change the implementation of ErrNotFound and AlreadyExists to a struct type (#665)

with an exposed interface.

Not checking for a specific sentinel error reduces coupling between packages
and allows adding context like the resource ID and resource type.

server/datastore/inmem/app.go

@@ -1,9 +1,6 @@
 package inmem
 
-import (
-	"github.com/kolide/kolide-ose/server/errors"
-	"github.com/kolide/kolide-ose/server/kolide"
-)
+import "github.com/kolide/kolide-ose/server/kolide"
 
 func (d *Datastore) NewAppConfig(info *kolide.AppConfig) (*kolide.AppConfig, error) {
 	d.mtx.Lock()
@@ -22,7 +19,7 @@ func (d *Datastore) AppConfig() (*kolide.AppConfig, error) {
 		return d.orginfo, nil
 	}
 
-	return nil, errors.ErrNotFound
+	return nil, notFound("AppConfig")
 }
 
 func (d *Datastore) SaveAppConfig(info *kolide.AppConfig) error {

server/datastore/inmem/campaigns.go

@@ -4,7 +4,6 @@ import (
 	"fmt"
 	"time"
 
-	"github.com/kolide/kolide-ose/server/errors"
 	"github.com/kolide/kolide-ose/server/kolide"
 )
 
@@ -24,7 +23,7 @@ func (d *Datastore) DistributedQueryCampaign(id uint) (*kolide.DistributedQueryC
 
 	campaign, ok := d.distributedQueryCampaigns[id]
 	if !ok {
-		return nil, errors.ErrNotFound
+		return nil, notFound("DistributedQueryCampaign").WithID(id)
 	}
 
 	return &campaign, nil
@@ -35,7 +34,7 @@ func (d *Datastore) SaveDistributedQueryCampaign(camp *kolide.DistributedQueryCa
 	defer d.mtx.Unlock()
 
 	if _, ok := d.distributedQueryCampaigns[camp.ID]; !ok {
-		return errors.ErrNotFound
+		return notFound("DistributedQueryCampaign").WithID(camp.ID)
 	}
 
 	d.distributedQueryCampaigns[camp.ID] = *camp
@@ -80,7 +79,7 @@ func (d *Datastore) NewDistributedQueryExecution(exec *kolide.DistributedQueryEx
 	for _, e := range d.distributedQueryExecutions {
 		if exec.HostID == e.HostID && exec.DistributedQueryCampaignID == e.DistributedQueryCampaignID {
 			fmt.Printf("%+v -- %+v\n", exec, d.distributedQueryExecutions)
-			return exec, errors.ErrExists
+			return exec, alreadyExists("DistributedQueryExecution", exec.HostID)
 		}
 	}
 

server/datastore/inmem/errors.go

@@ -0,0 +1,59 @@
+package inmem
+
+import "fmt"
+
+type notFoundError struct {
+	ID           uint
+	Message      string
+	ResourceType string
+}
+
+func notFound(kind string) *notFoundError {
+	return &notFoundError{
+		ResourceType: kind,
+	}
+}
+
+func (e *notFoundError) Error() string {
+	if e.ID == 0 {
+		return fmt.Sprintf("%s was not found in the datastore", e.ResourceType)
+	}
+	if e.Message != "" {
+		return fmt.Sprintf("%s, %s was not found in the datastore", e.ResourceType, e.Message)
+	}
+	return fmt.Sprintf("%s %d was not found in the datastore", e.ResourceType, e.ID)
+}
+
+func (e *notFoundError) WithID(id uint) error {
+	e.ID = id
+	return e
+}
+
+func (e *notFoundError) WithMessage(msg string) error {
+	e.Message = msg
+	return e
+}
+
+func (e *notFoundError) IsNotFound() bool {
+	return true
+}
+
+type existsError struct {
+	ID           uint
+	ResourceType string
+}
+
+func alreadyExists(kind string, id uint) error {
+	return &existsError{
+		ID:           id,
+		ResourceType: kind,
+	}
+}
+
+func (e *existsError) Error() string {
+	return fmt.Sprintf("%s %d already exists in the datastore", e.ResourceType, e.ID)
+}
+
+func (e *existsError) IsExists() bool {
+	return true
+}

server/datastore/inmem/hosts.go

@@ -6,7 +6,6 @@ import (
 	"strings"
 	"time"
 
