Help with status command for a docker container running working, but not command in preconditions

[alistaircol]

I have an issue which I can't figure out.

I want to add a precondition to assert that a docker container is running for a task.

---
version: 3

tasks:
  docker_shell:
    desc: Get into a local PHP container
    interactive: true
    silent: false
    preconditions:
    - sh: |
        docker-compose -f "{{.USER_WORKING_DIR}}/docker-compose.yml" exec php true > /dev/null 2>&1
      msg: "php container not running"
    cmds:
    - cmd: |
        docker-compose -f "{{.USER_WORKING_DIR}}/docker-compose.yml" exec php bash

I have a docker-compose.yml file with a service php which has bash installed.

The precondition should pass in my tests. The command is output correctly, the special variable {{.USER_WORKING_DIR}} is interpolated correctly. When I run the command separately, it exits with 0, i.e. success.

$ docker compose ps php --format=json | jq '.[0].State'
"running"

$ task docker_shell
task: php container not running
task: precondition not met

Changing the preconditions to assert the user working directory is usable in the precondition:

-echo "docker-compose -f "{{.USER_WORKING_DIR}}/docker-compose.yml" exec php true > /dev/null 2>&1" > blah.txt
+echo "docker-compose -f "{{.USER_WORKING_DIR}}/docker-compose.yml" exec php true > /dev/null 2>&1"

blah.txt has the working directory correctly in the command.

When I run the command from the file

$ docker-compose -f /absolute/path/docker-compose.yml exec php true > /dev/null 2>&1
$ echo $?
0

The quotes around the -f option are removed, but absolute path in my case doesn't have any whitespace/special characters so that isn't an issue.

---

When I use status instead of preconditions it will run the task.

    status:
    - |
      docker-compose -f "{{.USER_WORKING_DIR}}/docker-compose.yml" exec php true > /dev/null 2>&1

My question is why does it not pass with it as an item in the preconditions?