Refactor the hook logic into a reusable function

Hook logic exists twice. Let's refactor it into a function
so that it can be reused for more hooks.

Include some test cases.

Test cases don't like doing 'sudo mv', so let's not use it if not necessary.

Change-Id: I84d2fd66265c8e2e77faf16ce03e92790f2f51b8

devstack-vm-gate-wrap.sh

@@ -391,14 +391,7 @@ fi
 export DEVSTACK_GATE_TOPOLOGY=${DEVSTACK_GATE_TOPOLOGY:-aio}
 
 # Run pre test hook if we have one
-if function_exists "pre_test_hook"; then
-    echo "Running pre_test_hook"
-    xtrace=$(set +o | grep xtrace)
-    set -o xtrace
-    tsfilter pre_test_hook | tee $WORKSPACE/devstack-gate-pre-test-hook.txt
-    sudo mv $WORKSPACE/devstack-gate-pre-test-hook.txt $BASE/logs/
-    $xtrace
-fi
+call_hook_if_defined "pre_test_hook"
 
 # Run the gate function
 echo "Running gate_hook"
@@ -412,15 +405,10 @@ if [ $GATE_RETVAL -ne 0 ]; then
 fi
 
 # Run post test hook if we have one
-if [ $GATE_RETVAL -eq 0 ] && function_exists "post_test_hook"; then
-    echo "Running post_test_hook"
-    xtrace=$(set +o | grep xtrace)
-    set -o xtrace -o pipefail
-    tsfilter post_test_hook | tee $WORKSPACE/devstack-gate-post-test-hook.txt
+if [ $GATE_RETVAL -eq 0 ]; then
+    # Run post_test_hook if we have one
+    call_hook_if_defined "post_test_hook"
     RETVAL=$?
-    sudo mv $WORKSPACE/devstack-gate-post-test-hook.txt $BASE/logs/
-    set +o pipefail
-    $xtrace
 fi
 
 if [ $GATE_RETVAL -eq 137 ] && [ -f $WORKSPACE/gate.pid ] ; then

functions.sh

@@ -41,6 +41,23 @@ function function_exists {
     type $1 2>/dev/null | grep -q 'is a function'
 }
 
+function call_hook_if_defined {
+    local hook_name=$1
+    local filename=${2-$WORKSPACE/devstack-gate-$hook_name.txt}
+    local save_dir=${3-$BASE/logs/}
+    if function_exists $hook_name; then
+        echo "Running $hook_name"
+        xtrace=$(set +o | grep xtrace)
+        set -o xtrace -o pipefail
+        tsfilter $hook_name | tee $filename
+        local ret_val=$?
+        mv $filename $save_dir
+        set +o pipefail
+        $xtrace
+        return $ret_val
+    fi
+}
+
 # awk filter to timestamp the stream, including stderr merging
 function tsfilter {
     $@ 2>&1 | awk '

test-functions.sh

@@ -401,6 +401,59 @@ function test_workspace_branch_arg {
     assert_raises setup_workspace
 }
 
+function test_call_hook_if_defined {
+
+    local filename=test_call_hook_if_defined.txt
+    local save_dir=`pwd`/tmp
+
+    mkdir -p $save_dir
+
+    function demo_script {
+        local filename=$1
+        local save_dir=$2
+        # Clean up any files from previous tests
+        rm -f $save_dir/$filename
+        call_hook_if_defined test_hook $filename $save_dir
+        ret_val=$?
+        return $ret_val
+    }
+
+    # No hook defined returns success 0 & no file created
+    demo_script $filename $save_dir
+    ret_val=$?
+    assert_equal "$ret_val" "0"
+
+    [[ -e $save_dir/$filename ]]
+    file_exists=$?
+    assert_equal $file_exists 1
+
+    # Hook defined returns its error code and file with output
+    function test_hook {
+        echo "hello test_hook"
+        return 123
+    }
+    demo_script $filename $save_dir
+    ret_val=$?
+    assert_equal "$ret_val" "123"
+
+    [[ -e $save_dir/$filename ]]
+    file_exists=$?
+    assert_equal $file_exists 0
+
+    # Make sure the expected contents has length > 0
+    result_expected=`cat $save_dir/$filename | grep "hello test_hook"`
+    [[ ${#result_expected} -eq "0" ]]
+    assert_equal $? 1
+
+    # Hook defined with invalid file fails
+    demo_script /invalid/file.txt $save_dir
+    ret_val=$?
+    assert_equal "$ret_val" "1"
+
+    # Clean up
+    rm -rf $save_dir
+}
+
 # Run tests:
 #set -o xtrace
 test_branch_override
@@ -413,6 +466,7 @@ test_one_on_master
 test_periodic
 test_two_on_master
 test_workspace_branch_arg
+test_call_hook_if_defined
 
 if [[ ! -z "$ERROR" ]]; then
     echo