-	kolide_errors "github.com/kolide/kolide-ose/server/errors"
 	"github.com/kolide/kolide-ose/server/kolide"
 )
 
@@ -16,7 +15,7 @@ func (d *Datastore) NewHost(host *kolide.Host) (*kolide.Host, error) {
 
 	for _, h := range d.hosts {
 		if host.NodeKey == h.NodeKey || host.UUID == h.UUID {
-			return nil, kolide_errors.ErrExists
+			return nil, alreadyExists("Host", host.ID)
 		}
 	}
 
@@ -31,7 +30,7 @@ func (d *Datastore) SaveHost(host *kolide.Host) error {
 	defer d.mtx.Unlock()
 
 	if _, ok := d.hosts[host.ID]; !ok {
-		return kolide_errors.ErrNotFound
+		return notFound("Host").WithID(host.ID)
 	}
 
 	for _, nic := range host.NetworkInterfaces {
@@ -50,7 +49,7 @@ func (d *Datastore) DeleteHost(host *kolide.Host) error {
 	defer d.mtx.Unlock()
 
 	if _, ok := d.hosts[host.ID]; !ok {
-		return kolide_errors.ErrNotFound
+		return notFound("Host").WithID(host.ID)
 	}
 
 	delete(d.hosts, host.ID)
@@ -63,7 +62,7 @@ func (d *Datastore) Host(id uint) (*kolide.Host, error) {
 
 	host, ok := d.hosts[id]
 	if !ok {
-		return nil, kolide_errors.ErrNotFound
+		return nil, notFound("Host").WithID(id)
 	}
 
 	return host, nil
@@ -161,7 +160,7 @@ func (d *Datastore) AuthenticateHost(nodeKey string) (*kolide.Host, error) {
 		}
 	}
 
-	return nil, kolide_errors.ErrNotFound
+	return nil, notFound("AuthenticateHost")
 }
 
 func (d *Datastore) MarkHostSeen(host *kolide.Host, t time.Time) error {

server/datastore/inmem/invites.go

@@ -1,10 +1,10 @@
 package inmem
 
 import (
+	"fmt"
 	"sort"
 	"time"
 
-	"github.com/kolide/kolide-ose/server/errors"
 	"github.com/kolide/kolide-ose/server/kolide"
 )
 
@@ -15,7 +15,7 @@ func (d *Datastore) NewInvite(invite *kolide.Invite) (*kolide.Invite, error) {
 
 	for _, in := range d.invites {
 		if in.Email == invite.Email {
-			return nil, errors.ErrExists
+			return nil, alreadyExists("Invite", invite.ID)
 		}
 	}
 
@@ -76,7 +76,7 @@ func (d *Datastore) Invite(id uint) (*kolide.Invite, error) {
 	if invite, ok := d.invites[id]; ok {
 		return invite, nil
 	}
-	return nil, errors.ErrNotFound
+	return nil, alreadyExists("Invite", id)
 }
 
 // InviteByEmail retrieves an invite for a specific email address.
@@ -89,7 +89,8 @@ func (d *Datastore) InviteByEmail(email string) (*kolide.Invite, error) {
 			return invite, nil
 		}
 	}
-	return nil, errors.ErrNotFound
+	return nil, notFound("Invite").
+		WithMessage(fmt.Sprintf("with email address: %s", email))
 }
 
 // SaveInvite saves an invitation in the datastore.
@@ -98,7 +99,7 @@ func (d *Datastore) SaveInvite(invite *kolide.Invite) error {
 	defer d.mtx.Unlock()
 
 	if _, ok := d.invites[invite.ID]; !ok {
-		return errors.ErrNotFound
+		return notFound("Invite").WithID(invite.ID)
 	}
 
 	d.invites[invite.ID] = invite
@@ -111,7 +112,7 @@ func (d *Datastore) DeleteInvite(invite *kolide.Invite) error {
 	defer d.mtx.Unlock()
 
 	if _, ok := d.invites[invite.ID]; !ok {
-		return errors.ErrNotFound
+		return notFound("Invite").WithID(invite.ID)
 	}
 	delete(d.invites, invite.ID)
 	return nil

server/datastore/inmem/labels.go

@@ -7,7 +7,6 @@ import (
 	"strings"
 	"time"
 
