From: Vratko Polak <vrpolak@cisco.com>
Date: Wed, 10 Jul 2019 11:59:50 +0000 (+0200)
Subject: Bash functions style cleanup
X-Git-Url: https://gerrit.fd.io/r/gitweb?p=csit.git;a=commitdiff_plain;h=36d56bdb7f9f394047e2df3f29bf47db877b649c

Bash functions style cleanup

+ Update rst documentation for bash style
 + Command substitution:
  + Clarify when to use backticks.
  + Recommend avoiding nested command substitution.
  + Do not recommend putting command substitution results into quotes.
 + Function definition content:
  + Move "set -exuo pipefail" after comment only blocks.
  + Other set flags allowed for functions with good reasons.
+ Apply the new recommendations.
 - Blank lines unified in code but no written recommendation in rst.
+ Add missing references to functions called, variables read or set.
 + Add TODOs to where lists would be long.
+ Minor improvements to function descriptions.
+ Make "if" expressions more python-like.
+ Add missing "|| die" (or "|| true") where spotted.
+ Downgrade DEFAULT_NIC to a local variable.
+ Add TODO to list reasons for blacklisted tags.

Change-Id: I05dce030a8c2cb1b3a242d8b977e8fe150d8ee20
Signed-off-by: Vratko Polak <vrpolak@cisco.com>
---

diff --git a/docs/bash_code_style.rst b/docs/bash_code_style.rst
index e5dbc9c06e..e955f72ab4 100644
--- a/docs/bash_code_style.rst
+++ b/docs/bash_code_style.rst
@@ -82,22 +82,24 @@ Safety
 
     + TODO: Consider giving examples both for good and bad usage.
 
-  + Command substitution on right hand side of assignment should be safe
+  + Command substitution on right hand side of assignment are safe
     without quotes.
 
-    + But still, quotes are RECOMMENDED, unless line length is a concern.
-
     + Note that command substitution limits the scope for quotes,
       so it is NOT REQUIRED to escape the quotes in deeper levels.
 
-    + TODO: Do we prefer backtics, or "dollar round-bracket"?
+    + Both backtics and "dollar round-bracket" provide command substitution.
+      The folowing rules are RECOMMENDED:
+
+      + For simple constructs, use "dollar round-bracket".
 
-      + Backticks are more readable, especially when there are
-        round brackets in the surrounding text.
+      + If there are round brackets in the surrounding text, use backticks,
+        as some editor highlighting logic can get confused.
 
-      + Backticks do not allow nested command substitution.
+      + Avoid nested command substitution.
 
-        + But we might want to avoid nested command substitution anyway?
+        + Put intermediate results into local variables,
+          use "|| die" on each step of command substitution.
 
   + Code SHOULD NOT be structured in a way where
     word splitting is intended.
@@ -541,21 +543,25 @@ Library documentation
 
 + Then SHALL be the function definitions, and inside:
 
-  + "set -exuo pipefail" again.
-
-  + Following that SHALL be the function documentation explaining API contract.
+  + The body SHALL sart with the function documentation explaining API contract.
     Similar to Robot [Documentation] or Python function-level docstring.
 
     + See below.
 
-  + Following that SHALL be varius TODOs, FIXMEs and code itself.
+  + Following that SHALL be various top-level TODOs and FIXMEs.
+
+    + TODO: Document (in an appropriate place) how TODOs differ from FIXMEs.
+
+  + "set -exuo pipefail" SHALL be the first executable line
+    in the function body, except functions which legitimely need
+    different flags. Those SHALL also start with appropriate "set" command(s).
+
+  + Lines containing code itself SHALL follow.
 
     + "Code itself" SHALL include comment lines
       explaining any non-obvious logic.
 
-    + TODO: Document (in an appropriate place) how TODOs differ from FIXMEs.
-
-  + There SHALL be two empty lines before next function definition.
+  + There SHALL be two empty lines between function definitions.
 
 More details on function documentation:
 
diff --git a/resources/libraries/bash/function/ansible.sh b/resources/libraries/bash/function/ansible.sh
index 663861e8d8..5bf122e4b0 100644
--- a/resources/libraries/bash/function/ansible.sh
+++ b/resources/libraries/bash/function/ansible.sh
@@ -17,6 +17,7 @@ set -exuo pipefail
 
 
 function ansible_hosts () {
+
     # Run ansible playbook on hosts in working topology file. Ansible scope is
     # determined by tags passed as parameters to this function.
     #
@@ -51,15 +52,15 @@ function ansible_hosts () {
 
 function installed () {
 
-    set -exuo pipefail
-
     # Check if the given utility is installed. Fail if not installed.
     #
     # Arguments:
     # - ${1} - Utility to check.
-    # Returns:
+    # Returns (implicitly):
     # - 0 - If command is installed.
     # - 1 - If command is not installed.
 
+    set -exuo pipefail
+
     command -v "${1}"
-}
\ No newline at end of file
+}
diff --git a/resources/libraries/bash/function/artifacts.sh b/resources/libraries/bash/function/artifacts.sh
index fc9c886a3b..fe755af9d9 100644
--- a/resources/libraries/bash/function/artifacts.sh
+++ b/resources/libraries/bash/function/artifacts.sh
@@ -17,12 +17,17 @@
 set -exuo pipefail
 
 function download_artifacts () {
-    # Get and/or install VPP artifacts from packagecloud.io.
+
+    # Download or install VPP artifacts from packagecloud.io.
     #
     # Variables read:
     # - CSIT_DIR - Path to existing root of local CSIT git repository.
     # Variables set:
     # - REPO_URL - FD.io Packagecloud repository.
+    # Functions conditionally called (see their documentation for side effects):
+    # - download_ubuntu_artifacts
+    # - download_centos_artifacts
+    # - download_opensuse_artifacts
 
     set -exuo pipefail
 
@@ -51,12 +56,14 @@ function download_artifacts () {
 }
 
 function download_ubuntu_artifacts () {
-    # Get and/or install Ubuntu VPP artifacts from packagecloud.io.
+
+    # Download or install Ubuntu VPP artifacts from packagecloud.io.
     #
     # Variables read:
     # - REPO_URL - FD.io Packagecloud repository.
     # - VPP_VERSION - VPP version.
-    # - INSTALL - If install packages or download only. Default: download
+    # - INSTALL - Whether install packages (if set to "true") or download only.
+    #             Default: "false".
 
     set -exuo pipefail
 
@@ -112,7 +119,7 @@ function download_ubuntu_artifacts () {
     done
     set -x
 
