diff --git a/.github/workflows/linter.yml b/.github/workflows/linter.yml
new file mode 100644
index 0000000..8ba436f
--- /dev/null
+++ b/.github/workflows/linter.yml
@@ -0,0 +1,53 @@
+---
+###########################
+###########################
+## Linter GitHub Actions ##
+###########################
+###########################
+name: Lint Code Base
+
+#
+# Documentation:
+# https://help.github.com/en/articles/workflow-syntax-for-github-actions
+#
+
+#############################
+# Start the job on all push #
+#############################
+on:
+  push:
+    branches-ignore: [master]
+    # Remove the line above to run when pushing to master
+  pull_request:
+    branches: [master]
+
+###############
+# Set the Job #
+###############
+jobs:
+  build:
+    # Name the Job
+    name: Lint Code Base
+    # Set the agent to run on
+    runs-on: ubuntu-latest
+
+    ##################
+    # Load all steps #
+    ##################
+    steps:
+      ##########################
+      # Checkout the code base #
+      ##########################
+      - name: Checkout Code
+        uses: actions/checkout@v2
+
+      ################################
+      # Run Linter against code base #
+      ################################
+      - name: Lint Code Base
+        uses: github/super-linter@v3
+        env:
+          VALIDATE_ALL_CODEBASE: false
+          LINTER_RULES_PATH: /
+          DEFAULT_BRANCH: master
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
diff --git a/.github/workflows/push.yml b/.github/workflows/push.yml
index 20657c1..5e26057 100644
--- a/.github/workflows/push.yml
+++ b/.github/workflows/push.yml
@@ -8,7 +8,7 @@ jobs:
     steps:
       - uses: actions/checkout@v1
       - name: Publish to Docker Hub
-        uses: elgohr/Publish-Docker-Github-Action@2.7
+        uses: elgohr/Publish-Docker-Github-Action@v5
         with:
           name: stefanprodan/hrval
           username: ${{ secrets.DOCKER_USERNAME }}
diff --git a/.hadolint.yml b/.hadolint.yml
new file mode 100644
index 0000000..0464523
--- /dev/null
+++ b/.hadolint.yml
@@ -0,0 +1,2 @@
+ignored:
+  - DL3018
diff --git a/Dockerfile b/Dockerfile
index c39c7f3..a414fa0 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,6 +1,6 @@
-FROM garethr/kubeval:latest
+FROM garethr/kubeval:0.15.0
 
-RUN apk --no-cache add curl bash git
+RUN apk --no-cache add curl bash git openssh-client
 
 COPY LICENSE README.md /
 
diff --git a/README.md b/README.md
index 1c1ff25..06b0ff6 100644
--- a/README.md
+++ b/README.md
@@ -2,8 +2,9 @@
 
 ![CI](https://github.com/stefanprodan/hrval-action/workflows/CI/badge.svg)
 [![Docker](https://img.shields.io/badge/Docker%20Hub-stefanprodan%2Fhrval-blue)](https://hub.docker.com/r/stefanprodan/hrval)
+[![GitHub Super-Linter](https://github.com/stefanprodan/hrval-action/workflows/Lint%20Code%20Base/badge.svg)](https://github.com/marketplace/actions/super-linter)
 
-This GitHub action validates a Flux 
+This GitHub action validates a Flux
 [Helm Release](https://docs.fluxcd.io/projects/helm-operator/en/latest/references/helmrelease-custom-resource.html)
 Kubernetes custom resources with [kubeval](https://github.com/instrumenta/kubeval).
 