-	kolide_errors "github.com/kolide/kolide-ose/server/errors"
 	"github.com/kolide/kolide-ose/server/kolide"
 	"github.com/patrickmn/sortutil"
 )
@@ -18,7 +17,7 @@ func (d *Datastore) NewLabel(label *kolide.Label) (*kolide.Label, error) {
 	d.mtx.Lock()
 	for _, l := range d.labels {
 		if l.Name == label.Name {
-			return nil, kolide_errors.ErrExists
+			return nil, alreadyExists("Label", l.ID)
 		}
 	}
 

server/datastore/inmem/packs.go

@@ -3,7 +3,6 @@ package inmem
 import (
 	"sort"
 
-	"github.com/kolide/kolide-ose/server/errors"
 	"github.com/kolide/kolide-ose/server/kolide"
 )
 
@@ -12,7 +11,7 @@ func (d *Datastore) NewPack(pack *kolide.Pack) (*kolide.Pack, error) {
 
 	for _, q := range d.packs {
 		if pack.Name == q.Name {
-			return nil, errors.ErrExists
+			return nil, alreadyExists("Pack", q.ID)
 		}
 	}
 
@@ -28,7 +27,7 @@ func (d *Datastore) NewPack(pack *kolide.Pack) (*kolide.Pack, error) {
 
 func (d *Datastore) SavePack(pack *kolide.Pack) error {
 	if _, ok := d.packs[pack.ID]; !ok {
-		return errors.ErrNotFound
+		return notFound("Pack").WithID(pack.ID)
 	}
 
 	d.mtx.Lock()
@@ -40,7 +39,7 @@ func (d *Datastore) SavePack(pack *kolide.Pack) error {
 
 func (d *Datastore) DeletePack(pid uint) error {
 	if _, ok := d.packs[pid]; !ok {
-		return errors.ErrNotFound
+		return notFound("Pack").WithID(pid)
 	}
 
 	d.mtx.Lock()
@@ -55,7 +54,7 @@ func (d *Datastore) Pack(id uint) (*kolide.Pack, error) {
 	pack, ok := d.packs[id]
 	d.mtx.Unlock()
 	if !ok {
-		return nil, errors.ErrNotFound
+		return nil, notFound("Pack").WithID(id)
 	}
 
 	return pack, nil

server/datastore/inmem/password_reset.go

@@ -1,7 +1,8 @@
 package inmem
 
 import (
-	"github.com/kolide/kolide-ose/server/errors"
+	"fmt"
+
 	"github.com/kolide/kolide-ose/server/kolide"
 )
 
@@ -19,7 +20,7 @@ func (d *Datastore) SavePasswordResetRequest(req *kolide.PasswordResetRequest) e
 	defer d.mtx.Unlock()
 
 	if _, ok := d.passwordResets[req.ID]; !ok {
-		return errors.ErrNotFound
+		return notFound("PasswordResetRequest").WithID(req.ID)
 	}
 
 	d.passwordResets[req.ID] = req
@@ -31,7 +32,7 @@ func (d *Datastore) DeletePasswordResetRequest(req *kolide.PasswordResetRequest)
 	defer d.mtx.Unlock()
 
 	if _, ok := d.passwordResets[req.ID]; !ok {
-		return errors.ErrNotFound
+		return notFound("PasswordResetRequest").WithID(req.ID)
 	}
 
 	delete(d.passwordResets, req.ID)
@@ -58,7 +59,7 @@ func (d *Datastore) FindPassswordResetByID(id uint) (*kolide.PasswordResetReques
 		return req, nil
 	}
 
-	return nil, errors.ErrNotFound
+	return nil, notFound("PasswordResetRequest").WithID(id)
 }
 
 func (d *Datastore) FindPassswordResetsByUserID(userID uint) ([]*kolide.PasswordResetRequest, error) {
@@ -73,7 +74,8 @@ func (d *Datastore) FindPassswordResetsByUserID(userID uint) ([]*kolide.Password
 	}
 
 	if len(resets) == 0 {
-		return nil, errors.ErrNotFound
+		return nil, notFound("PasswordResetRequest").
+			WithMessage(fmt.Sprintf("for user id %d", userID))
 	}
 
 	return resets, nil
@@ -89,7 +91,7 @@ func (d *Datastore) FindPassswordResetByToken(token string) (*kolide.PasswordRes
 		}
 	}
 
