nomad: add initial jobspec

This is important if we want Nomad to regulate and limit the amount of 
memory that jobs use.

jobs/test/test.job

@@ -1,7 +0,0 @@
-#!/usr/bin/env bash
-
-RUN "uptime";
-
-COPY "${JOBFILE_DIR}/testfile.txt" "/tmp";
-
-RUN "rm /tmp/testfile.txt";

jobs/test/testfile.txt

@@ -1 +0,0 @@
-it works!

src/steps-config/80-nomad.sh

@@ -0,0 +1,18 @@
+#!/usr/bin/env bash
+
+nomad_mode="$(ask_multichoice "Nomad installation mode" "none" "client" "server" "both")";
+
+if [[ "${nomad_mode}" != "none" ]]; then
+	queue_apt_install "hashicorp-nomad";
+	case "${nomad_mode}" in
+		client )
+			queue_apt_install "hashicorp-nomad-systemd-client";
+			;;
+		server )
+			queue_apt_install "hashicorp-nomad-systemd-server";
+			;;
+		both )
+			queue_apt_install "hashicorp-nomad-systemd-both";
+			;;
+	esac
+fi

src/steps-postinstall/75-consul.sh

@@ -12,7 +12,7 @@ subtask_end "$?";
 # No UFW rules required, as we're now using wesher/wireguard, and allowing all inbound traffic on that interface
 
 subtask_begin "Starting Consul and enabling on boot";
-systemctl consul;
+systemctl enable --now consul;
 subtask_end "$?";
 
 task_end "$?";

src/steps-postinstall/80-nomad.sh

@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+
+
+task_begin "Installing Nomad configuration";
+# /etc/nomad is created by the apt postinstall script
+
+subtask_begin "Copying configuration files";
+cp "configs/nomad-client.hcl" "/etc/nomad/client.hcl";
+cp "configs/nomad-server.hcl" "/etc/nomad/server.hcl";
+cp "configs/nomad-both.hcl" "/etc/nomad/both.hcl";
+subtask_end "$?";
+
+# No UFW rules required, as we're now using wesher/wireguard, and allowing all inbound traffic on that interface
+
+subtask_begin "Starting Nomad and enabling on boot";
+systemctl enable --now nomad;
+subtask_end "$?";
+
+task_end "$?";

src/steps-preinstall/50-cgroups-memory.sh

@@ -0,0 +1,39 @@
+#!/usr/bin/env bash
+
+check_cgroups_memory() {
+	task_begin "Checking memory cgroups";
+	
+	cgroups_enabled="$(awk '/memory/ { print $2 }' < /proc/cgroups)";
+	
+	if [[ "${cgroups_enabled}" -ne 0 ]]; then
+		echo ">>> memory cgroups already enabled";
+		return 0;
+	fi
+	
+	
+	filepath_cmdline="/boot/cmdline.txt";
+	if [[ ! -e "${filepath_cmdline}" ]]; then
+		filepath_cmdline="/boot/firmware/cmdline.txt";
+	fi
+	if [[ ! -e "${filepath_cmdline}" ]]; then
+		echo ">>> Failed to find cmdline.txt; can't check for cgroups";
+		return 1;
+	fi
+	
+	if grep -q cgroup_enable=memory /boot/cmdline.txt; then
+		echo ">>> memory cgroups already present in cmdline.txt, a reboot is required to apply the update";
+		return 0;
+	fi
+	
+	echo ">>> memory cgroups not present in cmdline.txt, enabling....";
+	(tr -d '\n' <"${filepath_cmdline}" && echo " cgroup_enable=memory cgroup_memory=1") | sudo tee "${filepath_cmdline}.new";
+	
+	sudo mv "${filepath_cmdline}" "${filepath_cmdline}.old-$(date +"%Y-%m-%d")";
+	sudo mv "${filepath_cmdline}.new" "${filepath_cmdline}";
+	
+	echo ">>> New contents of cmdline.txt:";
+	cat "${filepath_cmdline}";
+	echo ">>> A reboot is required to apply the changes.";
+	
+	task_end "$?" "Failed to check memory cgroups"
+}