@@ -30,17 +31,17 @@ jobs:
     steps:
       - uses: actions/checkout@v1
       - name: Validate Helm Releases in test dir
-        uses: stefanprodan/hrval-action@v3.1.0
+        uses: stefanprodan/hrval-action@master
         with:
           helmRelease: test/
       - name: Validate Helm Release from Helm Repo
-        uses: stefanprodan/hrval-action@v3.1.0
+        uses: stefanprodan/hrval-action@master
         with:
           helmRelease: test/flagger.yaml
           helmVersion: v2
           kubernetesVersion: 1.17.0
       - name: Validate Helm Release from Git Repo
-        uses: stefanprodan/hrval-action@v3.1.0
+        uses: stefanprodan/hrval-action@master
         with:
           helmRelease: test/podinfo.yaml
           helmVersion: v3
@@ -75,7 +76,10 @@ PASS - flagger/templates/deployment.yaml contains a valid Deployment
 
 ## Usage with private charts repositories
 
-To allow the action to be able to clone private charts repositories, you must [create a GitHub private access token](https://help.github.com/en/github/authenticating-to-github/creating-a-personal-access-token-for-the-command-line) and [add it as a secret](https://help.github.com/en/actions/automating-your-workflow-with-github-actions/creating-and-using-encrypted-secrets#creating-encrypted-secrets) to the target repository. NOTE: secret names *cannot* start with `GITHUB_` as these are reserved.
+### Private GitHub/GitLab repository
+To allow the action to be able to clone charts from private GitHub repositories,
+you must [create a GitHub private access token](https://help.github.com/en/github/authenticating-to-github/creating-a-personal-access-token-for-the-command-line)
+and [add it as a secret](https://help.github.com/en/actions/automating-your-workflow-with-github-actions/creating-and-using-encrypted-secrets#creating-encrypted-secrets) to the target repository. NOTE: secret names *cannot* start with `GITHUB_` as these are reserved.
 
 You can then pass the secret (in this case, `GH_TOKEN`) into the action like so:
 ```yaml
@@ -89,13 +93,17 @@ jobs:
     steps:
       - uses: actions/checkout@v1
       - name: Validate Helm Releases in test dir
-        uses: stefanprodan/hrval-action@v3.1.0
+        uses: stefanprodan/hrval-action@master
         with:
           helmRelease: test/
         env:
           GITHUB_TOKEN: ${{ secrets.GH_TOKEN }}
 ```
 
+Gitlab CI Token is also possible using `GITLAB_CI_TOKEN`.
+
+### AWS S3
+
 If you set `awsS3Repo: true`,  make sure you set the appropriate environment variables for helm s3 plugin to work.  Example:
 ```yaml
 name: CI
@@ -108,7 +116,7 @@ jobs:
     steps:
       - uses: actions/checkout@v1
       - name: Validate Helm Releases in test dir
-        uses: stefanprodan/hrval-action@v3.1.0
+        uses: stefanprodan/hrval-action@master
         with:
           helmRelease: test/
           awsS3Repo: true
@@ -122,11 +130,107 @@ jobs:
 
 ```
 
-Gitlab CI Token is also possible using `GITLAB_CI_TOKEN`.
+### HTTP(S) Helm chart repository
+
+To allow fetching Helm charts from private Helm chart repositories you need to
+pass a list of Helm repositories in `HTTP_PRIVATE_CHART_REPOS` environment variable as JSON.
+
+```json
+{
+  "repositories": [
+    {
+      "url": "https://raw.githubusercontent.com/username/helm-chart-repository/master/",
+      "username": "YOUR_USERNAME",
+      "password": "YOUR_PASSWORD"
+    },
+    {
+      "url": "https://raw.githubusercontent.com/username/another-helm-chart-repository/master/",
+      "username": "YOUR_USERNAME",
+      "password": "YOUR_PASSWORD"
+    }
+  ]
+}
+```
+
+It should be passed [as a secret](https://docs.github.com/en/free-pro-team@latest/actions/reference/encrypted-secrets#creating-encrypted-secrets)
+to keep credentials secure.
+
+```yaml
+name: CI
+
+on: [push, pull_request]
+
+jobs:
+  hrval:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v1
+      - name: Validate Helm Releases in test dir
+        uses: stefanprodan/hrval-action@master
+        with:
+          helmRelease: test/
+        env:
+          HTTP_PRIVATE_CHART_REPOS: ${{ secrets.HTTP_PRIVATE_CHART_REPOS }}
+```
+
+
+## Usage with pull requests containing changes of Helm chart source located in base repository branch
+
+If a base repository branch of pull request is referenced in helm release,
+you need to pass `HRVAL_BASE_BRANCH` and `HRVAL_HEAD_BRANCH` environment variables
+to an action to make sure it will check out amended version of the chart
+from a head repository branch.
+
+
+```yaml
+name: CI
+
+on: [pull_request]
+
+jobs:
+  hrval:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v1
+      - name: Validate Helm Releases in test dir
+        uses: stefanprodan/hrval-action@master
+        with:
+          helmRelease: test/
+        env:
+          HRVAL_BASE_BRANCH: ${{ github.base_ref }}
+          HRVAL_HEAD_BRANCH: ${{ github.head_ref }}
+```
+
+## Usage with Helm source caching enabled
+
+Sometimes single Helm release might be referenced multiple times in a single Flux repository,
+for example if staging branch of Helm chart repository is used as a release ref across all staging releases.
+A property named `helmSourcesCacheEnabled` enables caching for such releases,
+so a single Helm repository chart version or Git repository ref
+will be retrieved only once, and cached version will be used for validation of another releases which reuse same sources.
+
+
+```yaml
+name: CI
+
+on: [pull_request]
+
+jobs:
+  hrval:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v1
+      - name: Validate Helm Releases in test dir
+        uses: stefanprodan/hrval-action@master
+        with:
+          helmRelease: test/
+          helmSourcesCacheEnabled: true
+```
+
 