-    if [ "${INSTALL:-false}" = true ]; then
+    if [[ "${INSTALL:-false}" == "true" ]]; then
         sudo apt-get -y install "${artifacts[@]}" || {
             die "Install VPP artifacts failed."
         }
@@ -124,12 +131,14 @@ function download_ubuntu_artifacts () {
 }
 
 function download_centos_artifacts () {
-    # Get and/or install CentOS VPP artifacts from packagecloud.io.
+
+    # Download or install CentOS VPP artifacts from packagecloud.io.
     #
     # Variables read:
     # - REPO_URL - FD.io Packagecloud repository.
     # - VPP_VERSION - VPP version.
-    # - INSTALL - If install packages or download only. Default: download
+    # - INSTALL - Whether install packages (if set to "true") or download only.
+    #             Default: "false".
 
     set -exuo pipefail
 
@@ -145,7 +154,7 @@ function download_centos_artifacts () {
         artifacts+=(${packages[@]/%/-${VPP_VERSION-}})
     fi
 
-    if [ "${INSTALL:-false}" = true ]; then
+    if [[ "${INSTALL:-false}" == "true" ]]; then
         sudo yum -y install "${artifacts[@]}" || {
             die "Install VPP artifact failed."
         }
@@ -157,12 +166,14 @@ function download_centos_artifacts () {
 }
 
 function download_opensuse_artifacts () {
-    # Get and/or install OpenSuSE VPP artifacts from packagecloud.io.
+
+    # Download or install OpenSuSE VPP artifacts from packagecloud.io.
     #
     # Variables read:
     # - REPO_URL - FD.io Packagecloud repository.
     # - VPP_VERSION - VPP version.
-    # - INSTALL - If install packages or download only. Default: download
+    # - INSTALL - Whether install packages (if set to "true") or download only.
+    #             Default: "false".
 
     set -exuo pipefail
 
@@ -178,7 +189,7 @@ function download_opensuse_artifacts () {
         artifacts+=(${packages[@]/%/-${VPP_VERSION-}})
     fi
 
-    if [ "${INSTALL:-false}" = true ]; then
+    if [[ "${INSTALL:-false}" == "true" ]]; then
         sudo yum -y install "${artifacts[@]}" || {
             die "Install VPP artifact failed."
         }
diff --git a/resources/libraries/bash/function/artifacts_hc.sh b/resources/libraries/bash/function/artifacts_hc.sh
index 86c7f49819..7a866f6596 100644
--- a/resources/libraries/bash/function/artifacts_hc.sh
+++ b/resources/libraries/bash/function/artifacts_hc.sh
@@ -16,12 +16,16 @@
 set -exuo pipefail
 
 function download_artifacts_hc () {
-    # Get and/or install HC artifacts from packagecloud.io.
+
+    # Download or install HC artifacts from packagecloud.io.
     #
     # Variables read:
     # - CSIT_DIR - Path to existing root of local CSIT git repository.
     # Variables set:
     # - REPO_URL - FD.io Packagecloud repository.
+    # Functions conditionally called (see their documentation for side effects):
+    # - download_ubuntu_artifacts_hc
+    # - download_centos_artifacts_hc
 
     set -exuo pipefail
 
@@ -48,12 +52,14 @@ function download_artifacts_hc () {
 }
 
 function download_ubuntu_artifacts_hc () {
-    # Get and/or install Ubuntu HC artifacts from packagecloud.io.
+
+    # Download or install Ubuntu HC artifacts from packagecloud.io.
     #
     # Variables read:
     # - REPO_URL - FD.io Packagecloud repository.
     # - HC_VERSION - HC version.
-    # - INSTALL - If install packages or download only. Default: download
+    # - INSTALL - Whether install packages (if set to "true") or download only.
+    #             Default: "false".
 
     set -exuo pipefail
 
@@ -69,7 +75,7 @@ function download_ubuntu_artifacts_hc () {
         artifacts+=(${hc[@]/%/=${HC_VERSION-}})
     fi
 
-    if [ "${INSTALL:-false}" = true ]; then
+    if [[ "${INSTALL:-false}" == "true" ]]; then
         sudo apt-get -y install "${artifacts[@]}" || {
             die "Install HC artifacts failed."
         }
@@ -81,12 +87,14 @@ function download_ubuntu_artifacts_hc () {
 }
 
 function download_centos_artifacts_hc () {
-    # Get and/or install CentOS HC artifacts from packagecloud.io.
+
+    # Download or install CentOS HC artifacts from packagecloud.io.
     #
     # Variables read:
     # - REPO_URL - FD.io Packagecloud repository.
     # - HC_VERSION - HC version.
-    # - INSTALL - If install packages or download only. Default: download
+    # - INSTALL - Whether install packages (if set to "true") or download only.
+    #             Default: "false".
 
     set -exuo pipefail
 
@@ -102,7 +110,7 @@ function download_centos_artifacts_hc () {
         artifacts+=(${hc[@]/%/-${HC_VERSION-}})
     fi
 
-    if [ "${INSTALL:-false}" = true ]; then
+    if [[ "${INSTALL:-false}" == "true" ]]; then
         sudo yum -y install "${artifacts[@]}" || {
             die "Install HC artifact failed."
         }
@@ -112,4 +120,3 @@ function download_centos_artifacts_hc () {
         }
     fi
 }
-
diff --git a/resources/libraries/bash/function/branch.sh b/resources/libraries/bash/function/branch.sh
index e340a0c658..558a2b617e 100644
--- a/resources/libraries/bash/function/branch.sh
+++ b/resources/libraries/bash/function/branch.sh
@@ -21,8 +21,6 @@ set -exuo pipefail
 
 function checkout_csit_for_vpp () {
 
-    set -exuo pipefail
-
     # This should be useful mainly for vpp-csit jobs (and timed csit-vpp jobs),
     # which want to use csit oper branches (especially for vpp stable branches).
     # This allows the Jenkins job to checkout CSIT master branch,
@@ -51,6 +49,8 @@ function checkout_csit_for_vpp () {
     # Functions called:
     # - die - Print to stderr and exit, defined in "common" library.
 
