werf new release: v2.0 with Nelm by default

[shurup]

Briefly

We're happy to announce a new major update for werf with its v2.0 released!

The main change is the new deployment engine Nelm is now the default and the only deployment engine in werf. Nelm is backwards-compatible with Helm, so, in general, you don’t need to change anything and can deploy your Helm charts with werf just as before.

Background & details

Nelm brings new major features and improvements to werf, some of them are:

• Server-Side Apply (SSA) instead of 3-Way Merge (3WM). It is a much more robust way to update resources in a cluster;
• werf plan command, which shows expected changes in the cluster during the next deployment;
• Heavily parallelized resource change/tracking operations during deployment;
• Improved CRD deployment support;
• Heavily improved resource tracking;
• Fixed numerous deployment-related Helm bugs and issues, such as this one.

There are more features that still need some polishing, such as a way to directly describe dependencies between the resources instead of relying on hooks, weights and init-containers, or capabilities to use all hook-specific features like helm.sh/hook: pre-install or helm.sh/hook: before-hook-creation,hook-succeeded for non-hook resources. We will announce these features separately as soon as we think they are ready for general use.

Configuration

Here's how you can try werf v2.0 out:

source $(trdl use werf 2 stable)

With v2.0, there are some minor breaking changes. The full list is available here.

We encourage you to migrate to v2.0 as soon as possible. The migration will be much easier than it was from v1.1 to v1.2 because there are not many breaking changes in v2.0. werf v1.2 will stay in maintenance mode.

Also, starting from v2.0, we will follow semantic versioning in werf and we plan to release a new major version of werf every year. This will allow us to move faster without compromising backwards compatibility in minor/patch updates. In exchange, we will double down on our efforts to preserve backwards compatibility in minor and patch updates.