add variables support for wasip2 sdk

Signed-off-by: Rajat Jindal <[email protected]>

Author: rajatjindal

v2/examples/variables/go.mod

@@ -0,0 +1,12 @@
+module github.com/spinframework/spin-go-sdk/v2/examples/kv
+
+go 1.24.1
+
+require github.com/spinframework/spin-go-sdk/v2 v2.0.0
+
+require (
+	github.com/julienschmidt/httprouter v1.3.0 // indirect
+	go.bytecodealliance.org/cm v0.2.2 // indirect
+)
+
+replace github.com/spinframework/spin-go-sdk/v2 => ../../

v2/examples/variables/go.sum

@@ -0,0 +1,4 @@
+github.com/julienschmidt/httprouter v1.3.0 h1:U0609e9tgbseu3rBINet9P48AI/D3oJs4dN7jwJOQ1U=
+github.com/julienschmidt/httprouter v1.3.0/go.mod h1:JR6WtHb+2LUe8TCKY3cZOxFyyO8IZAc4RVcycCCAKdM=
+go.bytecodealliance.org/cm v0.2.2 h1:M9iHS6qs884mbQbIjtLX1OifgyPG9DuMs2iwz8G4WQA=
+go.bytecodealliance.org/cm v0.2.2/go.mod h1:JD5vtVNZv7sBoQQkvBvAAVKJPhR/bqBH7yYXTItMfZI=

v2/examples/variables/main.go

@@ -0,0 +1,24 @@
+package main
+
+import (
+	"fmt"
+	"net/http"
+
+	spinhttp "github.com/spinframework/spin-go-sdk/v2/http"
+	"github.com/spinframework/spin-go-sdk/v2/variables"
+)
+
+func init() {
+	spinhttp.Handle(func(w http.ResponseWriter, r *http.Request) {
+
+		// Get variable value `message` defined in spin.toml.
+		val, err := variables.Get("message")
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+		fmt.Fprintln(w, "message: ", val)
+	})
+}
+
+func main() {}

v2/examples/variables/spin.toml

@@ -0,0 +1,22 @@
+spin_manifest_version = 2
+
+[application]
+name = "variables-example"
+authors = ["Fermyon Engineering <[email protected]>"]
+description = "A simple Spin application written in (Tiny)Go."
+version = "1.0.0"
+
+[variables]
+object = { default = "teapot" }
+
+[[trigger.http]]
+route = "/..."
+component = "variables"
+
+[component.variables]
+source = "main.wasm"
+[component.variables.variables]
+message = "I'm a {{object}}"
+
+[component.hello.build]
+command = "tinygo build -target=wasip2 --wit-package $(go list -mod=readonly -m -f '{{.Dir}}' github.com/spinframework/spin-go-sdk/v2)/wit --wit-world http-trigger -gc=leaking -no-debug -o main.wasm main.go"

v2/integration_test.go

@@ -42,15 +42,15 @@ type testSpin struct {
 	cmd    *exec.Cmd
 }
 
-func startSpin(t *testing.T, dir string) *testSpin {
+func startSpin(t *testing.T, dir string, extraArgs ...string) *testSpin {
 	buildApp(t, dir)
 
 	url := getFreePort(t)
 
 	// long timeout because... ci
 	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Minute)
 
-	cmd := exec.CommandContext(ctx, spinBinary, "up", "--listen", url)
+	cmd := exec.CommandContext(ctx, spinBinary, append([]string{"up", "--listen", url}, extraArgs...)...)
 	cmd.Dir = dir
 	stderr := new(bytes.Buffer)
 	cmd.Stderr = stderr
@@ -144,6 +144,30 @@ func TestKeyValue(t *testing.T) {
 	}
 }
 
