adding a float subcommand for future proofing

Author: Scott Nichols

README.md

@@ -12,8 +12,30 @@ go get github.com/n3wscott/buoy
 
 ## Usage
 
+```shell
+Usage:
+  buoy [command]
+
+Available Commands:
+  float       Find latest versions of dependencies based on a release.
+  help        Help about any command
+
+Flags:
+  -h, --help   help for buoy
+
+Use "buoy [command] --help" for more information about a command.
 ```
-buoy go.mod $release
+
+### Float
+
+```shell
+Usage:
+  buoy float go.mod [flags]
+
+Flags:
+  -d, --domain string    domain filter (default "knative.dev")
+  -h, --help             help for float
+  -r, --release string   release should be '<major>.<minor>' (i.e.: 1.23 or v1.23) [required]
 ```
 
 Example: 
@@ -26,15 +48,28 @@ knative.dev/serving@v0.15.3
 knative.dev/test-infra@release-0.15
 ```
 
-Note: the following are equivalent: 
+Or set the domain to and target release of that dependency:
+
+```shell script
+$ buoy float go.mod --release 0.18 --domain k8s.io
+k8s.io/api@v0.18.10
+k8s.io/apiextensions-apiserver@v0.18.10
+k8s.io/apimachinery@v0.18.10
+k8s.io/client-go@v0.18.10
+k8s.io/code-generator@v0.18.10
+k8s.io/gengo@master
+k8s.io/klog@master
+```
+
+Note: the following are equivalent releases: 
 
 - `v0.1`
 - `v0.1.0`
 - `0.1`
 - `0.1.0`
 
 
-## Rules
+### Float Rules
 
 Buoy will select a `ref` for a found dependency, in this order:
 
@@ -45,3 +80,4 @@ Buoy will select a `ref` for a found dependency, in this order:
 ## TODO:
 
 - Support `go-import` with more than one import on a single page.
+- Support release branch templates. For now, hardcoded to Knative style.

buoy.go

@@ -2,66 +2,41 @@ package main
 
 import (
 	"fmt"
-	"io/ioutil"
-	"strings"
-
-	"github.com/blang/semver/v4"
-	"github.com/n3wscott/buoy/pkg/git"
-	"github.com/n3wscott/buoy/pkg/golang"
+	"github.com/n3wscott/buoy/pkg/float"
 	"github.com/spf13/cobra"
-	"golang.org/x/mod/modfile"
 )
 
 func main() {
 	var domain string
+	var release string
 
-	var buoy = &cobra.Command{
-		Use:  "buoy go.mod v0.10",
-		Args: cobra.MinimumNArgs(2),
+	var floatCmd = &cobra.Command{
+		Use:   "float go.mod",
+		Short: "Find latest versions of dependencies based on a release.",
+		Args:  cobra.ExactArgs(1),
 		RunE: func(cmd *cobra.Command, args []string) error {
 			gomod := args[0]
-			b, err := ioutil.ReadFile(gomod)
-			if err != nil {
-				return err
-			}
 
-			file, err := modfile.Parse(gomod, b, nil)
+			refs, err := float.Float(gomod, release, domain)
 			if err != nil {
 				return err
 			}
 
-			packages := make([]string, 0)
-			for _, r := range file.Require {
-				if strings.Contains(r.Mod.Path, domain) {
-					packages = append(packages, r.Mod.Path)
-				}
-			}
-
-			this, err := semver.ParseTolerant(args[1])
-			for _, p := range packages {
-				meta, err := golang.GetMetaImport(p)
-				if err != nil {
-					panic(err)
-				}
-
-				if meta.VCS != "git" {
-					panic(fmt.Errorf("unknown VCS: %s", meta.VCS))
-				}
-
-				repo, err := git.GetRepo(p, meta.RepoRoot)
-				if err != nil {
-					panic(err)
-				}
-
-				fmt.Printf("%s\n", repo.BestRefFor(this))
+			for _, r := range refs {
+				fmt.Printf("%s\n", r)
 			}
 			return nil
 		},
 	}
 
-	buoy.Flags().StringVarP(&domain, "domain", "d", "knative.dev", "domain filter")
+	floatCmd.Flags().StringVarP(&domain, "domain", "d", "knative.dev", "domain filter")
+	floatCmd.Flags().StringVarP(&release, "release", "r", "", "release should be '<major>.<minor>' (i.e.: 1.23 or v1.23) [required]")
+	_ = floatCmd.MarkFlagRequired("release")
+
+	var buoyCmd = &cobra.Command{Use: "buoy"}
+	buoyCmd.AddCommand(floatCmd)
 
-	if err := buoy.Execute(); err != nil {
+	if err := buoyCmd.Execute(); err != nil {
 		panic(err)
 	}
 }

pkg/float/float.go

@@ -0,0 +1,53 @@
+package float
+
+import (
+	"fmt"
+	"github.com/blang/semver/v4"
+	"github.com/n3wscott/buoy/pkg/git"
+	"github.com/n3wscott/buoy/pkg/golang"
+	"golang.org/x/mod/modfile"
+	"io/ioutil"
+	"strings"
+)
+
+func Float(gomod, release, domain string) ([]string, error) {
+	b, err := ioutil.ReadFile(gomod)
+	if err != nil {
+		return nil, err
+	}
+
+	file, err := modfile.Parse(gomod, b, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	packages := make([]string, 0)
+	for _, r := range file.Require {
+		// Look for requirements that have the prefix of domain.
+		if strings.HasPrefix(r.Mod.Path, domain) {
+			packages = append(packages, r.Mod.Path)
+		}
+	}
+
+	this, err := semver.ParseTolerant(release)
+
+	refs := make([]string, 0)
+	for _, p := range packages {
+		meta, err := golang.GetMetaImport(p)
+		if err != nil {
+			panic(err)
+		}
+
+		if meta.VCS != "git" {
+			return nil, fmt.Errorf("unknown VCS: %s", meta.VCS)
+		}
+
+		repo, err := git.GetRepo(p, meta.RepoRoot)
+		if err != nil {
+			return nil, err
+		}
+
+		refs = append(refs, repo.BestRefFor(this))
+	}
+	return refs, nil
+}