 ## CI alternatives
 
-The validation scripts can be used in any CI system. 
+The validation scripts can be used in any CI system.
 
 CircleCI example:
 
@@ -135,7 +239,7 @@ version: 2.1
 jobs:
   hrval:
     docker:
-      - image: stefanprodan/hrval
+      - image: stefanprodan/hrval:latest
     steps:
       - checkout
       - run:
diff --git a/action.yml b/action.yml
index 6867f8d..0b3693a 100644
--- a/action.yml
+++ b/action.yml
@@ -26,6 +26,9 @@ inputs:
   awsS3Plugin:
     description: '(Optional) AWS S3 Plugin to be used in the helm plugin install command'
     default: ''
+  helmSourcesCacheEnabled:
+    description: '(Optional) Enabled Helm source caching, so same release or ref will not be downloaded twice.'
+    default: 'false'
 outputs:
   numFilesTested:
     description: The number of HelmRelease files which were tested
@@ -41,3 +44,4 @@ runs:
     - ${{ inputs.awsS3Repo }}
     - ${{ inputs.awsS3RepoName }}
     - ${{ inputs.awsS3RepoPlugin }}
+    - ${{ inputs.helmSourcesCacheEnabled }}
diff --git a/src/deps.sh b/src/deps.sh
index 7885139..26feea2 100755
--- a/src/deps.sh
+++ b/src/deps.sh
@@ -2,12 +2,12 @@
 
 set -o errexit
 
-curl -sL https://storage.googleapis.com/kubernetes-release/release/$(curl -s https://storage.googleapis.com/kubernetes-release/release/stable.txt)/bin/linux/amd64/kubectl -o /usr/local/bin/kubectl && chmod +x /usr/local/bin/kubectl
+curl -sL "https://storage.googleapis.com/kubernetes-release/release/$(curl -s https://storage.googleapis.com/kubernetes-release/release/stable.txt)/bin/linux/amd64/kubectl" -o /usr/local/bin/kubectl && chmod +x /usr/local/bin/kubectl
 
-curl -sL https://github.com/mikefarah/yq/releases/download/3.1.0/yq_linux_amd64 -o /usr/local/bin/yq && chmod +x /usr/local/bin/yq
+curl -sL https://github.com/mikefarah/yq/releases/download/3.4.1/yq_linux_amd64 -o /usr/local/bin/yq && chmod +x /usr/local/bin/yq
 
 curl -sSL https://get.helm.sh/helm-v2.16.3-linux-amd64.tar.gz | tar xz && mv linux-amd64/helm /bin/helm && rm -rf linux-amd64
-helm init --client-only --kubeconfig=$HOME/.kube/kubeconfig
+helm init --client-only --kubeconfig="${HOME}/.kube/kubeconfig"
 
