Add docker-lib.sh

Author: philwebb

ci/images/docker-lib.sh

@@ -0,0 +1,112 @@
+# Based on: https://github.com/concourse/docker-image-resource/blob/master/assets/common.sh
+
+DOCKER_LOG_FILE=${DOCKER_LOG_FILE:-/tmp/docker.log}
+SKIP_PRIVILEGED=${SKIP_PRIVILEGED:-false}
+STARTUP_TIMEOUT=${STARTUP_TIMEOUT:-120}
+
+sanitize_cgroups() {
+  mkdir -p /sys/fs/cgroup
+  mountpoint -q /sys/fs/cgroup || \
+    mount -t tmpfs -o uid=0,gid=0,mode=0755 cgroup /sys/fs/cgroup
+
+  mount -o remount,rw /sys/fs/cgroup
+
+  sed -e 1d /proc/cgroups | while read sys hierarchy num enabled; do
+    if [ "$enabled" != "1" ]; then
+      # subsystem disabled; skip
+      continue
+    fi
+
+    grouping="$(cat /proc/self/cgroup | cut -d: -f2 | grep "\\<$sys\\>")" || true
+    if [ -z "$grouping" ]; then
+      # subsystem not mounted anywhere; mount it on its own
+      grouping="$sys"
+    fi
+
+    mountpoint="/sys/fs/cgroup/$grouping"
+
+    mkdir -p "$mountpoint"
+
+    # clear out existing mount to make sure new one is read-write
+    if mountpoint -q "$mountpoint"; then
+      umount "$mountpoint"
+    fi
+
+    mount -n -t cgroup -o "$grouping" cgroup "$mountpoint"
+
+    if [ "$grouping" != "$sys" ]; then
+      if [ -L "/sys/fs/cgroup/$sys" ]; then
+        rm "/sys/fs/cgroup/$sys"
+      fi
+
+      ln -s "$mountpoint" "/sys/fs/cgroup/$sys"
+    fi
+  done
+
+  if ! test -e /sys/fs/cgroup/systemd ; then
+    mkdir /sys/fs/cgroup/systemd
+    mount -t cgroup -o none,name=systemd none /sys/fs/cgroup/systemd
+  fi
+}
+
+start_docker() {
+  mkdir -p /var/log
+  mkdir -p /var/run
+
+  if [ "$SKIP_PRIVILEGED" = "false" ]; then
+    sanitize_cgroups
+
+    # check for /proc/sys being mounted readonly, as systemd does
+    if grep '/proc/sys\s\+\w\+\s\+ro,' /proc/mounts >/dev/null; then
+      mount -o remount,rw /proc/sys
+    fi
+  fi
+
+  local mtu=$(cat /sys/class/net/$(ip route get 8.8.8.8|awk '{ print $5 }')/mtu)
+  local server_args="--mtu ${mtu}"
+  local registry=""
+
+  server_args="${server_args}"
+
+  for registry in $3; do
+    server_args="${server_args} --insecure-registry ${registry}"
+  done
+
+  if [ -n "$4" ]; then
+    server_args="${server_args} --registry-mirror $4"
+  fi
+
+  try_start() {
+    dockerd --data-root /scratch/docker ${server_args} >$DOCKER_LOG_FILE 2>&1 &
+    echo $! > /tmp/docker.pid
+
+    sleep 1
+
+    echo waiting for docker to come up...
+    until docker info >/dev/null 2>&1; do
+      sleep 1
+      if ! kill -0 "$(cat /tmp/docker.pid)" 2>/dev/null; then
+        return 1
+      fi
+    done
+  }
+
+  export server_args DOCKER_LOG_FILE
+  declare -fx try_start
+  trap stop_docker EXIT
+
+  if ! timeout ${STARTUP_TIMEOUT} bash -ce 'while true; do try_start && break; done'; then
+    echo Docker failed to start within ${STARTUP_TIMEOUT} seconds.
+    return 1
+  fi
+}
+
+stop_docker() {
+  local pid=$(cat /tmp/docker.pid)
+  if [ -z "$pid" ]; then
+    return 0
+  fi
+
+  kill -TERM $pid
+}
+