Use kubectl to build and push docker image to ECR

build-and-push.sh

#!/bin/bash

# Build and push a docker image to ECR, with an ad-hoc pod running in kubernetes. no need for local docker installation.

# Prerequisites:
# - tar, gzip, kubectl, aws cli
# - kubectl access to kubernetes cluster
# - aws cli with access to ECR

# Caveats:
# - Files or folders starting with '.' (except for `.dockerignore`) will not be included in the build context to avoid problems with .git, .venv, .env, etc.

# Usage:
# ./build-and-push.sh <registry>/<image>:<tag> <path-to-dockerfile> <path-to-context>
# example:
# ./build-and-push.sh xxxxxxxxxxxx.dkr.ecr.us-east-1.amazonaws.com/my-image:1.2.3 ./Dockerfile .

set -eo pipefail
IMAGE=${1?:"first argument must be in the form of <registry>/<image> or <registry>/<image>:<tag>"}
DOCKERFILE=${2?:"second argument must be the path to the dockerfile"}
CONTEXT=${3?:"third argument must be the path to the context. for example: '.'"}

# extract aws region from registry name
AWS_REGION=$(echo $IMAGE | cut -d'.' -f4)

# extract the registry name from the image name
REGISTRY=$(echo $IMAGE | cut -d'/' -f1)

BUILDER_IMAGE="gcr.io/kaniko-project/executor:v1.23.0-debug"
CRANE_IMAGE="docker.io/meirp3/crane:0.19.1"

ECR_PASS=$(aws ecr get-login-password --region ${AWS_REGION})

TEMP_FOLDER=$(mktemp -d)

cp -r ${CONTEXT}/* ${TEMP_FOLDER} || :
cp -r ${CONTEXT}/.dockerignore ${TEMP_FOLDER} || :

cat "${DOCKERFILE}" > ${TEMP_FOLDER}/Dockerfile

CURRENT_DIR=$(pwd)
cd ${TEMP_FOLDER}

tar -cf - . | gzip --best | kubectl run kaniko-$RANDOM \
--rm --stdin=true \
--image=${BUILDER_IMAGE} --restart=Never \
--overrides="
{
  \"apiVersion\": \"v1\",
  \"spec\": {
    \"initContainers\": [
      {
        \"name\": \"configure-ecr-auth\",
        \"image\": \"${CRANE_IMAGE}\",
        \"stdin\": true,
        \"stdinOnce\": true,
        \"volumeMounts\": [
          {
            \"name\": \"docker-config\",
            \"mountPath\": \"/root/.docker/\"
          }
        ],
        \"args\": [
          \"auth\",
          \"login\",
          \"$REGISTRY\",
          \"-u\",
          \"AWS\",
          \"-p\",
          \"$ECR_PASS\"
        ]
      }
    ],
    \"containers\": [
      {
        \"name\": \"kaniko\",
        \"image\": \"${BUILDER_IMAGE}\",
        \"stdin\": true,
        \"stdinOnce\": true,
        \"args\": [
          \"--cache\",
          \"--cache-repo=${IMAGE%:*}\",          
          \"--dockerfile=Dockerfile\",
          \"--context=tar://stdin\",
          \"--destination=${IMAGE}\"
        ],
        \"volumeMounts\": [
          {
            \"name\": \"docker-config\",
            \"mountPath\": \"/kaniko/.docker/\"
          }
        ]        
      }
    ],
    \"volumes\": [
      {
        \"name\": \"docker-config\",
        \"emptyDir\": {}
      }
    ]
  }
}
"

cd ${CURRENT_DIR}
rm -rf ${TEMP_FOLDER}