Allow for scheme-less strings (#3)

* allow scheme-less URIs, block out app/ package

* Update to allow scheme-less strings; move guts of cmd/runtimevar in to /app

---------

Co-authored-by: sfomuseumbot <sfomuseumbot@localhost>

app/runtimevar/flags.go

@@ -0,0 +1,15 @@
+package runtimevar
+
+import (
+	"flag"
+
+	"github.com/sfomuseum/go-flags/flagset"
+)
+
+var timeout int
+
+func DefaultFlagSet() *flag.FlagSet {
+	fs := flagset.NewFlagSet("publish")
+	fs.IntVar(&timeout, "timeout", 0, "The maximum number of second in which a variable can be resolved. If 0 no timeout is applied.")
+	return fs
+}

app/runtimevar/options.go

@@ -0,0 +1,34 @@
+package runtimevar
+
+import (
+	"context"
+	"flag"
+	"fmt"
+
+	"github.com/sfomuseum/go-flags/flagset"
+)
+
+type RunOptions struct {
+	Timeout int
+	Vars    []string
+}
+
+func OptionsFromFlagSet(ctx context.Context, fs *flag.FlagSet) (*RunOptions, error) {
+
+	flagset.Parse(fs)
+
+	err := flagset.SetFlagsFromEnvVars(fs, "RUNTIMEVAR")
+
+	if err != nil {
+		return nil, fmt.Errorf("Failed to derive flags from environment variables, %w", err)
+	}
+
+	vars := fs.Args()
+
+	opts := &RunOptions{
+		Timeout: timeout,
+		Vars:    vars,
+	}
+
+	return opts, nil
+}

app/runtimevar/runtimetvar.go

@@ -0,0 +1,51 @@
+package runtimevar
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"log/slog"
+	"time"
+
+	"github.com/sfomuseum/runtimevar"
+)
+
+func Run(ctx context.Context, logger *slog.Logger) error {
+	fs := DefaultFlagSet()
+	return RunWithFlagSet(ctx, fs, logger)
+}
+
+func RunWithFlagSet(ctx context.Context, fs *flag.FlagSet, logger *slog.Logger) error {
+
+	opts, err := OptionsFromFlagSet(ctx, fs)
+
+	if err != nil {
+		return fmt.Errorf("Failed to derive options from flagset, %w", err)
+	}
+
+	return RunWithOptions(ctx, opts, logger)
+}
+
+func RunWithOptions(ctx context.Context, opts *RunOptions, logger *slog.Logger) error {
+
+	if opts.Timeout > 0 {
+
+		c, cancel := context.WithTimeout(ctx, time.Duration(opts.Timeout)*time.Second)
+		defer cancel()
+
+		ctx = c
+	}
+
+	for _, uri := range opts.Vars {
+
+		str_var, err := runtimevar.StringVar(ctx, uri)
+
+		if err != nil {
+			return fmt.Errorf("Failed to derive variable, %w", err)
+		}
+
+		fmt.Printf(str_var)
+	}
+
+	return nil
+}

cmd/runtimevar/main.go

@@ -2,41 +2,21 @@ package main
 
 import (
 	"context"
-	"flag"
-	"fmt"
-	"log"
-	"time"
+	"log/slog"
+	"os"
 
-	"github.com/sfomuseum/runtimevar"
-	_ "gocloud.dev/runtimevar/awsparamstore"
-	_ "gocloud.dev/runtimevar/constantvar"
-	_ "gocloud.dev/runtimevar/filevar"
+	"github.com/sfomuseum/runtimevar/app/runtimevar"
 )
 
 func main() {
 
-	timeout := flag.Int("timeout", 0, "The maximum number of second in which a variable can be resolved. If 0 no timeout is applied.")
-
-	flag.Parse()
-
 	ctx := context.Background()
+	logger := slog.Default()
 
