Merge pull request #3397 from rhaidou/Update-docs-deploymentstring

Documentation for additional docker options

docs/deployment_string.md

@@ -40,6 +40,9 @@ Because Horizon uses the Docker API to start the containers on an edge node, man
     - `max_cpus`: `1.5` - how much of the available CPU resources the service's container can use. For instance, if the host machine has two CPUs and you set value to 1.5, the container is guaranteed to use at most one and a half of the CPUs
     - `log_driver`: the logging driver (e.g. `json-file`) to use for container logs, instead of default one (syslog)
     - `secrets`: `{"ai_secret": {"description": "The token for cloud AI service."}, "sql_secret": {}}` - a list of secret names and the descriptions. The `description` can be omitted. A secret name is just a user defined string. A pattern or a deployment policy will associate it with the name of the secret in the secret provider. The horizon agent will mount the secrets at '/open-horizon-secrets' within the service's containers. Each secret name appears as a file in that directory, containing the details of the secret from the secret provider. Each secret file is a JSON encoded file containing the "key" and "value" set when the secret was created with the hzn secretsmanager secret add command.
+    - `user`: Sets the username or UID used. root (id = 0) is the default user within a container. The image developer can create additional users. Those users are accessible by name. When passing a numeric ID, the user does not have to exist in the container.
+    - `pid`: Set the PID (Process) Namespace mode for the container. `container:<name|id>` joins another container's PID namespace. `host` use the host's PID namespace inside the container. In certain cases you want your container to share the host’s process namespace, basically allowing processes within the container to see all of the processes on the system.
+    - `sysctls`: Sysctl settings are exposed via Kubernetes, allowing users to modify certain kernel parameters at runtime for namespaces within a container. The parameters cover various subsystems, such as: networking (common prefix: net.), kernel (common prefix: kernel.), virtual memory (common prefix: vm.), MDADM (common prefix: dev.). To get a list of all parameters, you can run: `sudo sysctl -a`
 
 ## clusterDeployment String Fields