fix(docker): Multi-arch Docker images, attempt two (#2114)

* fix(docker): fix base image for multi-platform build (#2099)

* Correct indentation of run commands

* Split installation of packages into the ones needed at run time and build time

This allows us to now repeat the packages which need to be uninstalled again by
making use of a virtual package, which - when removed - removes the packages
installed as a dependency of it.

* Remove unnecessary `rm -rf /var/cache/apk/*` command

It's no needed when `apt add` is run with the `--no-cache` option.

* Add vertical spacing so it's clearer what is happening when

* Test the downloaded binaries to make sure they work on the platform

This can help find issues where binaries are downloaded for the wrong platform
compared to the architecture the Docker image is built for.

* Install dumb-init via apk

It's available as a package for Alpine Linux in version 1.2.5 as well, which
makes it easier to handle for the different architectures.

* Get git-lfs binaries in the right architecture for the Docker image

This makes use of the `TARGETPLATFORM` argument which automatically is
populated by Docker BuildKit with a string such as "linux/amd64" when the image
is being build for an x86_64 architecture.

* Install gosu for the right architecture

The `case` statement was taken from
https://github.com/BretFisher/multi-platform-docker-build as a way of
translating the platform name into what we needed for downloading gosu.

* fix(docker): fix installation of git-lfs in armv7 image (#2100)

This uses a similar pattern than what is used for `GOSU_ARCH` to map the
`TARGETPLATFORM` argument into the name of the architecture git-lfs use for
their release binaries, as "linux/arm/v7" otherwise would be mapped into "v7"
which is wrong.

* fix(docker): download Terraform and conftest versions maching image architecture (#2101)

* Remove Terraform versions from Docker image which don't have all archs

Terraform versions earlier than 0.11.15 does not have binaries available for
both amd64, arm64 and armv7, so are being dropped as we can't install the older
versions in all the architectures the Docker image is built for.

* Download Terraform version depending on the architecture Docker image is for

This avoids us having arm64 binaries for the ARM Docker images, which won't
work.

* Download arm64 conftest binaries for arm64 Docker image

This doesn't fix the armv7 Docker image because conftest doesn't have a binary
available for that, so it for now still downloads the x86_64 binary, which is
likely to not work - but it's the same as it did before.

* Correct path to dumb-init in docker-entrypoint.sh

The path changed after dumb-init was switched to be installed via `apk` rather
than downloaded directly as a binary.

Dockerfile

@@ -9,34 +9,48 @@ RUN CGO_ENABLED=0 go build -trimpath -ldflags "-s -w" -v -o atlantis .
 # The runatlantis/atlantis-base is created by docker-base/Dockerfile.
 FROM ghcr.io/runatlantis/atlantis-base:2022.03.03 AS base
 
+# Get the architecture the image is being built for
+ARG TARGETPLATFORM
+
 # install terraform binaries
 ENV DEFAULT_TERRAFORM_VERSION=1.1.7
 
