Usage with Docker

In order to use it with Docker and docker-compose, place it alongside Dockerfile, build it into the image with exec permissions and reference it in docker-compose.yml.

- Dockerfile
- wait-for-it.sh

#Dockerfile
...
COPY wait-for-it.sh /wait-for-it.sh
RUN chmod +x /wait-for-it.sh
...

#docker-compose.yml
...
  my-service:
    build:
      context: "."
      container_name: my_container
      command: ["/wait-for-it.sh", "mysql:3306", "--", [entrypoint function]]
...

[douglas-gibbons]

Thanks @agustisanchez - I like it. Depending on your setup, you might also copy wait-for-it.sh in as a mounted volume, such as this:

version: '3'

services:
  hello-world:
    image: ubuntu
    volumes:
      - ./wait-for-it.sh:/usr/local/bin/wait-for-it.sh
    command:
      - wait-for-it.sh
      - github.com:80
      - --
      - echo
      - "hello world"

[jakzal]

Multistage builds can be leveraged to install wait-for-it with apt-get:

FROM debian:buster-slim as wait-for-it
RUN apt-get update && apt-get install -y "wait-for-it"

FROM debian:buster-slim
COPY --from=wait-for-it /usr/bin/wait-for-it /usr/bin/wait-for-it

If there was an official docker image for wait-for-it (i.e. wait-for-it/wait-for-it) we could potentially do:

FROM debian:buster-slim
COPY --from=wait-for-it/wait-for-it /usr/bin/wait-for-it /usr/bin/wait-for-it