Add strict mode

Dockerfile

@@ -14,7 +14,8 @@ ENV LANG="en_US.UTF-8" \
   PORTAINER_ENDPOINT="1"
   HTTPIE_VERIFY_SSL="yes" \
   VERBOSE_MODE="false" \
-  DEBUG_MODE="false"
+  DEBUG_MODE="false" \
+  STRICT_MODE="false"
 
 RUN apk --update add \
   bash \

README.md

@@ -18,7 +18,7 @@ Script was created for the latest Portainer API, which at the time of writing is
 
 ## How to use
 
-The provided `psu` script allows to deploy/update/undeploy Portainer stacks. Settings can be passed through envvars and/or flags. Both envvars and flags can be mixed but flags will always overwrite envvar values. When deploying a stack, if it doesn't exist a new one is created, otherwise it's updated.
+The provided `psu` script allows to deploy/update/undeploy Portainer stacks. Settings can be passed through envvars and/or flags. Both envvars and flags can be mixed but flags will always overwrite envvar values. When deploying a stack, if it doesn't exist a new one is created, otherwise it's updated (unless strict mode is active).
 
 ### With envvars
 
@@ -35,6 +35,7 @@ This is particularly useful for CI/CD pipelines.
 - `HTTPIE_VERIFY_SSL` ("yes" or "no", optional): Whether to verify SSL certificate or not. Defaults to `"yes"`.
 - `VERBOSE_MODE` ("true" or "false", optional): Whether to activate verbose output mode or not. Defaults to `"false"`.
 - `DEBUG_MODE` ("true" or "false", optional): Whether to activate debug output mode or not. Defaults to `"false"`. See [debug mode warning](#debug-mode) below.
+- `STRICT_MODE` ("true" or "false", optional): Whether to activate strict mode or not. Defaults to `"false"`. See [strict mode](#strict-mode) below.
 
 #### Examples
 
@@ -73,7 +74,9 @@ This is more suitable for standalone script usage.
 - `-e` (int, optional): Which endpoint to use. Defaults to `1`.
 - `-s` ("yes" or "no", optional): Whether to verify SSL certificate or not. Defaults to `"yes"`.
 - `-v` ("true" or "false", optional): Whether to activate verbose output mode or not. Defaults to `"false"`.
-- `-d` ("true" or "false", optional): Whether to activate debug output mode or not. Defaults to `"false"`. See [debug mode warning](#debug-mode) below.
+- `-d` ("true" or "false", optional): Whether to activate debug output mode or not. Defaults to `"false"`. See [debug mode warning](
+#debug-mode) below.
+- `-t` ("true" or "false", optional): Whether to activate strict mode or not. Defaults to `"false"`. See [strict mode](#strict-mode) below.
 
 #### Examples
 
@@ -91,6 +94,12 @@ This is more suitable for standalone script usage.
 
 Debug mode can be enabled through [DEBUG_MODE envvar](#with-envvars) or [-d flag](with-flags).
 
+### Strict mode
+
+In strict mode the script never updates an existent stack, and instead exits with an error. Following the same principle, it never removes an unexistent stack.
+
+Strict mode can be enabled through [STRICT_MODE envvar](#with-envvars) or [-t flag](with-flags).
+
 ## License
 
 Source code contained by this project is licensed under the [GNU General Public License version 3](https://www.gnu.org/licenses/gpl-3.0.en.html). See [LICENSE](LICENSE) file for reference.

psu

@@ -84,7 +84,7 @@ deploy () {
 
   # If the stack does not exist
   if [ -z "$STACK" ]; then
-    echo_verbose "Stack $PORTAINER_STACK_NAME not found."
+    echo_verbose "Stack $PORTAINER_STACK_NAME does not exist."
 
     # Get Docker info
     echo_verbose "Getting Docker info..."
@@ -154,7 +154,11 @@ deploy () {
 
     rm json.tmp
   else
-    echo_verbose "Stack $PORTAINER_STACK_NAME found."
+    if [ $STRICT_MODE == "true" ]; then
+      echo "Error: Stack $PORTAINER_STACK_NAME already exists."
+      exit 1
+    fi
+    echo_verbose "Stack $PORTAINER_STACK_NAME exists."
 
     echo_verbose "Preparing stack JSON..."
     STACK_ID="$(echo "$STACK" | jq -j ".Id")"
@@ -187,10 +191,15 @@ deploy () {
 ##################
 undeploy () {
   if [ -z "$STACK" ]; then
-    echo_verbose "Stack $PORTAINER_STACK_NAME not found."
-    exit 0
+    if [ $STRICT_MODE == "true" ]; then
+      echo "Error: Stack $PORTAINER_STACK_NAME does not exist."
+      exit 1
+    else
+      echo_verbose "Stack $PORTAINER_STACK_NAME does not exist. No need to undeploy it."
+      exit 0
+    fi
   fi
-  echo_verbose "Stack $PORTAINER_STACK_NAME found."
+  echo_verbose "Stack $PORTAINER_STACK_NAME exists."
 
   STACK_ID="$(echo "$STACK" | jq -j ".Id")"
   echo_debug "Stack ID -> $STACK_ID"
@@ -217,9 +226,10 @@ PORTAINER_PRUNE=${PORTAINER_PRUNE:-"false"}
 HTTPIE_VERIFY_SSL=${HTTPIE_VERIFY_SSL:-"yes"}
 VERBOSE_MODE=${VERBOSE_MODE:-"false"}
 DEBUG_MODE=${DEBUG_MODE:-"false"}
+STRICT_MODE=${STRICT_MODE:-"false"}
 
 # Set arguments through flags (overwrite envvars)
-while getopts a:u:p:l:n:c:e:rsvd option; do
+while getopts a:u:p:l:n:c:e:rsvdt option; do
   case "${option}" in
     a) ACTION=${OPTARG} ;;
     u) PORTAINER_USER=${OPTARG} ;;
@@ -232,6 +242,7 @@ while getopts a:u:p:l:n:c:e:rsvd option; do
     s) HTTPIE_VERIFY_SSL="no" ;;
     v) VERBOSE_MODE="true" ;;
     d) DEBUG_MODE="true" ;;
+    t) STRICT_MODE="true" ;;
   esac
 done