Combine host and trampoline OS images into one CI job (#4273)

There are two OS build jobs that each check out and build many
repositories in order to build a host image. By combining them
into one job, we only pay the cost of this checkout and build
phase once. It doesn't actually save a lot of wall time because
the two jobs run in parallel, but it saves starting a VM and
about 20 minutes of compute time.

.github/buildomat/jobs/host-image.sh

@@ -1,11 +1,12 @@
 #!/bin/bash
 #:
-#: name = "helios / build OS image"
+#: name = "helios / build OS images"
 #: variety = "basic"
 #: target = "helios-2.0"
 #: rust_toolchain = "1.72.1"
 #: output_rules = [
-#:	"=/work/helios/image/output/os.tar.gz",
+#:	"=/work/helios/upload/os-host.tar.gz",
+#:	"=/work/helios/upload/os-trampoline.tar.gz",
 #: ]
 #: access_repos = [
 #:	"oxidecomputer/amd-apcb",
@@ -44,14 +45,49 @@ TOP=$PWD
 
 source "$TOP/tools/include/force-git-over-https.sh"
 
-# Checkout helios at a pinned commit into /work/helios
-git clone https://github.com/oxidecomputer/helios.git /work/helios
-cd /work/helios
+# Check out helios into /work/helios
+HELIOSDIR=/work/helios
+git clone https://github.com/oxidecomputer/helios.git "$HELIOSDIR"
+cd "$HELIOSDIR"
+# Record the branch and commit in the output
+git status --branch --porcelain=2
+# Setting BUILD_OS to no makes setup skip repositories we don't need for
+# building the OS itself (we are just building an image from already built OS).
+BUILD_OS=no gmake setup
+
+# Commands that "helios-build" would ask us to run (either explicitly or
+# implicitly, to avoid an error).
+rc=0
+pfexec pkg install -q /system/zones/brand/omicron1/tools || rc=$?
+case $rc in
+    # `man pkg` notes that exit code 4 means no changes were made because
+    # there is nothing to do; that's fine. Any other exit code is an error.
+    0 | 4) ;;
+    *) exit $rc ;;
+esac
+
+pfexec zfs create -p "rpool/images/$USER"
+
 
 # TODO: Consider importing zones here too?
 
 cd "$TOP"
+OUTPUTDIR="$HELIOSDIR/upload"
+mkdir "$OUTPUTDIR"
+
+banner OS
 ./tools/build-host-image.sh -B \
     -S /input/package/work/zones/switch-asic.tar.gz \
-    /work/helios \
+    "$HELIOSDIR" \
     /input/package/work/global-zone-packages.tar.gz
+
+mv "$HELIOSDIR/image/output/os.tar.gz" "$OUTPUTDIR/os-host.tar.gz"
+
+banner Trampoline
+
+./tools/build-host-image.sh -R \
+    "$HELIOSDIR" \
+    /input/package/work/trampoline-global-zone-packages.tar.gz
+
+mv "$HELIOSDIR/image/output/os.tar.gz" "$OUTPUTDIR/os-trampoline.tar.gz"
+

.github/buildomat/jobs/tuf-repo.sh

@@ -19,10 +19,7 @@
 #: job = "helios / package"
 #:
 #: [dependencies.host]
-#: job = "helios / build OS image"
-#:
-#: [dependencies.trampoline]
-#: job = "helios / build trampoline OS image"
+#: job = "helios / build OS images"
 #:
 #: [[publish]]
 #: series = "rot-all"
@@ -139,7 +136,7 @@ name = "$kind"
 version = "$VERSION"
 [artifact.$kind.source]
 kind = "file"
-path = "/input/$kind/work/helios/image/output/os.tar.gz"
+path = "/input/host/work/helios/upload/os-$kind.tar.gz"
 EOF
 done
 

tools/build-host-image.sh

@@ -92,22 +92,6 @@ function main
     # Move to the helios checkout
     cd "$HELIOS_PATH"
 
-    # Create the "./helios-build" command, which lets us build images
-    gmake setup
-
-    # Commands that "./helios-build" would ask us to run (either explicitly
-    # or implicitly, to avoid an error).
-    rc=0
-    pfexec pkg install -q /system/zones/brand/omicron1/tools || rc=$?
-    case $rc in
-        # `man pkg` notes that exit code 4 means no changes were made because
-        # there is nothing to do; that's fine. Any other exit code is an error.
-        0 | 4) ;;
-        *) exit $rc ;;
-    esac
-
-    pfexec zfs create -p rpool/images/"$USER"
-
     HELIOS_REPO=https://pkg.oxide.computer/helios/2/dev/
 
     # Build an image name that includes the omicron and host OS hashes