Add --no-cache flag

Author: Lantero

README.md

@@ -241,6 +241,7 @@ This function is implemented in the /build endpoint, and supports both POST and
 POST
 
 The POST method expects the build request in the request's body as a JSON object.
+The optional "nocache" field can be set to true to force a rebuild bypassing the cache.
 
 Example
 
@@ -269,13 +270,29 @@ Example
 	  }
 	}
 
+Force a rebuild bypassing the cache:
+
+	curl -X POST http://localhost:8000/build -d \
+	'{
+	  "k6":"v1.4.0",
+	  "dependencies":[
+	    {
+		"name":"k6/x/kubernetes",
+		"constraints":">v0.8.0"
+	    }
+	  ],
+	  "platform":"linux/amd64",
+	  "nocache":true
+	}' | jq .
+
 GET
 
 The GET method expects the build requests in the query parameters:
 - platform: platform to build the binary for (e.g. linux/arm64). This is required
 - k6: the k6 version constrains (e.g. k6=v1.2.0)
 - dep: a dependency in the form name:version (e.g. dep=k6/x/faker:v0.4.0).
   Multple dependencies can be defined in a request.
+- nocache: set to "true" to force a rebuild bypassing the cache (e.g. nocache=true)
 
 Example
 
@@ -294,6 +311,10 @@ Example
 	  }
 	}
 
+Force a rebuild bypassing the cache:
+
+	curl -X GET "http://localhost:8000/build?platform=linux/amd64&k6=v1.4.0&dep=k6/x/kubernetes:>v0.8.0&nocache=true" | jq .
+
 Caching
 
 The GET method can be used to allow caching the build results. This method returns the ETag header with the

cmd/server/server.go

@@ -44,6 +44,7 @@ This function is implemented in the /build endpoint, and supports both POST and
 POST
 
 The POST method expects the build request in the request's body as a JSON object.
+The optional "nocache" field can be set to true to force a rebuild bypassing the cache.
 
 Example
 
@@ -72,13 +73,29 @@ Example
 	  }
 	}
 
+Force a rebuild bypassing the cache:
+
+	curl -X POST http://localhost:8000/build -d \
+	'{
+	  "k6":"v1.4.0",
+	  "dependencies":[
+	    {
+		"name":"k6/x/kubernetes",
+		"constraints":">v0.8.0"
+	    }
+	  ],
+	  "platform":"linux/amd64",
+	  "nocache":true
+	}' | jq .
+
 GET
 
 The GET method expects the build requests in the query parameters:
 - platform: platform to build the binary for (e.g. linux/arm64). This is required
 - k6: the k6 version constrains (e.g. k6=v1.2.0)
 - dep: a dependency in the form name:version (e.g. dep=k6/x/faker:v0.4.0).
   Multple dependencies can be defined in a request.
+- nocache: set to "true" to force a rebuild bypassing the cache (e.g. nocache=true)
 
 Example
 
@@ -97,6 +114,10 @@ Example
 	  }
 	}
 
+Force a rebuild bypassing the cache:
+
+	curl -X GET "http://localhost:8000/build?platform=linux/amd64&k6=v1.4.0&dep=k6/x/kubernetes:>v0.8.0&nocache=true" | jq .
+
 Caching
 
 The GET method can be used to allow caching the build results. This method returns the ETag header with the

pkg/api/api.go

@@ -28,6 +28,7 @@ type BuildRequest struct {
 	K6Constrains string               `json:"k6,omitempty"`
 	Dependencies []k6build.Dependency `json:"dependencies,omitempty"`
 	Platform     string               `json:"platform,omitempty"`
+	NoCache      bool                 `json:"nocache,omitempty"`
 }
 
 // BuildResponse defines the response for a BuildRequest

pkg/api/context.go

@@ -0,0 +1,20 @@
+package api
+
+import "context"
+
+type contextKey int
+
+const (
+	noCacheKey contextKey = iota
+)
+
+// WithNoCache returns a context with the nocache flag set
+func WithNoCache(ctx context.Context, noCache bool) context.Context {
+	return context.WithValue(ctx, noCacheKey, noCache)
+}
+
+// NoCache returns the nocache flag from the context
+func NoCache(ctx context.Context) bool {
+	v, _ := ctx.Value(noCacheKey).(bool)
+	return v
+}

