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package fcapi
import (
"bytes"
"context"
"encoding/json"
"fmt"
"io"
"net"
"net/http"
"os"
"time"
)
type BootSource struct {
KernelImagePath string `json:"kernel_image_path"`
BootArgs string `json:"boot_args"`
}
type Drive struct {
DriveID string `json:"drive_id"`
PathOnHost string `json:"path_on_host"`
IsRootDevice bool `json:"is_root_device"`
IsReadOnly bool `json:"is_read_only"`
}
type MachineConfig struct {
VcpuCount int `json:"vcpu_count"`
MemSizeMiB int `json:"mem_size_mib"`
SMT bool `json:"smt"`
}
type NetworkInterface struct {
IfaceID string `json:"iface_id"`
HostDevName string `json:"host_dev_name"`
GuestMAC string `json:"guest_mac"`
}
type Config struct {
BootSource BootSource `json:"boot-source"`
Drives []Drive `json:"drives"`
MachineConfig MachineConfig `json:"machine-config"`
NetworkInterfaces []NetworkInterface `json:"network-interfaces"`
}
func WriteConfig(path string, c Config) error {
raw, err := json.MarshalIndent(c, "", " ")
if err != nil {
return err
}
return os.WriteFile(path, append(raw, '\n'), 0o600)
}
func Argv(firecracker, vmmID, configFile, socket string) []string {
return []string{firecracker, "--id", vmmID, "--config-file", configFile, "--api-sock", socket}
}
type Instance struct {
ID string `json:"id"`
State string `json:"state"`
VMMVersion string `json:"vmm_version"`
AppName string `json:"app_name"`
}
const StateRunning = "Running"
type Client struct {
socket string
http *http.Client
}
func NewClient(socket string, timeout time.Duration) *Client {
t := &http.Transport{
DialContext: func(ctx context.Context, _, _ string) (net.Conn, error) {
var d net.Dialer
return d.DialContext(ctx, "unix", socket)
},
DisableKeepAlives: true,
}
return &Client{socket: socket, http: &http.Client{Transport: t, Timeout: timeout}}
}
func (c *Client) Describe(ctx context.Context) (Instance, error) {
req, err := http.NewRequestWithContext(ctx, http.MethodGet, "http://localhost/", nil)
if err != nil {
return Instance{}, err
}
resp, err := c.http.Do(req)
if err != nil {
return Instance{}, fmt.Errorf("fcapi: GET / over %s: %w", c.socket, err)
}
defer resp.Body.Close()
body, _ := io.ReadAll(resp.Body)
if resp.StatusCode != http.StatusOK {
return Instance{}, fmt.Errorf("fcapi: GET / answered %s: %s", resp.Status, bytes.TrimSpace(body))
}
var in Instance
if err := json.Unmarshal(body, &in); err != nil {
return Instance{}, fmt.Errorf("fcapi: GET /: %w", err)
}
return in, nil
}
func (c *Client) SendCtrlAltDel(ctx context.Context) error {
req, err := http.NewRequestWithContext(ctx, http.MethodPut, "http://localhost/actions",
bytes.NewReader([]byte(`{"action_type":"SendCtrlAltDel"}`)))
if err != nil {
return err
}
req.Header.Set("Content-Type", "application/json")
resp, err := c.http.Do(req)
if err != nil {
return fmt.Errorf("fcapi: PUT /actions SendCtrlAltDel over %s: %w", c.socket, err)
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusNoContent && resp.StatusCode != http.StatusOK {
body, _ := io.ReadAll(resp.Body)
return fmt.Errorf("fcapi: SendCtrlAltDel answered %s: %s", resp.Status, bytes.TrimSpace(body))
}
return nil
}
