Setup swapfile in tests/cgroup if needed (#386)

bin/helpers

@@ -344,6 +344,33 @@ certificateFingerprintShort() (
   certificateFingerprint "${1}" | head -c12
 )
 
+# setup_swap: create a temporary swapfile for lxd-ci usage but only if there is no existing swap.
+setup_swap() {
+    if [ "$(swapon --noheading --raw)" != "" ]; then
+        # Swap detected, nothing to do
+        return
+    fi
+
+    SIZE="${1:-1G}"
+    LXD_CI_SWAPFILE="$(mktemp --tmpdir lxd-ci.swapfile.XXXXXXX)"
+    fallocate -l "${SIZE}" "${LXD_CI_SWAPFILE}"
+    chmod 0000 "${LXD_CI_SWAPFILE}"
+    mkswap "${LXD_CI_SWAPFILE}"
+    swapon "${LXD_CI_SWAPFILE}"
+    export LXD_CI_SWAPFILE
+}
+
+# teardown_swap: deactivate and remove any swapfile created by lxd-ci
+teardown_swap() {
+    if [ -z "${LXD_CI_SWAPFILE:-}" ]; then
+        return
+    fi
+
+    swapoff "${LXD_CI_SWAPFILE}"
+    rm "${LXD_CI_SWAPFILE}"
+}
+
+
 # cleanup: report if the test passed or not and return the appropriate return code.
 cleanup() {
     set +e
@@ -393,6 +420,9 @@ cleanup() {
         exit 1
     fi
 
+    # Teardown any swapfile created by lxd-ci
+    teardown_swap
+
     echo "Test passed"
     exit 0
 }

tests/cgroup

@@ -1,6 +1,9 @@
 #!/bin/bash
 set -eu
 
+# Setup swap if none exist
+setup_swap
+
 # Install dependencies
 install_deps jq iperf3