adding diff_opts to allow adding aditional helm diff options. (Ty…

…positoire#125)

* adding diff_opts

* version bump to 1.37.1

---------

Co-authored-by: Xing Du <xing.du@opendoor.com>

README.md

@@ -143,7 +143,8 @@ Deploy an helm chart
 -   `kubeconfig`: _Optional._ String containing a kubeconfig. Overrides `kubeconfig_path` and source configuration for cluster, token, and admin config.
 -   `kubeconfig_path`: _Optional._ File containing a kubeconfig. Overrides source configuration for cluster, token, and admin config.
 -   `show_diff`: _Optional._ Show the diff that is applied if upgrading an existing successful release. (Default: false)
--   `skip_missing_values:` _Optional._ Missing values files are skipped if they are specified in the values but do not exist. (Default false)
+-   `diff_opts`: _Optional._ Additional options to be appended to `helm diff` command. (Default: "")
+-   `skip_missing_values:` _Optional._ Missing values files are skipped if they are specified in the values but do not exist.(Default false)
 
 ## Example
 
@@ -306,3 +307,24 @@ jobs:
       chart: oci://01234567890.dkr.ecr.us-west-2.amazonaws.com/myapp-helm-repo
   # ...
 ```
+
+If `helm` chart contains `lookup` function
+```yaml
+resources:
+- name: myapp-helm
+  type: helm
+  source:
+    env_vars:
+      HELM_DIFF_USE_INSECURE_SERVER_SIDE_DRY_RUN: true
+    #...
+jobs:
+  # ...
+  plan:
+  - put: myapp-helm
+    params:
+      chart: ...
+      show_diff: true
+      diff_opts: "--dry-run=server"
+      # ...
+  # ...
+```

VERSION

@@ -1 +1 @@
-1.37.0
+1.37.1

assets/out

@@ -37,6 +37,7 @@ test_logs=$(jq -r '.params.test_logs // "false"' < $payload)
 devel=$(jq -r '.params.devel // "false"' < $payload)
 force=$(jq -r '.params.force // "false"' < $payload)
 show_diff=$(jq -r '.params.show_diff // "false"' < $payload)
+diff_opts=$(jq -r '.params.diff_opts // ""' < $payload)
 post_renderer=$(jq -r '.params.post_renderer // ""' < $payload)
 reuse_values=$(jq -r '.params.reuse_values // "false"' < $payload)
 reset_values=$(jq -r '.params.reset_values // "false"' < $payload)
@@ -300,7 +301,7 @@ helm_upgrade() {
 
   if [ "$show_diff" = true ] ; then
     echo "Release diff:"
-    $helm_bin diff --no-color=false "${helm_diff_args[@]}" | tee "$logfile"
+    $helm_bin diff --no-color=false "${helm_diff_args[@]}" ${diff_opts}| tee "$logfile"
   fi
 
   echo "Running command helm ${helm_echo_args[@]} | tee $logfile"