# Containerized Nginx on Container Optimized OS
This module manages a `cloud-config` configuration that starts a containerized [Nginx](https://nginx.org/en/) service on Container Optimized OS, using the [hello demo image](https://hub.docker.com/r/nginxdemos/hello/).
The resulting `cloud-config` can be customized in a number of ways:
- a custom Nginx configuration can be set in `/etc/nginx/conf.d` using the `nginx_config` variable
- additional files (eg for hosts or zone files) can be passed in via the `files` variable
- a completely custom `cloud-config` can be passed in via the `cloud_config` variable, and additional template variables can be passed in via `config_variables`
The default instance configuration inserts iptables rules to allow traffic on port 80.
Logging and monitoring are enabled via the [Google Cloud Logging driver](https://docs.docker.com/config/containers/logging/gcplogs/) configured for the CoreDNS container, and the [Node Problem Detector](https://cloud.google.com/container-optimized-os/docs/how-to/monitoring) service started by default on boot.
The module renders the generated cloud config in the `cloud_config` output, to be used in instances or instance templates via the `user-data` metadata.
For convenience during development or for simple use cases, the module can optionally manage a single instance via the `test_instance` variable. If the instance is not needed the `instance*tf` files can be safely removed. Refer to the [top-level README](../README.md) for more details on the included instance.
## Examples
### Default configuration
This example will create a `cloud-config` that uses the module's defaults, creating a simple hello web server showing host name and request id.
```hcl
module "cos-nginx" {
source = "./modules/cloud-config-container/nginx"
}
# use it as metadata in a compute instance or template
resource "google_compute_instance" "default" {
metadata = {
user-data = module.cos-nginx.cloud_config
}
```
### Nginx instance
This example shows how to create the single instance optionally managed by the module, providing all required attributes in the `test_instance` variable. The instance is purposefully kept simple and should only be used in development, or when designing infrastructures.
```hcl
module "cos-nginx" {
source = "./modules/cloud-config-container/nginx"
test_instance = {
project_id = "my-project"
zone = "europe-west1-b"
name = "cos-nginx"
type = "f1-micro"
network = "default"
subnetwork = "https://www.googleapis.com/compute/v1/projects/my-project/regions/europe-west1/subnetworks/my-subnet"
}
}
```
## Variables
| name | description | type | required | default |
|---|---|:---:|:---:|:---:|
| cloud_config | Cloud config template path. If null default will be used. | string
| | null
|
| config_variables | Additional variables used to render the cloud-config and Nginx templates. | map(any)
| | {}
|
| file_defaults | Default owner and permissions for files. | object({…})
| | {…}
|
| files | Map of extra files to create on the instance, path as key. Owner and permissions will use defaults if null. | map(object({…}))
| | {}
|
| image | Nginx container image. | string
| | "nginxdemos/hello:plain-text"
|
| nginx_config | Nginx configuration path, if null container default will be used. | string
| | null
|
## Outputs
| name | description | sensitive |
|---|---|:---:|
| cloud_config | Rendered cloud-config file to be passed as user-data instance metadata. | |