feat: parametrise elixir version

.semaphore/push_parametrised_versions.yml

@@ -0,0 +1,19 @@
+version: v1.0
+name: Push to Dockerhub - elixir ${{parameters.ELIXIR_IMAGE_TAG}}
+agent:
+  machine:
+    type: e1-standard-2
+    os_image: ubuntu1804
+blocks:
+  - name: Push
+    task:
+      jobs:
+        - name: build and push parametrised versions
+          commands:
+            - checkout
+            - docker login
+            - make setup
+            - make build ELIXIR_IMAGE_TAG=$ELIXIR_IMAGE_TAG
+            - make push ELIXIR_IMAGE_TAG=$ELIXIR_IMAGE_TAG
+      secrets:
+        - name: dockerhub-robot

.semaphore/semaphore.yml

@@ -20,3 +20,11 @@ promotions:
     pipeline_file: push.yml
     auto_promote:
       when: branch = 'master' AND result = 'passed'
+
+  - name: Push Parametrised versions to Dockerhub
+    pipeline_file: push_parametrised_versions.yml
+    parameters:
+      env_vars:
+        - required: true
+          name: ELIXIR_IMAGE_TAG
+          default_value: 1.13.4-alpine

Dockerfile

@@ -1,13 +1,11 @@
-FROM elixir:1.13.4-alpine
-MAINTAINER Rendered Text <[email protected]>
+ARG ELIXIR_IMAGE_TAG=1.13.4-alpine
+FROM elixir:$ELIXIR_IMAGE_TAG
 
-ENV MIX_ENV test
 
 RUN apk add --update git && mix local.hex --force
-
-RUN mix archive.install hex bunt 0.2.0 --force
+RUN mix archive.install hex bunt --force
 RUN mix archive.install hex poison --force
-RUN mix archive.install hex credo 1.6.5 --force
+RUN mix archive.install hex credo --force
 
 RUN mkdir -p /home/credo
 ADD .credo.exs /home/credo/.credo.exs

Makefile

@@ -1,16 +1,16 @@
 .PHONY: build push
 
 DOCKER_IMAGE_TAG=$(shell git rev-parse --short HEAD)
+ELIXIR_IMAGE_TAG?=1.13.4-alpine
 
 build:
-	docker build -t renderedtext/credo .
+	docker build -t renderedtext/credo --build-arg ELIXIR_IMAGE_TAG=elixir-$(ELIXIR_IMAGE_TAG) .
 
 push:
-	docker tag renderedtext/credo:latest renderedtext/credo:$(DOCKER_IMAGE_TAG)
-	docker push renderedtext/credo:$(DOCKER_IMAGE_TAG)
-	docker push renderedtext/credo:latest
+	docker tag renderedtext/credo:latest renderedtext/credo:elixir-$(ELIXIR_IMAGE_TAG)
+	docker push renderedtext/credo:elixir-$(ELIXIR_IMAGE_TAG)
 
 setup:
 	docker run --privileged --rm tonistiigi/binfmt --install all
 	docker buildx create --name mybuilder
-	docker buildx use mybuilder
+	docker buildx use mybuilder