Add Dqlite remove endpoint (KU-1719) (#57)

* Add /v2/dqlite/remove endpoint (#55)
* validate capi-auth-token on dqlite/remove (#56)

pkg/api/v2/consts.go

@@ -0,0 +1,6 @@
+package v2
+
+const (
+	// CAPIAuthTokenHeader is the header used to pass the CAPI auth token.
+	CAPIAuthTokenHeader = "capi-auth-token"
+)

pkg/api/v2/register.go

@@ -53,4 +53,27 @@ func (a *API) RegisterServer(server *http.ServeMux, middleware func(f http.Handl
 		}
 		httputil.Response(w, map[string]string{"status": "OK"})
 	}))
+
+	// POST v2/dqlite/remove
+	server.HandleFunc(fmt.Sprintf("%s/dqlite/remove", HTTPPrefix), middleware(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodPost {
+			w.WriteHeader(http.StatusMethodNotAllowed)
+			return
+		}
+
+		req := RemoveFromDqliteRequest{}
+		if err := httputil.UnmarshalJSON(r, &req); err != nil {
+			httputil.Error(w, http.StatusBadRequest, fmt.Errorf("failed to unmarshal JSON: %w", err))
+			return
+		}
+
+		token := r.Header.Get(CAPIAuthTokenHeader)
+
+		if rc, err := a.RemoveFromDqlite(r.Context(), req, token); err != nil {
+			httputil.Error(w, rc, fmt.Errorf("failed to remove from dqlite: %w", err))
+			return
+		}
+
+		httputil.Response(w, nil)
+	}))
 }

pkg/api/v2/remove.go

@@ -0,0 +1,33 @@
+package v2
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+
+	snaputil "github.com/canonical/microk8s-cluster-agent/pkg/snap/util"
+)
+
+// RemoveFromDqliteRequest represents a request to remove a node from the dqlite cluster.
+type RemoveFromDqliteRequest struct {
+	// RemoveEndpoint is the endpoint of the node to remove from the dqlite cluster.
+	RemoveEndpoint string `json:"remove_endpoint"`
+}
+
+// RemoveFromDqlite implements the "POST /v2/dqlite/remove" endpoint and removes a node from the dqlite cluster.
+func (a *API) RemoveFromDqlite(ctx context.Context, req RemoveFromDqliteRequest, token string) (int, error) {
+	isValid, err := a.Snap.IsCAPIAuthTokenValid(token)
+	if err != nil {
+		return http.StatusInternalServerError, fmt.Errorf("failed to validate CAPI auth token: %w", err)
+	}
+
+	if !isValid {
+		return http.StatusUnauthorized, fmt.Errorf("invalid CAPI auth token %q", token)
+	}
+
+	if err := snaputil.RemoveNodeFromDqlite(ctx, a.Snap, req.RemoveEndpoint); err != nil {
+		return http.StatusInternalServerError, fmt.Errorf("failed to remove node from dqlite: %w", err)
+	}
+
+	return http.StatusOK, nil
+}

pkg/api/v2/remove_test.go

@@ -0,0 +1,74 @@
+package v2_test
+
+import (
+	"context"
+	"errors"
+	"net/http"
+	"testing"
+
+	. "github.com/onsi/gomega"
+
+	v2 "github.com/canonical/microk8s-cluster-agent/pkg/api/v2"
+	"github.com/canonical/microk8s-cluster-agent/pkg/snap/mock"
+)
+
+func TestRemove(t *testing.T) {
+	t.Run("RemoveFails", func(t *testing.T) {
+		cmdErr := errors.New("failed to run command")
+		apiv2 := &v2.API{
+			Snap: &mock.Snap{
+				RunCommandErr:      cmdErr,
+				CAPIAuthTokenValid: true,
+			},
+		}
+
+		rc, err := apiv2.RemoveFromDqlite(context.Background(), v2.RemoveFromDqliteRequest{RemoveEndpoint: "1.1.1.1:1234"}, "token")
+
+		g := NewWithT(t)
+		g.Expect(err).To(MatchError(cmdErr))
+		g.Expect(rc).To(Equal(http.StatusInternalServerError))
+	})
+
+	t.Run("InvalidToken", func(t *testing.T) {
+		apiv2 := &v2.API{
+			Snap: &mock.Snap{
+				CAPIAuthTokenValid: false, // explicitly set to false
+			},
+		}
+
+		rc, err := apiv2.RemoveFromDqlite(context.Background(), v2.RemoveFromDqliteRequest{RemoveEndpoint: "1.1.1.1:1234"}, "token")
+
+		g := NewWithT(t)
+		g.Expect(err).To(HaveOccurred())
+		g.Expect(rc).To(Equal(http.StatusUnauthorized))
+	})
+
+	t.Run("TokenFileNotFound", func(t *testing.T) {
+		tokenErr := errors.New("token file not found")
+		apiv2 := &v2.API{
+			Snap: &mock.Snap{
+				CAPIAuthTokenError: tokenErr,
+			},
+		}
+
+		rc, err := apiv2.RemoveFromDqlite(context.Background(), v2.RemoveFromDqliteRequest{RemoveEndpoint: "1.1.1.1:1234"}, "token")
+
+		g := NewWithT(t)
+		g.Expect(err).To(MatchError(tokenErr))
+		g.Expect(rc).To(Equal(http.StatusInternalServerError))
+	})
+
+	t.Run("RemovesSuccessfully", func(t *testing.T) {
+		apiv2 := &v2.API{
+			Snap: &mock.Snap{
+				CAPIAuthTokenValid: true,
+			},
+		}
+
+		rc, err := apiv2.RemoveFromDqlite(context.Background(), v2.RemoveFromDqliteRequest{RemoveEndpoint: "1.1.1.1:1234"}, "token")
+
+		g := NewWithT(t)
+		g.Expect(err).ToNot(HaveOccurred())
+		g.Expect(rc).To(Equal(http.StatusOK))
+	})
+}

