docs: Improve README. Resolves #6 [skip ci]

README.md

@@ -1,17 +1,60 @@
-# Tower Agent
+## Tower Agent
 
 Tower Agent allows Tower to launch pipelines on HPC clusters that do not allow direct access throw an SSH client.
 
 Tower Agent it's a standalone process that when executed in a node that can submit jobs to the cluster (i.e. the login node) it establishes an authenticated secure reverse connection with Tower, allowing Tower to submit and monitor new
 jobs. The jobs are submitted on behalf of the same user that it's running the agent process.
 
-## Build binary version
+### Installation
 
+Tower Agent it is distributed as a single binary executable file. You only need to download it and execute it.
+
+1. Download the latest Agent binary from Github: 
+```
+wget https://github.com/seqeralabs/tower-cli/releases/download/v0.3/tw_0.3_fbb1932_linux.zip -O tw-agent
 ```
-/gradlew nativeBuild
+
+2. Make it executable:
 ```
+chmod +x ./tw-agent
+```
+
+3. (OPTIONAL) Move it into a folder that is in your path.
 
-## Links
+### Quick start
 
-- GraalVM build tools: https://graalvm.github.io/native-build-tools
+Before running the Agent:
+- You need to create a **personal access token** at Tower. See [here](https://help.tower.nf/api/overview/#authentication).
+- At Tower you need to add new **Tower Agent** credentials in a workspace. See [here](https://help.tower.nf/credentials/overview/).
+- When you create the credentials you'll get an **Agent Connection ID**. You can use that one or just set your own, the important is that you use the same connection ID at the workspace credentials and when you run the agent.
+
+Running the Agent:
+
+- The agent has to be always running to accept incoming requests from Tower. For this we recommend that you run it using a terminal multiplexer like [tmux](https://github.com/tmux/tmux) or [GNU Screen](https://www.gnu.org/software/screen/), so that it keeps running even if you close the SSH session.
+```
+./tw-agent -t <your personal access token> <your agent connection ID>
+```
 
+### Tips
+
+- Alternative you can define the `TOWER_ACCESS_TOKEN` environment variable, and then you don't need to pass the personal access token as an option.
+- If you are using an on premises Tower you can set the API url using `TOWER_API_ENDPOINT` environment variable or the `--url` option.
+
+### Usage
+```
+Usage: tw-agent [OPTIONS] AGENT_CONNECTION_ID
+
+Nextflow Tower Agent
+
+Parameters:
+*     AGENT_CONNECTION_ID   Agent connection ID to identify this agent
+
+Options:
+  -t, --access-token=<token>
+                            Tower personal access token (TOWER_ACCESS_TOKEN)
+  -u, --url=<url>           Tower server API endpoint URL. Defaults to tower.nf (TOWER_API_ENDPOINT)
+      --no-secure           Explicitly allow to connect to a non-SSL secured Tower server (this is not recommended)
+  -h, --help                Show this help message and exit.
+  -V, --version             Print version information and exit.
+
+```

src/main/java/io/seqera/tower/agent/Agent.java

@@ -63,7 +63,7 @@ public class Agent implements Runnable {
     @Parameters(index = "0", paramLabel = "AGENT_CONNECTION_ID", description = "Agent connection ID to identify this agent", arity = "1")
     String agentKey;
 
-    @Option(names = {"-t", "--access-token"}, description = "Tower personal access token (TOWER_ACCESS_TOKEN)", defaultValue = "${TOWER_ACCESS_TOKEN}")
+    @Option(names = {"-t", "--access-token"}, description = "Tower personal access token (TOWER_ACCESS_TOKEN)", defaultValue = "${TOWER_ACCESS_TOKEN}", required = true)
     String token;
 
     @Option(names = {"-u", "--url"}, description = "Tower server API endpoint URL. Defaults to tower.nf (TOWER_API_ENDPOINT)", defaultValue = "${TOWER_API_ENDPOINT:-https://api.tower.nf}", required = true)