+    set -exuo pipefail
+
     case "${1}" in
         "stable/"*)
             branch_id="origin/${1/stable\//oper-rls}"
@@ -74,10 +74,10 @@ function checkout_csit_for_vpp () {
     csit_branch="${csit_branch#origin/}" || die
     override_ref="${CSIT_REF-}"
     if [[ -n "${override_ref}" ]]; then
-        git fetch --depth=1 https://gerrit.fd.io/r/csit "${override_ref}"
-        git checkout FETCH_HEAD
+        git fetch --depth=1 https://gerrit.fd.io/r/csit "${override_ref}" || die
+        git checkout FETCH_HEAD || die
     else
-        git checkout "${csit_branch}"
+        git checkout "${csit_branch}" || die
     fi
-    popd
+    popd || die
 }
diff --git a/resources/libraries/bash/function/common.sh b/resources/libraries/bash/function/common.sh
index 96c7940f79..078ed70197 100644
--- a/resources/libraries/bash/function/common.sh
+++ b/resources/libraries/bash/function/common.sh
@@ -23,7 +23,6 @@ set -exuo pipefail
 
 
 function activate_docker_topology () {
-    set -exuo pipefail
 
     # Create virtual vpp-device topology. Output of the function is topology
     # file describing created environment saved to a file.
@@ -34,9 +33,12 @@ function activate_docker_topology () {
     # - NODENESS - Node multiplicity of desired testbed.
     # - FLAVOR - Node flavor string, usually describing the processor.
     # - IMAGE_VER_FILE - Name of file that contains the image version.
+    # - CSIT_DIR - Directory where ${IMAGE_VER_FILE} is located.
     # Variables set:
     # - WORKING_TOPOLOGY - Path to topology file.
 
+    set -exuo pipefail
+
     source "${BASH_FUNCTION_DIR}/device.sh" || {
         die "Source failed!"
     }
@@ -48,7 +50,7 @@ function activate_docker_topology () {
             # We execute reservation over csit-shim-dcr (ssh) which runs sourced
             # script's functions. Env variables are read from ssh output
             # back to localhost for further processing.
-            hostname=$(grep search /etc/resolv.conf | cut -d' ' -f3)
+            hostname=$(grep search /etc/resolv.conf | cut -d' ' -f3) || die
             ssh="ssh root@${hostname} -p 6022"
             run="activate_wrapper ${NODENESS} ${FLAVOR} ${device_image}"
             # backtics to avoid https://midnight-commander.org/ticket/2142
@@ -91,8 +93,6 @@ function activate_docker_topology () {
 
 function activate_virtualenv () {
 
-    set -exuo pipefail
-
     # Update virtualenv pip package, delete and create virtualenv directory,
     # activate the virtualenv, install requirements, set PYTHONPATH.
 
@@ -107,6 +107,8 @@ function activate_virtualenv () {
     # Functions called:
     # - die - Print to stderr and exit.
 
+    set -exuo pipefail
+
     root_path="${1-$CSIT_DIR}"
     env_dir="${root_path}/env"
     req_path=${2-$CSIT_DIR/requirements.txt}
@@ -130,8 +132,6 @@ function activate_virtualenv () {
 
 function archive_tests () {
 
-    set -exuo pipefail
-
     # Create .tar.xz of generated/tests for archiving.
     # To be run after generate_tests, kept separate to offer more flexibility.
 
@@ -140,6 +140,8 @@ function archive_tests () {
     # File rewriten:
     # - ${ARCHIVE_DIR}/tests.tar.xz - Archive of generated tests.
 
+    set -exuo pipefail
+
     tar c "${GENERATED_DIR}/tests" | xz -9e > "${ARCHIVE_DIR}/tests.tar.xz" || {
         die "Error creating archive of generated tests."
     }
@@ -148,8 +150,6 @@ function archive_tests () {
 
 function check_download_dir () {
 
-    set -exuo pipefail
-
     # Fail if there are no files visible in ${DOWNLOAD_DIR}.
     #
     # Variables read:
@@ -159,6 +159,8 @@ function check_download_dir () {
     # Functions called:
     # - die - Print to stderr and exit.
 
+    set -exuo pipefail
+
     if [[ ! "$(ls -A "${DOWNLOAD_DIR}")" ]]; then
         die "No artifacts downloaded!"
     fi
@@ -167,12 +169,12 @@ function check_download_dir () {
 
 function cleanup_topo () {
 
-    set -exuo pipefail
-
     # Variables read:
     # - WORKING_TOPOLOGY - Path to topology yaml file of the reserved testbed.
     # - PYTHON_SCRIPTS_DIR - Path to directory holding the reservation script.
 
+    set -exuo pipefail
+
     python "${PYTHON_SCRIPTS_DIR}/topo_cleanup.py" -t "${WORKING_TOPOLOGY}"
     # Not using "|| die" as some callers might want to ignore errors,
     # e.g. in teardowns, such as unreserve.
@@ -181,8 +183,6 @@ function cleanup_topo () {
 
 function common_dirs () {
 
-    set -exuo pipefail
-
     # Set global variables, create some directories (without touching content).
 
     # Variables set:
@@ -200,6 +200,8 @@ function common_dirs () {
     # Functions called:
     # - die - Print to stderr and exit.
 
+    set -exuo pipefail
+
     BASH_FUNCTION_DIR="$(dirname "$(readlink -e "${BASH_SOURCE[0]}")")" || {
         die "Some error during localizing this source directory."
     }
@@ -239,8 +241,6 @@ function common_dirs () {
 
 function compose_pybot_arguments () {
 
-    set -exuo pipefail
-
     # Variables read:
     # - WORKING_TOPOLOGY - Path to topology yaml file of the reserved testbed.
     # - DUT - CSIT test/ subdirectory, set while processing tags.
@@ -251,6 +251,8 @@ function compose_pybot_arguments () {
     # - PYBOT_ARGS - String holding part of all arguments for pybot.
     # - EXPANDED_TAGS - Array of strings pybot arguments compiled from tags.
 
+    set -exuo pipefail
+
     # No explicit check needed with "set -u".
     PYBOT_ARGS=("--loglevel" "TRACE")
     PYBOT_ARGS+=("--variable" "TOPOLOGY_PATH:${WORKING_TOPOLOGY}")
@@ -282,8 +284,10 @@ function compose_pybot_arguments () {
 
 function copy_archives () {
 
-    set -exuo pipefail
-
+    # Create additional archive if workspace variable is set.
+    # This way if script is running in jenkins all will be
+    # automatically archived to logs.fd.io.
+    #
     # Variables read:
     # - WORKSPACE - Jenkins workspace, copy only if the value is not empty.
     #   Can be unset, then it speeds up manual testing.
@@ -294,9 +298,8 @@ function copy_archives () {
     # Functions called:
     # - die - Print to stderr and exit.
 
