fix: VMs can be restarted

Previously, the temporary file for the cloud-init configuration ISO
was left attached to the VM. This meant the VM couldn't be turned off
and back on again: the temporary no longer existed.

Now we detach the ISO file after the VM has booted.

As a side effect, vmadm has gained start and shutdown subcommands, so
that the fix can be tested.

1 files changed, 31 insertions, 0 deletions

diff --git a/src/cmd/start.rs b/src/cmd/start.rs
new file mode 100644
index 0000000..a69f54c
--- /dev/null
+++ b/src/cmd/start.rs
@@ -0,0 +1,31 @@
+//! The `start` sub-command.
+
+use crate::libvirt::{Libvirt, VirtError};
+use crate::spec::Specification;
+use crate::util::wait_for_ssh;
+use log::info;
+
+/// Errors from this module.
+#[derive(Debug, thiserror::Error)]
+pub enum StartError {
+    /// Error from libvirt.
+    #[error(transparent)]
+    VirtError(#[from] VirtError),
+
+    /// Error doing I/O.
+    #[error(transparent)]
+    IoError(#[from] std::io::Error),
+}
+
+/// Start existing VMs corresponding to specifications.
+pub fn start(specs: &[Specification]) -> Result<(), StartError> {
+    let libvirt = Libvirt::connect("qemu:///system")?;
+    for spec in specs {
+        info!("starting virtual machine {}", spec.name);
+        libvirt.start(&spec.name)?;
+    }
+    for spec in specs {
+        wait_for_ssh(&spec.name);
+    }
+    Ok(())
+}