+func TestVariables(t *testing.T) {
+	spin := startSpin(t, "variables/testdata/variables")
+	defer spin.cancel()
+
+	resp := retryGet(t, spin.url)
+	spin.cancel()
+	if resp.Body == nil {
+		t.Fatal("body is nil")
+	}
+	t.Log(resp.Status)
+	b, err := io.ReadAll(resp.Body)
+	resp.Body.Close()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// assert response body
+	want := "message:  I'm a teapot\n"
+	got := string(b)
+	if want != got {
+		t.Fatalf("body is not equal: want = %q got = %q", want, got)
+	}
+}
+
 // TestBuildExamples ensures that the tinygo examples will build successfully.
 func TestBuildExamples(t *testing.T) {
 	examples, err := os.ReadDir("examples")

v2/variables/testdata/variables/go.mod

@@ -0,0 +1,12 @@
+module github.com/spinframework/spin-go-sdk/v2/examples/kv
+
+go 1.24.1
+
+require github.com/spinframework/spin-go-sdk/v2 v2.0.0
+
+require (
+	github.com/julienschmidt/httprouter v1.3.0 // indirect
+	go.bytecodealliance.org/cm v0.2.2 // indirect
+)
+
+replace github.com/spinframework/spin-go-sdk/v2 => ../../../

v2/variables/testdata/variables/go.sum

@@ -0,0 +1,4 @@
+github.com/julienschmidt/httprouter v1.3.0 h1:U0609e9tgbseu3rBINet9P48AI/D3oJs4dN7jwJOQ1U=
+github.com/julienschmidt/httprouter v1.3.0/go.mod h1:JR6WtHb+2LUe8TCKY3cZOxFyyO8IZAc4RVcycCCAKdM=
+go.bytecodealliance.org/cm v0.2.2 h1:M9iHS6qs884mbQbIjtLX1OifgyPG9DuMs2iwz8G4WQA=
+go.bytecodealliance.org/cm v0.2.2/go.mod h1:JD5vtVNZv7sBoQQkvBvAAVKJPhR/bqBH7yYXTItMfZI=

v2/variables/testdata/variables/main.go

@@ -0,0 +1,23 @@
+package main
+
+import (
+	"fmt"
+	"net/http"
+
+	spinhttp "github.com/spinframework/spin-go-sdk/v2/http"
+	"github.com/spinframework/spin-go-sdk/v2/variables"
+)
+
+func init() {
+	spinhttp.Handle(func(w http.ResponseWriter, r *http.Request) {
+		// Get variable value `message` defined in spin.toml.
+		val, err := variables.Get("message")
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+		fmt.Fprintln(w, "message: ", val)
+	})
+}
+
+func main() {}

v2/variables/testdata/variables/spin.toml

@@ -0,0 +1,22 @@
+spin_manifest_version = 2
+
+[application]
+name = "variables-example"
+authors = ["Fermyon Engineering <[email protected]>"]
+description = "A simple Spin application written in (Tiny)Go."
+version = "1.0.0"
+
+[variables]
+object = { default = "teapot" }
+
+[[trigger.http]]
+route = "/..."
+component = "variables"
+
+[component.variables]
+source = "main.wasm"
+[component.variables.variables]
+message = "I'm a {{object}}"
+
+[component.variables.build]
+command = "tinygo build -target=wasip2 --wit-package $(go list -mod=readonly -m -f '{{.Dir}}' github.com/spinframework/spin-go-sdk/v2)/wit --wit-world http-trigger -gc=leaking -no-debug -o main.wasm main.go"

v2/variables/variables.go

@@ -0,0 +1,37 @@
+package variables
+
+import (
+	"fmt"
+
+	"github.com/spinframework/spin-go-sdk/v2/internal/fermyon/spin/v2.0.0/variables"
+)
+
+// Get an application variable value for the current component.
+//
+// The name must match one defined in in the component manifest.
+func Get(key string) (string, error) {
+	result := variables.Get(key)
+	if result.IsErr() {
+		return "", errorVariantToError(*result.Err())
+	}
+
+	// stdout.GetStdout().Write(cm.ToList([]byte(fmt.Sprintf("key: %s, val is %q \n", key, *result.OK()))))
+	return *result.OK(), nil
+}
+
+func errorVariantToError(err variables.Error) error {
+	switch {
+	case err.InvalidName() != nil:
+		return fmt.Errorf(*err.InvalidName())
+	case err.Provider() != nil:
+		return fmt.Errorf(*err.Provider())
+	case err.Undefined() != nil:
+		return fmt.Errorf(*err.Undefined())
+	default:
+		if err.Other() != nil {
+			return fmt.Errorf(*err.Other())
+		}
+
+		return fmt.Errorf("no error provided by host implementation")
+	}
+}