-    # We will create additional archive if workspace variable is set.
-    # This way if script is running in jenkins all will be
-    # automatically archived to logs.fd.io.
+    set -exuo pipefail
+
     if [[ -n "${WORKSPACE-}" ]]; then
         mkdir -p "${WORKSPACE}/archives/" || die "Archives dir create failed."
         cp -rf "${ARCHIVE_DIR}"/* "${WORKSPACE}/archives" || die "Copy failed."
@@ -305,6 +308,7 @@ function copy_archives () {
 
 
 function deactivate_docker_topology () {
+
     # Deactivate virtual vpp-device topology by removing containers.
     #
     # Variables read:
@@ -316,9 +320,9 @@ function deactivate_docker_topology () {
     case_text="${NODENESS}_${FLAVOR}"
     case "${case_text}" in
         "1n_skx")
-            hostname=$(grep search /etc/resolv.conf | cut -d' ' -f3)
+            hostname=$(grep search /etc/resolv.conf | cut -d' ' -f3) || die
             ssh="ssh root@${hostname} -p 6022"
-            env_vars="$(env | grep CSIT_ | tr '\n' ' ' )"
+            env_vars=$(env | grep CSIT_ | tr '\n' ' ' ) || die
             ${ssh} "$(declare -f); deactivate_wrapper ${env_vars}" || {
                 die "Topology cleanup via shim-dcr failed!"
             }
@@ -337,6 +341,7 @@ function deactivate_docker_topology () {
 
 
 function die () {
+
     # Print the message to standard error end exit with error code specified
     # by the second argument.
     #
@@ -355,8 +360,6 @@ function die () {
 
 function die_on_pybot_error () {
 
-    set -exuo pipefail
-
     # Source this fragment if you want to abort on any failed test case.
     #
     # Variables read:
@@ -364,6 +367,8 @@ function die_on_pybot_error () {
     # Functions called:
     # - die - Print to stderr and exit.
 
+    set -exuo pipefail
+
     if [[ "${PYBOT_EXIT_STATUS}" != "0" ]]; then
         die "Test failures are present!" "${PYBOT_EXIT_STATUS}"
     fi
@@ -372,8 +377,6 @@ function die_on_pybot_error () {
 
 function generate_tests () {
 
-    set -exuo pipefail
-
     # Populate ${GENERATED_DIR}/tests based on ${CSIT_DIR}/tests/.
     # Any previously existing content of ${GENERATED_DIR}/tests is wiped before.
     # The generation is done by executing any *.py executable
@@ -387,8 +390,10 @@ function generate_tests () {
     # Directories replaced:
     # - ${GENERATED_DIR}/tests - Overwritten by the generated tests.
 
-    rm -rf "${GENERATED_DIR}/tests"
-    cp -r "${CSIT_DIR}/tests" "${GENERATED_DIR}/tests"
+    set -exuo pipefail
+
+    rm -rf "${GENERATED_DIR}/tests" || die
+    cp -r "${CSIT_DIR}/tests" "${GENERATED_DIR}/tests" || die
     cmd_line=("find" "${GENERATED_DIR}/tests" "-type" "f")
     cmd_line+=("-executable" "-name" "*.py")
     file_list=$("${cmd_line[@]}") || die
@@ -405,8 +410,6 @@ function generate_tests () {
 
 function get_test_code () {
 
-    set -exuo pipefail
-
     # Arguments:
     # - ${1} - Optional, argument of entry script (or empty as unset).
     #   Test code value to override job name from environment.
@@ -417,6 +420,8 @@ function get_test_code () {
     # - NODENESS - Node multiplicity of desired testbed.
     # - FLAVOR - Node flavor string, usually describing the processor.
 
+    set -exuo pipefail
+
     TEST_CODE="${1-}" || die "Reading optional argument failed, somehow."
     if [[ -z "${TEST_CODE}" ]]; then
         TEST_CODE="${JOB_NAME-}" || die "Reading job name failed, somehow."
@@ -462,18 +467,18 @@ function get_test_code () {
 
 function get_test_tag_string () {
 
-    set -exuo pipefail
-
     # Variables read:
     # - GERRIT_EVENT_TYPE - Event type set by gerrit, can be unset.
     # - GERRIT_EVENT_COMMENT_TEXT - Comment text, read for "comment-added" type.
     # - TEST_CODE - The test selection string from environment or argument.
     # Variables set:
-    # - TEST_TAG_STRING - The string following "perftest" in gerrit comment,
-    #   or empty.
+    # - TEST_TAG_STRING - The string following trigger word in gerrit comment.
+    #   May be empty, not set on event types not adding comment.
 
     # TODO: ci-management scripts no longer need to perform this.
 
+    set -exuo pipefail
+
     trigger=""
     if [[ "${GERRIT_EVENT_TYPE-}" == "comment-added" ]]; then
         case "${TEST_CODE}" in
@@ -509,8 +514,6 @@ function get_test_tag_string () {
 
 function reserve_and_cleanup_testbed () {
 
-    set -exuo pipefail
-
     # Reserve physical testbed, perform cleanup, register trap to unreserve.
     # When cleanup fails, remove from topologies and keep retrying
     # until all topologies are removed.
@@ -530,6 +533,8 @@ function reserve_and_cleanup_testbed () {
     # Traps registered:
     # - EXIT - Calls cancel_all for ${WORKING_TOPOLOGY}.
 
+    set -exuo pipefail
+
     while [[ ${TOPOLOGIES[@]} ]]; do
         for topo in "${TOPOLOGIES[@]}"; do
             set +e
@@ -600,8 +605,8 @@ function reserve_and_cleanup_testbed () {
 
 function run_pybot () {
 
-    set -exuo pipefail
-
+    # Run pybot with options based on input variables. Create output_info.xml
+    #
     # Variables read:
     # - CSIT_DIR - Path to existing root of local CSIT git repository.
     # - ARCHIVE_DIR - Path to store robot result files in.
@@ -612,6 +617,8 @@ function run_pybot () {
     # Functions called:
     # - die - Print to stderr and exit.
 
+    set -exuo pipefail
+
     all_options=("--outputdir" "${ARCHIVE_DIR}" "${PYBOT_ARGS[@]}")
     all_options+=("--noncritical" "EXPECTED_FAILING")
     all_options+=("${EXPANDED_TAGS[@]}")
@@ -628,24 +635,25 @@ function run_pybot () {
     all_options+=("--report" "none")
     all_options+=("--output" "${ARCHIVE_DIR}/output_info.xml")
     all_options+=("${ARCHIVE_DIR}/output.xml")
-    rebot "${all_options[@]}"
+    rebot "${all_options[@]}" || true
     popd || die "Change directory operation failed."
 }
 
 
 function select_tags () {
 
-    set -exuo pipefail
-
     # Variables read:
     # - WORKING_TOPOLOGY - Path to topology yaml file of the reserved testbed.
     # - TEST_CODE - String affecting test selection, usually jenkins job name.
     # - TEST_TAG_STRING - String selecting tags, from gerrit comment.
     #   Can be unset.
     # - TOPOLOGIES_DIR - Path to existing directory with available tpologies.
+    # - BASH_FUNCTION_DIR - Directory with input files to process.
     # Variables set:
     # - TAGS - Array of processed tag boolean expressions.
 
