feat: Add HELM_GIT_CHART_CACHE_STRATEGY variable to customize chart caching (#319)

hwo411 · web-flow · commit 45db101cbada · 2025-06-05T21:41:42.000+02:00
* Add `HELM_GIT_CHART_CACHE_STRATEGY` variable to customize chart caching

* Update single chart test to work with helm 2 and fix regexp to match exact name and regardless of number of whitespaces or presence of quotes
diff --git a/README.md b/README.md
@@ -74,6 +74,7 @@ Pulling value files:
 `HELM_GIT_TRACE`|Setting this value to `1` increases `helm-git` log level to the maximum and keeps temporary dirs at shutdown. |`0`
 `HELM_GIT_REPO_CACHE`|Path to use as a Git repository cache to avoid fetching repos more than once. If empty, caching of Git repositories is disabled.|`""`
 `HELM_GIT_CHART_CACHE`|Path to use as a Helm chart cache to avoid re-packaging/re-indexing charts. If empty, caching of Helm charts is disabled.|`""`
+`HELM_GIT_CHART_CACHE_STRATEGY`|Strategy to use when caching charts. If `repo` then all charts from the same repo will use the same cache. If `chart`, caching will only build single chart for each chart if `package` is `1`. Any other values preserves the default behavior: each chart has its own cache and all packages are built every time if `package` is `1`.|`""`
 
 ### Arguments
 
diff --git a/helm-git-plugin.sh b/helm-git-plugin.sh
@@ -53,8 +53,12 @@ readonly cache_repos_enabled
 cache_charts_enabled=0
 if [ -n "${HELM_GIT_CHART_CACHE:-}" ]; then
   cache_charts_enabled=1
+  cache_charts_strategy="${HELM_GIT_CHART_CACHE_STRATEGY:-}"
+else
+  cache_charts_strategy=""
 fi
 readonly cache_charts_enabled
+readonly cache_charts_strategy
 
 ## Tooling
 
@@ -322,6 +326,10 @@ parse_uri() {
   readonly helm_file
   trace "helm_file: $helm_file"
 
+  helm_chart_name=$(echo "$helm_file" | sed -r 's/-[^-]+.tgz$//')
+  readonly helm_chart_name
+  trace "helm_chart_name: $helm_chart_name"
+
   git_repo="${_git_scheme}://${_uri_authority}/${_git_path}"
   readonly git_repo
   trace "git_repo: $git_repo"
@@ -384,7 +392,11 @@ main() {
   trace "helm_repo_uri: $helm_repo_uri"
 
   if [ "$cache_charts_enabled" = 1 ]; then
-    _request_hash=$(echo "${_raw_uri}" | md5sum | cut -d " " -f1)
+    if [ "$cache_charts_strategy" = "repo" ]; then
+      _request_hash=$(echo "${helm_repo_uri}" | md5sum | cut -d " " -f1)
+    else
+      _request_hash=$(echo "${_raw_uri}" | md5sum | cut -d " " -f1)
+    fi
 
     _cache_folder="${HELM_GIT_CHART_CACHE}/${_request_hash}"
 
@@ -452,7 +464,12 @@ main() {
 
   chart_search_root="$git_sub_path"
 
-  chart_search=$(find "$chart_search_root" -maxdepth 2 -name "Chart.yaml" -print)
+  if [ "$helm_chart_name" != "index.yaml" ] && [ "$cache_charts_enabled" = "1" ] && [ "$cache_charts_strategy" = "chart" ]; then
+    chart_search=$(find "$chart_search_root" -maxdepth 2 -name "Chart.yaml" -exec grep -lE "name:\s*('|\")?${helm_chart_name}('|\")?(\s+|$)" {} +)
+  else
+    chart_search=$(find "$chart_search_root" -maxdepth 2 -name "Chart.yaml" -print)
+  fi
+
   chart_search_count=$(echo "$chart_search" | wc -l)
 
