From 9e24048019cb0105cc84d9df211da09569b2ecd7 Mon Sep 17 00:00:00 2001
From: Alejandro Pedraza <alejandro@buoyant.io>
Date: Fri, 6 Dec 2024 10:34:05 -0500
Subject: [PATCH] Ignore DELETE event, remove unused file

This removes treatment of the DELETE event on the inotifywait subshell, which is a leftover from when we implemented an "interface" mode (see #242), and we no longer act on this event.

This also removes the file `cni-plugin/deployment/linkerd-cni.conf.default` that wasn't being used anymore.
---
 Dockerfile-cni-plugin                         |  1 -
 .../deployment/linkerd-cni.conf.default       | 24 -------------------
 cni-plugin/deployment/scripts/install-cni.sh  | 16 ++++---------
 3 files changed, 4 insertions(+), 37 deletions(-)
 delete mode 100644 cni-plugin/deployment/linkerd-cni.conf.default

diff --git a/Dockerfile-cni-plugin b/Dockerfile-cni-plugin
index b9ca86bb..e25fe2eb 100644
--- a/Dockerfile-cni-plugin
+++ b/Dockerfile-cni-plugin
@@ -48,7 +48,6 @@ COPY --from=go /go/bin/linkerd-cni /opt/cni/bin/
 COPY --from=cni-repair-controller /build/linkerd-cni-repair-controller /usr/lib/linkerd/
 COPY LICENSE .
 COPY cni-plugin/deployment/scripts/install-cni.sh .
-COPY cni-plugin/deployment/linkerd-cni.conf.default .
 COPY cni-plugin/deployment/scripts/filter.jq .
 ENV PATH=/linkerd:/opt/cni/bin:$PATH
 CMD ["install-cni.sh"]
diff --git a/cni-plugin/deployment/linkerd-cni.conf.default b/cni-plugin/deployment/linkerd-cni.conf.default
deleted file mode 100644
index 68f76cef..00000000
--- a/cni-plugin/deployment/linkerd-cni.conf.default
+++ /dev/null
@@ -1,24 +0,0 @@
-{
-    "name": "linkerd-cni",
-    "type": "linkerd-cni",
-    "log_level": "info",
-    "policy": {
-        "type": "k8s",
-        "k8s_api_root": "https://__KUBERNETES_SERVICE_HOST__:__KUBERNETES_SERVICE_PORT__",
-        "k8s_auth_token": "__SERVICEACCOUNT_TOKEN__"
-    },
-    "kubernetes": {
-        "kubeconfig": "__KUBECONFIG_FILEPATH__"
-    },
-    "linkerd": {
-        "incoming-proxy-port": 4143,
-        "outgoing-proxy-port": 4140,
-        "proxy-uid": 2102,
-        "proxy-gid": 2102,
-        "ports-to-redirect": [],
-        "inbound-ports-to-ignore": [],
-        "outbound-ports-to-ignore": [],
-        "simulate": false,
-        "use-wait-flag": false
-    }
-}
diff --git a/cni-plugin/deployment/scripts/install-cni.sh b/cni-plugin/deployment/scripts/install-cni.sh
index 6afd6de9..218e3bfa 100755
--- a/cni-plugin/deployment/scripts/install-cni.sh
+++ b/cni-plugin/deployment/scripts/install-cni.sh
@@ -257,14 +257,7 @@ sync() {
 
   local config_file_count
   local new_sha
-  if [ "$ev" = 'DELETE' ]; then
-    # When the event type is 'DELETE', we check to see if there are any `*conf` or `*conflist`
-    # files on the host's filesystem.
-    config_file_count=$(find "${HOST_CNI_NET}" -maxdepth 1 -type f \( -iname '*conflist' -o -iname '*conf' \) | sort | wc -l)
-    if [ "$config_file_count" -eq 0 ]; then
-      log "No active CNI configuration file found after $ev event"
-    fi
-  elif [ "$ev" = 'CREATE' ] || [ "$ev" = 'MOVED_TO' ] || [ "$ev" = 'MODIFY' ]; then
+  if [ "$ev" = 'CREATE' ] || [ "$ev" = 'MOVED_TO' ] || [ "$ev" = 'MODIFY' ]; then
     # When the event type is 'CREATE', 'MOVED_TO' or 'MODIFY', we check the
     # previously observed SHA (updated with each file watch) and compare it
     # against the new file's SHA. If they differ, it means something has
@@ -287,14 +280,13 @@ sync() {
 
 # Monitor will start a watch on host's CNI config directory
 monitor() {
-  inotifywait -m "${HOST_CNI_NET}" -e create,delete,moved_to,modify |
+  inotifywait -m "${HOST_CNI_NET}" -e create,moved_to,modify |
     while read -r directory action filename; do
       if [[ "$filename" =~ .*.(conflist|conf)$ ]]; then 
         log "Detected change in $directory: $action $filename"
         sync "$filename" "$action" "$cni_conf_sha"
-        # When file exists (i.e we didn't deal with a DELETE ev)
-        # then calculate its sha to be used the next turn.
-        if [[ -e "$directory/$filename" && "$action" != 'DELETE' ]]; then
+        # calculate file SHA to use in the next iteration
+        if [[ -e "$directory/$filename" ]]; then
           cni_conf_sha="$(sha256sum "$directory/$filename" | while read -r s _; do echo "$s"; done)"
         fi
       fi