internal: create package yeet

2 files changed, 93 insertions, 0 deletions

diff --git a/internal/yeet/doc.go b/internal/yeet/doc.go
new file mode 100644
index 0000000..04ceec6
--- /dev/null
+++ b/internal/yeet/doc.go
@@ -0,0 +1,2 @@
+// Package yeet is a set of small helper functions useful for yeeting out scripts.
+package yeet
diff --git a/internal/yeet/yeet.go b/internal/yeet/yeet.go
new file mode 100644
index 0000000..9028aef
--- /dev/null
+++ b/internal/yeet/yeet.go
@@ -0,0 +1,91 @@
+package yeet
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"os"
+	"os/exec"
+	"strings"
+	"time"
+
+	"github.com/pkg/errors"
+)
+
+// current working directory and date:time tag of app boot (useful for tagging slugs)
+var (
+	WD      string
+	DateTag string
+)
+
+func init() {
+	lwd, err := os.Getwd()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	WD = lwd
+	DateTag = time.Now().Format("010220061504")
+}
+
+// ShouldWork explodes if the given command with the given env, working dir and context fails.
+func ShouldWork(ctx context.Context, env []string, dir string, cmdName string, args ...string) {
+	loc, err := exec.LookPath(cmdName)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	cmd := exec.CommandContext(ctx, loc, args...)
+	cmd.Dir = dir
+	cmd.Env = env
+
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+
+	log.Printf("starting process, env: %v, pwd: %s, cmd: %s, args: %v", env, dir, loc, args)
+	err = cmd.Run()
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+
+/// Output returns the output of a command or an error.
+func output(ctx context.Context, cmd string, args ...string) (string, error) {
+	c := exec.CommandContext(ctx, cmd, args...)
+	c.Env = os.Environ()
+	c.Stderr = os.Stderr
+	b, err := c.Output()
+	if err != nil {
+		return "", errors.Wrapf(err, `failed to run %v %q`, cmd, args)
+	}
+	return string(b), nil
+}
+
+// GitTag returns the curreng git tag.
+func GitTag(ctx context.Context) (string, error) {
+	s, err := output(ctx, "git", "describe", "--tags")
+	if err != nil {
+		ee, ok := errors.Cause(err).(*exec.ExitError)
+		if ok && ee.Exited() {
+			// probably no git tag
+			return "dev", nil
+		}
+		return "", err
+	}
+
+	return strings.TrimSuffix(s, "\n"), nil
+}
+
+// DockerTag tags a docker image
+func DockerTag(ctx context.Context, org, repo, image string) (string, error) {
+	tag, err := GitTag(ctx)
+	if err != nil {
+		return "", err
+	}
+
+	repoTag := fmt.Sprintf("%s/%s:%s", org, repo, tag)
+
+	ShouldWork(ctx, nil, WD, "docker", "tag", image, repoTag)
+
+	return repoTag, nil
+}