This is a simple example to show how to inject skaffold lifecycles with user-defined hooks.
Run:
skaffold build --cache-artifacts=false
You should see the artifact hooks-example being built along with the execution of a pre-build hook trigger and a post-build hook trigger.
Now with an active kubernetes cluster, run:
skaffold dev
This will start a pod running the hooks-example image. The app simply reads the contents of hello.txt file once and stores it and repeatedly prints it out.
[hooks-example] Hello World!
[hooks-example] Hello World!
[hooks-example] Hello World!
...
If you change the text of hello.txt file, say to Hello World!!, Skaffold will sync it into the running container.
You should also see a pre-sync hook that just echoes the filename that has changed, and a post-sync hook that sends a SIGHUP signal to the app. The app responds accordingly by reloading the modified hello.txt file and printing it to the console.
[hooks-example] Hello World!
[hooks-example] Hello World!
[hooks-example] Hello World!
Syncing 1 files for hooks-example:e3c03bbaf0830afb79d586c5a0d5ce7510a027585fb0cbc88db9bd14bfbad139
Starting pre-sync hooks for artifact "hooks-example"...
file changes detected: hello.txt
Completed pre-sync hooks for artifact "hooks-example"
Starting post-sync hooks for artifact "hooks-example"...
[hooks-example] + kill -HUP 1
Completed post-sync hooks for artifact "hooks-example"
Watching for changes...
[hooks-example] Hello World!!
[hooks-example] Hello World!!
[hooks-example] Hello World!!
...