schema: Generate Go and Typescript from Thema coremodels (#49193)

* Add go code generator for coremodels

* Just generate the entire coremodel for now

Maybe we'll need more flexibility as more coremodels are added, but for
now this is fine.

* Add note on type comment about stability, grodkit

* Remove local replace directive for thema

* Generate typescript from coremodel

* Update pkg/coremodel/dashboard/addenda.go

Co-authored-by: Ryan McKinley <ryantxu@gmail.com>

* Update cuetsy to new release

* Update thema to latest

* Fix enum generation for FieldColorModeId

* Put main generated object at the end of the file

* Tweaks to generated Go output

* Retweak back to var

* Add generated coremodel test

* Remove local replace statement again

* Add Make target and call into cuetsy cmd from gen

* Rename and comment linsrc for readability

* Move key codegen bits into reusable package

* Move body of cuetsifier into codegen pkg

Also genericize the diffing output into reusable WriteDiffer.

* Refactor coremodel generator to use WriteDiffer

* Add gen-cue step to CI

* Whip all the codegen automation into shape

* Add simplistic coremodel canonicality controls

* Remove erroneously committed test

* Bump thema version

* Remove dead code

* Improve wording of non-canonicality comment

Co-authored-by: Ryan McKinley <ryantxu@gmail.com>

pkg/framework/coremodel/gen.go

@@ -0,0 +1,93 @@
+// go:build ignore
+//go:build ignore
+// +build ignore
+
+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"cuelang.org/go/cue/cuecontext"
+	gcgen "github.com/grafana/grafana/pkg/codegen"
+	"github.com/grafana/thema"
+)
+
+var lib = thema.NewLibrary(cuecontext.New())
+
+const sep = string(filepath.Separator)
+
+// Generate Go and Typescript implementations for all coremodels, and populate the
+// coremodel static registry.
+func main() {
+	if len(os.Args) > 1 {
+		fmt.Fprintf(os.Stderr, "coremodel code generator does not currently accept any arguments\n, got %q", os.Args)
+		os.Exit(1)
+	}
+
+	cwd, err := os.Getwd()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "could not get working directory: %s", err)
+		os.Exit(1)
+	}
+
+	// TODO this binds us to only having coremodels in a single directory. If we need more, compgen is the way
+	grootp := strings.Split(cwd, sep)
+	groot := filepath.Join(sep, filepath.Join(grootp[:len(grootp)-3]...))
+
+	cmroot := filepath.Join(groot, "pkg", "coremodel")
+	tsroot := filepath.Join(groot, "packages", "grafana-schema", "src", "schema")
+
+	items, err := ioutil.ReadDir(cmroot)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "could not read coremodels parent dir %s: %s\n", cmroot, err)
+		os.Exit(1)
+	}
+
+	var lins []*gcgen.ExtractedLineage
+	for _, item := range items {
+		if item.IsDir() {
+			lin, err := gcgen.ExtractLineage(filepath.Join(cmroot, item.Name(), "lineage.cue"), lib)
+			if err != nil {
+				fmt.Fprintf(os.Stderr, "could not process coremodel dir %s: %s\n", cmroot, err)
+				os.Exit(1)
+			}
+
+			lins = append(lins, lin)
+		}
+	}
+
+	wd := gcgen.NewWriteDiffer()
+	for _, ls := range lins {
+		wdg, err := ls.GenerateGoCoremodel(filepath.Join(cmroot, ls.Lineage.Name()))
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "failed to generate Go for %s: %s\n", ls.Lineage.Name(), err)
+			os.Exit(1)
+		}
+		wd.Merge(wdg)
+
+		wdt, err := ls.GenerateTypescriptCoremodel(filepath.Join(tsroot, ls.Lineage.Name()))
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "failed to generate TypeScript for %s: %s\n", ls.Lineage.Name(), err)
+			os.Exit(1)
+		}
+		wd.Merge(wdt)
+	}
+
+	if _, set := os.LookupEnv("CODEGEN_VERIFY"); set {
+		err = wd.Verify()
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "generated code is not up to date:\n%s\nrun `make gen-cue` to regenerate\n\n", err)
+			os.Exit(1)
+		}
+	} else {
+		err = wd.Write()
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "error while writing generated code to disk:\n%s\n", err)
+			os.Exit(1)
+		}
+	}
+}

pkg/framework/coremodel/interface.go

@@ -1,5 +1,9 @@
 package coremodel
 
+// Generates all code derived from coremodel Thema lineages that's used directly
+// by both the frontend and backend.
+//go:generate go run gen.go
+
 import (
 	"github.com/grafana/thema"
 )