+    set -exuo pipefail
+
     # NIC SELECTION
     start_pattern='^  TG:'
     end_pattern='^ \? \?[A-Za-z0-9]\+:'
@@ -658,40 +666,44 @@ function select_tags () {
     reserved=$(sed "${sed_command}" "${WORKING_TOPOLOGY}" \
                | grep -hoP "model: \K.*" | sort -u)
     # All topologies DUT NICs - Selected topology DUT NICs
-    exclude_nics=($(comm -13 <(echo "${reserved}") <(echo "${available}")))
+    exclude_nics=($(comm -13 <(echo "${reserved}") <(echo "${available}"))) || {
+        die "Computation of excluded NICs failed."
+    }
 
-    # Select default NIC
+    # Select default NIC tag.
     case "${TEST_CODE}" in
         *"3n-dnv"* | *"2n-dnv"*)
-            DEFAULT_NIC='nic_intel-x553'
+            default_nic="nic_intel-x553"
             ;;
         *"3n-tsh"*)
-            DEFAULT_NIC='nic_intel-x520-da2'
+            default_nic="nic_intel-x520-da2"
             ;;
         *)
-            DEFAULT_NIC='nic_intel-x710'
+            default_nic="nic_intel-x710"
             ;;
     esac
 
+    # Tag file directory shorthand.
+    tfd="${BASH_FUNCTION_DIR}"
     case "${TEST_CODE}" in
         # Select specific performance tests based on jenkins job type variable.
         *"ndrpdr-weekly"* )
-            readarray -t test_tag_array < "${BASH_FUNCTION_DIR}/mlr-weekly.txt"
+            readarray -t test_tag_array < "${tfd}/mlr-weekly.txt" || die
             ;;
         *"mrr-daily"* )
-            readarray -t test_tag_array < "${BASH_FUNCTION_DIR}/mrr-daily.txt"
+            readarray -t test_tag_array < "${tfd}/mrr-daily.txt" || die
             ;;
         *"mrr-weekly"* )
-            readarray -t test_tag_array < "${BASH_FUNCTION_DIR}/mrr-weekly.txt"
+            readarray -t test_tag_array < "${tfd}/mrr-weekly.txt" || die
             ;;
         * )
             if [[ -z "${TEST_TAG_STRING-}" ]]; then
                 # If nothing is specified, we will run pre-selected tests by
                 # following tags.
-                test_tag_array=("mrrAND${DEFAULT_NIC}AND1cAND64bANDip4base"
-                                "mrrAND${DEFAULT_NIC}AND1cAND78bANDip6base"
-                                "mrrAND${DEFAULT_NIC}AND1cAND64bANDl2bdbase"
-                                "mrrAND${DEFAULT_NIC}AND1cAND64bANDl2xcbase"
+                test_tag_array=("mrrAND${default_nic}AND1cAND64bANDip4base"
+                                "mrrAND${default_nic}AND1cAND78bANDip6base"
+                                "mrrAND${default_nic}AND1cAND64bANDl2bdbase"
+                                "mrrAND${default_nic}AND1cAND64bANDl2xcbase"
                                 "!dot1q" "!drv_avf")
             else
                 # If trigger contains tags, split them into array.
@@ -701,6 +713,10 @@ function select_tags () {
     esac
 
     # Blacklisting certain tags per topology.
+    #
+    # Reasons for blacklisting:
+    # - ipsechw - Blacklisted on testbeds without crypto hardware accelerator.
+    # TODO: Add missing reasons here (if general) or where used (if specific).
     case "${TEST_CODE}" in
         *"2n-skx"*)
             test_tag_array+=("!ipsechw")
@@ -763,7 +779,7 @@ function select_tags () {
         if [[ "${TEST_TAG_STRING-}" == *"nic_"* ]]; then
             prefix="${prefix}mrrAND"
         else
-            prefix="${prefix}mrrAND${DEFAULT_NIC}AND"
+            prefix="${prefix}mrrAND${default_nic}AND"
         fi
     fi
     for tag in "${test_tag_array[@]}"; do
@@ -782,8 +798,6 @@ function select_tags () {
 
 function select_vpp_device_tags () {
 
-    set -exuo pipefail
-
     # Variables read:
     # - TEST_CODE - String affecting test selection, usually jenkins job name.
     # - TEST_TAG_STRING - String selecting tags, from gerrit comment.
@@ -791,6 +805,8 @@ function select_vpp_device_tags () {
     # Variables set:
     # - TAGS - Array of processed tag boolean expressions.
 
+    set -exuo pipefail
+
     case "${TEST_CODE}" in
         # Select specific performance tests based on jenkins job type variable.
         * )
@@ -827,13 +843,13 @@ function select_vpp_device_tags () {
 
 function select_os () {
 
-    set -exuo pipefail
-
     # Variables set:
     # - VPP_VER_FILE - Name of File in CSIT dir containing vpp stable version.
     # - IMAGE_VER_FILE - Name of File in CSIT dir containing the image name.
     # - PKG_SUFFIX - Suffix of OS package file name, "rpm" or "deb."
 
+    set -exuo pipefail
+
     os_id=$(grep '^ID=' /etc/os-release | cut -f2- -d= | sed -e 's/\"//g') || {
         die "Get OS release failed."
     }
@@ -858,8 +874,6 @@ function select_os () {
 
 function select_topology () {
 
-    set -exuo pipefail
-
     # Variables read:
     # - NODENESS - Node multiplicity of testbed, either "2n" or "3n".
     # - FLAVOR - Node flavor string, currently either "hsw" or "skx".
@@ -871,9 +885,12 @@ function select_topology () {
     # Functions called:
     # - die - Print to stderr and exit.
 
+    set -exuo pipefail
+
     case_text="${NODENESS}_${FLAVOR}"
     case "${case_text}" in
         # TODO: Move tags to "# Blacklisting certain tags per topology" section.
+        # TODO: Double link availability depends on NIC used.
         "1n_vbox")
             TOPOLOGIES=( "${TOPOLOGIES_DIR}"/*vpp_device*.template )
             TOPOLOGIES_TAGS="2_node_single_link_topo"
@@ -919,6 +936,7 @@ function select_topology () {
 
 
 function untrap_and_unreserve_testbed () {
+
     # Use this as a trap function to ensure testbed does not remain reserved.
     # Perhaps call directly before script exit, to free testbed for other jobs.
     # This function is smart enough to avoid multiple unreservations (so safe).
@@ -957,10 +975,13 @@ function untrap_and_unreserve_testbed () {
 
 
 function warn () {
+
     # Print the message to standard error.
     #
     # Arguments:
     # - ${@} - The text of the message.
 