-	return nil, errors.ErrNotFound
+	return nil, notFound("PasswordResetRequest")
 }
 
 func (d *Datastore) FindPassswordResetByTokenAndUserID(token string, userID uint) (*kolide.PasswordResetRequest, error) {
@@ -102,5 +104,5 @@ func (d *Datastore) FindPassswordResetByTokenAndUserID(token string, userID uint
 		}
 	}
 
-	return nil, errors.ErrNotFound
+	return nil, notFound("PasswordResetRequest")
 }

server/datastore/inmem/queries.go

@@ -15,7 +15,7 @@ func (d *Datastore) NewQuery(query *kolide.Query) (*kolide.Query, error) {
 
 	for _, q := range d.queries {
 		if query.Name == q.Name {
-			return nil, errors.ErrExists
+			return nil, alreadyExists("Query", q.ID)
 		}
 	}
 
@@ -30,7 +30,7 @@ func (d *Datastore) SaveQuery(query *kolide.Query) error {
 	defer d.mtx.Unlock()
 
 	if _, ok := d.queries[query.ID]; !ok {
-		return errors.ErrNotFound
+		return notFound("Query").WithID(query.ID)
 	}
 
 	d.queries[query.ID] = query
@@ -42,7 +42,7 @@ func (d *Datastore) DeleteQuery(query *kolide.Query) error {
 	defer d.mtx.Unlock()
 
 	if _, ok := d.queries[query.ID]; !ok {
-		return errors.ErrNotFound
+		return notFound("Query").WithID(query.ID)
 	}
 
 	delete(d.queries, query.ID)
@@ -79,7 +79,7 @@ func (d *Datastore) Query(id uint) (*kolide.Query, error) {
 
 	query, ok := d.queries[id]
 	if !ok {
-		return nil, errors.ErrNotFound
+		return nil, notFound("Query").WithID(id)
 	}
 
 	query.AuthorName = d.getUserNameByID(query.AuthorID)

server/datastore/inmem/scheduled_queries.go

@@ -3,7 +3,6 @@ package inmem
 import (
 	"sort"
 
-	"github.com/kolide/kolide-ose/server/errors"
 	"github.com/kolide/kolide-ose/server/kolide"
 )
 
@@ -24,7 +23,7 @@ func (d *Datastore) SaveScheduledQuery(sq *kolide.ScheduledQuery) (*kolide.Sched
 	defer d.mtx.Unlock()
 
 	if _, ok := d.scheduledQueries[sq.ID]; !ok {
-		return nil, errors.ErrNotFound
+		return nil, notFound("ScheduledQuery").WithID(sq.ID)
 	}
 
 	d.scheduledQueries[sq.ID] = sq
@@ -36,7 +35,7 @@ func (d *Datastore) DeleteScheduledQuery(id uint) error {
 	defer d.mtx.Unlock()
 
 	if _, ok := d.scheduledQueries[id]; !ok {
-		return errors.ErrNotFound
+		return notFound("ScheduledQuery").WithID(id)
 	}
 
 	delete(d.scheduledQueries, id)
@@ -49,7 +48,7 @@ func (d *Datastore) ScheduledQuery(id uint) (*kolide.ScheduledQuery, error) {
 
 	sq, ok := d.scheduledQueries[id]
 	if !ok {
-		return nil, errors.ErrNotFound
+		return nil, notFound("ScheduledQuery").WithID(id)
 	}
 
 	sq.Name = d.queries[sq.QueryID].Name

server/datastore/inmem/sessions.go

@@ -1,9 +1,9 @@
 package inmem
 
 import (
+	"fmt"
 	"time"
 
-	"github.com/kolide/kolide-ose/server/errors"
 	"github.com/kolide/kolide-ose/server/kolide"
 )
 
@@ -16,7 +16,7 @@ func (d *Datastore) SessionByKey(key string) (*kolide.Session, error) {
 			return session, nil
 		}
 	}
-	return nil, errors.ErrNotFound
+	return nil, notFound("Session")
 }
 
 func (d *Datastore) SessionByID(id uint) (*kolide.Session, error) {
@@ -26,7 +26,7 @@ func (d *Datastore) SessionByID(id uint) (*kolide.Session, error) {
 	if session, ok := d.sessions[id]; ok {
 		return session, nil
 	}
-	return nil, errors.ErrNotFound
+	return nil, notFound("Session").WithID(id)
 }
 
