USHIFT-2543: add overrides for CI scripts

Add the ability to override settings used by the CI scripts for local
developer workflows.

.gitignore

@@ -9,3 +9,4 @@ ansible/*.txt
 test/variables.yaml
 test/scenario_settings.sh
 __pycache__
+test/dev_overrides.sh

test/README.md

@@ -698,3 +698,26 @@ The keys are then mounted for the job and copied to the `~/.aws/config` and
 
 > The procedure assumes that the `microshift-build-cache-<region>` bucket exists
 > in the appropriate region.
+
+### Local Developer Overrides
+
+In some cases, it is necessary to override default values used by the
+CI scripts to make them work in the local environment. If the file
+`./test/dev_overrides.sh` exists, it is sourced by the test framework
+scripts after initializing the common defaults and before computing
+any per-script defaults.
+
+For example, creating the file with this content
+
+```
+#!/bin/bash
+export AWS_BUCKET_NAME=microshift-build-cache-us-west-2
+export CI_JOB_NAME=local-dev
+```
+
+will ensure that a valid AWS bucket is used as the source of image
+cache data and that scripts that check for the CI job name will have a
+name pattern set to compare.
+
+NOTE: Include the shebang line with the shell set and export variables
+to avoid issues with the shellcheck linter.

test/bin/common.sh

@@ -207,3 +207,11 @@ SCENARIO_BUILD_TAG_PREV="$(date -d "yesterday" '+%y%m%d')"
 # The location of the awscli binary.
 # shellcheck disable=SC2034  # used elsewhere
 AWSCLI="${OUTPUTDIR}/bin/aws"
+
+# The location of developer overrides files.
+DEV_OVERRIDES="${TESTDIR}/dev_overrides.sh"
+if [ -f "${DEV_OVERRIDES}" ]; then
+    # The file will not exist, so we should not ask shellcheck to look for it.
+    # shellcheck disable=SC1090
+    source "${DEV_OVERRIDES}"
+fi

test/dev_overrides.sh.example

@@ -0,0 +1,8 @@
+#!/bin/bash
+
+# Variables used by ci_phase_iso_build.sh
+export AWS_BUCKET_NAME=microshift-build-cache-us-west-2
+export CI_JOB_NAME=local-dev
+
+# build_images.sh
+export SKIP_LOG_COLLECTION=true