+    set -exuo pipefail
+
     echo "$@" >&2
 }
diff --git a/resources/libraries/bash/function/device.sh b/resources/libraries/bash/function/device.sh
index 0b1a090fd6..0eda008abb 100644
--- a/resources/libraries/bash/function/device.sh
+++ b/resources/libraries/bash/function/device.sh
@@ -14,9 +14,11 @@
 set -exuo pipefail
 
 # This library defines functions used by multiple entry scripts.
+# Deliberately not depending on common.sh to allow standalone usage.
 # Keep functions ordered alphabetically, please.
 
 function activate_wrapper () {
+
     # Acts as wrapper for activate docker topology.
     #
     # Variables read:
@@ -37,6 +39,7 @@ function activate_wrapper () {
 
 
 function bind_interfaces_to_containers () {
+
     # Bind linux network interface to container and create symlink for PCI
     # address in container.
     #
@@ -83,6 +86,7 @@ function bind_interfaces_to_containers () {
 
 
 function bind_interfaces_to_driver () {
+
     # Bind network interface specified by parameter to driver specified by
     # parameter.
     #
@@ -90,9 +94,11 @@ function bind_interfaces_to_driver () {
     # - ADDR - PCI address of network interface.
     # - DRIVER - Kernel driver.
 
+    set -exuo pipefail
+
     pci_path="/sys/bus/pci/devices/${ADDR}"
     drv_path="/sys/bus/pci/drivers/${DRIVER}"
-    vd="$(cat ${pci_path}/vendor ${pci_path}/device)" || {
+    vd=$(cat ${pci_path}/vendor ${pci_path}/device) || {
         die "Failed to retrieve interface details!"
     }
     set +e
@@ -108,6 +114,7 @@ function bind_interfaces_to_driver () {
 
 
 function clean_environment () {
+
     # Cleanup environment by removing topology containers and shared volumes
     # and binding interfaces back to original driver.
     #
@@ -143,10 +150,13 @@ function clean_environment () {
 
 
 function clean_environment_on_exit () {
+
     # Cleanup environment by removing topology containers and binding
     # interfaces back to original driver only if exit code is not 0.
     # This function acts as workaround as 'set -eu' does not trigger ERR trap.
 
+    set -exuo pipefail
+
     if [ $? -ne 0 ]; then
         clean_environment || die
     fi
@@ -154,6 +164,7 @@ function clean_environment_on_exit () {
 
 
 function deactivate_wrapper () {
+
     # Acts as wrapper for deactivate docker topology.
     #
     # Variables read:
@@ -169,9 +180,12 @@ function deactivate_wrapper () {
 
 
 function die () {
+
     # Print the message to standard error end exit with error code specified
     # by the second argument.
     #
+    # Duplicate of common.sh function, as this file is also used standalone.
+    #
     # Hardcoded values:
     # - The default error message.
     # Arguments:
@@ -186,6 +200,7 @@ function die () {
 
 
 function enter_mutex () {
+
     # Enter mutual exclusion for protecting execution from starvation and
     # deadlock.
 
@@ -208,6 +223,7 @@ function enter_mutex () {
 
 
 function exit_mutex () {
+
     # Exit mutual exclusion.
 
     set -exuo pipefail
@@ -222,11 +238,12 @@ function exit_mutex () {
 
 
 function get_available_interfaces () {
+
     # Find and get available Virtual functions.
     #
     # Arguments:
-    # - ${1} - Node flavor string, usually describing the processor and node
-    # multiplicity of desired testbed, separated by underscore.
+    # - ${1} - Nodeness, as set by common.sh get_test_code.
+    # - ${2} - Flavor, as set by common.sh get_test_code.
     # Variables set:
     # - DUT1_NETDEVS - List of network devices allocated to DUT1 container.
     # - DUT1_PCIDEVS - List of PCI addresses allocated to DUT1 container.
@@ -347,6 +364,7 @@ function get_available_interfaces () {
 
 
 function get_krn_driver () {
+
     # Get kernel driver from linux network device name.
     #
     # Variables read:
@@ -364,6 +382,7 @@ function get_krn_driver () {
 
 
 function get_mac_addr () {
+
     # Get MAC address from linux network device name.
     #
     # Variables read:
@@ -382,6 +401,7 @@ function get_mac_addr () {
 
 
 function get_pci_addr () {
+
     # Get PCI address in <domain>:<bus:<device>.<func> format from linux network
     # device name.
     #
@@ -405,34 +425,41 @@ function get_pci_addr () {
 
 function installed () {
 
-    set -exuo pipefail
-
     # Check if the given utility is installed. Fail if not installed.
     #
+    # Duplicate of common.sh function, as this file is also used standalone.
+    #
     # Arguments:
     # - ${1} - Utility to check.
     # Returns:
     # - 0 - If command is installed.
     # - 1 - If command is not installed.
 
+    set -exuo pipefail
+
     command -v "${1}"
 }
 
 
 function print_env_variables () {
+
     # Get environment variables prefixed by CSIT_.
 
     set -exuo pipefail
 
-    env | grep CSIT_
+    env | grep CSIT_ || true
 }
 
 
 function read_env_variables () {
+
     # Read environment variables from parameters.
     #
     # Arguments:
     # - ${@} - Variables passed as an argument.
+    # Variables read, set or exported: Multiple,
+    # see the code for the current list.
+    # TODO: Do we need to list them and their meanings?
 
     set -exuo pipefail
 
@@ -454,6 +481,7 @@ function read_env_variables () {
 
 
 function set_env_variables () {
+
     # Set environment variables.
     #
     # Variables read:
@@ -465,6 +493,7 @@ function set_env_variables () {
     # - TG_NETMACS - List of network devices MAC addresses of TG container.
     # - TG_PCIDEVS - List of PCI addresses of devices of TG container.
     # - TG_DRIVERS - List of interface drivers to TG container.
+    # Variables set: TODO.
 
     set -exuo pipefail
 
@@ -502,6 +531,7 @@ function set_env_variables () {
 
 
 function start_topology_containers () {
+
     # Starts csit-sut-dcr docker containers for TG/DUT1.
     #
     # Variables read:
@@ -551,11 +581,11 @@ function start_topology_containers () {
 
