Merge pull request #120 from nats-io/cm

mention configuration management options

README.md

@@ -31,6 +31,9 @@ JetStream is the [NATS.io](https://nats.io) persistence engine that will support
     + [Querying](#querying-1)
     + [Consuming Pull-Based Consumers](#consuming-pull-based-consumers)
     + [Consuming Push-Based Consumers](#consuming-push-based-consumers)
+- [Configuration Management](#configuration-management)
+  * [`nats` CLI](#nats-cli)
+  * [Terraform](#terraform)
 - [Model Deep Dive](#model-deep-dive)
   * [Stream Limits and Retention Modes](#stream-limits-and-retention-modes)
   * [Acknowledgement Models](#acknowledgement-models)
@@ -774,6 +777,105 @@ Note the subject here of the received message is reported as `ORDERS.processed`
 
 This Consumer needs no ack, so any new message into the ORDERS system will show up here in real time.
 
+## Configuration Management
+
+In many cases managing the configuration in your application code is the best model, many teams though wish to pre-create Streams and Consumers. We support [Terraform](https://www.terraform.io/) today in addition to the `nats` CLI, more methods might be added in future, these tools can be called by your CI or other Operations Workflows.
+
+### `nats` CLI
+
+The `nats` CLI can be used to manage Streams and Consumers easily using it's `--config` flag, for example:
+
+### Add a new Stream
+
+This creates a new Stream based on `orders.json`. The `orders.json` file can be extracted from an existing stream using `nats stream info ORDERS | jq .config`
+
+```
+$ nats str add ORDERS --config orders.json
+```
+
+### Edit an existing Stream
+
+This edits an existing stream ensuring it complies with the configuration in `orders.json`
+```
+$ nats str edit ORDERS --config orders.json
+```
+
+### Add a New Consumer
+
+This creates a new Consumer based on `orders_new.json`. The `orders_new.json` file can be extracted from an existing stream using `nats con info ORDERS NEW | jq .config`
+
+```
+$ nats con add ORDERS NEW --config orders_new.json
+```
+
+### Terraform
+
+Terraform is a Cloud configuration tool from Hashicorp found at [terraform.io](https://www.terraform.io/), we maintain a Provider for Terraform called [terraform-provider-jetstream](https://github.com/nats-io/terraform-provider-jetstream/) that can maintain JetStream using Terraform.
+
+#### Setup
+
+Our provider is not hosted by Hashicorp so installation is a bit more complex than typical. Browse to the [Release Page](https://github.com/nats-io/terraform-provider-jetstream/releases) and download the release for your platform and extract it into your Terraform plugins directory.
+
+```
+$ unzip -l terraform-provider-jetstream_0.0.2_darwin_amd64.zip
+Archive:  terraform-provider-jetstream_0.0.2_darwin_amd64.zip
+  Length      Date    Time    Name
+---------  ---------- -----   ----
+    11357  03-09-2020 10:48   LICENSE
+     1830  03-09-2020 12:53   README.md
+ 24574336  03-09-2020 12:54   terraform-provider-jetstream_v0.0.2
+```
+
+Place the `terraform-provider-jetstream_v0.0.2` file in `~/.terraform.d/plugins/terraform-provider-jetstream_v0.0.2`
+
+In your project you can configure the Provider like this:
+
+```terraform
+provider "jetstream" {
+  servers = "connect.ngs.global"
+  credentials = "ngs_jetstream_admin.creds"
+}
+```
+
+And start using it, here's an example that create the `ORDERS` example. Review the [Project README](https://github.com/nats-io/terraform-provider-jetstream#readme) for full details.
+
+```terraform
+resource "jetstream_stream" "ORDERS" {
+  name     = "ORDERS"
+  subjects = ["ORDERS.*"]
+  storage  = "file"
+  max_age  = 60 * 60 * 24 * 365
+}
+
+resource "jetstream_consumer" "ORDERS_NEW" {
+  stream_id      = jetstream_stream.ORDERS.id
+  durable_name   = "NEW"
+  deliver_all    = true
+  filter_subject = "ORDERS.received"
+  sample_freq    = 100
+}
+
+resource "jetstream_consumer" "ORDERS_DISPATCH" {
+  stream_id      = jetstream_stream.ORDERS.id
+  durable_name   = "DISPATCH"
+  deliver_all    = true
+  filter_subject = "ORDERS.processed"
+  sample_freq    = 100
+}
+
+resource "jetstream_consumer" "ORDERS_MONITOR" {
+  stream_id        = jetstream_stream.ORDERS.id
+  durable_name     = "MONITOR"
+  deliver_last     = true
+  ack_policy       = "none"
+  delivery_subject = "monitor.ORDERS"
+}
+
+output "ORDERS_SUBJECTS" {
+  value = jetstream_stream.ORDERS.subjects
+}
+```
+
 ## Model Deep Dive
 
 The Orders example touched on a lot of features, but some like different Ack models and message limits, need a bit more detail. This section will expand on the above and fill in some blanks.