Add examples to installation

Summary:
Examples are added in release/examples directory. Each example
must have its own directory with populate.cyp file inside it.
This file contains graph creation queries written in OpenCypher.
When memgraph is built, database snapshots for each example are
created in release/examples/build directory. During memgraph
installation these snapshots are copied to share/memgraph/examples.

Reviewers: teon.banek, mferencevic

Reviewed By: teon.banek

Subscribers: pullbot

Differential Revision: https://phabricator.memgraph.io/D1036

.gitignore

@@ -18,6 +18,7 @@
 Testing/
 build
 build/
+release/examples/build
 cmake-build-*
 cmake/DownloadProject/
 dist/

CMakeLists.txt

@@ -220,6 +220,7 @@ set(CPACK_DEBIAN_PACKAGE_HOMEPAGE https://memgraph.com)
 set(CPACK_DEBIAN_PACKAGE_CONTROL_EXTRA
     "${CMAKE_CURRENT_SOURCE_DIR}/cmake/debian/conffiles;"
     "${CMAKE_CURRENT_SOURCE_DIR}/cmake/debian/copyright;"
+    "${CMAKE_CURRENT_SOURCE_DIR}/cmake/debian/prerm;"
     "${CMAKE_CURRENT_SOURCE_DIR}/cmake/debian/postrm;"
     "${CMAKE_CURRENT_SOURCE_DIR}/cmake/debian/postinst;")
 set(CPACK_DEBIAN_PACKAGE_SHLIBDEPS ON)

cmake/debian/postinst

@@ -27,6 +27,8 @@ case "$1" in
         chmod 750 /var/lib/memgraph || exit 1
         chown memgraph:adm /var/log/memgraph || exit 1
         chmod 750 /var/log/memgraph || exit 1
+        # Make examples directory immutable (optional)
+        chattr +i -R /usr/share/memgraph/examples || true
     ;;
 
     abort-upgrade|abort-remove|abort-deconfigure)

cmake/debian/prerm

@@ -18,6 +18,8 @@ set -e
 
 case "$1" in
     remove|upgrade|deconfigure|failed-upgrade)
+        # Remove optional immutability from examples directory to allow removal
+        chattr -i -R /usr/share/memgraph/examples || true
         if [ -d /run/systemd/system ]; then
             deb-systemd-invoke stop memgraph.service >/dev/null
         fi

release/examples/build_examples

@@ -0,0 +1,44 @@
+#!/bin/bash -e
+
+script_dir="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+build_dir="build"
+query="populate.cyp"
+
+cd $script_dir
+
+if [ -d "$build_dir" ]; then
+  rm -rf "$build_dir"
+fi
+
+mkdir "$build_dir"
+
+
+for dir in queries/*/
+do
+  cd $script_dir # position to script execution dir
+
+  dir=${dir%*/}
+  example=${dir#*/}
+
+  # create snapshots directory for each example
+  snapshots_dir="$build_dir/$example"
+  mkdir -p "$snapshots_dir"
+
+  # run memgraph with durability_directory pointing
+  # to examples snapshots_dir
+  cd ../../build/
+  ./memgraph --durability-directory "$script_dir/$snapshots_dir/" \
+             --snapshot-on-exit > /dev/null 2>&1 &
+  memgraph_pid=$!
+  sleep 2 # wait for memgraph to start
+
+  cd tests/manual
+  # create data using bolt-client
+  ./bolt_client < "$script_dir/$dir/$query" > /dev/null 2>&1 || exit 1
+
+  # kill memgraph
+  kill $memgraph_pid
+
+  # wait for memgraph to terminate
+  wait $memgraph_pid
+done

src/CMakeLists.txt

@@ -118,3 +118,9 @@ install(FILES ${CMAKE_SOURCE_DIR}/release/LICENSE.md
 install(FILES ${CMAKE_SOURCE_DIR}/release/memgraph.service
         DESTINATION /lib/systemd/system)
 
+# Install examples
+set(examples ${CMAKE_SOURCE_DIR}/release/examples)
+install(CODE "execute_process(COMMAND ${examples}/build_examples
+                              WORKING_DIRECTORY ${examples})")
+install(DIRECTORY ${examples}/build/ DESTINATION share/memgraph/examples)
+