refactor build tooling

.dockerignore

@@ -0,0 +1,6 @@
+.git
+.github
+.vscode
+coverage.out
+local-example
+tmp

.drone.yml

@@ -7,14 +7,15 @@ build_config: &build_config
   image: golang:1
   environment:
     - GO111MODULE=on
-    - GOPROXY=https://proxy.golang.org 
+    - GOPROXY=https://proxy.golang.org
     - CGO_ENABLED=0
   commands:
     - go build -a -ldflags "-X main.version=${DRONE_TAG:-other} -X main.rev=${DRONE_COMMIT}"
 
 publish_config: &publish_config
   image: plugins/docker
   repo: nytimes/drone-gke
+  dockerfile: Dockerfile
   secrets:
     - docker_username
     - docker_password
@@ -24,7 +25,7 @@ pipeline:
     image: golang:1
     environment:
       - GO111MODULE=on
-      - GOPROXY=https://proxy.golang.org 
+      - GOPROXY=https://proxy.golang.org
       - CGO_ENABLED=0
     commands:
       - go mod download
@@ -44,6 +45,8 @@ pipeline:
 
   publish_develop:
     <<: *publish_config
+    build_args:
+    - GCLOUD_SDK_TAG=alpine
     tag:
       - "develop"
     when:
@@ -52,19 +55,23 @@ pipeline:
 
   publish_latest:
     <<: *publish_config
+    build_args:
+    - GCLOUD_SDK_TAG=alpine
     auto_tag: true
 
   publish_1_10:
     <<: *publish_config
+    build_args:
+    - GCLOUD_SDK_TAG=217.0.0-alpine
     auto_tag: true
     auto_tag_suffix: "k8s-1.10"
-    dockerfile: Dockerfile.1.10
 
   publish_1_11:
     <<: *publish_config
+    build_args:
+    - GCLOUD_SDK_TAG=241.0.0-alpine
     auto_tag: true
     auto_tag_suffix: "k8s-1.11"
-    dockerfile: Dockerfile.1.11
 
   slack:
     image: plugins/slack

.editorconfig

@@ -0,0 +1,21 @@
+root = true
+
+[*]
+indent_style = space
+indent_size = 2
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[*.md]
+trim_trailing_whitespace = false
+
+[*.go]
+indent_style = tab
+
+[{go.mod,go.sum}]
+indent_style = tab
+
+[Makefile]
+indent_style = tab

.gitignore

@@ -1 +1,4 @@
+.vscode
 /drone-gke
+coverage.out
+tmp

CONTRIBUTING.md

@@ -1,6 +1,6 @@
-# Contributing to Drone-GKE
+# Contributing to drone-gke
 
-Drone-GKE is an open source project started by handful of developers at The New York Times and open to the entire open source community.
+`drone-gke` is an open source project started by a handful of developers at The New York Times and open to the entire open source community.
 
 We really appreciate your help!
 
@@ -28,6 +28,244 @@ Before submitting changes, please follow these guidelines:
 1. Make sure code follows the ['Go Code Review Comments'](https://github.com/golang/go/wiki/CodeReviewComments).
 1. Open a Pull Request.
 
