Docker On Run / On Ready / On Start

Imagine: After the mongodb start, it will dump db2dump and restore it.

Then, how to implement an "On Run" / "On Ready" event on Docker?

How to

You can use the HEALTHCHECK to do something like these examples:

• Docker Image
• Docker Image with variables
• Docker Compose

Documentation

• Docker Heath Check reference
• Docker-Compose Health Check reference

Issues & References

• docker/compose#1809
  • docker/compose#1809 (comment)
• compose-spec/compose-spec#84
  • compose-spec/compose-spec#84 (comment)

Example output

• You can see the error cat: /test.txt: No such file or directory until the health check is ready.
• You can see only one x inside /test.txt after run, because the init script was executed only once.

Creating network "tmp_default" with the default driver
Creating tmp_test_1 ... done
Attaching to tmp_test_1
test_1  | + set +e
test_1  | + true
test_1  | + cat /test.txt
test_1  | cat: /test.txt: No such file or directory
test_1  | + sleep 3
test_1  | + true
test_1  | + cat /test.txt
test_1  | cat: /test.txt: No such file or directory
test_1  | + sleep 3
test_1  | + true
test_1  | + cat /test.txt
test_1  | x
test_1  | + sleep 3
test_1  | + true
test_1  | + cat /test.txt
test_1  | x
test_1  | + sleep 3
test_1  | + true
test_1  | + cat /test.txt
test_1  | x
test_1  | + sleep 3