command: ["/bin/sh","-c"]
args: ["command one; command two; command three"]
The first part(command: ["/bin/sh","-c"]) just tells the machine to run a shell and then run the following commands. The portion in args is where the actual commands are passed to the shell. You use semicolon to separate the commands. OR an easier wary in my opinion is to build your own dockerfile. Use RUN to execute your commands. For further details, refer to the Kubernetes Course.