Make a way for containers to have dependencies during the build #6093
Description
Description of the issue
Docker Compose 1.17.0 introduced support for specifying a network for containers to attach themselves to during the build process. Unfortunately, since docker-compose doesn't start a container's dependencies until after the build, you can't use this option to allow containers to communicate with each other.
I'd like to solve that problem, whether by changing the default behavior to allow communication with dependencies during the build, or by introducing a new option in the compose file that specifies which dependencies need to be started during the build.
Steps to reproduce the issue
- Create a project with the following files:
docker-compose.yml:
version: '3.5'
services:
some_dependency:
image: httpd
myapp:
build:
context: .
network: myapp_default
depends_on:
- some_dependency
networks:
default:
name: myapp_defaultDockerfile:
FROM alpine
RUN apk add --no-cache curl
RUN curl http://some_dependency/ > file- Run
docker-compose build --no-cache
Observed result
some_dependency uses an image, skipping
Building myapp
Step 1/3 : FROM alpine
---> 11cd0b38bc3c
Step 2/3 : RUN apk add --no-cache curl
---> Running in b7efd52675f0
fetch http://dl-cdn.alpinelinux.org/alpine/v3.8/main/x86_64/APKINDEX.tar.gz
fetch http://dl-cdn.alpinelinux.org/alpine/v3.8/community/x86_64/APKINDEX.tar.gz
(1/5) Installing ca-certificates (20171114-r3)
(2/5) Installing nghttp2-libs (1.32.0-r0)
(3/5) Installing libssh2 (1.8.0-r3)
(4/5) Installing libcurl (7.61.0-r0)
(5/5) Installing curl (7.61.0-r0)
Executing busybox-1.28.4-r0.trigger
Executing ca-certificates-20171114-r3.trigger
OK: 6 MiB in 18 packages
Removing intermediate container b7efd52675f0
---> e639a58808ca
Step 3/3 : RUN curl http://some_dependency/ > file
---> Running in 7ba3dfaae446
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
0 0 0 0 0 0 0 0 --:--:-- 0:00:04 --:--:-- 0curl: (6) Could not resolve host: some_dependency
Service 'myapp' failed to build: The command '/bin/sh -c curl http://some_dependency/ > file' returned a non-zero code: **6**
However, if you manually start some_dependency with docker-compose up --detach some_dependency before running the build, everything works fine:
some_dependency uses an image, skipping
Building myapp
Step 1/3 : FROM alpine
---> 11cd0b38bc3c
Step 2/3 : RUN apk add --no-cache curl
---> Running in 1f4dead4514b
fetch http://dl-cdn.alpinelinux.org/alpine/v3.8/main/x86_64/APKINDEX.tar.gz
fetch http://dl-cdn.alpinelinux.org/alpine/v3.8/community/x86_64/APKINDEX.tar.gz
(1/5) Installing ca-certificates (20171114-r3)
(2/5) Installing nghttp2-libs (1.32.0-r0)
(3/5) Installing libssh2 (1.8.0-r3)
(4/5) Installing libcurl (7.61.0-r0)
(5/5) Installing curl (7.61.0-r0)
Executing busybox-1.28.4-r0.trigger
Executing ca-certificates-20171114-r3.trigger
OK: 6 MiB in 18 packages
Removing intermediate container 1f4dead4514b
---> c14e434d64e1
Step 3/3 : RUN curl http://some_dependency/ > file
---> Running in 17c25eaed969
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 45 100 45 0 0 6428 0 --:--:-- --:--:-- --:--:-- 6428
Removing intermediate container 17c25eaed969
---> 07c9c20086cd
Successfully built 07c9c20086cd
Successfully tagged dockercomposebuilddependencies_myapp:latest
Expected result
There should be some way to ensure some_dependency is started during the build process for myapp.
Either that should just be the default behavior of depends_on, or perhaps there could be a depends_on option within the build configuration that ensures network access is properly set up during the build.