   echo "$chart_search" | {
diff --git a/tests/06-helm-git-cache.bats b/tests/06-helm-git-cache.bats
@@ -48,3 +48,45 @@ load 'test-helper'
     run stat "$HELM_GIT_OUTPUT/cert-manager-v0.5.2.tgz"
     [ $status = 0 ]
 }
+
+@test "helm_cli fetch index.yaml and ensure chart cert-manager-v0.5.2.tgz is cached if strategy=repo" {
+    enable_chart_cache
+    set_chart_cache_strategy "repo"
+    run helm_init "$HELM_HOME"
+    [ $status = 0 ]
+    run "$HELM_BIN" plugin install "$HELM_GIT_DIRNAME"
+    [ $status = 0 ]
+    run "$HELM_BIN" fetch -d "$HELM_GIT_OUTPUT" "git+https://github.com/jetstack/cert-manager@contrib/charts/index.yaml?ref=v0.5.2"
+    [ $status = 0 ]
+    echo "$output" | grep "Helm request not found in cache"
+    run "$HELM_BIN" fetch -d "$HELM_GIT_OUTPUT" "git+https://github.com/jetstack/cert-manager@contrib/charts/cert-manager-v0.5.2.tgz?ref=v0.5.2"
+    [ $status = 0 ]
+    echo "$output" | grep "Returning cached helm request"
+    run stat "$HELM_GIT_OUTPUT/cert-manager-v0.5.2.tgz"
+    [ $status = 0 ]
+}
+
+@test "helm_cli fetch gateway and ensure only single chart is packaged" {
+    enable_chart_cache
+    run helm_init "$HELM_HOME"
+    [ $status = 0 ]
+    run "$HELM_BIN" plugin install "$HELM_GIT_DIRNAME"
+    [ $status = 0 ]
+    run "$HELM_BIN" fetch -d "$HELM_GIT_OUTPUT" "git+https://github.com/istio/istio@install/kubernetes/helm/istio-1.1.0.tgz?ref=1.1.0"
+    [ $status = 0 ]
+    echo "$output" | grep "Helm request not found in cache"
+    run stat "$HELM_GIT_OUTPUT/istio-1.1.0.tgz"
+    [ $status = 0 ]
+    run bats_pipe ls -1 "$HELM_GIT_CHART_CACHE"/*/* \| grep -v index.yaml \| wc -l \| awk '{print $1}'
+    [ "$output" -gt "1" ]
+    run rm -rf "$HELM_GIT_CHART_CACHE"/*/*
+    set_chart_cache_strategy "chart"
+    run "$HELM_BIN" fetch -d "$HELM_GIT_OUTPUT" "git+https://github.com/istio/istio@install/kubernetes/helm/istio-1.1.0.tgz?ref=1.1.0"
+    [ $status = 0 ]
+    echo "$output" | grep "Helm request not found in cache"
+    run stat "$HELM_GIT_OUTPUT/istio-1.1.0.tgz"
+    [ $status = 0 ]
+    run bats_pipe ls -1 "$HELM_GIT_CHART_CACHE"/*/* \| grep -v index.yaml \| wc -l \| awk '{print $1}'
+    [ "$output" = "1" ]
+}
+
diff --git a/tests/test-helper.bash b/tests/test-helper.bash
@@ -50,3 +50,7 @@ enable_repo_cache() {
     HELM_GIT_REPO_CACHE=$(mktemp -d "$BATS_TMPDIR/helm-git.repo-cache.XXXXXX")
     export HELM_GIT_REPO_CACHE
 }
+set_chart_cache_strategy() {
+    HELM_GIT_CHART_CACHE_STRATEGY="$1"
+    export HELM_GIT_CHART_CACHE_STRATEGY
+}

Original file line number	Diff line number	Diff line change
`@@ -50,3 +50,7 @@ enable_repo_cache() {`
`50`	`50`	`HELM_GIT_REPO_CACHE=$(mktemp -d "$BATS_TMPDIR/helm-git.repo-cache.XXXXXX")`
`51`	`51`	`export HELM_GIT_REPO_CACHE`
`52`	`52`	`}`
	`53`	`+set_chart_cache_strategy() {`
	`54`	`+ HELM_GIT_CHART_CACHE_STRATEGY="$1"`
	`55`	`+ export HELM_GIT_CHART_CACHE_STRATEGY`
	`56`	`+}`