 func (d *Datastore) ListSessionsForUser(id uint) ([]*kolide.Session, error) {
@@ -40,7 +40,8 @@ func (d *Datastore) ListSessionsForUser(id uint) ([]*kolide.Session, error) {
 		}
 	}
 	if len(sessions) == 0 {
-		return nil, errors.ErrNotFound
+		return nil, notFound("Session").
+			WithMessage(fmt.Sprintf("for user id %d", id))
 	}
 	return sessions, nil
 }
@@ -61,7 +62,7 @@ func (d *Datastore) NewSession(session *kolide.Session) (*kolide.Session, error)
 
 func (d *Datastore) DestroySession(session *kolide.Session) error {
 	if _, ok := d.sessions[session.ID]; !ok {
-		return errors.ErrNotFound
+		return notFound("Session").WithID(session.ID)
 	}
 	delete(d.sessions, session.ID)
 	return nil
@@ -79,7 +80,7 @@ func (d *Datastore) DestroyAllSessionsForUser(id uint) error {
 func (d *Datastore) MarkSessionAccessed(session *kolide.Session) error {
 	session.AccessedAt = time.Now().UTC()
 	if _, ok := d.sessions[session.ID]; !ok {
-		return errors.ErrNotFound
+		return notFound("Session").WithID(session.ID)
 	}
 	d.sessions[session.ID] = session
 	return nil

server/datastore/inmem/users.go

@@ -1,9 +1,9 @@
 package inmem
 
 import (
+	"fmt"
 	"sort"
 
-	"github.com/kolide/kolide-ose/server/errors"
 	"github.com/kolide/kolide-ose/server/kolide"
 )
 
@@ -13,7 +13,7 @@ func (d *Datastore) NewUser(user *kolide.User) (*kolide.User, error) {
 
 	for _, in := range d.users {
 		if in.Username == user.Username {
-			return nil, errors.ErrExists
+			return nil, alreadyExists("User", in.ID)
 		}
 	}
 
@@ -33,7 +33,8 @@ func (d *Datastore) User(username string) (*kolide.User, error) {
 		}
 	}
 
-	return nil, errors.ErrNotFound
+	return nil, notFound("User").
+		WithMessage(fmt.Sprintf("with username %s", username))
 }
 
 func (d *Datastore) ListUsers(opt kolide.ListOptions) ([]*kolide.User, error) {
@@ -87,7 +88,8 @@ func (d *Datastore) UserByEmail(email string) (*kolide.User, error) {
 		}
 	}
 
-	return nil, errors.ErrNotFound
+	return nil, notFound("User").
+		WithMessage(fmt.Sprintf("with email address %s", email))
 }
 
 func (d *Datastore) UserByID(id uint) (*kolide.User, error) {
@@ -98,7 +100,7 @@ func (d *Datastore) UserByID(id uint) (*kolide.User, error) {
 		return user, nil
 	}
 
-	return nil, errors.ErrNotFound
+	return nil, notFound("User").WithID(id)
 }
 
 func (d *Datastore) SaveUser(user *kolide.User) error {
@@ -106,7 +108,7 @@ func (d *Datastore) SaveUser(user *kolide.User) error {
 	defer d.mtx.Unlock()
 
 	if _, ok := d.users[user.ID]; !ok {
-		return errors.ErrNotFound
+		return notFound("User").WithID(user.ID)
 	}
 
 	d.users[user.ID] = user

server/datastore/mysql/errors.go

@@ -0,0 +1,59 @@
+package mysql
+
+import "fmt"
+
+type notFoundError struct {
+	ID           uint
+	Message      string
+	ResourceType string
+}
+
+func notFound(kind string) *notFoundError {
+	return &notFoundError{
+		ResourceType: kind,
+	}
+}
+
+func (e *notFoundError) Error() string {
+	if e.ID == 0 {
+		return fmt.Sprintf("%s was not found in the datastore", e.ResourceType)
+	}
+	if e.Message != "" {
+		return fmt.Sprintf("%s, %s was not found in the datastore", e.ResourceType, e.Message)
+	}
+	return fmt.Sprintf("%s %d was not found in the datastore", e.ResourceType, e.ID)
+}
+
+func (e *notFoundError) WithID(id uint) error {
+	e.ID = id
+	return e
+}
+
+func (e *notFoundError) WithMessage(msg string) error {
+	e.Message = msg
+	return e
+}
+
+func (e *notFoundError) IsNotFound() bool {
+	return true
+}
+
+type existsError struct {
+	ID           uint
+	ResourceType string
+}
+
+func alreadyExists(kind string, id uint) error {
+	return &existsError{
+		ID:           id,
+		ResourceType: kind,
+	}
+}
+
+func (e *existsError) Error() string {
+	return fmt.Sprintf("%s %d already exists in the datastore", e.ResourceType, e.ID)
+}
+
+func (e *existsError) IsExists() bool {
+	return true
+}

