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| -rw-r--r-- | docs/tips-and-tricks.md | 24 |
1 files changed, 13 insertions, 11 deletions
diff --git a/docs/tips-and-tricks.md b/docs/tips-and-tricks.md index 73328fa0a1f7..5401ac91e5a3 100644 --- a/docs/tips-and-tricks.md +++ b/docs/tips-and-tricks.md @@ -17,24 +17,26 @@ of Deployments and other resource types when `ConfigMap` or `Secret` objects are updated. It is possible to make use of annotations and templating functions in -Kontemplate to force updates to these resources anyways (assuming that the -`ConfigMap` or `Secret` contains interpolated variables). +Kontemplate to force updates to these resources anyways. For example: ```yaml -# A ConfigMap that contains some data structure in JSON format +# A ConfigMap that contains some configuration for your app --- kind: ConfigMap metadata: name: app-config data: - configFile: {{ .appConfig | json }} + app.conf: | + name: {{ .appName }} + foo: bar ``` -Now whenever the `appConfig` variable changes we would like to update the -`Deployment` making use of it, too. We can do this by adding a hash of the -configuration to the annotations of the created `Pod` objects: +Now whenever the `appName` variable changes or we make an edit to the +`ConfigMap` we would like to update the `Deployment` making use of it, too. We +can do this by adding a hash of the parsed template to the annotations of the +created `Pod` objects: ```yaml @@ -46,7 +48,7 @@ spec: template: metadata: annotations: - configHash: {{ .appConfig | json | sha256sum }} + configHash: {{ insertTemplate "app-config.yaml" | sha256sum }} spec: containers: - name: app @@ -60,9 +62,9 @@ spec: name: app-config ``` -Now if the `ConfigMap` object appears first in the resource files, `kubectl` -will apply the resources sequentially and the updated annotation will cause -a rolling update of all relevant pods. +Now any change to the `ConfigMap` - either by directly editing the yaml file or +via a changed template variable - will cause the annotation to change, +triggering a rolling update of all relevant pods. ## direnv & pass |