Merge branch '929-make-install-openappstack-sh-idempotent' into 'master'

Resolve "Make install-openappstack.sh idempotent"

Closes #929

See merge request openappstack/openappstack!479

install/install-openappstack.sh

@@ -17,8 +17,8 @@ branch=${CI_COMMIT_REF_NAME:-}
 echo "Tracking branch $branch for https://open.greenhost.net/openappstack/openappstack flux repo"
 
 # Create oas and oas-apps namespaces
-kubectl create namespace oas
-kubectl create namespace oas-apps
+kubectl get namespace oas 2>/dev/null || kubectl create namespace oas
+kubectl get namespace oas-apps 2>/dev/null || kubectl create namespace oas-apps
 
 # Generate oauth and SSO secrets
 python "$(dirname "$0")/generate_secrets.py" single-sign-on