 # In the official Atlantis image we only have the latest of each Terraform version.
-RUN AVAILABLE_TERRAFORM_VERSIONS="0.8.8 0.9.11 0.10.8 0.11.15 0.12.31 0.13.7 0.14.11 0.15.5 1.0.11 ${DEFAULT_TERRAFORM_VERSION}" && \
+RUN AVAILABLE_TERRAFORM_VERSIONS="0.11.15 0.12.31 0.13.7 0.14.11 0.15.5 1.0.11 ${DEFAULT_TERRAFORM_VERSION}" && \
+    case ${TARGETPLATFORM} in \
+        "linux/amd64") TERRAFORM_ARCH=amd64 ;; \
+        "linux/arm64") TERRAFORM_ARCH=arm64 ;; \
+        "linux/arm/v7") TERRAFORM_ARCH=arm ;; \
+    esac && \
     for VERSION in ${AVAILABLE_TERRAFORM_VERSIONS}; do \
-        curl -LOs https://releases.hashicorp.com/terraform/${VERSION}/terraform_${VERSION}_linux_amd64.zip && \
+        curl -LOs https://releases.hashicorp.com/terraform/${VERSION}/terraform_${VERSION}_linux_${TERRAFORM_ARCH}.zip && \
         curl -LOs https://releases.hashicorp.com/terraform/${VERSION}/terraform_${VERSION}_SHA256SUMS && \
-        sed -n "/terraform_${VERSION}_linux_amd64.zip/p" terraform_${VERSION}_SHA256SUMS | sha256sum -c && \
+        sed -n "/terraform_${VERSION}_linux_${TERRAFORM_ARCH}.zip/p" terraform_${VERSION}_SHA256SUMS | sha256sum -c && \
         mkdir -p /usr/local/bin/tf/versions/${VERSION} && \
-        unzip terraform_${VERSION}_linux_amd64.zip -d /usr/local/bin/tf/versions/${VERSION} && \
+        unzip terraform_${VERSION}_linux_${TERRAFORM_ARCH}.zip -d /usr/local/bin/tf/versions/${VERSION} && \
         ln -s /usr/local/bin/tf/versions/${VERSION}/terraform /usr/local/bin/terraform${VERSION} && \
-        rm terraform_${VERSION}_linux_amd64.zip && \
+        rm terraform_${VERSION}_linux_${TERRAFORM_ARCH}.zip && \
         rm terraform_${VERSION}_SHA256SUMS; \
     done && \
     ln -s /usr/local/bin/tf/versions/${DEFAULT_TERRAFORM_VERSION}/terraform /usr/local/bin/terraform
 
 ENV DEFAULT_CONFTEST_VERSION=0.30.0
 
 RUN AVAILABLE_CONFTEST_VERSIONS="${DEFAULT_CONFTEST_VERSION}" && \
+    case ${TARGETPLATFORM} in \
+        "linux/amd64") CONFTEST_ARCH=x86_64 ;; \
+        "linux/arm64") CONFTEST_ARCH=arm64 ;; \
+        # There is currently no compiled version of conftest for armv7
+        "linux/arm/v7") CONFTEST_ARCH=x86_64 ;; \
+    esac && \
     for VERSION in ${AVAILABLE_CONFTEST_VERSIONS}; do \
-        curl -LOs https://github.com/open-policy-agent/conftest/releases/download/v${VERSION}/conftest_${VERSION}_Linux_x86_64.tar.gz && \
+        curl -LOs https://github.com/open-policy-agent/conftest/releases/download/v${VERSION}/conftest_${VERSION}_Linux_${CONFTEST_ARCH}.tar.gz && \
         curl -LOs https://github.com/open-policy-agent/conftest/releases/download/v${VERSION}/checksums.txt && \
-        sed -n "/conftest_${VERSION}_Linux_x86_64.tar.gz/p" checksums.txt | sha256sum -c && \
+        sed -n "/conftest_${VERSION}_Linux_${CONFTEST_ARCH}.tar.gz/p" checksums.txt | sha256sum -c && \
         mkdir -p /usr/local/bin/cft/versions/${VERSION} && \
-        tar -C  /usr/local/bin/cft/versions/${VERSION} -xzf conftest_${VERSION}_Linux_x86_64.tar.gz && \
+        tar -C /usr/local/bin/cft/versions/${VERSION} -xzf conftest_${VERSION}_Linux_${CONFTEST_ARCH}.tar.gz && \
         ln -s /usr/local/bin/cft/versions/${VERSION}/conftest /usr/local/bin/conftest${VERSION} && \
-        rm conftest_${VERSION}_Linux_x86_64.tar.gz && \
+        rm conftest_${VERSION}_Linux_${CONFTEST_ARCH}.tar.gz && \
         rm checksums.txt; \
     done
 

docker-base/Dockerfile

@@ -17,21 +17,40 @@ RUN addgroup atlantis && \
     chmod g=u /home/atlantis/ && \
     chmod g=u /etc/passwd
 