 curl -sSL https://get.helm.sh/helm-v3.1.1-linux-amd64.tar.gz | tar xz && mv linux-amd64/helm /bin/helmv3 && rm -rf linux-amd64
 helmv3 version
diff --git a/src/hrval-all.sh b/src/hrval-all.sh
index b5977b3..eea89b5 100755
--- a/src/hrval-all.sh
+++ b/src/hrval-all.sh
@@ -9,21 +9,62 @@ HELM_VER=${4-v2}
 HRVAL="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )/hrval.sh"
 AWS_S3_REPO=${5-false}
 AWS_S3_REPO_NAME=${6-""}
-AWS_S3_PLUGIN={$7-""}
+AWS_S3_PLUGIN="${7-""}"
+HELM_SOURCES_CACHE_ENABLED=${8-""}
+
+function configurePrivateChartRepositories() {
+
+  local tempDir
+  tempDir="$(mktemp -d)"
+  echo "$HTTP_PRIVATE_CHART_REPOS" > "$tempDir/repositories.json"
+  local numberOfRepositories
+  numberOfRepositories=$(yq r "$tempDir/repositories.json" --length repositories)
+
+  for (( i = 0; i < numberOfRepositories; i++ )); do
+      local url
+      url=$(yq r "$tempDir/repositories.json" repositories[$i].url)
+      local username
+      username=$(yq r "$tempDir/repositories.json" repositories[$i].username)
+      local password
+      password=$(yq r "$tempDir/repositories.json" repositories[$i].password)
+      local repoMD5
+      repoMD5=$(/bin/echo "$url" | /usr/bin/md5sum | cut -f1 -d" ")
+
+      >&2 echo "Adding Helm chart repository '$url'"
+      if [[ ${HELM_VER} == "v3" ]]; then
+        helmv3 repo add "$repoMD5" "${url}" --username "${username}" --password "${password}"
+        helmv3 repo update
+      else
+        helm repo add "$repoMD5" "${url}" --username "${username}" --password "${password}"
+        helm repo update
+      fi
+  done
+}
+
+if [[ -v HTTP_PRIVATE_CHART_REPOS ]]; then
+  echo "Configuring Helm chart repositories"
+  configurePrivateChartRepositories
+fi
+
+if [ "${HELM_SOURCES_CACHE_ENABLED}" == "true" ]; then
+  CACHEDIR=$(mktemp -d)
+else
+  CACHEDIR="${CACHEDIR}"
+fi
 
 if [[ ${HELM_VER} == "v2" ]]; then
     helm init --client-only
 fi
 
 if [[ ${AWS_S3_REPO} == true ]]; then
-    helm plugin install ${AWS_S3_PLUGIN}
-    helm repo add ${AWS_S3_REPO_NAME} s3:/${AWS_S3_REPO_NAME}/charts
+    helm plugin install "${AWS_S3_PLUGIN}"
+    helm repo add "${AWS_S3_REPO_NAME}" "s3:/${AWS_S3_REPO_NAME}/charts"
     helm repo update
 fi
 
 # If the path provided is actually a file, just run hrval against this one file
 if test -f "${DIR}"; then
-  ${HRVAL} ${DIR} ${IGNORE_VALUES} ${KUBE_VER} ${HELM_VER}
+  ${HRVAL} "${DIR}" "${IGNORE_VALUES}" "${KUBE_VER}" "${HELM_VER}" "${CACHEDIR}"
   exit 0
 fi
 
@@ -34,7 +75,7 @@ if [ ! -d "$DIR" ]; then
 fi
 
 function isHelmRelease {
-  KIND=$(yq r ${1} kind)
+  KIND=$(yq r "${1}" kind)
   if [[ ${KIND} == "HelmRelease" ]]; then
       echo true
   else
@@ -43,11 +84,15 @@ function isHelmRelease {
 }
 
