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Lanai-CLI Init and GNU Make

This package provides a set of templates for GNU Make. Together with lanai-cli, they provide an opinionated way that automates common software development tasks.

An Opinionated Approach

The commands and processes described below represents an opinionated approach to software development lifecycle. It addresses the case where multiple projects are developed in parallel. For example, a team could be developing a service and a library in tandem, where the service is dependent on the library. In this document, you will see the library in this example being referred to as PRIVATE_MODS, which stands for "private module". It signifies this module is under development (i.e. private to the development team). You can still use this pattern if your library module is a public repository but being developed in parallel.

In a project with one or more private modules, our workflow is the following:

  1. Developers will check out both the service project and the private modules.
  2. Service project's go.mod file will require the private modules by branch.
  3. Service project's go.mod file will have replace directives to point to checked out copies of the private modules.
  4. Developers are expected to check in the go.mod file with the replace directive.
  5. During the CI/CD process, the dependency for the private modules are updated to the head of the specified branch, and the replace directives in the go.mod file are dropped.
  6. When a build is published, a copy of the code with the modified go.mod is version tagged and pushed.

This process allows developers to work on the service and library project with ease, while allowing the CI/CD process to build against the expected code base.

If your project does not have any private modules, simply omit the PRIVATE_MODS arguments in the commands.

Bootstrap a Project

To bootstrap a project from scratch, copy the Makefile.tmpl into your project root directory, and rename it to Makefile. This Makefile contains the targets that can bootstrap the rest of the targets needed during the development lifecycle.

Setting Up Local Environment

make init-once

This target is used to set up your local development environment. You should run this target if your project uses any private modules, and the private module repositories are not publicly accessible.

This target takes the PRIVATE_MODS argument. This argument takes a comma separated list of private modules.

make init-once PRIVATE_MODS="github.com/<org>/<my-private-dependency>@v0.1.0,github.my-domain.com/<org>/<repo>@0.2.1

Running this target will configure your git command to use ssh instead of https to access these module repos. It will also append these module repos to the GOPRIVATE variable so that go does not use the public Go module proxy of the public checksum database.

If your project does not use any private modules, you do not need to run this target.

Generate Project Specific Make File and Docker File

make init

Pre-requisite:

  1. a go.mod file that has go-lanai as a required module.
  2. a Module.yml that describes your project. The Module.yml can have the following entries
name: europa # name of the project

execs: # your project's executables. these entries will be used to generate the dockerlaunch.sh file
  europa:
    main: cmd/europa/main.go 
    port: 8080 # specify a port to indicate this binary represents a web app. 
  migrate:
    main: cmd/europa/migrate.go
    type: migrator # specify migrator type to indicate this binary is responsible for database migration.

generates: # packages that have the golang generate directive. they will be used to generate Makefile target that triggers the go generate directive.
  - path: "pkg/swagger"
  - path: "pkg/security/example"

resources: # resources that should be published together with the binary. they will be used to generate Makefile target for copying the resources into the build
  - pattern: "configs" # this is the pattern to find them in the source directory
    output: "configs" # this is the directory to copy them to in the dist directory 
  - pattern: "web"
    output: "web"

This target does the following:

  1. Installs the lanai-cli command line tool.
  2. Invoke the lanai-cli init command to generate make files and docker files specific to your project.

The following sections will describe these two steps in detail.

Installing lanai-cli

make init installs the lanai-cli command line tool by calling the make init-cli sub-target which handles a variety of use cases.

First case is where the go.mod file has a replace directive that points go-lanai to a local copy. This case is most common for developers who have local modification to go-lanai. In this case, this target will install lanai-cli from the local checked out location of go-lanai.

If the local location is not valid, it will install go-lanai according to the required version. This is most common in the CI/CD pipeline.

If the go.mod does not have a replace directive for go-lanai, it will install according to the required version.

Except when installing using local copy via the replace directive, you can use the CLI_TAG argument to override the version of lanai-cli to be installed. The CLI_TAG argument can be either a branch name or a tag in the go-lanai repo.

i.e. make init-cli CLI_TAG=main.

Invoking lanai-cli init

After installing lanai-cli, the make init target generates a set of files based on the information from Module.yml by invoking the lanai-cli init command.

It will generate the following files:

  • Makefile-Build This file contains the targets specific to your project. Such as executables to build, resources to copy.
  • Makefile-Generated This file contains targets that are usually used by CI/CD.
  • Dockerfile This file will be used to build the image for your service. It will expose ports listed in the Module.yml file.
  • dockerlaunch.sh The entry point of the docker image. It will use the executable listed in the Module.yml file.

The recommended practice is to check in Makefile-Build, Dockerfile and dockerlaunch.sh. These files are specific to your project, and you may want to modify them as you need. make init will not overwrite existing files, so your changes can persist. If you updated Module.yml and want to re-generate them. You need to use the FORCE flag. i.e make init FORCE=true

Makefile-Generated is project agnostic. It's not expected to be checked in and will be re-generated during the CI/CD process.

