevm.rs

@@ -4,12 +4,12 @@
 use clap::Args;
 use std::collections::HashMap;
 
+use crate::config::{KrunvmConfig, NetworkMode};
 use crate::utils::{path_pairs_to_hash_map, port_pairs_to_hash_map, PathPair, PortPair};
-use crate::{KrunvmConfig, APP_NAME};
 
 use super::list::printvm;
 
-/// Change the configuration of a microVM
+/// Change the config of a microVM
 #[derive(Args, Debug)]
 pub struct ChangeVmCmd {
     /// Name of the VM to be modified
@@ -46,6 +46,9 @@ pub struct ChangeVmCmd {
     /// Port(s) in format "host_port:guest_port" to be exposed to the host
     #[arg(long = "port")]
     ports: Vec<PortPair>,
+
+    #[arg(long)]
+    network_mode: Option<NetworkMode>,
 }
 
 impl ChangeVmCmd {
@@ -130,12 +133,17 @@ impl ChangeVmCmd {
             cfg_changed = true;
         }
 
+        if let Some(network_mode) = self.network_mode {
+            vmcfg.network_mode = network_mode;
+            cfg_changed = true;
+        }
+
         println!();
         printvm(vmcfg);
         println!();
 
         if cfg_changed {
-            confy::store(APP_NAME, &cfg).unwrap();
+            crate::config::save(cfg).unwrap();
         }
     }
 }

src/commands/config.rs

@@ -1,7 +1,7 @@
 // Copyright 2021 Red Hat, Inc.
 // SPDX-License-Identifier: Apache-2.0
 
-use crate::{KrunvmConfig, APP_NAME};
+use crate::config::{KrunvmConfig, NetworkMode};
 use clap::Args;
 
 /// Configure global values
@@ -18,6 +18,10 @@ pub struct ConfigCmd {
     /// DNS server to use in the microVM
     #[arg(long)]
     dns: Option<String>,
+
+    /// Default network mode to use
+    #[arg(long)]
+    network_mode: Option<NetworkMode>,
 }
 
 impl ConfigCmd {
@@ -47,11 +51,18 @@ impl ConfigCmd {
             cfg_changed = true;
         }
 
+        if let Some(network_mode) = self.network_mode {
+            if network_mode != cfg.default_network_mode {
+                cfg.default_network_mode = network_mode;
+                cfg_changed = true;
+            }
+        }
+
         if cfg_changed {
-            confy::store(APP_NAME, &cfg).unwrap();
+            crate::config::save(cfg).unwrap();
         }
 
-        println!("Global configuration:");
+        println!("Global config:");
         println!(
             "Default number of CPUs for newly created VMs: {}",
             cfg.default_cpus

src/commands/create.rs

@@ -1,6 +1,8 @@
 // Copyright 2021 Red Hat, Inc.
 // SPDX-License-Identifier: Apache-2.0
 
+use crate::config::{KrunvmConfig, NetworkMode, VmConfig};
+use crate::APP_NAME;
 use clap::Args;
 use std::fs;
 use std::io::Write;
@@ -12,8 +14,6 @@ use crate::utils::{
     get_buildah_args, mount_container, path_pairs_to_hash_map, port_pairs_to_hash_map,
     umount_container, BuildahCommand, PathPair, PortPair,
 };
-use crate::{KrunvmConfig, VmConfig, APP_NAME};
-
 #[cfg(target_os = "macos")]
 const KRUNVM_ROSETTA_FILE: &str = ".krunvm-rosetta";
 
@@ -51,6 +51,10 @@ pub struct CreateCmd {
     #[arg(long = "port")]
     ports: Vec<PortPair>,
 
+    /// Network mode to use
+    #[arg(long)]
+    network_mode: Option<NetworkMode>,
+
     /// Create a x86_64 microVM even on an Aarch64 host
     #[arg(short, long)]
     #[cfg(target_os = "macos")]
@@ -68,6 +72,9 @@ impl CreateCmd {
         let mapped_ports = port_pairs_to_hash_map(self.ports);
         let image = self.image;
         let name = self.name;
+        let network_mode = self
+            .network_mode
+            .unwrap_or_else(|| cfg.default_network_mode.clone());
 
         if let Some(ref name) = name {
             if cfg.vmconfig_map.contains_key(name) {
@@ -160,6 +167,7 @@ https://threedots.ovh/blog/2022/06/quick-look-at-rosetta-on-linux/
             workdir: workdir.to_string(),
             mapped_volumes,
             mapped_ports,
+            network_mode,
         };
 
         let rootfs = mount_container(cfg, &vmcfg).unwrap();

src/commands/delete.rs

@@ -1,7 +1,8 @@
 // Copyright 2021 Red Hat, Inc.
 // SPDX-License-Identifier: Apache-2.0
 
-use crate::{KrunvmConfig, APP_NAME};
+use crate::config;
+use crate::config::KrunvmConfig;
 use clap::Args;
 
 use crate::utils::{remove_container, umount_container};
@@ -26,6 +27,6 @@ impl DeleteCmd {
         umount_container(cfg, &vmcfg).unwrap();
         remove_container(cfg, &vmcfg).unwrap();
 
-        confy::store(APP_NAME, &cfg).unwrap();
+        config::save(cfg).unwrap()
     }
 }

src/commands/list.rs

@@ -1,7 +1,7 @@
 // Copyright 2021 Red Hat, Inc.
 // SPDX-License-Identifier: Apache-2.0
 
-use crate::{KrunvmConfig, VmConfig};
+use crate::config::{KrunvmConfig, VmConfig};
 use clap::Args;
 
 /// List microVMs
@@ -33,6 +33,7 @@ pub fn printvm(vm: &VmConfig) {
     println!(" DNS server: {}", vm.dns);
     println!(" Buildah container: {}", vm.container);
     println!(" Workdir: {}", vm.workdir);
+    println!(" Network mode: {:?}", vm.network_mode);
     println!(" Mapped volumes: {:?}", vm.mapped_volumes);
     println!(" Mapped ports: {:?}", vm.mapped_ports);
 }