update section about restart condition

docs/index.html

@@ -3754,13 +3754,12 @@ The test message should show up in the logstash container logs.
 
 - We're lucky: the parameters (`--log-driver` and `--log-opt`) are exactly the same!
 
-- We will use the `--restart-condition` flag so that the container doesn't restart forever
 
 .exercise[
 
 - Send a test message:
   ```bash
-    docker service create --restart-condition none \
+    docker service create \
            --log-driver gelf --log-opt gelf-address=udp://127.0.0.1:12201 \
            alpine echo hello
   ```
@@ -3769,6 +3768,31 @@ The test message should show up in the logstash container logs.
 
 The test message should show up as well in the logstash container logs.
 
+--
+
+In fact, *multiple messages will show up, and continue to show up every few seconds!*
+
+---
+
+## Restart conditions
+
+- By default, if a container exits (or is killed with `docker kill`, or runs out of memory ...),
+  the Swarm will restart it (possibly on a different machine)
+
+- This behavior can be changed by setting the *restart condition* parameter
+
+.exercise[
+
+- Change the restart condition so that Swarm doesn't try to restart our container forever:
+  ```bash
+  docker service update `xxx` --restart-condition none
+  ```
+]
+
+Available restart conditions are `none`, `any`, and `on-error`.
+
+You can also set `--restart-delay`, `--restart-max-attempts`, and `--restart-window`.
+
 ---
 
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