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| -rw-r--r-- | README.md | 1 | ||||
| -rw-r--r-- | docs/cluster-config.md | 2 | ||||
| -rw-r--r-- | docs/resource-sets.md | 146 |
3 files changed, 148 insertions, 1 deletions
diff --git a/README.md b/README.md index 4a31cd69d6f5..d287f6001bea 100644 --- a/README.md +++ b/README.md @@ -19,6 +19,7 @@ Check out a Kontemplate setup example and the feature list below! * [Simple, yet powerful templates](docs/templates.md) * [Clean cluster configuration files](docs/cluster-config.md) +* [Resources organised as simple resource sets](docs/resource-sets.md) * [Integration with pass](docs/pass.md) * [Integration with kubectl](docs/kubectl.md) diff --git a/docs/cluster-config.md b/docs/cluster-config.md index 1bf4944e910f..3bc59a63057f 100644 --- a/docs/cluster-config.md +++ b/docs/cluster-config.md @@ -73,7 +73,7 @@ As mentioned above, extra variables can be loaded from additional YAML or JSON f have a file called `test-secrets.yaml` which contains variables that should be shared between a `test` and `dev` cluster, you could include it in your context as such: -``` +```yaml # test-secrets.yaml: mySecretVar: foo-bar-12345 diff --git a/docs/resource-sets.md b/docs/resource-sets.md new file mode 100644 index 000000000000..1d5eeabc5ac4 --- /dev/null +++ b/docs/resource-sets.md @@ -0,0 +1,146 @@ +Resource Sets +================ + +Resource sets are collections of Kubernetes resources that should be passed to `kubectl` together. + +Technically a resource set is simply a folder with a few YAML and/or JSON templates in it. + + +# Creating resource sets + +Simply create a folder in your Kontemplate repository and place a YAML or JSON file in it. These +files get interpreted as [templates][] during Kontemplate runs and variables (as well as template +logic or functions) will be interpolated. + +Refer to the template documentation for information on how to write templates. + +## Default variables + +Sometimes it is useful to specify default values for variables that should be interpolated during +a run if the [cluster configuration][] does not specify a variable explicitly. + +This can be done simply by placing a `default.yaml` or `default.json` file in the resource set +folder and filling it with key/value pairs of the intended default variables. + +Kontemplate will error during interpolation if any variables are left unspecified. + +# Including resource sets + +Under the cluster configuration `include` key resource sets are included and required variables +are specified. For example: + +```yaml +include: + - name: some-api + values: + version: 1.2-SNAPSHOT +``` + +This will include a resource set from a folder called `some-api` and set the specified `version` variable. + +## Fields + +The available fields when including a resource set are these: + +### `name` + +The `name` field contains the name of the resource set. This name can be used to refer to the resource set +when specifying explicit includes or excludes during a run. + +By default it is assumed that the `name` is the path to the resource set folder, but this can be overridden. + +This field is **required**. + +### `path` + +The `path` field specifies an explicit path to a resource set folder in the case that it should differ from +the resource set's `name`. + +This field is **optional**. + +### `values` + +The `values` field specifies key/values pairs of variables that should be available during templating. + +This field is **optional**. + +### `include` + +The `include` field specifies additional resource sets that should be included and that should inherit the +variables of this resource set. + +The fully qualified names of "nested" resource sets are set to `${PARENT_NAME}/${CHILD_NAME}` and paths are +merged in the same way. + +This makes it easy to organise different resource sets as "groups" to include / exclude them collectively +during runs. + +This field is **optional**. + +## Multiple includes + +Resource sets can be included multiple times with different configurations. In this case it is recommended +to set the `path` and `name` fields explicitly. For example: + +```yaml +include: + - name: forwarder-europe + path: tools/forwarder + values: + source: europe + - name: forwarder-asia + path: tools/forwarder + values: + source: asia +``` + +The two different configurations can be referred to by their set names, but will use the same resource +templates with different configurations. + +## Nesting resource sets + +As mentioned above for the `include` field, resource sets can be nested. This lets users group resource +sets in logical ways using simple folder structures. + +Assuming a folder structure like: + +``` +├── backend +│ ├── auth-api +│ ├── message-api +│ └── order-api +└── frontend + ├── app-page + └── login-page +``` + +With each of these folders being a resource set, they could be included in a cluster configuration like so: + +```yaml +include: + - name: backend + include: + - name: auth-api + - name: message-api + - name: order-api + - name: frontend: + include: + - name: app-page + - name: login-page +``` + +Kontemplate could then be run with, for example, `--include backend` to only include the resource sets nested +in the backend group. Specific resource sets can also be targeted, for example as `--include backend/order-api`. + +Variables specified in the parent resource set are inherited by the children. + +### Caveats + +Two caveats apply that users should be aware of: + +1. The parent resource set can not contain any resource templates itself. + +2. Only one level of nesting is supported. Specifying `include` again on a nested resource set will be ignored. + +[templates]: templates.md +[cluster configuration]: cluster-config.md |