From 4a7d7c6ad9497eb02c5a9038d5d01db242ab37b8 Mon Sep 17 00:00:00 2001
From: James Andariese <james@strudelline.net>
Date: Thu, 27 Apr 2023 10:14:29 -0500
Subject: [PATCH] add adopt-helm and instructions

---
 README.md           |  13 +++++
 argo1/adopt-helm.sh | 121 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 134 insertions(+)
 create mode 100644 argo1/adopt-helm.sh

diff --git a/README.md b/README.md
index 4808080..0e47dca 100644
--- a/README.md
+++ b/README.md
@@ -68,5 +68,18 @@ pre-bootstrap files:
  - `install.sh`
  - `uninstall.sh`
 
+## Adopting a helm chart
+
+To adopt an existing helm chart, there is an adopt-helm.sh script.  It is not perfectly
+reliable, however, so ensure the output makes sense.
+
+1. Setup your helm release how you need it to work
+2. `cd argo1`
+2. `bash adopt-helm.sh release-name`
+3. Follow configuration instructions
+4. Validate templates/release-name.yaml
+ - Especially, check that the repoURL is correct.
+5. Commit templates/release-name.yaml and values.yaml
+
 
 [argo-crds]: https://argo-cd.readthedocs.io/en/stable/operator-manual/installation/
diff --git a/argo1/adopt-helm.sh b/argo1/adopt-helm.sh
new file mode 100644
index 0000000..b48928a
--- /dev/null
+++ b/argo1/adopt-helm.sh
@@ -0,0 +1,121 @@
+#!/bin/bash
+
+cd "$(dirname "$0")"
+
+SOURCE_RELEASE="$1"
+
+eval "$(
+  helm list -A -o json | jq -r --arg release $SOURCE_RELEASE '
+      .[]
+    | select(.name == $release)
+    | (
+        @sh "CHART=\(     .chart | split("-") | .[0:-1] | join("-") )",
+        @sh "VERSION=\(   .chart | split("-") | .[-1] )",
+        @sh "RELEASE=\(   .name )",
+        @sh "NAMESPACE=\( .namespace )"
+      )
+  '
+)"
+
+TEMPLATE="${PWD}/templates/${RELEASE}.yaml"
+if [ -e "$TEMPLATE" ];then
+  1>&2 echo "$TEMPLATE: already exists.  aborting."
+  exit 1
+fi
+
+REPO="$(
+    helm repo list -o json \
+  | jq -r '.[].url' \
+  | xargs -P 8 -L 1 bash -c '
+      if helm show readme --repo "$1" $0 > /dev/null 2>&1;then
+        echo $1
+      fi
+    ' "$CHART" \
+  | sort | uniq
+)"
+
+REPOS_MATCHING="$(echo "$REPO" | grep . | wc -l | tr -d ' \t\n\r\v')"
+
+if [ x"$REPOS_MATCHING" != x"1" ];then
+  1>&2 echo "found $REPOS_MATCHING repos with $CHART. aborting."
+  1>&2 echo "$REPO"
+  exit 1
+fi
+
+if [ x"$CHART" = x"$VERSION" ];then 1>&2 echo "could not parse chart version from name"; exit 1; fi
+
+VALUES="$(helm get values -n "$NAMESPACE" "$RELEASE" -o yaml)"
+
+echo -n '# {{ if (index .Values "'"$RELEASE"'").enabled }}
+---
+apiVersion: argoproj.io/v1alpha1
+kind: Application
+metadata:
+  name: "{{ .Release.Name }}-'"$RELEASE"'"
+  namespace: argocd
+  finalizers:
+    - resources-finalizer.argocd.argoproj.io
+spec:
+  project: default
+  source:
+    chart: "'"$CHART"'"
+    repoURL: "'"$REPO"'"
+    targetRevision: "'"$VERSION"'"
+    helm:
+      values: |-
+        {{ (index .Values "'"$RELEASE"'").values | nindent 8 }}
+      # the next line preserves the release name.
+      # this is optional but recommended for singleton services.
+      releaseName: "'"$RELEASE"'"
+  destination:
+    server: "https://kubernetes.default.svc"
+    namespace: "'"$NAMESPACE"'"
+  syncPolicy:
+    automated:
+      prune: true
+      selfHeal: true
+    syncOptions:
+      - CreateNamespace=true
+    retry:
+      limit: 10
+      backoff:
+        duration: 5s
+        factor: 2
+        maxDuration: 3m0s
+# {{- end }}
+' > "$TEMPLATE"
+
+if [ x"$VALUES" = x"null" ];then
+  SAMPLE_VALUES="## (sample configs from $CHART -- choose one) ## 
+
+### (minimal config) ###
+$CHART: {enabled: true}
+
+### (skeleton config) ###
+$CHART:
+  enabled: true
+  values: |
+    # values.yaml contents here
+"
+else
+  SAMPLE_VALUES="
+## (sample config from $CHART) ##
+
+$RELEASE:
+  enabled: true
+  values: |
+$(echo "$VALUES" | sed -e 's/^/    /')
+"
+fi
+
+which pbcopy > /dev/null 2>&1 && (echo "$SAMPLE_VALUES" | pbcopy)
+
+printf '#####
+A new template has been added at %s.
+
+Please finish configuring this template by adding the following to values.yaml and customizing:
+
+%s
+
+(this has also been copied to your clipboard on macos
+' "$TEMPLATE" "$SAMPLE_VALUES"