-	if *timeout > 0 {
-
-		c, cancel := context.WithTimeout(ctx, time.Duration(*timeout)*time.Second)
-		defer cancel()
-
-		ctx = c
-	}
-
-	for _, uri := range flag.Args() {
-
-		str_var, err := runtimevar.StringVar(ctx, uri)
-
-		if err != nil {
-			log.Fatal(err)
-		}
+	err := runtimevar.Run(ctx, logger)
 
-		fmt.Printf(str_var)
+	if err != nil {
+		logger.Error("Failed to run application", "error", err)
+		os.Exit(1)
 	}
 }

go.mod

@@ -4,6 +4,7 @@ go 1.18
 
 require (
 	github.com/aaronland/go-aws-auth v1.3.1
+	github.com/sfomuseum/go-flags v0.10.0
 	gocloud.dev v0.36.0
 )
 

go.sum

@@ -99,6 +99,8 @@ github.com/jmespath/go-jmespath/internal/testify v1.5.1/go.mod h1:L3OGu8Wl2/fWfC
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
+github.com/sfomuseum/go-flags v0.10.0 h1:1OC1ACxpWMsl3XQ9OeNVMQj7Zi2CzufP3Rym3mPI8HU=
+github.com/sfomuseum/go-flags v0.10.0/go.mod h1:VXOnnX1/yxQpX2yiwHaBV6aCmhtszQOL5bL1/nNo3co=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
 github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=

string.go

@@ -3,13 +3,13 @@ package runtimevar
 import (
 	"context"
 	"fmt"
-	"github.com/aaronland/go-aws-auth"	
+	"net/url"
+
+	"github.com/aaronland/go-aws-auth"
 	gc "gocloud.dev/runtimevar"
 	"gocloud.dev/runtimevar/awsparamstore"
 	_ "gocloud.dev/runtimevar/constantvar"
 	_ "gocloud.dev/runtimevar/filevar"
-	_ "log"
-	"net/url"
 )
 
 // StringVar returns the latest string value contained by 'uri', which is expected
@@ -19,7 +19,11 @@ func StringVar(ctx context.Context, uri string) (string, error) {
 	u, err := url.Parse(uri)
 
 	if err != nil {
-		return "", err
+		return "", fmt.Errorf("Failed to parse URI, %w", err)
+	}
+
+	if u.Scheme == "" {
+		return u.Path, nil
 	}
 
 	q := u.Query()
@@ -49,7 +53,7 @@ func StringVar(ctx context.Context, uri string) (string, error) {
 				return "", fmt.Errorf("Failed to create AWS session credentials, %w", err)
 			}
 
-			v, v_err = awsparamstore.OpenVariableV2(aws_auth, u.Host, gc.StringDecoder, nil)			
+			v, v_err = awsparamstore.OpenVariableV2(aws_auth, u.Host, gc.StringDecoder, nil)
 		}
 
 	default:
@@ -64,15 +68,15 @@ func StringVar(ctx context.Context, uri string) (string, error) {
 	}
 
 	if v_err != nil {
-		return "", v_err
+		return "", fmt.Errorf("Failed to open variable, %w", v_err)
 	}
 
 	defer v.Close()
 
 	snapshot, err := v.Latest(ctx)
 
 	if err != nil {
-		return "", err
+		return "", fmt.Errorf("Failed to derive latest snapshot for variable, %w", err)
 	}
 
 	return snapshot.Value.(string), nil

string_test.go

@@ -15,6 +15,8 @@ func TestConstantVar(t *testing.T) {
 
 	tests := map[string]string{
 		"constant://?val=hello+world": "hello world",
+		"/foo/bar/baz":                "/foo/bar/baz",
+		"test":                        "test",
 	}
 
 	for uri, expected := range tests {

vendor/modules.txt

@@ -185,6 +185,9 @@ github.com/googleapis/gax-go/v2/internal
 # github.com/jmespath/go-jmespath v0.4.0
 ## explicit; go 1.14
 github.com/jmespath/go-jmespath
+# github.com/sfomuseum/go-flags v0.10.0
+## explicit; go 1.16
+github.com/sfomuseum/go-flags/flagset
 # go.opencensus.io v0.24.0
 ## explicit; go 1.13
 go.opencensus.io