The current workspace layout does not work well for us in many cases, and given our rethink of the location of morphologies, some of the initial design choices don't make sense, so we've had a think about how they could work in the future. Summary ======= 1 branch per workspace morph checkout -> morph clone morph edit creates repos based on their morphology path Walkthrough =========== `morph clone` ------------- We want to create a new workspace. Now that workspaces and system branches have merged, there is no `morph init` command, so we just use `morph clone`. $ morph clone baserock:baserock/definitions Created new workspace in "baserock" $ ls baserock $ cd baserock $ ls -A .morph-system-branch definitions We created `.morph-system-branch` to track internal state, such as where the root repository is, and the repository which contains our morphologies is called `definitions`. The name of the system branch is the second-last path component, while the morphologies repository is the last. $ cd definitions $ ls release.morph devel-system-x86_64-generic.morph build-essential foundation ... Cluster and System morphologies are in the top level of the repository, PLUS the strata have their own subdirectories. $ cd foundation $ ls morph systemd.morph ... Chunk morphologies are now in the stratum's subdirectory. The stratum morphology itself is called `morph` in that subdirectory. *NOTE*: This layout is not mandatory, morphologies are referenced by a full file path, so you can name them whatever you want now. If we now look at `systemd.morph` we seed that it now has the `repo` and `ref` fields. $ cat systemd.morph name: systemd kind: chunk repo: upstream:systemd ref: baserock/morph commit: dc8ee9a30e2df2568f2b37e3fb61e4b0bb601b build-system: autotools ... *NOTE*: We haven't finalised the chunk morphology format yet, but we want to be able to put repo and ref in there. `morph edit` ------------ Supposing we want to make changes, we use `morph edit`. It has changed from being given a system, stratum and chunk, to just the morphology path. $ morph edit foundation/systemd.morph Checked-out "foundation/systemd.morph" at "~/baserock/foundation/systemd" $ cd ../../foundation/systemd $ git branch * master/foundation/systemd The branch that this checkout is using, is the name of our system branch, with the morphology path appended. This is required, since multiple chunk morphologies can be for the same repository. They may be at different refs, but we give them a new ref for this branch, and if we don't give each chunk a unique ref, we can't push all of them, since there will be a conflict. *NOTE* This will un-share repositories in the case where they also use the same ref (e.g. gcc in build-essential). We may want a scheme to share this. *NOTE* The HEAD of our definitions repository being `master` means that we can't push this branch since: 1. Trove's Gitano rule-set prevents you pushing branches to repositories in upstream: that don't start with your trove prefix (e.g. baserock/) 2. Git won't accept master/* as a valid ref, since master exists. Some suggested fixes are: 1. Have the HEAD ref of definitions repository always start with your trove prefix. 2. Prepend the trove prefix if it doesn't already start with it 3. Fetch in upstream's refs in a different namespace and slacken Gitano's rule-set to allow pushing to branches that don't start with your trove prefix *NOTE* It's also possible that you have multiple morphologies repositories on your trove. You could get a name conflict if two of them have a system branch of the same name, and edit the same chunk, which would be a surprising GOTCHA if you need to make the same change to multiple repositories (e.g. a security fix affecting a component in both systems). It would be possible to avoid this by requiring unique branch names, but for the security update case, this is an odd restriction that unreasonable to check, since you need to keep track of the locations of every morphologies repository. `deprecated commands` --------------------- `morph init` is now deprecated, since you don't create a workspace independently of the system branch any more. `morph checkout` became `morph clone`. `morph branch` no longer exists. We still need to specify a way to create a new branch. The simplest thing to do would be to add a new option to `morph clone` to specify what we want to call the new branch. Alternatively, we have a different step for renaming your current branch, or creating a new branch and switching to that. This *could* be with git's own commands, if we determine the current branch from the current branch of the root repository.