 # Find yaml files in directory recursively
-DIR_PATH=$(echo ${DIR} | sed "s/^\///;s/\/$//")
 FILES_TESTED=0
-for f in `find ${DIR} -type f -name '*.yaml' -or -name '*.yml'`; do
-  if [[ $(isHelmRelease ${f}) == "true" ]]; then
-    ${HRVAL} ${f} ${IGNORE_VALUES} ${KUBE_VER} ${HELM_VER}
+declare -a FOUND_FILES=()
+while read -r file; do
+    FOUND_FILES+=( "$file" )
+done < <(find "${DIR}" -type f -name '*.yaml' -o -name '*.yml')
+
+for f in "${FOUND_FILES[@]}"; do
+  if [[ $(isHelmRelease "${f}") == "true" ]]; then
+    ${HRVAL} "${f}" "${IGNORE_VALUES}" "${KUBE_VER}" "${HELM_VER}" "${CACHEDIR}"
     FILES_TESTED=$(( FILES_TESTED+1 ))
   else
     echo "Ignoring ${f} not a HelmRelease"
diff --git a/src/hrval.sh b/src/hrval.sh
index f522ce0..4c533bc 100755
--- a/src/hrval.sh
+++ b/src/hrval.sh
@@ -2,10 +2,11 @@
 
 set -o errexit
 
-HELM_RELEASE=${1}
-IGNORE_VALUES=${2}
-KUBE_VER=${3-master}
-HELM_VER=${4-v2}
+HELM_RELEASE="${1}"
+IGNORE_VALUES="${2}"
+KUBE_VER="${3-master}"
+HELM_VER="${4-v2}"
+CACHEDIR="${5-""}"
 
 if test ! -f "${HELM_RELEASE}"; then
   echo "\"${HELM_RELEASE}\" Helm release file not found!"
@@ -15,94 +16,207 @@ fi
 echo "Processing ${HELM_RELEASE}"
 
 function isHelmRelease {
-  KIND=$(yq r ${1} kind)
-  if [[ ${KIND} == "HelmRelease" ]]; then
+  KIND=$(yq r "${1}" kind)
+  if [[ "${KIND}" == "HelmRelease" ]]; then
       echo true
   else
     echo false
   fi
 }
 
+
 function download {
-  CHART_REPO=$(yq r ${1} spec.chart.repository)
-  CHART_NAME=$(yq r ${1} spec.chart.name)
-  CHART_VERSION=$(yq r ${1} spec.chart.version)
+  CHART_REPO="$(yq r "${1}" spec.chart.repository)"
+  CHART_NAME="$(yq r "${1}" spec.chart.name)"
+  CHART_VERSION="$(yq r "${1}" spec.chart.version)"
   CHART_DIR=${2}/${CHART_NAME}
-  helm repo add ${CHART_NAME} ${CHART_REPO}
-  helm fetch --version ${CHART_VERSION} --untar ${CHART_NAME}/${CHART_NAME} --untardir ${2}
-  echo ${CHART_DIR}
+
+  CHART_REPO_MD5=$(/bin/echo "${CHART_REPO}" | /usr/bin/md5sum | cut -f1 -d" ")
+
+
+  if [[ ${HELM_VER} == "v3" ]]; then
+    if [[ $(helmv3 repo list -o yaml  | yq r - "[*].name" | grep "$CHART_REPO_MD5") == "$CHART_REPO_MD5" ]]; then
+      CHART_REPO_ALREADY_ADDED=true
+    else
+      CHART_REPO_ALREADY_ADDED=false
+    fi
+  else
+    if [[ $(helm repo list -o yaml  | yq r - "[*].Name" | grep "$CHART_REPO_MD5") == "$CHART_REPO_MD5" ]]; then
+      CHART_REPO_ALREADY_ADDED=true
+    else
+      CHART_REPO_ALREADY_ADDED=false
+    fi
+  fi
+
+  if [[ "$CHART_REPO_ALREADY_ADDED" = false ]]; then
+    if [[ "${HELM_VER}" == "v3" ]]; then
+      helmv3 repo add "${CHART_REPO_MD5}" "${CHART_REPO}"
+      helmv3 repo update
+    else
+      helm repo add "${CHART_REPO_MD5}" "${CHART_REPO}"
+      helm repo update
+    fi
+  fi
+
+  if [[ ${HELM_VER} == "v3" ]]; then
+    helmv3 fetch --version "${CHART_VERSION}" --untar "${CHART_REPO_MD5}/${CHART_NAME}" --untardir "${2}"
+  else
+    helm fetch --version "${CHART_VERSION}" --untar "${CHART_REPO_MD5}/${CHART_NAME}" --untardir "${2}"
+  fi
+
+  echo "${CHART_DIR}"
 }
 