-# Install dumb-init, gosu and git-lfs.
-ENV DUMB_INIT_VERSION=1.2.5
+# Install gosu and git-lfs.
 ENV GOSU_VERSION=1.14
 ENV GIT_LFS_VERSION=3.1.2
-RUN apk add --no-cache ca-certificates gnupg curl git unzip bash openssh libcap openssl && \
-    curl -L -s --output /bin/dumb-init "https://github.com/Yelp/dumb-init/releases/download/v${DUMB_INIT_VERSION}/dumb-init_${DUMB_INIT_VERSION}_x86_64" && \
-    chmod +x /bin/dumb-init && \
+
+# Automatically populated with the architecture the image is being built for.
+ARG TARGETPLATFORM
+
+# Install packages needed for running Atlantis.
+RUN apk add --no-cache ca-certificates curl git unzip bash openssh libcap dumb-init && \
+    # Install packages needed for building dependencies.
+    apk add --no-cache --virtual .build-deps gnupg openssl && \
     mkdir -p /tmp/build && \
     cd /tmp/build && \
-    curl -L -s --output git-lfs.tar.gz "https://github.com/git-lfs/git-lfs/releases/download/v${GIT_LFS_VERSION}/git-lfs-linux-amd64-v${GIT_LFS_VERSION}.tar.gz" && \
+
+    # git-lfs
+    case ${TARGETPLATFORM} in \
+        "linux/amd64") GIT_LFS_ARCH=amd64 ;; \
+        "linux/arm64") GIT_LFS_ARCH=arm64 ;; \
+        "linux/arm/v7") GIT_LFS_ARCH=arm ;; \
+    esac && \
+    curl -L -s --output git-lfs.tar.gz "https://github.com/git-lfs/git-lfs/releases/download/v${GIT_LFS_VERSION}/git-lfs-linux-${GIT_LFS_ARCH}-v${GIT_LFS_VERSION}.tar.gz" && \
     tar -xf git-lfs.tar.gz && \
     chmod +x git-lfs && \
     mv git-lfs /usr/bin/git-lfs && \
-    curl -L -s --output gosu "https://github.com/tianon/gosu/releases/download/${GOSU_VERSION}/gosu-amd64" && \
-    curl -L -s --output gosu.asc "https://github.com/tianon/gosu/releases/download/${GOSU_VERSION}/gosu-amd64.asc" && \
+    git-lfs --version && \
+
+    # gosu
+    case ${TARGETPLATFORM} in \
+        "linux/amd64") GOSU_ARCH=amd64 ;; \
+        "linux/arm64") GOSU_ARCH=arm64 ;; \
+        "linux/arm/v7") GOSU_ARCH=armhf ;; \
+    esac && \
+    curl -L -s --output gosu "https://github.com/tianon/gosu/releases/download/${GOSU_VERSION}/gosu-${GOSU_ARCH}" && \
+    curl -L -s --output gosu.asc "https://github.com/tianon/gosu/releases/download/${GOSU_VERSION}/gosu-${GOSU_ARCH}.asc" && \
     for server in $(shuf -e ipv4.pool.sks-keyservers.net \
                             hkp://p80.pool.sks-keyservers.net:80 \
                             keyserver.ubuntu.com \
@@ -42,13 +61,15 @@ RUN apk add --no-cache ca-certificates gnupg curl git unzip bash openssh libcap
     gpg --batch --verify gosu.asc gosu && \
     chmod +x gosu && \
     cp gosu /bin && \
-        cd /tmp && \
-        rm -rf /tmp/build && \
-        gpgconf --kill dirmngr && \
-        gpgconf --kill gpg-agent && \
-        apk del gnupg openssl && \
-        rm -rf /root/.gnupg && \
-        rm -rf /var/cache/apk/*
+    gosu --version && \
+
+    # Cleanup
+    cd /tmp && \
+    rm -rf /tmp/build && \
+    gpgconf --kill dirmngr && \
+    gpgconf --kill gpg-agent && \
+    apk del .build-deps && \
+    rm -rf /root/.gnupg
 
 # Set up nsswitch.conf for Go's "netgo" implementation
 # - https://github.com/golang/go/blob/go1.9.1/src/net/conf.go#L194-L275

docker-entrypoint.sh

@@ -1,4 +1,4 @@
-#!/bin/dumb-init /bin/sh
+#!/usr/bin/dumb-init /bin/sh
 set -e
 
 # Modified: https://github.com/hashicorp/docker-consul/blob/2c2873f9d619220d1eef0bc46ec78443f55a10b5/0.X/docker-entrypoint.sh