container showing "unhealthy"

[DHS1001]

The container is up and running, but the status shows "unhealthy" with the error message below:

OCI runtime exec failed: exec failed: unable to start container process: exec: "curl": executable file not found in $PATH: unknown

[daedric7]

    healthcheck:
      test: wget --no-verbose --tries=1 --spider https://blinko.yourdomain.com || exit 1
      interval: 30s
      timeout: 10s
      retries: 5
      start_period: 10s