docker: install for linux

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

scripts/setup-docker-linux.sh

@@ -0,0 +1,51 @@
+#!/usr/bin/env bash
+
+set -eu
+
+: "${TOOLDIR=}"
+: "${RUNDIR=}"
+: "${DOCKER_HOST=}"
+
+export PATH="$TOOLDIR::$PATH"
+
+if [ -z "$DOCKER_HOST" ]; then
+  echo >&2 'error: DOCKER_HOST required'
+  false
+fi
+
+if ! command -v dockerd &> /dev/null; then
+  echo >&2 'error: dockerd missing from PATH'
+  false
+fi
+
+(
+  echo "Starting dockerd"
+  set -x
+  exec dockerd \
+    --host="$DOCKER_HOST" \
+    --exec-root="$RUNDIR/execroot" \
+    --data-root="$RUNDIR/data" \
+    --pidfile="$RUNDIR/docker.pid" \
+    --userland-proxy=false \
+    2>&1 | tee "$RUNDIR/dockerd.log"
+) &
+
+tries=60
+echo "Waiting for daemon to start..."
+while ! docker version &> /dev/null; do
+	((tries--))
+	if [ $tries -le 0 ]; then
+		printf "\n"
+		if [ -z "$DOCKER_HOST" ]; then
+			echo >&2 "error: daemon failed to start"
+			echo >&2 "  check $RUNDIR/docker.log for details"
+		else
+			echo >&2 "error: daemon at $DOCKER_HOST fails to 'docker version':"
+			docker version >&2 || true
+		fi
+		false
+	fi
+	printf "."
+	sleep 2
+done
+printf "\n"