EC2: Add new "small" AMIs

These are the same as the standard "base" images except:

* They don't have kernel or world debug symbols,
* They don't have FreeBSD tests,
* They don't have 32-bit libraries,
* They don't have LLDB,
* They don't have the Amazon SSM Agent pre-installed,
* They don't default to installing the awscli at first boot.

This reduces the amount of disk space in use when the EC2 instance
finishes booting from ~5 GB to ~1 GB.

Sponsored by:	Amazon
Differential Revision:	https://reviews.freebsd.org/D46509

(cherry picked from commit 647299caa06e38622dc05a4358f9407b62a9bdda)

2 files changed, 46 insertions, 1 deletions

diff --git a/release/Makefile.vm b/release/Makefile.vm
index 8c48c0a13dc9..3bfe2d8bfee0 100644
--- a/release/Makefile.vm
+++ b/release/Makefile.vm
@@ -35,9 +35,10 @@ BASIC-CLOUDINIT_FSLIST?=	ufs zfs
 BASIC-CLOUDINIT_DESC?=	Images for VM with cloudinit disk config support
 EC2_FORMAT=	raw
 EC2_FSLIST?=	ufs zfs
-EC2_FLAVOURS?=	BASE CLOUD-INIT
+EC2_FLAVOURS?=	BASE CLOUD-INIT SMALL
 EC2-BASE_DESC=	Amazon EC2 image
 EC2-CLOUD-INIT_DESC=	Amazon EC2 Cloud-Init image
+EC2-SMALL_DESC=	Amazon EC2 small image
 GCE_FORMAT=	raw
 GCE_FSLIST?=	ufs zfs
 GCE_DESC=	Google Compute Engine image
diff --git a/release/tools/ec2-small.conf b/release/tools/ec2-small.conf
new file mode 100644
index 000000000000..858836717f5a
--- /dev/null
+++ b/release/tools/ec2-small.conf
@@ -0,0 +1,44 @@
+#!/bin/sh
+
+. ${WORLDDIR}/release/tools/ec2.conf
+
+# Build with a 4.9 GB partition; the growfs rc.d script will expand
+# the partition to fill the root disk after the EC2 instance is launched.
+# Note that if this is set to <N>G, we will end up with an <N+1> GB disk
+# image since VMSIZE is the size of the filesystem partition, not the disk
+# which it resides within.  (This overrides the default in ec2.conf.)
+export VMSIZE=5000m
+
+# Flags to installworld/kernel: We don't want debug symbols (kernel or
+# userland), 32-bit libraries, tests, or the debugger.
+export INSTALLOPTS="WITHOUT_DEBUG_FILES=YES WITHOUT_KERNEL_SYMBOLS=YES \
+    WITHOUT_LIB32=YES WITHOUT_TESTS=YES WITHOUT_LLDB=YES"
+
+# Packages to install into the image we're creating.  In addition to packages
+# present on all EC2 AMIs, we install:
+# * ec2-scripts, which provides a range of EC2ification startup scripts,
+# * firstboot-freebsd-update, to install security updates at first boot,
+# * firstboot-pkgs, to install packages at first boot, and
+# * isc-dhcp44-client, used for IPv6 network setup.
+export VM_EXTRA_PACKAGES="${VM_EXTRA_PACKAGES} ec2-scripts \
+    firstboot-freebsd-update firstboot-pkgs isc-dhcp44-client"
+
+# Services to enable in rc.conf(5).
+export VM_RC_LIST="${VM_RC_LIST} ec2_configinit ec2_ephemeral_swap \
+    ec2_fetchkey ec2_loghostkey firstboot_freebsd_update firstboot_pkgs \
+    growfs sshd"
+
+vm_extra_pre_umount() {
+	# Any EC2 ephemeral disks seen when the system first boots will
+	# be "new" disks; there is no "previous boot" when they might have
+	# been seen and used already.
+	touch ${DESTDIR}/var/db/ec2_ephemeral_diskseen
+
+	# Configuration common to all EC2 AMIs
+	ec2_common
+
+	# Standard FreeBSD network configuration
+	ec2_base_networking
+
+	return 0
+}