diff options
Diffstat (limited to 'tvix/tests/tvix-init.go')
| -rw-r--r-- | tvix/tests/tvix-init.go | 97 |
1 files changed, 75 insertions, 22 deletions
diff --git a/tvix/tests/tvix-init.go b/tvix/tests/tvix-init.go index a81001159ae2..97a24bab3547 100644 --- a/tvix/tests/tvix-init.go +++ b/tvix/tests/tvix-init.go @@ -1,6 +1,7 @@ package main import ( + "fmt" "log" "os" "os/exec" @@ -37,11 +38,41 @@ func parseCmdline(cmdline string) map[string]string { return out } +// mounts the nix store from the virtiofs tag to the given destination, +// creating the destination if it doesn't exist already. +func mountTvixStore(dest string) error { + if err := os.MkdirAll(dest, os.ModePerm); err != nil { + return fmt.Errorf("unable to mkdir dest: %w", err) + } + if err := run("mount", "-t", "virtiofs", "tvix", dest, "-o", "ro"); err != nil { + return fmt.Errorf("unable to run mount: %w", err) + } + + return nil +} + func main() { - log.Println("Running tvix-init…") + fmt.Print(` + ______ _ ____ _ __ + /_ __/ __(_) __ / _/___ (_) /_ + / / | | / / / |/_/ / // __ \/ / __/ + / / | |/ / /> < _/ // / / / / /_ +/_/ |___/_/_/|_| /___/_/ /_/_/\__/ + +`) - log.Println("Creating /nix/store") - os.MkdirAll("/nix/store", os.ModePerm) + // Set PATH to "/bbin", so we can find the u-root tools + os.Setenv("PATH", "/bbin") + + if err := run("mount", "-t", "proc", "none", "/proc"); err != nil { + log.Printf("Failed to mount /proc: %v\n", err) + } + if err := run("mount", "-t", "sysfs", "none", "/sys"); err != nil { + log.Printf("Failed to mount /sys: %v\n", err) + } + if err := run("mount", "-t", "devtmpfs", "devtmpfs", "/dev"); err != nil { + log.Printf("Failed to mount /dev: %v\n", err) + } cmdline, err := os.ReadFile("/proc/cmdline") if err != nil { @@ -49,37 +80,59 @@ func main() { } cmdlineFields := parseCmdline(string(cmdline)) - log.Println("Mounting…") - if err := run("mount", "-t", "virtiofs", "tvix", "/nix/store", "-o", "ro"); err != nil { - log.Printf("Failed to run mount: %v\n", err) - } - - // If tvix.find is set, invoke find /nix/store if _, ok := cmdlineFields["tvix.find"]; ok { - log.Println("Listing…") + // If tvix.find is set, invoke find /nix/store + if err := mountTvixStore("/nix/store"); err != nil { + log.Printf("Failed to mount tvix store: %v\n", err) + } + if err := run("find", "/nix/store"); err != nil { log.Printf("Failed to run find command: %s\n", err) } - } + } else if _, ok := cmdlineFields["tvix.shell"]; ok { + // If tvix.shell is set, mount the nix store to /nix/store directly, + // then invoke the elvish shell + if err := mountTvixStore("/nix/store"); err != nil { + log.Printf("Failed to mount tvix store: %v\n", err) + } - // If tvix.shell is set, invoke the elvish shell - if v, ok := cmdlineFields["tvix.shell"]; ok { - log.Printf("Invoking shell%s\n…", v) if err := run("elvish"); err != nil { log.Printf("Failed to run shell: %s\n", err) } - } + } else if v, ok := cmdlineFields["tvix.run"]; ok { + // If tvix.run is set, mount the nix store to /nix/store directly, + // then invoke the command. + if err := mountTvixStore("/nix/store"); err != nil { + log.Printf("Failed to mount tvix store: %v\n", err) + } + + if err := run(v); err != nil { + log.Printf("Failed to run command: %s\n", err) + } + } else if v, ok := cmdlineFields["init"]; ok { + // If init is set, invoke the binary specified (with switch_root), + // and prepare /fs beforehand as well. + os.Mkdir("/fs", os.ModePerm) + if err := run("mount", "-t", "tmpfs", "none", "/fs"); err != nil { + log.Fatalf("Failed to mount /fs tmpfs: %s\n", err) + } + + // Mount /fs/nix/store + if err := mountTvixStore("/fs/nix/store"); err != nil { + log.Fatalf("Failed to mount tvix store: %v\n", err) + } - // If tvix.exec is set, invoke the binary specified - if v, ok := cmdlineFields["tvix.exec"]; ok { - log.Printf("Invoking %s\n…", v) - if err := syscall.Exec(v, []string{v}, []string{}); err != nil { - log.Printf("Failed to exec: %s\n", err) + // Invoke switch_root, which will take care of moving /proc, /sys and /dev. + if err := syscall.Exec("/bbin/switch_root", []string{"switch_root", "/fs", v}, []string{}); err != nil { + log.Printf("Failed to switch root: %s\n", err) } + } else { + log.Printf("No command detected, not knowing what to do!") } - log.Println("Powering off") + // This is only reached in the non switch_root case. + log.Printf("Nothing left to be done, powering off.") if err := run("poweroff"); err != nil { - log.Printf("Failed to run command: %v\n", err) + log.Printf("Failed to run poweroff command: %v\n", err) } } |