Merge pull request #82 from kgncloud/patch-1

Add Healthcheck to Dockerfile

Dockerfile

@@ -9,3 +9,6 @@ RUN npm ci
 COPY . .
 
 EXPOSE 3000
+
+HEALTHCHECK --interval=30s --timeout=10s --start-period=5s --retries=3 \
+  CMD wget --quiet --tries=1 --spider http://localhost:3000 || exit 1

docs/docker-swarm-usage.md

@@ -0,0 +1,43 @@
+# Docker Swarm Usage
+
+## Healthcheck
+
+The [Docker Image](../Dockerfile) includes a Healthcheck with the following options:
+
+```
+--interval=30s
+```
+> Specifies the time interval at which the health check should be performed. In this case, the health check will be performed every 30 seconds.
+
+<br>
+
+```
+--timeout=10s
+```
+> Specifies the amount of time to wait for a response from the health check command. If the response does not arrive within 10 seconds, the health check will be considered a failure.
+
+<br>
+
+```
+--start-period=5s
+```
+> Specifies the amount of time to wait before starting the health check process. In this case, the health check process will begin 5 seconds after the container is started.
+
+<br>
+
+```
+--retries=3
+```
+> Specifies the number of times Docker should retry the health check before considering the container to be unhealthy.
+
+<br>
+
+
+The CMD instruction is used to define the command that will be run as part of the health check. 
+In this case, the command is `wget --quiet --tries=1 --spider http://localhost:3000/ || exit 1`. This command will attempt to connect to `http://localhost:3000/` 
+and if it fails it will exit with a status code of `1`. If this command returns a status code other than `0`, the health check will be considered a failure.
+
+Overall, this HEALTHCHECK instruction is defining a health check process that will run every 30 seconds, wait up to 10 seconds for a response, 
+begin 5 seconds after the container is started, and retry up to 3 times. 
+The health check will consist of attempting to connect to http://localhost:3000/ and will consider the container to be unhealthy if it is unable to connect.
+

docs/host-your-own.md

@@ -82,6 +82,8 @@ docker run -d --restart=unless-stopped --name=pairdrop -p 127.0.0.1:3000:3000 gh
 >
 > To specify options replace `npm run start:prod` according to [the documentation below.](#options--flags-1)
 
+> The Docker Image includes a Healthcheck. To learn more see [Docker Swarm Usage](./docker-swarm-usage.md#docker-swarm-usage)
+
 ### Docker Image self-built
 #### Build the image
 ```bash
@@ -101,6 +103,8 @@ docker run -d --restart=unless-stopped --name=pairdrop -p 127.0.0.1:3000:3000 -i
 >
 > To specify options replace `npm run start:prod` according to [the documentation below.](#options--flags-1)
 
+> The Docker Image includes a Healthcheck. To learn more see [Docker Swarm Usage](./docker-swarm-usage.md#docker-swarm-usage)
+
 <br>
 
 ## Deployment with Docker Compose