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SC4S installation can now be automated with Ansible. All you need to do now is provide list of hosts on which you want to run SC4S and basic configuration (Splunk endpoint, HEC token, TLS configuration, etc.). This manual assumes that you have proper knowledge of Docker Swarm as setting up proper Swarm architecture/configuration is users duty.

Initial Configuration

All you need to do before running sc4s with Ansible is providing env_file. In the env file provide at least proper Splunk endpoint and HEC token. Create a file in ansible/resources catalog or edit example file.

#Uncomment the following line if using untrusted SSL certificates

Next provide a list of hosts on which you want to run Docker Swarm cluster and host application in inventory file:



You can run your cluster with one or more manager nodes for more info about setting up a swarm refer to official docker documentation. NOTICE: One of biggest advantages of using Docker Swarm for hosting SC4S is Swarm internal load balancer (routing mesh). To get to know the details refer to docker documentation.

Additionally, you can provide extra service configurations (ex. number of replicas) in /ansible/app/docker-compose.yml file:

version: "3.7"
      replicas: 2

Deploy SC4S

Now you can run ansible playbook to deploy the application if you have ansible installed on your host or use 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

Once you are in containers remote shell you can run Docker Swam ansible playbook. If you are authenticating via username/password:

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

or using key pair:

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

If the process was finished properly you should be able to check state of Swarm cluster and deployed stack from manager’s node remote shell: Verify if stack was created: sudo docker stack ls

sc4s 1 Swarm

You can scale your number of services: sudo docker service update --replicas 2 sc4s_sc4s

See services running in a given stack: sudo docker stack services sc4s

1xv9vvbizf3m sc4s_sc4s replicated 2/2 :514->514/tcp, :601->601/tcp, :6514->6514/tcp, :514->514/udp

Verify Proper Operation

SC4S has a number of “preflight” checks to ensure that the container starts properly and that the syntax of the underlying syslog-ng configuration is correct. After this step completes, to verify SC4S is properly communicating with Splunk, execute the following search in Splunk:

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

This should yield an event similar to the following:

syslog-ng starting up; version='3.28.1'

You can verify if all services in swarm cluster are working by checking sc4s_container field in splunk- each service should be recognized by different container id. All other fields should be the same.

When the startup process proceeds normally (without syntax errors). If you do not see this, follow the steps below before proceeding to deeper-level troubleshooting:

  • Check to see that the URL, token, and TLS/SSL settings are correct, and that the appropriate firewall ports are open (8088 or 443).
  • Check to see that the proper indexes are created in Splunk, and that the token has access to them.
  • Ensure the proper operation of the load balancer if used.
  • Lastly, execute the following command to check the sc4s startup process running in the container (on the node that is hosting sc4s service).
sudo docker|podman ps

You will get an ID and , next:

docker|podman logs <ID | image name> 

You should see events similar to those below in the output:

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 goss
starting syslog-ng