+## Development
+
+### Workflow
+
+The git workflow follows [GitFlow](https://datasift.github.io/gitflow/IntroducingGitFlow.html).
+
+New features should be based on the `master` branch.
+
+### Dependencies
+
+#### Core
+
+```sh
+# run tests for required core dependencies
+make check
+```
+
+#### Go
+
+[Go Modules](https://blog.golang.org/using-go-modules) is used to manage dependencies.
+
+### Build, Test, Push
+
+#### Building the `drone-gke` executable
+
+```sh
+make drone-gke
+```
+
+#### Testing the `drone-gke` executable
+
+```sh
+make test-coverage
+```
+
+#### Building the `drone-gke` docker image
+
+Using a custom repo name:
+
+```sh
+docker_repo_name=alice make docker-image
+```
+
+Using a custom tag:
+
+```sh
+docker_tag=alpha make docker-image
+```
+
+#### Pushing `drone-gke` docker images
+
+> :warning: By default, `make docker-push` will attempt to push to [`nytimes/drone-gke`](https://hub.docker.com/r/nytimes/drone-gke)
+
+Push existing image to custom repo using custom tag:
+
+```sh
+docker_repo_name=alice docker_tag=alpha make docker-push
+```
+
+### Running `drone-gke` locally
+
+> :warning: Valid GCP service account credentials are required. See ["Creating test serivce account credentials"](#creating-test-service-account-credentials) for more details.
+
+#### Configuring [`TOKEN`](DOCS.md#secrets)
+
+If you created test service account credentials using ["Creating test serivce account credentials"](#creating-test-service-account-credentials), those credentials will be used by default.
+
+If using service account credentials that you created manually:
+
+```sh
+# replace with correct path
+export TOKEN="$(cat /path/to/keyfile.json)"
+```
+
+#### Configuring cluster related values
+
+If you have an existing `gcloud` configuration for `container/cluster`, `compute/zone`, or `compute/region`, those values will be used by default.
+
+Otherwise manually configure the following using appropriate values:
+
+```sh
+export PLUGIN_CLUSTER=dev
+export PLUGIN_ZONE=us-east1-b
+# -- or --
+export PLUGIN_REGION=us-east1
+```
+
+By default, `PLUGIN_NAMESPACE` will be set to `drone-gke-test`.
+
+If you'd like to use the namespace currently configured with `kubectl`:
+
+```sh
+export PLUGIN_NAMESPACE=$(kubectl config view --minify --output 'jsonpath={..namespace}')
+```
+
+Otherwise manually configure a different namespace value:
+
+```sh
+export PLUGIN_NAMESPACE=my-test-ns
+```
+
+#### Running a `drone-gke` docker image
+
+> :warning: Assumes `TOKEN` and any cluster related parameters have already been set / exported within the current terminal session
+
+Using sample configurations within `local-example`:
+
+```sh
+# `dry-run` and `verbose` are both enabled by default
+make run
+
+# disable via the respective `PLUGIN_*` environment variables
+PLUGIN_DRY_RUN=0 PLUGIN_VERBOSE=0 make run
+```
+
+Using custom configurations with default files:
+
+```sh
+# Deploy manifest templates in my-custom-configs
+
+# my-custom-configs
+# ├── .kube.sec.yml
+# ├── .kube.yml
+# └── vars.json
+
+export CONFIG_HOME=$(pwd)/my-custom-configs
+make run
+```
+
+Using custom configurations with _custom_ files:
+
+```sh
+# Deploy manifest templates in my-super-custom-configs
+
+# my-super-custom-configs
+# ├── app.yml
+# ├── custom-vars.json
+# └── secrets.yml
+
+export CONFIG_HOME=$(pwd)/my-super-custom-configs
+export PLUGIN_SECRET_TEMPLATE=${CONFIG_HOME}/secrets.yml
+export PLUGIN_TEMPLATE=${CONFIG_HOME}/app.yml
+export PLUGIN_VARS="$(cat ${CONFIG_HOME}/custom-vars.json)"
+make run
+```
+
+If you've built the docker image using a custom repo or tag:
+
+```sh
+export docker_repo_name=alice
+export docker_tag=alpha
+make run
+```
+
+To print the commands that would be executed, without _actually_ executing them:
+
+```sh
+make run -n
+```
+
+### Tips and Tricks
+
+#### `make e2e`
+
+`make e2e` is an alias for:
+
+```sh
+make drone-gke
+make test-coverage
+make docker-image
+make test-resources
+make run
+```
+
+Build and test the `drone-gke` binary, build a `drone-gke` docker image tagged using a custom repo name, and run that docker image against a custom test cluster:
+
+```sh
+export docker_repo_name=alice
+export PLUGIN_CLUSTER=my-test-cluster
+make e2e
+```
+
+#### `make release`
+
+> :warning: By default, `make release` will attempt to push to [`nytimes/drone-gke`](https://hub.docker.com/r/nytimes/drone-gke)
+
+`make release` is an alias for:
+
+```sh
+make drone-gke
+make test-coverage
+make docker-image
+make docker-push
+```
+
+Build, test, and push new image using custom repo, tag values:
+
+```sh
+export docker_repo_name=alice
+export docker_tag=alpha
+make release
+```
+
+#### Creating test serivce account credentials
+
+> :warning: The following requires access to an active GCP project, a GCP user account with sufficient privileges, properly configured `gcloud`, and `terraform` executables. Please review ["Creating and managing service accounts"](https://cloud.google.com/iam/docs/creating-managing-service-accounts) and the Terraform ["Google Cloud Platform Provider"](https://www.terraform.io/docs/providers/google/index.html) documentation before continuing.
+
+##### Setup
+
+Verify `gcloud` configuration:
+
+```sh
+# the current / active GCP project will be the owner of your test service account resources
+gcloud config list
+```
+
+##### Creation and configuration
+
+Run following to verify the test resources that will be created / configured:
+
+```sh
+make terraform/test.tfplan
+```
+
+Run the following to create / configure the test resources:
+
+```sh
+make test-resources
+```
+
+##### Clean up
+
+Once you've finished testing, don't forget to delete these test resources:
+
+```sh
+make destroy-test-resources
+```
+
 ## License
 
-Unless otherwise noted, the Drone-GKE source files are distributed under the Apache 2.0-style license found in the LICENSE file.
+Unless otherwise noted, `drone-gke` is distributed under the Apache 2.0-style license found in [LICENSE](LICENSE).