+
+function fetch {
+  cd "${1}"
+  git init -q
+  git remote add origin "${3}"
+  git fetch -q origin
+  git checkout -q "${4}"
+  cd "${5}"
+  echo "${2}"
+}
+
+
 function clone {
   ORIGIN=$(git rev-parse --show-toplevel)
-  GIT_REPO=$(yq r ${1} spec.chart.git)
+  CHART_GIT_REPO=$(yq r "${1}" spec.chart.git)
+  RELEASE_GIT_REPO=$(git remote get-url origin)
+
+  CHART_BASE_URL=$(echo "${CHART_GIT_REPO}" | sed -e 's/ssh:\/\///' -e 's/http:\/\///' -e 's/https:\/\///' -e 's/git@//' -e 's/:/\//' -e 's/\.git$//')
+  RELEASE_BASE_URL=$(echo "${RELEASE_GIT_REPO}" | sed -e 's/ssh:\/\///' -e 's/http:\/\///' -e 's/https:\/\///' -e 's/git@//' -e 's/:/\//' -e 's/\.git$//')
+
   if [[ -n "${GITHUB_TOKEN}" ]]; then
-    BASE_URL=$(echo "${GIT_REPO}" | sed -e 's/ssh:\/\///' -e 's/git@//' -e 's/:/\//')
-    GIT_REPO="https://${GITHUB_TOKEN}:x-oauth-basic@${BASE_URL}"
+    CHART_GIT_REPO="https://${GITHUB_TOKEN}:x-oauth-basic@${CHART_BASE_URL}"
   elif [[ -n "${GITLAB_CI_TOKEN}" ]]; then
-    BASE_URL=$(echo "${GIT_REPO}" | sed -e 's/ssh:\/\///' -e 's/git@//' -e 's/:/\//')
-    GIT_REPO="https://gitlab-ci-token:${GITLAB_CI_TOKEN}@${BASE_URL}"
+    CHART_GIT_REPO="https://gitlab-ci-token:${GITLAB_CI_TOKEN}@${CHART_BASE_URL}"
+  fi
+
+  GIT_REF=$(yq r "${1}" spec.chart.ref)
+  CHART_PATH=$(yq r "${1}" spec.chart.path)
+
+  if [ -n "${3}" ]; then
+    if [[ "${CHART_BASE_URL}" == "${RELEASE_BASE_URL}" ]] && [[ "${GIT_REF}" == "${4}" ]]; then
+      # Clone from the head repository branch/ref
+      fetch "${2}" "${2}/${CHART_PATH}" "${RELEASE_GIT_REPO}" "${3}" "${ORIGIN}"
+    else
+      # Regular clone
+      fetch "${2}" "${2}/${CHART_PATH}" "${CHART_GIT_REPO}" "${GIT_REF}" "${ORIGIN}"
+    fi
+  else
+      fetch "${2}" "${2}/${CHART_PATH}" "${CHART_GIT_REPO}" "${GIT_REF}" "${ORIGIN}"
   fi
-  GIT_REF=$(yq r ${1} spec.chart.ref)
-  CHART_PATH=$(yq r ${1} spec.chart.path)
-  cd ${2}
-  git init -q
-  git remote add origin ${GIT_REPO}
-  git fetch -q origin
-  git checkout -q ${GIT_REF}
-  cd ${ORIGIN}
-  echo ${2}/${CHART_PATH}
 }
 