server/errors/errors.go

@@ -1,17 +1,6 @@
 package errors
 
-import (
-	goerrs "errors"
-	"net/http"
-)
-
-var (
-	// ErrNotFound is returned when the datastore resource cannot be found
-	ErrNotFound = goerrs.New("resource not found")
-
-	// ErrExists is returned when creating a datastore resource that already exists
-	ErrExists = goerrs.New("resource already created")
-)
+import "net/http"
 
 // Kolide's internal representation for errors. It can be used to wrap another
 // error (stored in Err), and additionally contains fields for public

server/kolide/datastore.go

@@ -17,3 +17,16 @@ type Datastore interface {
 	Drop() error
 	Migrate() error
 }
+
+// NotFoundError is returned when the datastore resource cannot be found.
+type NotFoundError interface {
+	error
+	IsNotFound() bool
+}
+
+// AlreadyExists is returned when creating a datastore resource that already
+// exists.
+type AlreadyExistsError interface {
+	error
+	IsExists() bool
+}

server/service/service_invites.go

@@ -3,7 +3,6 @@ package service
 import (
 	"encoding/base64"
 
-	kolide_errors "github.com/kolide/kolide-ose/server/errors"
 	"github.com/kolide/kolide-ose/server/kolide"
 	"golang.org/x/net/context"
 )
@@ -14,7 +13,8 @@ func (svc service) InviteNewUser(ctx context.Context, payload kolide.InvitePaylo
 	if err == nil {
 		return nil, newInvalidArgumentError("email", "a user with this account already exists")
 	}
-	if err != kolide_errors.ErrNotFound {
+
+	if _, ok := err.(kolide.NotFoundError); !ok {
 		return nil, err
 	}
 

server/service/service_invites_test.go

@@ -1,6 +1,7 @@
 package service
 
 import (
+	"errors"
 	"testing"
 
 	"golang.org/x/net/context"
@@ -8,7 +9,6 @@ import (
 	"github.com/WatchBeam/clock"
 	"github.com/kolide/kolide-ose/server/config"
 	"github.com/kolide/kolide-ose/server/datastore/inmem"
-	"github.com/kolide/kolide-ose/server/errors"
 	"github.com/kolide/kolide-ose/server/kolide"
 	"github.com/stretchr/testify/assert"
 )
@@ -44,7 +44,7 @@ func TestInviteNewUser(t *testing.T) {
 				InvitedBy: &nosuchAdminID,
 				Admin:     boolPtr(false),
 			},
-			wantErr: errors.ErrNotFound,
+			wantErr: errors.New("User 999 was not found in the datastore"),
 		},
 		{
 			payload: kolide.InvitePayload{
@@ -67,9 +67,11 @@ func TestInviteNewUser(t *testing.T) {
 	for _, tt := range inviteTests {
 		t.Run("", func(t *testing.T) {
 			invite, err := svc.InviteNewUser(context.Background(), tt.payload)
-			assert.Equal(t, tt.wantErr, err)
-			if err != nil {
+			if tt.wantErr != nil {
+				assert.Equal(t, tt.wantErr.Error(), err.Error())
 				return
+			} else {
+				assert.Nil(t, err)
 			}
 			assert.Equal(t, *tt.payload.InvitedBy, invite.InvitedBy)
 		})

server/service/service_sessions.go

@@ -7,18 +7,16 @@ import (
 	"time"
 
