Clarify the client generation process

client/README.md

@@ -1,27 +1,58 @@
-# Longhorn API Client
+# Longhorn API client
 
-The code in this package are generated by [rancher/go-rancher](https://github.com/rancher/go-rancher).
-But in order to fix some compatibility issues, you need to use this [repo](https://github.com/niusmallnan/go-rancher), and you should checkout the `longhorn-v1` branch.
+The code in this package is generated by [rancher/go-rancher](https://github.com/rancher/go-rancher). But in order to
+fix some compatibility issues, you must use the `longhorn-v1` branch of this
+[repo](https://github.com/niusmallnan/go-rancher) instead.
 
 ## Generate code in go-rancher
 
-If you have a longhorn api URL, you can use this script:
+The version of go-rancher we use does not have Go module support. It must be cloned onto the correct location on the
+GOPATH and the Go tools must be executed with `GO111MODULE=off`. This might be unusual for developers used to working
+with modern Go.
 
+1. Run longhorn-manager. There may be an easier way, but generally, this means deploy Longhorn to a cluster using a
+   development version of the longhorn-manager container.
+2. Expose the longhorn-manager API. If running in a cluster, change the `spec.type` of the `longhorn-backend` service
+   from `ClusterIP` to `NodePort`. The IP is the IP of any node and the port is given by `spec.ports.nodePort`.
+3. Clone go-rancher to the correct location on your GOPATH and check out the correct branch.
+
+```bash
+cd $GOPATH/src/github.com/niusmallnan/
+git clone https://github.com/niusmallnan/go-rancher
+cd go-rancher
 ```
-./scripts/generate-longhorn-schemas.sh http://manager-api-ip:port
+
+4. Get dependencies.
+
+```bash
+```
+
+5. Generate code.
+
+```bash
+GO111MODULE=off scripts/generate-longhorn-schemas.sh http://<ip>:<port>
 ```
 
 ## Copy code to longhorn-manager
 
-Just use cp to copy these code is fine, but you should update package name in `longhorn-manager`:
+1. Copy the client to your project directory.
 
+```bash
+cp $GOPATH/src/github.com/niusmallnan/go-rancher/longhorn/*.go <project_directory>/client/
 ```
-cd longhorn-manager/client
+
+2. Correct the package name.
+
+```bash
+cd <project_directory>/client
 sed -i -e 's/package longhorn/package client/g' *.go
 ```
 
+3. Check the `git diff`. There are likely unrelated changes you did not intend. For now, just revert any changes that
+   don't appear to be directly related to your work. Maybe we can make the process more idempotent in the future.
+
 ## Notes:
 
 The generator currently no longer generates actions, so you need to ensure not to overwrite the `ActionUpdateAccessMode`
-in `generated_volume.go`. I currently don't have the time to look into this and since we are planning on reworking the api
-down the line, this is a low priority issue for now.
+in `generated_volume.go`. I currently don't have the time to look into this and since we are planning on reworking the
+api down the line, this is a low priority issue for now.