QuickDemo.md

SCiMMA Server Container Demo

This is a very script-like demo that does not involve any non-docker commands on the local machine and that does not hide what is going on like docker-compose. You should be able to copy and paste these commands anywhere that you run docker.

The Commands:

docker network create scimma-net
docker run -d --rm=true --network=scimma-net --name=scimma-server -v shared:/root/shared scimma/server:latest

docker run -i --rm=true --network=scimma-net -v shared:/root/shared scimma/client:latest kafkacat -P -b scimma-server:9092 -t test
docker run -i --rm=true --network=scimma-net -v shared:/root/shared scimma/client:latest kafkacat -L -b scimma-server:9092
docker run -i --rm=true --network=scimma-net -v shared:/root/shared scimma/client:latest kafkacat -C -b scimma-server:9092 -t test -e

docker run -i --rm=true --network=scimma-net -v shared:/root/shared scimma/client:latest hop publish kafka://scimma-server:9092/gcn /root/test_data/example.gcn3
docker run -i --rm=true --network=scimma-net -v shared:/root/shared scimma/client:latest hop subscribe -s EARLIEST kafka://scimma-server:9092/gcn 

docker kill scimma-server
docker network rm scimma-net

The first kafkacat command (with the -P option) may appear to hang, but it is waiting for input. Each input line is a message. End with Ctrl-D or Ctrl-C.

The rest of this page just explains the above commands.

Create a Network

        docker network create scimma-net

Create a docker network named scimma-net. The main benefit to creating a network is that container names automatically become resolvable using DNS.

Create the Server

     docker run -d --rm=true --network=scimma-net --name=scimma-server -v shared:/root/shared scimma/server:latest

Start a container using the image scimma/server:latest.

Options:

Option	Description
-d	run in the background (detach)
--rm=true	delete the container after it exits
--network=scimma-net	create an interface on the netowrk scimma-net
--name=scimma-server	use scimma-server as the name of the container
-v shared:/root/shared	create a named volumen named shared

Client Options

These options are common to the following scimma/client container commands.

Option	Description
-i	run container interactively (in the foreground)
--rm=true	delete the container after it exits
--network=scimma-net	create an interface on the netowrk scimma-net
-v shared:/root/shared	mount the named volume shared as /root/shared inside the container

Publish Messages

docker run -i --network=scimma-net -v shared:/root/shared scimma/client:latest kafkacat -P -b scimma-server:9092 -t test

Start a container based on the image scimma-client:latest and inside the container, run the command:

    kafkacat -P -b scimma-server:9092 -t test

Notice that the broker is specified using the name scimma-server which can be resolved inside the container because we are using the netowrk scimma-net.

This command reads from standard input and publishes one message for each line that it reads. You could pipe a file like so:

```
    cat MYFILE.txt | docker run -i --network=scimma-net -v shared:/root/shared scimma/client:latest kafkacat -P -b scimma-server:9092 -t test
```

List Metadata

docker run -i --network=scimma-net -v shared:/root/shared scimma/client:latest kafkacat -L -b scimma-server:9092

Start a container based on the image scimma-client:latest and inside the container, run the command:

    kafkacat -L -b scimma-server:9092

Consume Messages

docker run -i --network=scimma-net -v shared:/root/shared scimma/client:latest kafkacat -C -b scimma-server:9092 -t test -e

Start a container based on the image scimma-client:latest and inside the container, run the command:

    kafkacat -C -b scimma-server:9092 -t test -e

Publish a GCN

docker run -i --rm=true --network=scimma-net -v shared:/root/shared scimma/client:latest hop publish kafka://scimma-server:9092/gcn /root/test_data/example.gcn3

This command runs the hop command in a container. The file example.gcn3 is included as part of the container. You could mount a local directory containing GCNs as a volume in the client container and have the scimma client read files there.

Note that the Kafka topic, gcn, is specified as part of the URL.

Read the GCN

docker run -i --rm=true --network=scimma-net -v shared:/root/shared scimma/client:latest hop subscribe -s EARLIEST  kafka://scimma-server:9092/gcn

This uses hop in the client container to read the gcn topic starting from the first message.

Clean Up

docker kill scimma-server
docker network rm scimma-net

Shut down and remove the container scimma-server and remove the network scimma-net.