+
+function retrieve_sources {
+    HELM_RELEASE="${1}"
+    TMPDIR="${2}"
+
+    CHART_PATH=$(yq r "${HELM_RELEASE}" spec.chart.path)
+
+    if [[ -z "${CACHEDIR}" ]]; then
+
+      # Retrieve files directly into tempdir
+      if [[ -z "${CHART_PATH}" ]]; then
+        >&2 echo "Downloading to ${TMPDIR}"
+        CHART_DIR=$(download "${HELM_RELEASE}" "${TMPDIR}" "${HELM_VER}" | tail -n1)
+      else
+        >&2 echo "Cloning to ${TMPDIR}"
+        CHART_DIR=$(clone "${HELM_RELEASE}" "${TMPDIR}" "${HRVAL_HEAD_BRANCH}" "${HRVAL_BASE_BRANCH}" | tail -n1)
+      fi
+
+    else
+      # Retrieve existing helm chart source from cache, 
+      # or create new cache directory if it does not exist yet.
+
+      if [[ -z "${CHART_PATH}" ]]; then
+        # Caches releases from Helm repos
+
+        CHART_REPO=$(yq r "${HELM_RELEASE}" spec.chart.repository)
+        CHART_REPO_MD5=$(/bin/echo "${CHART_REPO}" | /usr/bin/md5sum | cut -f1 -d" ")
+        CHART_NAME=$(yq r "${HELM_RELEASE}" spec.chart.name)
+        CHART_VERSION=$(yq r "${HELM_RELEASE}" spec.chart.version)
+        CHART_LOCAL_PATH="${CACHEDIR}/${CHART_REPO_MD5}/${CHART_NAME}/${CHART_VERSION}"
+
+        if [[ ! -d ${CHART_LOCAL_PATH} ]]; then
+          mkdir -p "${CHART_LOCAL_PATH}"
+          >&2 echo "Downloading to ${CHART_LOCAL_PATH}"
+          CHART_DIR=$(download "${HELM_RELEASE}" "${CHART_LOCAL_PATH}" "${HELM_VER}" | tail -n1)
+        else
+          >&2 echo "Using cached sources from ${CHART_LOCAL_PATH}"
+          CHART_DIR="${CHART_LOCAL_PATH}/${CHART_NAME}"
+        fi
+
+      else
+          # Caches releases from Git repos
+
+          CHART_GIT_REPO=$(yq r "${1}" spec.chart.git)
+          CHART_PATH=$(yq r "${1}" spec.chart.path)
+          GIT_REF=$(yq r "${1}" spec.chart.ref)
+
+          CHART_LOCAL_PATH="${CACHEDIR}/${CHART_GIT_REPO}/${GIT_REF}"
+
+          if [[ ! -d "${CHART_LOCAL_PATH}" ]]; then
+            mkdir -p "${CHART_LOCAL_PATH}"
+            >&2 echo "Cloning to ${CHART_LOCAL_PATH}"
+            CHART_DIR=$(clone "${HELM_RELEASE}" "${CHART_LOCAL_PATH}" "${HRVAL_HEAD_BRANCH}" "${HRVAL_BASE_BRANCH}" | tail -n1)
+          else
+            >&2 echo "Using cached sources from ${CHART_LOCAL_PATH}"
+            CHART_DIR="${CHART_LOCAL_PATH}/${CHART_PATH}"
+          fi
+
+        fi
+
+    fi
+
+    echo "${CHART_DIR}"
+}
+
+
 function validate {
-  if [[ $(isHelmRelease ${HELM_RELEASE}) == "false" ]]; then
+  if [[ $(isHelmRelease "${HELM_RELEASE}") == "false" ]]; then
     echo "\"${HELM_RELEASE}\" is not of kind HelmRelease!"
     exit 1
   fi
 
-  TMPDIR=$(mktemp -d)
-  CHART_PATH=$(yq r ${HELM_RELEASE} spec.chart.path)
-
-  if [[ -z "${CHART_PATH}" ]]; then
-    echo "Downloading to ${TMPDIR}"
-    CHART_DIR=$(download ${HELM_RELEASE} ${TMPDIR}| tail -n1)
-  else
-    echo "Cloning to ${TMPDIR}"
-    CHART_DIR=$(clone ${HELM_RELEASE} ${TMPDIR}| tail -n1)
-  fi
+  TMPDIR="$(mktemp -d)"
+  CHART_DIR=$(retrieve_sources "${HELM_RELEASE}" "${TMPDIR}")
+  CHART_PATH=$(yq r "${HELM_RELEASE}" spec.chart.path)
 
