Prepare provider-ci for non-bridged providers

[danielrbradley]

Long term aims

• Remove duplication of provider-ci and native-provider-ci
• Reduce the cost & risk of changing CI.
• Resolve fragmentation of CI & makefile features.

Refactoring goals

• Re-use specific parts of the bridged-provider template.
• Make templates composable - so bridged-provider or go-provider can be composed of smaller templates.

Clean-up

We can use github search to investigate which parts of the configuration actually get used: https://github.com/search?q=org%3Apulumi+path%3A.ci-mgmt.yaml&type=code

Simplify configuration

Remove default env configuration. Put the common keys into a splice instead of in the default config.

• Add tool versions and just append any additional provider-specified env.
• Remove obsolete keys e.g. TRAVIS_OS_NAME
• Search shows that providers only ever add to the ENV config but never override existing values. Only exception being pulumi-docker setting PULUMI_GO_DEP_ROOT to the same path, but differently

Remove tool versions from env

We're generating all the files ourselves, so there's no reason to push the version into the env just to be read out when installing each tool. We can just put the version numbers directly into step template.

Remove setupPulumi and setupGo actions from config

Turn these into splices as they shouldn't be customisable via config - only their desired version should be configuration.

The .actions section shouldonly be used for preBuild and preTest.

Make it simpler to run the provider-ci binary directly

Make the 4 required arguments to provider-ci optional:

1. --config - default to .ci-mgmt.yaml.
2. --out - default to the current directory ('.')
3. --name - default to the config .provider field.
4. --template - add template to the config file

This avoids the need to generate a makefile template to make it easier to run the tool to pull templates:

- go run github.com/pulumi/ci-mgmt/provider-ci@master generate \
-		--name pulumi/pulumi-$(PACK) \
-		--out . \
-		--template bridged-provider \
-		--config $<
+ go run github.com/pulumi/ci-mgmt/provider-ci@master generate

This requires unbundling the config parsing from the generate method so we can parse the config before calling generate.

Composable templates

Implement the top-level "template" names as a simple switch statement. Each of these just calls into the GeneratePackage method for each sub-template it wants to include. The unbundling of the config parsing in the previous step will make this easier.

Note: When splices are collected, their relative path doesn't matter - only their filename, but we don't fail on duplicate names.

Default Config

We should change the original design from having a default config per template to a single global default config. This is because:

1. The config should be a minimal collection of possible keys.
2. The config keys needs to not clash between different sub-templates.

Sub-templates

Initially, the bridged-workflow template can be split up into the following parts each containing the listed files:

• config: .gitattributes & .golangci.yml
• devcontainer: devbox.* & .devcontainer/**
• bridged-build: Makefile, goreleaser.*, scripts/*
• bridged-workflows: .github/**

From this point, we should be able to generalise more of the bridged-workflows to be usable by other providers and moved into a general workflows template, while we also introduce new templates and sub-templates for native-workflows and go-provider-workflows and component-workflows where needed.