Swarm

swarm/README.md

@@ -32,7 +32,7 @@ redis
 Create a file called Dockerfile and paste this in:
 
 ```shell
-FROM python:3.4-alpine
+FROM python:3.7-alpine
 ADD . /code
 WORKDIR /code
 RUN pip install -r requirements.txt
@@ -108,7 +108,7 @@ Hello World! I have been seen 3 times.
 Bring the app down:
 
 ```shell
-$ docker-compose down --volumes
+vagrant@docker$ docker-compose down --volumes
 
 Stopping stackdemo_web_1 ... done
 Stopping stackdemo_redis_1 ... done
@@ -122,7 +122,7 @@ Push the generated image to the registry
 To distribute the web app’s image across the swarm, it needs to be pushed to the registry you set up earlier. With Compose, this is very simple:
 
 ```shell
-$ docker-compose push
+vagrant@docker$ docker-compose push
 
 Pushing web (127.0.0.1:5000/stackdemo:latest)...
 The push refers to a repository [127.0.0.1:5000/stackdemo]
@@ -133,4 +133,121 @@ c9fc143a069a: Pushed
 011b303988d2: Pushed
 latest: digest: sha256:a81840ebf5ac24b42c1c676cbda3b2cb144580ee347c07e1bc80e35e5ca76507 size: 1372
 The stack is now ready to be deployed.
+```
+### Create the swarm
+When you run the command to create a swarm, the Docker Engine starts running in swarm mode.
+
+Run docker swarm init to create a single-node swarm on the current node. The Engine sets up the swarm as follows:
+
+switches the current node into swarm mode.
+creates a swarm named default.
+designates the current node as a leader manager node for the swarm.
+names the node with the machine hostname.
+configures the manager to listen on an active network interface on port 2377.
+sets the current node to Active availability, meaning it can receive tasks from the scheduler.
+starts an internal distributed data store for Engines participating in the swarm to maintain a consistent view of the swarm and all services running on it.
+by default, generates a self-signed root CA for the swarm.
+by default, generates tokens for worker and manager nodes to join the swarm.
+creates an overlay network named ingress for publishing service ports external to the swarm.
+The output for docker swarm init provides the connection command to use when you join new worker nodes to the swarm:
+
+```shell
+$ docker swarm init
+Swarm initialized: current node (dxn1zf6l61qsb1josjja83ngz) is now a manager.
+```
+
+To add a worker to this swarm, run the following command:
+
+```shell
+    docker swarm join \
+    --token SWMTKN-1-49nj1cmql0jkz5s954yi3oex3nedyz0fb0xx14ie39trti4wxv-8vxv8rssmk743ojnwacrr2e7c \
+    192.168.99.100:2377
+```
+
+To add a manager to this swarm, run 'docker swarm join-token manager' and follow the instructions.
+
+To retrieve the join command including the join token for worker nodes, run:
+
+$ docker swarm join-token worker
+
+To add a worker to this swarm, run the following command:
+
+```shell
+    docker swarm join \
+    --token SWMTKN-1-49nj1cmql0jkz5s954yi3oex3nedyz0fb0xx14ie39trti4wxv-8vxv8rssmk743ojnwacrr2e7c \
+    192.168.99.100:2377
+
+This node joined a swarm as a worker.
+```
+
+NOTE: The IPs could change in your environment
+
+### Deploy the stack to the swarm
+Create the stack with docker stack deploy:
+
+```shell
+vagrant@docker$ docker stack deploy --compose-file docker-compose.yml stackdemo
+
+Ignoring unsupported options: build
+
+Creating network stackdemo_default
+Creating service stackdemo_web
+Creating service stackdemo_redis
+```
+
+The last argument is a name for the stack. Each network, volume and service name is prefixed with the stack name.
+
+Check that it’s running with docker stack services stackdemo:
+```shell
+vagrant@docker$ docker stack services stackdemo
+
+ID            NAME             MODE        REPLICAS  IMAGE
+orvjk2263y1p  stackdemo_redis  replicated  1/1       redis:3.2-alpine@sha256:f1ed3708f538b537eb9c2a7dd50dc90a706f7debd7e1196c9264edeea521a86d
+s1nf0xy8t1un  stackdemo_web    replicated  1/1       127.0.0.1:5000/stackdemo@sha256:adb070e0805d04ba2f92c724298370b7a4eb19860222120d43e0f6351ddbc26f
+```
+
+Once it’s running, you should see 1/1 under REPLICAS for both services. This might take some time if you have a multi-node swarm, as images need to be pulled.
+
+As before, you can test the app with curl:
+
+```shell
+vagrant@docker$ curl http://localhost:8000
+Hello World! I have been seen 1 times.
+
+vagrant@docker$ curl http://localhost:8000
+Hello World! I have been seen 2 times.
+
+vagrant@docker$ curl http://localhost:8000
+Hello World! I have been seen 3 times.
+```
+
+Thanks to Docker’s built-in routing mesh, you can access any node in the swarm on port 8000 and get routed to the app:
+
+```shell
+vagrant@docker$ curl http://address-of-other-node:8000
+Hello World! I have been seen 4 times.
+```
+
+Bring the stack down with docker stack rm:
+
+```shell
+vagrant@docker$ docker stack rm stackdemo
+
+Removing service stackdemo_web
+Removing service stackdemo_redis
+Removing network stackdemo_default
+```
+
+Bring the registry down with docker service rm:
+
+```shell
+vagrant@docker$ docker service rm registry
+```
+
+If you’re just testing things out on a local machine and want to bring your Docker Engine out of swarm mode, use docker swarm leave:
+
+```shell
+vagrant@docker$ docker swarm leave --force
+
+Node left the swarm.
 ```