go-cf-api

A proof of concept implementation as an alternative to cloud_controller_ng, written in Go.
Currently, this project is intended to be deployed alongside the existing cloud_controller_ng with a L7 router to forward requests to endpoints that have been completed to the Go implementation (based on both path and HTTP method). A deployment using this setup should pass CATS.

Since this project only implements a subset of the CF API endpoints, it should not be deployed standalone.

Deploying with cf-deployment

See the ADR for more information on this deployment approach.

To deploy go-cf-api into a cf-deployment, include this ops file. This will use HAProxy to route all requests to the go-cf-api where that endpoint and method has been implemented. Any endpoints that are not yet implemented by go-cf-api will continue to be served by cloud_controller_ng.

Links

• Documentation
• BOSH Release
• Opsfile for cf-deployment

Development Setup

Requirements

• Go version 1.17
• Mage (Makefile alternative in go) - go install github.com/magefile/mage
• Mysql and Postgres CLI Tools (mysql, mysqldump, psql, pgdump etc.)
• Additional tooling/CLIs - mage GetDependencies

Optional

• NodeJS and Yarn (for working with the documentation in /docs)
• Git LFS (to get assets resolved in /docs)
• Docker + docker-compose for running additional runtime dependencies

Prepare dev database

To run go-cf-api requires a migrated/existing Cloud Controller database. To help with this, there is a docker-compose.yml file to start the DB instances and SQL dumps from an existing cloud_controller_ng that can be imported to create a DB for testing.

There are mage commands for performing most common database operations. Run mage help to see the full list of available commands.

First start needed runtime components with:

docker compose up -d

[+] Running 3/0
 ⠿ Container go-cf-api_mariadb_1   Running                                                                                                                                                                                                                                                                   0.0s
 ⠿ Container go-cf-api_postgres_1  Running                                                                                                                                                                                                                                                                   0.0s
 ⠿ Container go-cf-api_uaa_1       Running

To ensure the DB is ready for use, it needs creating and loading with the relevant database dump.

Postgres

mage DBCreate config_psql.yaml
mage DBLoad config_psql.yaml database_dumps/3.102.0_psql_ccdb.sql

MySQL/MariaDB

mage DBCreate config_mysql.yaml
mage DBLoad config_mysql.yaml database_dumps/3.102.0_mysql_ccdb.sql

Useful database operations

• Drop database

   mage DBDelete config_psql.yaml

• Drop and create database and import new dump

   mage DBRecreate config_psql.yaml database_dumps/3.102.0_psql_ccdb.sql

Running commands

Different database code and types of test are conditionally compiled and run based on Go build tags.

To target a specific database and/or test set, use:

go -tags=psql,unit <go command>

To avoid having to type out tags every time, you can instead run:

export GOFLAGS="-tags=psql,unit"

This will make go test ./... just run the unit tests and also allow you to just run go run cmd/main.go config_psql.yaml

Available Tags are:

• mysql (adds mysql database support)
• psql (adds psql database support)
• unit (includes unittests)
• integration (includes integration tests)

Note here that you can build/run go-cf-api just with either mysql or psql support/tag. The intended way to support both dbs is to build two separate binaries and depending on the backend use the fitting one. The unit and integration tags are just relevant for running go test but either mysql or psql must be always provided otherwise there are missing imports.

Starting the go-cf-api

• Postgres

   go run --tags=psql cmd/main.go config_psql.yaml

• MySQL/MariaDB

   go run --tags=mysql cmd/main.go config_mysql.yaml

The default values in the config_{db}.yml and sqlboiler_{db}.toml files should match the credentials for each database in docker-compose.yml. You may need to modify these credentials to connect to an alternative DB setup.

The API should be accessible at

http://localhost:8080/v3

The API Documentation should be accessible at

http://localhost:8080/docs/v3

Building the go-cf-api binaries

The two binaries (for psql and mysql) can then be compiled for your current OS/architecture with:

mage build

Binaries are output to the /build directory.

The binaries can be compiled for other architectures by exporting the GOOS and GOARCH environment variables.

List of API endpoints

Following endpoints have implemented and should be equivalent to the endpoints from cloud_controller_ng.

go-cf-api Specific Endpoints

• http://localhost:8080/healhz (Health Endpoint)
• http://localhost:8080/metrics (Prometheus Metrics)
• http://localhost:8080/docs/v3 (API Documentation)

V3 API

• http://localhost:8080/
• http://localhost:8080/v3
• http://localhost:8080/v3/info
• http://localhost:8080/v3/buildpacks (GET)
• http://localhost:8080/v3/buildpacks/:guid (GET, POST)
• http://localhost:8080/v3/security_groups (GET)
• http://localhost:8080/v3/security_groups/:guid (GET)

Querying locally

To query most endpoints locally, you will need a JWT. The easiest way to get this is to create a UAA client with the uaac CLI then login with then cf CLI. To create a user called bob:

uaac target http://localhost:8095
uaac token client get admin -s adminsecret
uaac user add bob -p password --emails none@none.local
cf api http://localhost:8080
cf auth bob password

Now various endpoints can be queried using e.g. cf curl /v3/buildpacks

To authenticate as admin (for example to assign roles to bob):

cf auth admin adminsecret --client-credentials

Documentation

The documentation is based on docusaurus and can be found at https://pages.github.com/cloudfoundry/go-cf-api/. It is defined under /docs in this project and is then served by github-pages from the gh-pages branch which is detached from the other branches. A GitHub workflow ensures the gh-pages branch always reflects the state of the main branch's /docs folder.

Package documentation is auto generated using gomarkdoc and integrated into docusaurus, as is the API documentation which is generated from code comments via swag. Additionally, the go-cf-api binaries/go run cmd/main.go will also serve the versioned API documentation in a Swagger UI at:

http://localhost:8080/docs/v3

Some manual documentation such as project ADRs (architecture decision records) are included under /doc/adrs and /docs/docs. The /docs/docs/intro.md file is a symlink to this README.md. For further information how to build the documentation locally refer to the Docs README

Development tasks

Below is a summary of the most important development workflows and tools.

Generating DB models

To support different databases (Postgres and MySQL/MariaDB), we generate two sets of database models with sqlboiler. These are then included in the same package and given build tag comments to control when to compile each model set into the binary. Two binaries are then produced - one for each database. Attempting to use e.g. the mysql binary on a Postgres database will result in a startup error.

To facilitate the generating, combining and build tagging of the sqlboiler models, there is a mage task to automate it. Firstly one must have a mysql and psql instance running with a desired database schema already on them(in the ccdb database). Then one can run:

mage GenerateSQLBoiler

This will scan both databases schemas and generate go code to /internal/sotrage/db/models/ as well as add the relevant build tag comments to compile the correct models for each supported DB.

Running the linter

This project uses golangci-lint to ensure code is formatted correctly and return values are checked etc. To run the linter, run:

golangci-lint run --build-tags psql,unit,integration

There is a GitHub Action that runs the linter on every push. No code should be merged until it passes all the linter checks.

Running tests

Different tags are used to control which tests are run:

• Unit tests

   go test -tags="unit,psql" ./...

• Integration tests (Postgres) - require running database

   go test -tags=integration,psql -parallel=1 -p=1 ./... -args $PWD/config_psql.yaml

• Integration tests (MySQL/MariaDB) - require running database

   go test -tags=integration,mysql -parallel=1 -p=1 ./... -args $PWD/config_mysql.yaml