     # Run TG and DUT1. As initial version we do support only 2-node.
     params=(${dcr_stc_params} --name csit-tg-$(uuidgen) ${dcr_image})
-    DCR_UUIDS+=([tg]="$(docker run "${params[@]}")") || {
+    DCR_UUIDS+=([tg]=$(docker run "${params[@]}")) || {
         die "Failed to start TG docker container!"
     }
     params=(${dcr_stc_params} --name csit-dut1-$(uuidgen) ${dcr_image})
-    DCR_UUIDS+=([dut1]="$(docker run "${params[@]}")") || {
+    DCR_UUIDS+=([dut1]=$(docker run "${params[@]}")) || {
         die "Failed to start DUT1 docker container!"
     }
 
@@ -565,21 +595,21 @@ function start_topology_containers () {
 
     # Get Containers TCP ports.
     params=(${DCR_UUIDS[tg]})
-    DCR_PORTS+=([tg]="$(docker port "${params[@]}")") || {
+    DCR_PORTS+=([tg]=$(docker port "${params[@]}")) || {
         die "Failed to get port of TG docker container!"
     }
     params=(${DCR_UUIDS[dut1]})
-    DCR_PORTS+=([dut1]="$(docker port "${params[@]}")") || {
+    DCR_PORTS+=([dut1]=$(docker port "${params[@]}")) || {
         die "Failed to get port of DUT1 docker container!"
     }
 
     # Get Containers PIDs.
     params=(--format="{{ .State.Pid }}" ${DCR_UUIDS[tg]})
-    DCR_CPIDS+=([tg]="$(docker inspect "${params[@]}")") || {
+    DCR_CPIDS+=([tg]=$(docker inspect "${params[@]}")) || {
         die "Failed to get PID of TG docker container!"
     }
     params=(--format="{{ .State.Pid }}" ${DCR_UUIDS[dut1]})
-    DCR_CPIDS+=([dut1]="$(docker inspect "${params[@]}")") || {
+    DCR_CPIDS+=([dut1]=$(docker inspect "${params[@]}")) || {
         die "Failed to get PID of DUT1 docker container!"
     }
 }
@@ -587,8 +617,12 @@ function start_topology_containers () {
 function warn () {
     # Print the message to standard error.
     #
+    # Duplicate of common.sh function, as this file is also used standalone.
+    #
     # Arguments:
     # - ${@} - The text of the message.
 
+    set -exuo pipefail
+
     echo "$@" >&2
 }
diff --git a/resources/libraries/bash/function/gather.sh b/resources/libraries/bash/function/gather.sh
index 56b148d1e1..1fc2d3e604 100644
--- a/resources/libraries/bash/function/gather.sh
+++ b/resources/libraries/bash/function/gather.sh
@@ -24,8 +24,6 @@ set -exuo pipefail
 
 function gather_build () {
 
-    set -exuo pipefail
-
     # Variables read:
     # - TEST_CODE - String affecting test selection, usually jenkins job name.
     # - DOWNLOAD_DIR - Path to directory pybot takes the build to test from.
@@ -43,6 +41,8 @@ function gather_build () {
     # TODO: Separate DUT-from-TEST_CODE from gather-for-DUT,
     #   when the first one becomes relevant for per_patch.
 
+    set -exuo pipefail
+
     pushd "${DOWNLOAD_DIR}" || die "Pushd failed."
     case "${TEST_CODE}" in
         *"hc2vpp"*)
@@ -71,8 +71,6 @@ function gather_build () {
 
 function gather_dpdk () {
 
-    set -exuo pipefail
-
     # Ensure latest DPDK archive is downloaded.
     #
     # Variables read:
@@ -84,6 +82,8 @@ function gather_dpdk () {
     # Functions called:
     # - die - Print to stderr and exit, defined in common.sh
 
+    set -exuo pipefail
+
     dpdk_repo="https://fast.dpdk.org/rel"
     # Use downloaded packages with specific version
     if [[ "${TEST_CODE}" == *"daily"* ]] || \
@@ -117,8 +117,6 @@ function gather_dpdk () {
 
 function gather_ligato () {
 
-    set -exuo pipefail
-
     # Build docker image (with vpp, ligato and vpp-agent),
     # and put it to ${DOWNLOAD_DIR}/.
     #
@@ -155,6 +153,8 @@ function gather_ligato () {
     #   so maybe it is not worth introducing fragments/functions for the blocks.
     # TODO: This fragment is too long anyway, split it up.
 
+    set -exuo pipefail
+
     gather_vpp || die "The function should have died on error."
 
     mkdir -p /tmp/vpp && rm -f /tmp/vpp/* || {
@@ -244,8 +244,6 @@ function gather_ligato () {
 
 function gather_vpp () {
 
-    set -exuo pipefail
-
     # Variables read:
     # - BASH_FUNCTION_DIR - Bash directory with functions.
     # - TEST_CODE - The test selection string from environment or argument.
@@ -268,6 +266,8 @@ function gather_vpp () {
     # - ${CSIT_DIR}/resources/tools/scripts/download_install_vpp_pkgs.sh
     #   - Should download and extract requested files to ./.
 
+    set -exuo pipefail
+
     case "${TEST_CODE}" in
         # Not csit-vpp as this code is re-used by ligato gathering.
         "csit-"*)
diff --git a/resources/libraries/bash/function/per_patch.sh b/resources/libraries/bash/function/per_patch.sh
index 27fa0cfb06..61de6f7ade 100644
--- a/resources/libraries/bash/function/per_patch.sh
+++ b/resources/libraries/bash/function/per_patch.sh
@@ -15,13 +15,10 @@ set -exuo pipefail
 
 # This library defines functions used mainly by per patch entry scripts.
 # Generally, the functions assume "common.sh" library has been sourced already.
-
 # Keep functions ordered alphabetically, please.
 
 function archive_test_results () {
 
-    set -exuo pipefail
-
     # Arguments:
     # - ${1}: Directory to archive to. Required. Parent has to exist.
     # Variable set:
@@ -34,6 +31,8 @@ function archive_test_results () {
     # Functions called:
     # - die - Print to stderr and exit, defined in common.sh
 
+    set -exuo pipefail
+
     cd "${VPP_DIR}" || die "Change directory command failed."
     TARGET="$(readlink -f "$1")"
     mkdir -p "${TARGET}" || die "Directory creation failed."
@@ -47,8 +46,6 @@ function archive_test_results () {
 
 function archive_parse_test_results () {
 
-    set -exuo pipefail
-
     # Arguments:
     # - ${1}: Directory to archive to. Required. Parent has to exist.
     # Variables read:
@@ -58,6 +55,8 @@ function archive_parse_test_results () {
     # - archive_test_results - Archiving results.
     # - parse_bmrr_results - See definition in this file.
 
