SC4S installation can be automated with Ansible. To do this, you provide a list of hosts on which you want to run SC4S and the basic configuration, such as Splunk endpoint, HEC token, and TLS configuration. To perform this task, you must have existing understanding of Docker Swarm and be able to set up your Swarm architecture and configuration.

Step 1: Prepare your initial configuration¶

Before running SC4S with Ansible, provide env_file with your Splunk endpoint and HEC token:

SC4S_DEST_SPLUNK_HEC_DEFAULT_URL=http://xxx.xxx.xxx.xxx:8088
SC4S_DEST_SPLUNK_HEC_DEFAULT_TOKEN=xxxxxxxxxxxxxxxxxx
#Uncomment the following line if using untrusted SSL certificates
#SC4S_DEST_SPLUNK_HEC_DEFAULT_TLS_VERIFY=no

2. Provide a list of hosts on which you want to run your Docker Swarm cluster and the host application in the inventory file:

all:
  hosts:
  children:
    manager:
      hosts:
        manager_node_1:
          ansible_host:

    worker:
      hosts:
        worker_node_1:
          ansible_host:
        worker_node_2:
          ansible_host:

3. You can run your cluster with one or more manager nodes. One advantage of hosting SC4S with Docker Swarm is that you can leverage the Swarm internal load balancer. See your Swarm Mode documentation at Docker.

You can also provide extra service configurations, for example, the number of replicas, in the /ansible/app/docker-compose.yml file:
```
version: "3.7"
services:
  sc4s:
    deploy:
      replicas: 2
      ...
```

Step 2: Deploy SC4S on your configuration¶

If you have Ansible installed on your host, run the Ansible playbook to deploy SC4S. Otherwise, use the Docker Ansible image provided in the package:

# From repository root
docker-compose -f ansible/docker-compose.yml build
docker-compose -f ansible/docker-compose.yml up -d
docker exec -it ansible_sc4s /bin/bash

If you used the Docker Ansible image in Step 1, then from your container remote shell, run the Docker Swam Ansible playbook.

You can authenticate with username and password:

ansible-playbook -i path/to/inventory_swarm.yaml -u <username> --ask-pass path/to/playbooks/docker_swarm.yml

Or authenticate using key pair:

ansible-playbook -i path/to/inventory_swarm.yaml -u <username> --key-file <key_file> path/to/playbooks/docker_swarm.yml

If your deployment is successfull, you can check the state of the Swarm cluster and deployed stack from the manager node remote shell:

To verify that the stack is created: sudo docker stack ls

NAME	SERVICES	ORCHESTRATOR
sc4s	1	Swarm

To scale your number of services: sudo docker service update --replicas 2 sc4s_sc4s
To see services running in a given stack: sudo docker stack services sc4s

ID	NAME	MODE	REPLICAS	IMAGE	PORTS
1xv9vvbizf3m	sc4s_sc4s	replicated	2/2	ghcr.io/splunk/splunk-connect-for-syslog/container3:latest	:514->514/tcp, :601->601/tcp, :6514->6514/tcp, :514->514/udp

Step 3: validate your configuration¶

SC4S performs checks to ensure that the container starts properly and that the syntax of the underlying syslog-ng configuration is correct. Once the checks are complete, validate that SC4S properly communicate with Splunk. To do this, execute the following search in Splunk:

index=* sourcetype=sc4s:events "starting up"

You should see an event similar to the following:

syslog-ng starting up; version='3.28.1'

You can verify if all services in the Swarm cluster work by checking the sc4s_container in Splunk. Each service should have a different container ID. All other fields should be the same.

The startup process should proceed normally without syntax errors. If it does not, follow the steps below before proceeding to deeper-level troubleshooting:

Verify that the URL, token, and TLS/SSL settings are correct, and that the appropriate firewall ports are open (8088 or 443).
Verify that your indexes are created in Splunk, and that your token has access to them.
If you are using a load balancer, verify that it is operating properly.
Execute the following command to check the SC4S startup process running in the container.

sudo docker|podman ps

You will get an ID and image name:

docker|podman logs <ID | image name>

In the output, you should see events similar to this example:

SC4S_ENV_CHECK_HEC: Splunk HEC connection test successful to index=main for sourcetype=sc4s:fallback...
SC4S_ENV_CHECK_HEC: Splunk HEC connection test successful to index=main for sourcetype=sc4s:events...
syslog-ng checking config
sc4s version=v1.36.0
starting syslog-ng

If you do not see this output, see “Troubleshoot sc4s server” and “Troubleshoot resources” for more information.