upd

Dockerfile

@@ -1,10 +1,10 @@
 FROM gcr.io/kaniko-project/executor:v1.24.0-debug
 
-ENV HOME /root
-ENV USER root
+ENV HOME=/root
+ENV USER=root
 ENV SSL_CERT_DIR=/kaniko/ssl/certs
-ENV DOCKER_CONFIG /kaniko/.docker/
-ENV DOCKER_CREDENTIAL_GCR_CONFIG /kaniko/.config/gcloud/docker_credential_gcr_config.json
+ENV DOCKER_CONFIG=/kaniko/.docker/
+ENV DOCKER_CREDENTIAL_GCR_CONFIG=/kaniko/.config/gcloud/docker_credential_gcr_config.json
 
 # add the wrapper which acts as a drone plugin
 COPY ./plugin.sh /kaniko/plugin.sh

plugin.sh

@@ -65,9 +65,9 @@ if [[ "${PLUGIN_SKIP_UNUSED_STAGES:-}" == "true" ]]; then
 fi
 
 # full, redo, time
-# if [[ -n "${PLUGIN_SNAPSHOT_MODE:-}" ]]; then
-#     SNAPSHOT_MODE="--snapshot-mode=${PLUGIN_SNAPSHOT_MODE}"
-# fi
+if [[ -n "${PLUGIN_SNAPSHOT_MODE:-}" ]]; then
+    SNAPSHOT_MODE="--snapshot-mode=${PLUGIN_SNAPSHOT_MODE}"
+fi
 
 # auto_tag, if set auto_tag: true, auto generate .tags file
 # support format Major.Minor.Release or start with `v`