pkg/snap/interface.go

@@ -7,6 +7,18 @@ import (
 
 // Snap is how the cluster agent interacts with the snap.
 type Snap interface {
+	// GetSnapPath returns the path to a file or directory in the snap directory.
+	GetSnapPath(parts ...string) string
+	// GetSnapDataPath returns the path to a file or directory in the snap's data directory.
+	GetSnapDataPath(parts ...string) string
+	// GetSnapCommonPath returns the path to a file or directory in the snap's common directory.
+	GetSnapCommonPath(parts ...string) string
+	// GetCAPIPath returns the path to a file or directory in the CAPI directory.
+	GetCAPIPath(parts ...string) string
+
+	// RunCommand runs a shell command.
+	RunCommand(ctx context.Context, commands ...string) error
+
 	// GetGroupName is the group microk8s is using.
 	// The group name is "microk8s" for classic snaps and "snap_microk8s" for strict snaps.
 	GetGroupName() string
@@ -88,6 +100,9 @@ type Snap interface {
 	// GetKnownToken returns the token for a known user from the known_users.csv file.
 	GetKnownToken(username string) (string, error)
 
+	// IsCAPIAuthTokenValid returns true if token is a valid CAPI auth token.
+	IsCAPIAuthTokenValid(token string) (bool, error)
+
 	// SignCertificate signs the certificate signing request, and returns the certificate in PEM format.
 	SignCertificate(ctx context.Context, csrPEM []byte) ([]byte, error)
 

pkg/snap/mock/mock.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"io"
+	"path/filepath"
 	"strings"
 
 	"github.com/canonical/microk8s-cluster-agent/pkg/snap"
@@ -23,8 +24,21 @@ type JoinClusterCall struct {
 	Worker bool
 }
 
+// RunCommandCall contains the arguments passed to a specific call of the RunCommand method.
+type RunCommandCall struct {
+	Commands []string
+}
+
 // Snap is a generic mock for the snap.Snap interface.
 type Snap struct {
+	SnapDir       string
+	SnapDataDir   string
+	SnapCommonDir string
+	CAPIDir       string
+
+	RunCommandCalledWith []RunCommandCall
+	RunCommandErr        error
+
 	GroupName string
 
 	EnableAddonCalledWith    []string
@@ -72,6 +86,9 @@ type Snap struct {
 	KubeletTokens     map[string]string // map hostname to token
 	KnownTokens       map[string]string // map username to token
 
+	CAPIAuthTokenValid bool
+	CAPIAuthTokenError error
+
 	SignCertificateCalledWith []string // string(csrPEM)
 	SignedCertificate         string
 
@@ -86,6 +103,32 @@ type Snap struct {
 	JoinClusterCalledWith []JoinClusterCall
 }
 
+// GetSnapPath is a mock implementation for the snap.Snap interface.
+func (s *Snap) GetSnapPath(parts ...string) string {
+	return filepath.Join(append([]string{s.SnapDir}, parts...)...)
+}
+
+// GetSnapDataPath is a mock implementation for the snap.Snap interface.
+func (s *Snap) GetSnapDataPath(parts ...string) string {
+	return filepath.Join(append([]string{s.SnapDataDir}, parts...)...)
+}
+
+// GetSnapCommonPath is a mock implementation for the snap.Snap interface.
+func (s *Snap) GetSnapCommonPath(parts ...string) string {
+	return filepath.Join(append([]string{s.SnapCommonDir}, parts...)...)
+}
+
+// GetCAPIPath is a mock implementation for the snap.Snap interface.
+func (s *Snap) GetCAPIPath(parts ...string) string {
+	return filepath.Join(append([]string{s.CAPIDir}, parts...)...)
+}
+
+// RunCommand is a mock implementation for the snap.Snap interface.
+func (s *Snap) RunCommand(_ context.Context, commands ...string) error {
+	s.RunCommandCalledWith = append(s.RunCommandCalledWith, RunCommandCall{Commands: commands})
+	return s.RunCommandErr
+}
+
 // GetGroupName is a mock implementation for the snap.Snap interface.
 func (s *Snap) GetGroupName() string {
 	return s.GroupName
@@ -284,6 +327,11 @@ func (s *Snap) GetKnownToken(username string) (string, error) {
 	return "", fmt.Errorf("no known token for user %s", username)
 }
 
+// IsCAPIAuthTokenValid is a mock implementation for the snap.Snap interface.
+func (s *Snap) IsCAPIAuthTokenValid(token string) (bool, error) {
+	return s.CAPIAuthTokenValid, s.CAPIAuthTokenError
+}
+
 // RunUpgrade is a mock implementation for the snap.Snap interface.
 func (s *Snap) RunUpgrade(ctx context.Context, upgrade string, phase string) error {
 	s.RunUpgradeCalledWith = append(s.RunUpgradeCalledWith, fmt.Sprintf("%s %s", upgrade, phase))

pkg/snap/options.go

@@ -22,3 +22,10 @@ func WithCommandRunner(f func(context.Context, ...string) error) func(s *snap) {
 		s.runCommand = f
 	}
 }
+
+// WithCAPIPath configures the path to the CAPI directory.
+func WithCAPIPath(path string) func(s *snap) {
+	return func(s *snap) {
+		s.capiPath = path
+	}
+}