diff --git a/.ci/podman.mk b/.ci/podman.mk
index 62d11b14..b51b762f 100644
--- a/.ci/podman.mk
+++ b/.ci/podman.mk
@@ -1,25 +1,26 @@
 # Parse version from latest git semver tag
 GIT_TAG ?= $(shell git describe --tags --match v*.*.* 2>/dev/null || git rev-parse --short HEAD 2>/dev/null)
-GIT_BRANCH ?= $(shell git rev-parse --abbrev-ref HEAD 2>/dev/null | sed -e 's/[^a-zA-Z0-9]/-/g')
+GIT_BRANCH ?= $(shell git rev-parse --abbrev-ref HEAD 2>/dev/null)
 
-TAG := $(GIT_TAG)
+TAG ::= $(GIT_TAG)
 # append branch name to tag if NOT main nor master
 ifeq (,$(filter main master, $(GIT_BRANCH)))
 	# If branch is substring of tag, omit branch name
 	ifeq ($(findstring $(GIT_BRANCH), $(GIT_TAG)),)
 		# only append branch name if not equal tag
 		ifneq ($(GIT_TAG), $(GIT_BRANCH))
-			TAG = $(GIT_TAG)-$(GIT_BRANCH)
+			# Sanitize GIT_BRANCH to allowed Docker tag character set
+			TAG = $(GIT_TAG)-$(shell echo $$GIT_BRANCH | sed -e 's/[^a-zA-Z0-9]/-/g')
 		endif
 	endif
 endif
 
-ARCH := amd64
-ALL_ARCHS := amd64 arm64
+ARCH ::= amd64
+ALL_ARCHS ::= amd64 arm64
 _ARCH = $(or $(filter $(ARCH),$(ALL_ARCHS)),$(error $$ARCH [$(ARCH)] must be exactly one of "$(ALL_ARCHS)"))
 
 ifneq ($(TRIVY_REMOTE),)
-	TRIVY_OPTS := --server $(TRIVY_REMOTE)
+	TRIVY_OPTS ::= --server $(TRIVY_REMOTE)
 endif
 
 .SILENT: ; # no need for @
@@ -45,7 +46,7 @@ test:: ## test built artificats
 
 scan: ## Scan image using trivy
 	echo "Scanning $(IMAGE):$(TAG)-$(_ARCH) using Trivy $(TRIVY_REMOTE)"
-	trivy image $(TRIVY_OPTS) localhost/$(IMAGE):$(TAG)-$(_ARCH)
+	trivy image $(TRIVY_OPTS) --quiet --no-progress localhost/$(IMAGE):$(TAG)-$(_ARCH)
 
 # first tag and push all actual images
 # create new manifest for each tag and add all available TAG-ARCH before pushing
@@ -77,7 +78,7 @@ rm-image:
 
 ## some useful tasks during development
 ci-pull-upstream: ## pull latest shared .ci subtree
-	git stash && git subtree pull --prefix .ci ssh://git@git.zero-downtime.net/ZeroDownTime/ci-tools-lib.git master --squash && git stash pop
+	git subtree pull --prefix .ci ssh://git@git.zero-downtime.net/ZeroDownTime/ci-tools-lib.git master --squash -m "Merge latest ci-tools-lib"
 
 create-repo: ## create new AWS ECR public repository
 	aws ecr-public create-repository --repository-name $(IMAGE) --region $(REGION)
diff --git a/.ci/vars/buildPodman.groovy b/.ci/vars/buildPodman.groovy
index e33c2cf1..f1e87562 100644
--- a/.ci/vars/buildPodman.groovy
+++ b/.ci/vars/buildPodman.groovy
@@ -2,6 +2,9 @@
 
 def call(Map config=[:]) {
     pipeline {
+      options {
+        disableConcurrentBuilds()
+      }
       agent {
         node {
           label 'podman-aws-trivy'
@@ -10,6 +13,8 @@ def call(Map config=[:]) {
       stages {
         stage('Prepare') {
           steps {
+            sh 'mkdir -p reports'
+
             // we set pull tags as project adv. options
             // pull tags
             //withCredentials([gitUsernamePassword(credentialsId: 'gitea-jenkins-user')]) {
@@ -35,12 +40,13 @@ def call(Map config=[:]) {
 
         // Scan via trivy
         stage('Scan') {
-          environment {
-            TRIVY_FORMAT = "template"
-            TRIVY_OUTPUT = "reports/trivy.html"
-          }
           steps {
-            sh 'mkdir -p reports && make scan'
+            // we always scan and create the full json report
+            sh 'TRIVY_FORMAT=json TRIVY_OUTPUT="reports/trivy.json" make scan'
+
+            // render custom full html report
+            sh 'trivy convert -f template -t @/home/jenkins/html.tpl -o reports/trivy.html reports/trivy.json'
+
             publishHTML target: [
               allowMissing: true,
               alwaysLinkToLastBuild: true,
@@ -50,13 +56,12 @@ def call(Map config=[:]) {
               reportName: 'TrivyScan',
               reportTitles: 'TrivyScan'
             ]
+            sh 'echo "Trivy report at: $BUILD_URL/TrivyScan"'
 
-            // Scan again and fail on CRITICAL vulns, if not overridden
+            // fail build if issues found above trivy threshold
             script {
-              if (config.trivyFail == 'NONE') {
-                echo 'trivyFail == NONE, review Trivy report manually. Proceeding ...'
-              } else {
-                sh "TRIVY_EXIT_CODE=1 TRIVY_SEVERITY=${config.trivyFail} make scan"
+              if ( config.trivyFail ) {
+                sh "TRIVY_SEVERITY=${config.trivyFail} trivy convert --report summary --exit-code 1 reports/trivy.json"
               }
             }
           }