nova-image: use wget instead of cloud-init (via EC2 API)

The Openstack metadata service exposes the EC2 API. We use the
existing `ec2.nix` module to configure the hostname and ssh keys of an
Openstack Instance.

A test checks the ssh server is well configured.

This is mainly to reduce the size of the image (700MB). Also,
declarative features provided by cloud-init are not really useful
since we would prefer to use our `configuration.nix` file instead.

1 files changed, 61 insertions, 0 deletions

diff --git a/nixos/tests/common/ec2.nix b/nixos/tests/common/ec2.nix
new file mode 100644
index 00000000000..99a39473b61
--- /dev/null
+++ b/nixos/tests/common/ec2.nix
@@ -0,0 +1,61 @@
+{ pkgs, makeTest }:
+
+with pkgs.lib;
+
+{
+  makeEc2Test = { name, image, userData, script, hostname ? "ec2-instance", sshPublicKey ? null }:
+    let
+      metaData = pkgs.stdenv.mkDerivation {
+        name = "metadata";
+        buildCommand = ''
+          mkdir -p $out/1.0/meta-data
+          ln -s ${pkgs.writeText "userData" userData} $out/1.0/user-data
+          echo "${hostname}" > $out/1.0/meta-data/hostname
+          echo "(unknown)" > $out/1.0/meta-data/ami-manifest-path
+        '' + optionalString (sshPublicKey != null) ''
+          mkdir -p $out/1.0/meta-data/public-keys/0
+          ln -s ${pkgs.writeText "sshPublicKey" sshPublicKey} $out/1.0/meta-data/public-keys/0/openssh-key
+        '';
+      };
+    in makeTest {
+      name = "ec2-" + name;
+      nodes = {};
+      testScript =
+        ''
+          my $imageDir = ($ENV{'TMPDIR'} // "/tmp") . "/vm-state-machine";
+          mkdir $imageDir, 0700;
+          my $diskImage = "$imageDir/machine.qcow2";
+          system("qemu-img create -f qcow2 -o backing_file=${image}/nixos.qcow2 $diskImage") == 0 or die;
+          system("qemu-img resize $diskImage 10G") == 0 or die;
+
+          # Note: we use net=169.0.0.0/8 rather than
+          # net=169.254.0.0/16 to prevent dhcpcd from getting horribly
+          # confused. (It would get a DHCP lease in the 169.254.*
+          # range, which it would then configure and prompty delete
+          # again when it deletes link-local addresses.) Ideally we'd
+          # turn off the DHCP server, but qemu does not have an option
+          # to do that.
+          my $startCommand = "qemu-kvm -m 768";
+          $startCommand .= " -device virtio-net-pci,netdev=vlan0";
+          $startCommand .= " -netdev 'user,id=vlan0,net=169.0.0.0/8,guestfwd=tcp:169.254.169.254:80-cmd:${pkgs.micro-httpd}/bin/micro_httpd ${metaData}'";
+          $startCommand .= " -drive file=$diskImage,if=virtio,werror=report";
+          $startCommand .= " \$QEMU_OPTS";
+
+          my $machine = createMachine({ startCommand => $startCommand });
+
+          ${script}
+        '';
+    };
+
+  snakeOilPrivateKey = ''
+    -----BEGIN OPENSSH PRIVATE KEY-----
+    b3BlbnNzaC1rZXktdjEAAAAABG5vbmUAAAAEbm9uZQAAAAAAAAABAAAAMwAAAAtzc2gtZW
+    QyNTUxOQAAACDEPmwZv5dDPrMUaq0dDP+6eBTTe+QNrz14KBEIdhHd1QAAAJDufJ4S7nye
+    EgAAAAtzc2gtZWQyNTUxOQAAACDEPmwZv5dDPrMUaq0dDP+6eBTTe+QNrz14KBEIdhHd1Q
+    AAAECgwbDlYATM5/jypuptb0GF/+zWZcJfoVIFBG3LQeRyGsQ+bBm/l0M+sxRqrR0M/7p4
+    FNN75A2vPXgoEQh2Ed3VAAAADEVDMiB0ZXN0IGtleQE=
+    -----END OPENSSH PRIVATE KEY-----
+  '';
+
+  snakeOilPublicKey = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIMQ+bBm/l0M+sxRqrR0M/7p4FNN75A2vPXgoEQh2Ed3V EC2 test key";
+}