changed the way that the tests run, by running on top of a native ruby image, which allows other docker-compose files to overwrite the setting

docker-compose-2.1.yml

@@ -0,0 +1,4 @@
+version: '3'
+services:
+  httpx:
+    image: ruby:2.1-alpine

docker-compose-2.2.yml

@@ -0,0 +1,4 @@
+version: '3'
+services:
+  httpx:
+    image: ruby:2.2-alpine

docker-compose-2.3.yml

@@ -0,0 +1,4 @@
+version: '3'
+services:
+  httpx:
+    image: ruby:2.3-alpine

docker-compose-2.4.yml

@@ -0,0 +1,4 @@
+version: '3'
+services:
+  httpx:
+    image: ruby:2.4-alpine

docker-compose-2.5.yml

@@ -0,0 +1,4 @@
+version: '3'
+services:
+  httpx:
+    image: ruby:2.5-alpine

docker-compose-jruby-9.0.0.0.yml

@@ -0,0 +1,4 @@
+version: '3'
+services:
+  httpx:
+    image: jruby:9.1.15-alpine

docker-compose.yml

@@ -2,29 +2,26 @@ version: '3'
 services:
   httpx:
     environment:
-      - SSL_CERT_FILE=/httpx/test/support/ci/certs/ca-bundle.crt
+      - SSL_CERT_FILE=/home/test/support/ci/certs/ca-bundle.crt
       - HTTPBIN_HOST=nghttp2
-      - HTTPX_HTTP_PROXY=http://http_proxy:3128
-      - HTTPX_HTTPS_PROXY=http://http_proxy:3128
-      - HTTPX_SOCKS4_PROXY=socks4://socks_proxy:8080
-      - HTTPX_SOCKS4A_PROXY=socks4a://socks_proxy:8080
-      - HTTPX_SOCKS5_PROXY=socks5://socks_proxy:8080
+      - HTTPX_HTTP_PROXY=http://httpproxy:3128
+      - HTTPX_HTTPS_PROXY=http://httpproxy:3128
+      - HTTPX_SOCKS4_PROXY=socks4://socksproxy:8080
+      - HTTPX_SOCKS4A_PROXY=socks4a://socksproxy:8080
+      - HTTPX_SOCKS5_PROXY=socks5://socksproxy:8080
       - PARALLEL=1
       - CI=1
-    build:
-      context: .
-      dockerfile: test/support/ci/Dockerfile 
+    image: ruby:2.4-alpine
     depends_on:
-      - http_proxy 
-      - socks_proxy 
+      - httpproxy 
+      - socksproxy 
       - nghttp2
     volumes:
-      - ./lib:/httpx/lib
-      - ./test:/httpx/test
-    command:
-      "rake test:ci"
+      - ./:/home
+    entrypoint:
+      /home/test/support/ci/build.sh
 
-  socks_proxy:
+  socksproxy:
     image: qautomatron/docker-3proxy
     ports:
       - "8080:8080"
@@ -32,7 +29,7 @@ services:
     volumes:
       - ./test/support/ci:/etc/3proxy
 
-  http_proxy:
+  httpproxy:
     image: sameersbn/squid:3.3.8-23
     ports:
       - "3128:3128"

test/support/ci/Dockerfile

@@ -1,17 +0,0 @@
-FROM ruby:2.4-alpine
-
-RUN apk update && apk upgrade && \
-    apk add --no-cache g++ make git bash
-
-RUN mkdir -p /httpx/lib/httpx
-WORKDIR /httpx 
-
-COPY Gemfile Gemfile
-COPY httpx.gemspec httpx.gemspec
-COPY lib/httpx/version.rb lib/httpx/version.rb
-
-RUN bundle install
-
-COPY . .
-
-ENTRYPOINT ["bundle", "exec"]

test/support/ci/build.sh

@@ -0,0 +1,6 @@
+#!/bin/sh
+apk update && apk upgrade
+apk add --no-cache g++ make git bash
+cd /home && rm Gemfile.lock && bundle install && bundle exec rake test:ci
+
+