Template Strings are strings which are dynamically replaced by Preview during a deploy, allowing you to inject environment-specific values into your deployment.
Preview supports the use of Template Strings in both for all chart values and Kubernetes manifest files under the ./preview
directory.
For example, it is recommended to use the PREVIEWHQ_HOSTNAME
as part of your application's Ingress specification:
# .preview/chart-values/ingress:enabled: trueannotations:kubernetes.io/tls-acme: "true"path: /hosts:- host: ${PREVIEWHQ_HOSTNAME}paths:- /tls:- secretName: tls-secrethosts:- ${PREVIEWHQ_CLUSTER_HOSTNAME}- ${PREVIEWHQ_HOSTNAME}
There are 2 sets of Template Strings which can be utilized: one static set across all builds, and one set that is dynamically build based on image builds.
Template String | Description | Example |
| The hostname of the deployment, which will point to the root |
|
| The hostname of the cluster which the deployment is deployed on |
|
| The namespace which the deployment is deployed in to |
|
| The git hash being deployed | |
| The URL of the Preview-provided Docker image repository that | |
For each addition image specified in the images
block of the configuration, Preview injects a PREVIEWHQ_CUSTOM_IMAGE_TAG_{}
string, which is the Docker tag which was used for that custom build within the Docker image registry.
For example, if images
is as follows:
images:- name: frontenddockerfile: ./src/react/Dockerfilecontext: ./src/react- name: backenddockerfile: ./src/flask/Dockerfilecontext: ./src/flask
The the following additional Templates Strings are available:
PREVIEWHQ_CUSTOM_IMAGE_TAG_FRONTEND
PREVIEWHQ_CUSTOM_IMAGE_TAG_BACKEND