pkg/api/context_test.go

@@ -0,0 +1,52 @@
+package api
+
+import (
+	"context"
+	"testing"
+)
+
+func TestNoCache(t *testing.T) {
+	t.Parallel()
+
+	testCases := []struct {
+		title    string
+		setVal   *bool // nil means don't set
+		expected bool
+	}{
+		{
+			title:    "not set returns false",
+			setVal:   nil,
+			expected: false,
+		},
+		{
+			title:    "set to true returns true",
+			setVal:   boolPtr(true),
+			expected: true,
+		},
+		{
+			title:    "set to false returns false",
+			setVal:   boolPtr(false),
+			expected: false,
+		},
+	}
+
+	for _, tc := range testCases {
+		tc := tc
+		t.Run(tc.title, func(t *testing.T) {
+			t.Parallel()
+
+			ctx := context.Background()
+			if tc.setVal != nil {
+				ctx = WithNoCache(ctx, *tc.setVal)
+			}
+			got := NoCache(ctx)
+			if got != tc.expected {
+				t.Fatalf("expected %v, got %v", tc.expected, got)
+			}
+		})
+	}
+}
+
+func boolPtr(b bool) *bool {
+	return &b
+}

pkg/builder/builder.go

@@ -16,6 +16,7 @@ import (
 	"time"
 
 	"github.com/grafana/k6build"
+	"github.com/grafana/k6build/pkg/api"
 	"github.com/grafana/k6build/pkg/catalog"
 	"github.com/grafana/k6build/pkg/lock"
 	"github.com/grafana/k6build/pkg/store"
@@ -171,23 +172,27 @@ func (b *Builder) Build( //nolint:funlen
 	// Try to get the object, if not found, try to acquire a build lock.
 	// If the build lock is not acquired, assume some other builder is building the binary.
 	// Sleep and retry.
+	// If nocache is set, skip the cache lookup and go straight to building.
+	noCache := api.NoCache(ctx)
 	var artifactObject store.Object
 	for {
-		artifactObject, err = b.store.Get(ctx, id)
-		if err == nil {
-			b.metrics.storeHitsCounter.Inc()
-
-			return k6build.Artifact{
-				ID:           id,
-				Checksum:     artifactObject.Checksum,
-				URL:          artifactObject.URL,
-				Dependencies: resolvedVersions(resolved),
-				Platform:     platform,
-			}, nil
-		}
-
-		if !errors.Is(err, store.ErrObjectNotFound) {
-			return k6build.Artifact{}, k6build.NewWrappedError(k6build.ErrAccessingArtifact, err)
+		if !noCache {
+			artifactObject, err = b.store.Get(ctx, id)
+			if err == nil {
+				b.metrics.storeHitsCounter.Inc()
+
+				return k6build.Artifact{
+					ID:           id,
+					Checksum:     artifactObject.Checksum,
+					URL:          artifactObject.URL,
+					Dependencies: resolvedVersions(resolved),
+					Platform:     platform,
+				}, nil
+			}
+
+			if !errors.Is(err, store.ErrObjectNotFound) {
+				return k6build.Artifact{}, k6build.NewWrappedError(k6build.ErrAccessingArtifact, err)
+			}
 		}
 
 		acquired, unlock, err := b.lock.Try(ctx, id)

pkg/server/server.go

@@ -80,7 +80,7 @@ func (a *APIServer) BuildPost(w http.ResponseWriter, r *http.Request) {
 
 // BuildGet implements the request handler for the build request using get
 // the build arguments
-// /build?k6=version&platform=version&dep=name:constrains&dep=name:constrains
+// /build?k6=version&platform=version&dep=name:constrains&dep=name:constrains&nocache=true
 func (a *APIServer) BuildGet(w http.ResponseWriter, r *http.Request) {
 	w.Header().Add("Content-Type", "application/json")
 
@@ -91,6 +91,7 @@ func (a *APIServer) BuildGet(w http.ResponseWriter, r *http.Request) {
 		name, constraints, _ := strings.Cut(dep, ":")
 		req.Dependencies = append(req.Dependencies, k6build.Dependency{Name: name, Constraints: constraints})
 	}
+	req.NoCache = r.URL.Query().Get("nocache") == "true"
 
 	a.processBuildRequest(w, r, req)
 }
@@ -100,8 +101,13 @@ func (a *APIServer) processBuildRequest(w http.ResponseWriter, r *http.Request,
 
 	resp := api.BuildResponse{}
 
+	ctx := r.Context()
+	if req.NoCache {
+		ctx = api.WithNoCache(ctx, true)
+	}
+
 	artifact, err := a.srv.Build(
-		r.Context(),
+		ctx,
 		req.Platform,
 		req.K6Constrains,
 		req.Dependencies,