# ⎈ Helm Templexer
Render Helm charts for multiple environments with _explicit config_ while keeping the overhead at ease.
```shell
cat > my-app.toml <<EOF
version = "v1"
chart = "tests/data/nginx-chart"
release_name = "my-app"
output_path = "manifests"
[[deployments]]
name = "edge-eu-w4"
EOF
helm-templexer render my-app.toml
```
Outcome:
```text
❯ exa -TL3 manifests
manifests
└── edge-eu-w4
└── my-app
└── nginx-chart
```
## Configuration
**Please mind:** we are in _alpha_ - all APIs can change at any time. Keep an eye on the release notes.
Configuration can be provided as TOML, YAML or JSON - please also see the [examples](tests/data).
| `version` | Schema version to use | **required** | | `"v1"` |
| `helm_version` | SemVer version constraint to require | optional | `~3` | |
| `enabled` | Whether to render deployments or not | optional | `true` | |
| `chart` | Path to the chart to render | **required** | | `"path/to/some-chart"` |
| `namespace` | Namespace to pass on to `helm`; when omitted, no namespace is passed | optional | `""` | |
| `release_name` | Release name to pass to `helm` | **required** | | `"some-release"` |
| `output_path` | Base path to use for writing the manifests to disk.<br><br>The fully-qualified output path is built as follows (`config` refers to the top-level):<br>`config.output_path/deployment.name/<[config/deployment].release_name>` | **required** | | |
| `additional_options` | Pass additional options to `helm template`; you can use all supported options of the tool.<br><br>Common use case: use `--set-string` to provide a container tag to use.<br>This can be achieved by modifying the configuration file in your build pipeline using toml-cli, yq, jq | optional | `[]` | `["--set-string image.tag=42"]` |
| `values` | A list of base value files which are passed to each `helm template` call.<br>This is commonly used to provide a sane base config. | optional | `[]` | |
| `deployments` | The list of deployments to render. | **required** | | `[[deployments]]`<br>`name = "edge"` |
Deployments can override several top-level fields:
| `name` | Name of the deployment; only used in the output path | **required** | | `"edge-eu-w4"` |
| `enabled` | Allows for disabling individual deployments | optional | `true` | |
| `release_name` | Override the release name | optional | `""` | |
| `additional_options` | Additional options, as seen above, but specific to this deployment | optional | `[]` | |
| `values` | Value files to use for this deployment | optional | `[]` | |
## Additional Options to The Render Command
Use `--additional-options` to pass data to the underlying `helm template` call. Beware that these additional options get added to *every* call, i.e. to each deployment.
A common use case we found was to provide the container tag:
```shell
helm-templexer render --additional-options="--set-string image.tag=${revision}" my-app.toml
```
## Installation
Helm Templexer is written in [Rust](http://www.rust-lang.org/). You will need `rustc` version 1.35.0 or higher. The recommended way to install Rust is from the official download page. Once you have it set up, a simple `make install` will compile `helm-templexer` and install it into `$HOME/.cargo/bin`.
### Cargo Install
If you’re using a recent version of Cargo (0.5.0 or higher), you can use the `cargo install` command:
```shell
cargo install helm-templexer
```
Cargo will build the binary and place it in `$HOME/.cargo/bin` (this location can be overridden by setting the --root option).