ci: improve readability of chart diff output (#2894)

Author: merll

.github/workflows/svcaplbot-run-dyff.yml

@@ -81,9 +81,10 @@ jobs:
         run: |
           bin/compare.sh --diff-output tmp/diff-output.txt
           diff_text=$(cat tmp/diff-output.txt)
-          format_code='```'
+          format_code_start='```diff'
+          format_code_end='```'
           comment_text="Comparison of Helm chart templating output:
-          $format_code
+          $format_code_start
           $diff_text
-          $format_code"
+          $format_code_end"
           gh pr comment ${{ github.event.pull_request.number }} --body "$comment_text"

bin/compare.sh

@@ -2,6 +2,7 @@
 set -ue
 
 # Usage: bin/compare.sh -l name=loki
+# Optional: --diff-output <filename> writes the final diff to a file and skips common chart version information
 # Deps: dyff, helmfile
 # brew install homeport/tap/dyff
 # brew install helmfile
@@ -48,7 +49,7 @@ git -c core.hooksPath=/dev/null checkout $branchB
 # order of arguments matters so new changes are green color
 echo "Comparing $targetDirB with $targetDirA"
 if [ -n "$diffOutput" ]; then
-  "${script_dir}/dyff.sh" "$targetDirB" "$targetDirA" > "$diffOutput"
+  "${script_dir}/dyff.sh" "$targetDirB" "$targetDirA" --exclude-chart-versions > "$diffOutput"
   cat "$diffOutput"
 else
   "${script_dir}/dyff.sh" "$targetDirB" "$targetDirA"

bin/dyff.sh

@@ -1,8 +1,36 @@
 #!/bin/bash
 set -ue
 
-targetDirA=$1
-targetDirB=$2
+targetDirA=
+targetDirB=
+miscArgs=( --output github )
+
+while [ $# -ne 0 ]
+do
+  case "$1" in
+    --exclude-chart-versions)
+      miscArgs=( "${miscArgs[@]}" --exclude-regexp '.*metadata.labels.helm.sh/chart' --exclude-regexp '.*metadata.labels.app.kubernetes.io/version' )
+      ;;
+    *)
+      if [ -z "$targetDirA" ]; then
+        targetDirA=$1
+      elif [ -z "$targetDirB" ]; then
+        targetDirB=$1
+      else
+        echo "Extra argument $1"
+        return 1
+      fi
+      ;;
+  esac
+  shift
+done
+if [ -z "$targetDirA" ]; then
+  echo "Missing first argument"
+  return 1
+elif [ -z "$targetDirB" ]; then
+  echo "Missing second argument"
+  return 1
+fi
 
 set +e
 diff_output=$(diff -q -r "$targetDirA" "$targetDirB")
@@ -22,6 +50,6 @@ echo "$diff_output" | while read -r line; do
     # Use dyff to compare the files
     dyff between "$second_path" "$first_path" --omit-header \
       --exclude "data.tls.key" --exclude "/data/ca.crt" --exclude "/data/tls.crt" --exclude "/data/tls.key" \
-      --exclude-regexp "/checksum" --exclude-regexp "/webhooks.*" --ignore-order-changes
+      --exclude-regexp "/checksum" --exclude-regexp "/webhooks.*" --ignore-order-changes "${miscArgs[@]}"
   fi
 done