Apparently this was never properly tested and never worked. When the IPFS repo needs upgrading, the first call to ipfs, which is run before running the migration, fails with the error message "Error: ipfs repo needs migration".
To fix this, simply run the migration before any `ipfs config` calls but don't run it when `dataDir` is empty and we need to call `ipfs init`.
Writing a NixOS test for this would require keeping at least two versions of IPFS in Nixpkgs, which we don't currently do.
Use `recursiveUpdate` instead of the // operator, as recommended in https://nix.dev/anti-patterns/language#attr1-attr2-merge-operator. Without this change, setting `services.ipfs.extraConfig.Addresses.NoAnnounce` for example will cause `services.ipfs.apiAddress`, `services.ipfs.gatewayAddress` and `services.ipfs.swarmAddress` to be ignored.
https://github.com/ipfs/fs-repo-migrations/releases/tag/v2.0.2
This is pretty much a complete rewrite of the ipfs-migrator package.
In version 2.0.0 a major change was made to the way the migrator works. Before, there was one binary that contained every migration. Now every migration has its own binary. If fs-repo-migrations can't find a required binary in the PATH, it will download it off the internet. To prevent that, build every migration individually, symlink them all into one package and then wrap fs-repo-migrations so it finds the package with all the migrations.
The change to the IPFS NixOS module and the IPFS package is needed because without explicitly specifying a repo version to migrate to, fs-repo-migrations will query the internet to find the latest version. This fails in the sandbox, for example when testing the ipfs passthru tests.
While it may seem like the repoVersion and IPFS version are in sync and the code could be simplified, this is not the case. See https://github.com/ipfs/fs-repo-migrations#when-should-i-migrate for a table with the IPFS versions and corresponding repo versions.
Go 1.17 breaks the migrations, so use Go 1.16 instead. This is also the Go version used in their CI, see 3dc218e300/.github/workflows/test.yml (L4). See https://github.com/ipfs/fs-repo-migrations/pull/140#issuecomment-982715907 for a previous mention of this issue. The issue manifests itself when doing anything with a migration, for example `fs-repo-11-to-12 --help`:
```
panic: qtls.ClientHelloInfo doesn't match
goroutine 1 [running]:
github.com/marten-seemann/qtls-go1-15.init.0()
github.com/marten-seemann/qtls-go1-15@v0.1.1/unsafe.go:20 +0x132
```
Also add myself as a maintainer for this package.
This fixes the test failure discovered in https://github.com/NixOS/nixpkgs/pull/160914.
See https://github.com/ipfs/fs-repo-migrations/issues/148 to read some of my struggles with updating this package.
There is no need for a separate unit. Simplify the NixOS module by adding the shell code to preStart of the main unit, where the other initialization code already is.