-  HELM_RELEASE_NAME=$(yq r ${HELM_RELEASE} metadata.name)
-  HELM_RELEASE_NAMESPACE=$(yq r ${HELM_RELEASE} metadata.namespace)
+  HELM_RELEASE_NAME=$(yq r "${HELM_RELEASE}" metadata.name)
+  HELM_RELEASE_NAMESPACE=$(yq r "${HELM_RELEASE}" metadata.namespace)
 
-  if [[ ${IGNORE_VALUES} == "true" ]]; then
-    echo "Ingnoring Helm release values"
-    echo "" > ${TMPDIR}/${HELM_RELEASE_NAME}.values.yaml
+  if [[ "${IGNORE_VALUES}" == "true" ]]; then
+    echo "Ignoring Helm release values"
+    echo "" > "${TMPDIR}/${HELM_RELEASE_NAME}.values.yaml"
   else
     echo "Extracting values to ${TMPDIR}/${HELM_RELEASE_NAME}.values.yaml"
-    yq r ${HELM_RELEASE} spec.values > ${TMPDIR}/${HELM_RELEASE_NAME}.values.yaml
+    yq r -X "${HELM_RELEASE}" spec.values > "${TMPDIR}/${HELM_RELEASE_NAME}.values.yaml"
   fi
 
   echo "Writing Helm release to ${TMPDIR}/${HELM_RELEASE_NAME}.release.yaml"
   if [[ ${HELM_VER} == "v3" ]]; then
     if [[ "${CHART_PATH}" ]]; then
-      helmv3 dependency build ${CHART_DIR}
+      helmv3 dependency build "${CHART_DIR}"
     fi
-    helmv3 template ${HELM_RELEASE_NAME} ${CHART_DIR} \
-      --namespace ${HELM_RELEASE_NAMESPACE} \
+    helmv3 template "${HELM_RELEASE_NAME}" "${CHART_DIR}" \
+      --namespace "${HELM_RELEASE_NAMESPACE}" \
       --skip-crds=true \
-      -f ${TMPDIR}/${HELM_RELEASE_NAME}.values.yaml > ${TMPDIR}/${HELM_RELEASE_NAME}.release.yaml
+      -f "${TMPDIR}/${HELM_RELEASE_NAME}.values.yaml" > "${TMPDIR}/${HELM_RELEASE_NAME}.release.yaml"
   else
     if [[ "${CHART_PATH}" ]]; then
-      helm dependency build ${CHART_DIR}
+      helm dependency build "${CHART_DIR}"
     fi
-    helm template ${CHART_DIR} \
-      --name ${HELM_RELEASE_NAME} \
-      --namespace ${HELM_RELEASE_NAMESPACE} \
-      -f ${TMPDIR}/${HELM_RELEASE_NAME}.values.yaml > ${TMPDIR}/${HELM_RELEASE_NAME}.release.yaml
+    helm template "${CHART_DIR}" \
+      --name "${HELM_RELEASE_NAME}" \
+      --namespace "${HELM_RELEASE_NAMESPACE}" \
+      -f "${TMPDIR}/${HELM_RELEASE_NAME}.values.yaml" > "${TMPDIR}/${HELM_RELEASE_NAME}.release.yaml"
   fi
 
   echo "Validating Helm release ${HELM_RELEASE_NAME}.${HELM_RELEASE_NAMESPACE} against Kubernetes ${KUBE_VER}"
-  kubeval --strict --ignore-missing-schemas --kubernetes-version ${KUBE_VER} ${TMPDIR}/${HELM_RELEASE_NAME}.release.yaml
+  kubeval --strict --ignore-missing-schemas --kubernetes-version "${KUBE_VER}" "${TMPDIR}/${HELM_RELEASE_NAME}.release.yaml"
 }
 
 validate