 	"github.com/kolide/kolide-ose/server/contexts/viewer"
-	"github.com/kolide/kolide-ose/server/errors"
 	"github.com/kolide/kolide-ose/server/kolide"
 	"golang.org/x/net/context"
 )
 
 func (svc service) Login(ctx context.Context, username, password string) (*kolide.User, string, error) {
 	user, err := svc.userByEmailOrUsername(username)
-	switch err {
-	case nil:
-	case errors.ErrNotFound:
+	if _, ok := err.(kolide.NotFoundError); ok {
 		return nil, "", authError{reason: "no such user"}
-	default:
+	}
+	if err != nil {
 		return nil, "", err
 	}
 	if !user.Enabled {

server/service/service_users_test.go

@@ -8,7 +8,6 @@ import (
 	"github.com/kolide/kolide-ose/server/config"
 	"github.com/kolide/kolide-ose/server/contexts/viewer"
 	"github.com/kolide/kolide-ose/server/datastore/inmem"
-	kolide_errors "github.com/kolide/kolide-ose/server/errors"
 	"github.com/kolide/kolide-ose/server/kolide"
 
 	"github.com/WatchBeam/clock"
@@ -157,7 +156,7 @@ func TestCreateUser(t *testing.T) {
 			NeedsPasswordReset: boolPtr(true),
 			Admin:              boolPtr(false),
 			InviteToken:        &invites["admin2@example.com"].Token,
-			wantErr:            kolide_errors.ErrNotFound,
+			wantErr:            errors.New("Invite was not found in the datastore"),
 		},
 		{
 			Username:           stringPtr("admin3"),
@@ -190,7 +189,9 @@ func TestCreateUser(t *testing.T) {
 				AdminForcedPasswordReset: tt.NeedsPasswordReset,
 			}
 			user, err := svc.NewUser(ctx, payload)
-			require.Equal(t, tt.wantErr, err)
+			if tt.wantErr != nil {
+				require.Equal(t, tt.wantErr.Error(), err.Error())
+			}
 			if err != nil {
 				// skip rest of the test if error is not nil
 				return
@@ -321,7 +322,7 @@ func TestResetPassword(t *testing.T) {
 		{ // bad token
 			token:       "dcbaz",
 			newPassword: "123cat!",
-			wantErr:     kolide_errors.ErrNotFound,
+			wantErr:     errors.New("PasswordResetRequest was not found in the datastore"),
 		},
 		{ // missing token
 			newPassword: "123cat!",
@@ -353,7 +354,11 @@ func TestResetPassword(t *testing.T) {
 			assert.Nil(t, err)
 
 			serr := svc.ResetPassword(ctx, tt.token, tt.newPassword)
-			assert.Equal(t, tt.wantErr, pkg_errors.Cause(serr))
+			if tt.wantErr != nil {
+				assert.Equal(t, tt.wantErr.Error(), pkg_errors.Cause(serr).Error())
+			} else {
+				assert.Nil(t, serr)
+			}
 		})
 	}
 }

server/service/transport_error.go

@@ -5,7 +5,6 @@ import (
 	"net/http"
 
 	kithttp "github.com/go-kit/kit/transport/http"
-	"github.com/kolide/kolide-ose/server/errors"
 	"golang.org/x/net/context"
 )
 
@@ -94,10 +93,34 @@ func encodeError(ctx context.Context, err error, w http.ResponseWriter) {
 		return
 	}
 
+	type notFoundError interface {
+		error
+		IsNotFound() bool
+	}
+	if e, ok := err.(notFoundError); ok {
+		je := jsonError{
+			Message: "Resource Not Found",
+			Error:   e.Error(),
+		}
+		w.WriteHeader(http.StatusNotFound)
+		enc.Encode(je)
+	}
+
+	type existsError interface {
+		error
+		IsExists() bool
+	}
+	if e, ok := err.(existsError); ok {
+		je := jsonError{
+			Message: "Resource Already Exists",
+			Error:   e.Error(),
+		}
+		w.WriteHeader(http.StatusConflict)
+		enc.Encode(je)
+	}
+
 	// Other errors
 	switch domain {
-	case "service":
-		w.WriteHeader(codeFromErr(err))
 	case kithttp.DomainDecode:
 		w.WriteHeader(http.StatusBadRequest)
 	case kithttp.DomainDo:
@@ -109,14 +132,3 @@ func encodeError(ctx context.Context, err error, w http.ResponseWriter) {
 		"error": err.Error(),
 	})
 }
-
-func codeFromErr(err error) int {
-	switch err {
-	case errors.ErrNotFound:
-		return http.StatusNotFound
-	case errors.ErrExists:
-		return http.StatusConflict
-	default:
-		return http.StatusInternalServerError
-	}
-}