cmd/remote-session: use --init instead of dumb-init

I'd like to reuse the `cosa remote-session` bits to run non-cosa images
on remote builders. Since it's mostly a wrapper around `podman --remote`,
it has very few requirements on the target image.

One of the requirements I'd like to loosen is on `dumb-init`. That one
is easy to drop since podman has built-in support for making pid 1 an
init-like system. Use that instead.

We still need to override the entrypoint though so that we can run sleep
instead of cosa.

Author: jlebon

cmd/remote-session.go

@@ -144,8 +144,9 @@ func runCreate(c *cobra.Command, args []string) error {
 		"--volume=secex-data:/data.secex:ro",
 		"--uidmap=1000:0:1", "--uidmap=0:1:1000", "--uidmap=1001:1001:64536",
 		"--device=/dev/kvm", "--device=/dev/fuse", "--tmpfs=/tmp",
-		"--entrypoint=/usr/bin/dumb-init", remoteSessionOpts.CreateImage,
-		"sleep", remoteSessionOpts.CreateExpiration}
+		"--init", "--entrypoint=/usr/bin/sleep",
+		remoteSessionOpts.CreateImage,
+		remoteSessionOpts.CreateExpiration}
 	cmd := exec.Command("podman", podmanargs...)
 	cmd.Stdout = os.Stdout
 	cmd.Stderr = os.Stderr