Development

Running Tests and Linters

The following targets are found in Makefile-Build which is generated based on Makefile-Build.tmpl.

make test

Runs tests and produce test coverage report. This is the same target used in PR verification as well so any verification issue is repeatable locally.

make lint

Invoke go vet and golangci-lint linter.

Making Builds

make build

This command will create a dist folder. This folder will contain the executable binaries and any files that the binaries needs for execution.

This target takes VERSION and PRIVATE_MODS arguments. VERSION is the version number you want to give to this build. PRIVATE_MODS represents the private modules in your project's dependency. The build tool will look up the entries in PRIVATE_MODS in your service's go.mod and record their versions. All the information will be set into variables in the binary via ldflags, so that the binary can report its own build info.

The following variable will be set:

	BuildVersion
	BuildTime
	BuildHash
	BuildDeps

See the bootstrap package and pkg/bootstrap/build_info.go on how to access these variables in your binary.

make clean

Cleans the dist directory.

PR Verification

PR verification needs to check out the PR branch and ensure it builds and tests successfully. Same as on a development environment, make init needs to be executed to bootstrap lanai-cli and GNU Make. Usually we don't expect go-lanai to be checked out in this environment. So make init will use the version of go-lanai in the go.mod file. If you need a specific version of the lanai-cli, you can use the CLI_TAG argument.

The make verify target is designed to facilitate the PR verification process. This target takes PRIVATE_MODS as an argument. You can use this argument to specify the private module versions you want to verify this PR with. i.e. make verify PRIVATE_MODS=github.com/<org>/<my-private-dependency>@develop. If your project does not use private modules, or your private module is not being developed in tandem (i.e. it has a fixed version in go.mod instead of a replace directive), you can omit this argument.

This command executes the following steps.

  1. Run make pre to create a git tag tmp/pr-verify
  2. Run make update-dependency to update module dependency based on PRIVATE_MODS. This is done by invoking lanai-cli deps --modules=$(PRIVATE_MODS) This will modify the version of the private modules in go.mod according to the value of PRIVATE_MODS. If the UPDATE_DEPS_MARK argument is provided, a git tag will be created to save a record of this change.
  3. Run make drop-replace to drop the replace directive based on PRIVATE_MODS. This is done by invoking lanai-cli drop-replace --modules=$(PRIVATE_MODS) This will drop the replace directives for the PRIVATE_MODS. If the DROP_REPLACE_MARK argument is passed, a git tag will be created to save a record of this change.
  4. Run make clean.
  5. Run make test.
  6. Run make lint.
  7. Run make build. The PRIVATE_MODS argument will pass through to this target.
  8. Run make report. This will generate the test report
  9. RUN make post to revert the code to the git tag tmp/pre-verify

Note in step 2 lanai-cli will drop invalid replace directive before update dependency. It will run go mod tidy after updating dependency, and add the replace directive back. All the tags created are local and not pushed upstream.

Build For Distribution

Build

Similar to PR verification, making a distribution build involves checking out a copy of the project and build it with specific version of the private modules. In addition, source code needs to be tagged so that there's a record of the source code for this build.

The make dist target is designed for this purpose. This command also takes the PRIVATE_MODS argument. i.e. make dist PRIVATE_MODS=github.com/<org>/<my-private-dependency>@develop VERSION=4.0.0-20

This command executes the following steps:

  1. Run make pre to create a git tag tmp/pre-dist
  2. Run make update-dependency to update module dependency based on PRIVATE_MODS. This is done by invoking lanai-cli deps --modules=$(PRIVATE_MODS) This will modify the version of the private modules in go.mod according to the value of PRIVATE_MODS. A git tag will be created to save a record of this change.
  3. Run make drop-replace to drop the replace directive based on PRIVATE_MODS. This is done by invoking lanai-cli drop-replace --modules=$(PRIVATE_MODS) This will drop the replace directives for the PRIVATE_MODS. A git tag will be created to save a record of this change.
  4. Run make clean.
  5. Run make test.
  6. Run make pre-build-docker to make sure the code is at the git tag created by step 3.
  7. Run make build-docker. This command trigger the docker command to build a docker image. The image is built using the Dockerfile. The Dockerfile uses a builder pattern. Source code will be copied into the builder and the make build command will be run inside the builder to produce the desired distribution package. See Dockerfile.tmpl for more details.
  8. Run make post-dist to revert the code to the git tab tmp/pre-dist. Create a release tag v$(VERSION) using the tag created in step 3. Optionally merge back to the source branch if the SRC_BRANCH argument is provided.

All the tags created are local and not pushed upstream.

Publish

Use the make publish command to publish the image to docker hub. This should be run after make dist. For example, after make dist PRIVATE_MODS=github.com/<org>/<my-private-dependency>@develop VERSION=4.0.0-20) run make publish VERSION=4.0.0-20. This commands executes the following steps:

  1. Run make push-docker to push the image to docker registry. The required args are DOCKER_TAG and DOCKER_REPO. DOCKER_TAG will default to $(VERSION) DOCKER_REPO will default to registry-1.docker.io.
  2. Run git-push-tag to push the release tag created by make dist.