+    set -exuo pipefail
+
     archive_test_results "$1" || die
     parse_bmrr_results "${TARGET}" || {
         die "The function should have died on error."
@@ -67,8 +66,6 @@ function archive_parse_test_results () {
 
 function build_vpp_ubuntu_amd64 () {
 
-    set -exuo pipefail
-
     # This function is using Vagrant script to build VPP with all dependencies
     # that is ARCH/OS aware. VPP repo is SSOT for building mechanics and CSIT
     # is consuming artifacts. This way if VPP will introduce change in building
@@ -82,6 +79,8 @@ function build_vpp_ubuntu_amd64 () {
     # Functions called:
     # - die - Print to stderr and exit, defined in common.sh
 
+    set -exuo pipefail
+
     cd "${VPP_DIR}" || die "Change directory command failed."
     echo 'Building using "make build-root/vagrant/build.sh"'
     build-root/vagrant/"build.sh" || die "Vagrant VPP build script failed."
@@ -95,8 +94,6 @@ function build_vpp_ubuntu_amd64 () {
 
 function compare_test_results () {
 
-    set -exuo pipefail
-
     # Variables read:
     # - VPP_DIR - Path to directory with VPP git repo (at least built parts).
     # - ARCHIVE_DIR - Path to where robot result files are created in.
@@ -111,6 +108,8 @@ function compare_test_results () {
     # - 0 - If the comparison utility sees no regression (nor data error).
     # - 1 - If the comparison utility sees a regression (or data error).
 
+    set -exuo pipefail
+
     cd "${VPP_DIR}" || die "Change directory operation failed."
     # Reusing CSIT main virtualenv.
     pip install -r "${PYTHON_SCRIPTS_DIR}/perpatch_requirements.txt" || {
@@ -123,8 +122,6 @@ function compare_test_results () {
 
 function download_builds () {
 
-    set -exuo pipefail
-
     # This is mostly useful only for Sandbox testing, to avoid recompilation.
     #
     # Arguments:
@@ -138,6 +135,8 @@ function download_builds () {
     # Functions called:
     # - die - Print to stderr and exit, defined in common.sh
 
+    set -exuo pipefail
+
     cd "${VPP_DIR}" || die "Change directory operation failed."
     dirs=("build-root" "build_parent" "build_current" "archive" "csit_current")
     rm -rf ${dirs[@]} || {
@@ -152,8 +151,6 @@ function download_builds () {
 
 function initialize_csit_dirs () {
 
-    set -exuo pipefail
-
     # This could be in prepare_test, but download_builds also needs this.
     #
     # Variables read:
@@ -164,6 +161,8 @@ function initialize_csit_dirs () {
     # Functions called:
     # - die - Print to stderr and exit, defined in common.sh
 
+    set -exuo pipefail
+
     cd "${VPP_DIR}" || die "Change directory operation failed."
     rm -rf "csit_current" "csit_parent" || {
         die "Directory deletion failed."
@@ -176,8 +175,6 @@ function initialize_csit_dirs () {
 
 function parse_bmrr_results () {
 
-    set -exuo pipefail
-
     # Currently "parsing" is just two greps.
     # TODO: Re-use PAL parsing code, make parsing more general and centralized.
     #
@@ -190,6 +187,8 @@ function parse_bmrr_results () {
     # Functions called:
     # - die - Print to stderr and exit, defined in common.sh
 
+    set -exuo pipefail
+
     rel_dir="$(readlink -e "${1}")" || die "Readlink failed."
     in_file="${rel_dir}/output.xml"
     out_file="${rel_dir}/results.txt"
@@ -206,8 +205,6 @@ function parse_bmrr_results () {
 
 function select_build () {
 
-    set -exuo pipefail
-
     # Arguments:
     # - ${1} - Path to directory to copy VPP artifacts from. Required.
     # Variables read:
@@ -220,6 +217,8 @@ function select_build () {
     # Functions called:
     # - die - Print to stderr and exit, defined in common.sh
 
+    set -exuo pipefail
+
     cd "${VPP_DIR}" || die "Change directory operation failed."
     source_dir="$(readlink -e "$1")"
     rm -rf "${DOWNLOAD_DIR}"/* || die "Cleanup of download dir failed."
@@ -231,8 +230,6 @@ function select_build () {
 
 function set_aside_commit_build_artifacts () {
 
-    set -exuo pipefail
-
     # Function is copying VPP built artifacts from actual checkout commit for
     # further use and clean git.
     # Variables read:
@@ -245,6 +242,8 @@ function set_aside_commit_build_artifacts () {
     # Functions called:
     # - die - Print to stderr and exit, defined in common.sh
 
+    set -exuo pipefail
+
     cd "${VPP_DIR}" || die "Change directory operation failed."
     rm -rf "build_current" || die "Remove operation failed."
     mkdir -p "build_current" || die "Directory creation failed."
@@ -262,8 +261,6 @@ function set_aside_commit_build_artifacts () {
 
 function set_aside_parent_build_artifacts () {
 
-    set -exuo pipefail
-
     # Function is copying VPP built artifacts from parent checkout commit for
     # further use. Checkout to parent is not part of this function.
     # Variables read:
@@ -275,6 +272,8 @@ function set_aside_parent_build_artifacts () {
     # Functions called:
     # - die - Print to stderr and exit, defined in common.sh
 
+    set -exuo pipefail
+
     cd "${VPP_DIR}" || die "Change directory operation failed."
     rm -rf "build_parent" || die "Remove failed."
     mkdir -p "build_parent" || die "Directory creation operation failed."
@@ -284,21 +283,19 @@ function set_aside_parent_build_artifacts () {
 
 function set_perpatch_dut () {
 
-    set -exuo pipefail
-
     # Variables set:
     # - DUT - CSIT test/ subdirectory containing suites to execute.
 
     # TODO: Detect DUT from job name, when we have more than just VPP perpatch.
 
+    set -exuo pipefail
+
     DUT="vpp"
 }
 
 
 function set_perpatch_vpp_dir () {
 
-    set -exuo pipefail
-
     # Variables read:
     # - CSIT_DIR - Path to existing root of local CSIT git repository.
     # Variables set:
@@ -306,6 +303,8 @@ function set_perpatch_vpp_dir () {
     # Functions called:
     # - die - Print to stderr and exit, defined in common.sh
 
+    set -exuo pipefail
+
     # In perpatch, CSIT is cloned inside VPP clone.
     VPP_DIR="$(readlink -e "${CSIT_DIR}/..")" || die "Readlink failed."
 }