Enable review linter with exported docs check (netbirdio#1647)

Exported function and methods should have comments. This warns on undocumented exported functions and methods.

.golangci.yaml

@@ -63,6 +63,14 @@ linters-settings:
     enable:
       - nilness
 
+  revive:
+    rules:
+      - name: exported
+        severity: warning
+        disabled: false
+        arguments:
+          - "checkPrivateReceivers"
+          - "sayRepetitiveInsteadOfStutters"
   tenv:
     # The option `all` will run against whole test files (`_test.go`) regardless of method/function signatures.
     # Otherwise, only methods that take `*testing.T`, `*testing.B`, and `testing.TB` as arguments are checked.
@@ -93,6 +101,7 @@ linters:
     - nilerr # finds the code that returns nil even if it checks that the error is not nil
     - nilnil # checks that there is no simultaneous return of nil error and an invalid value
     - predeclared # predeclared finds code that shadows one of Go's predeclared identifiers
+    - revive # Fast, configurable, extensible, flexible, and beautiful linter for Go. Drop-in replacement of golint.
     - sqlclosecheck # checks that sql.Rows and sql.Stmt are closed
     - thelper # thelper detects Go test helpers without t.Helper() call and checks the consistency of test helpers.
     - wastedassign # wastedassign finds wasted assignment statements

client/internal/auth/oauth.go

@@ -26,7 +26,7 @@ type HTTPClient interface {
 }
 
 // AuthFlowInfo holds information for the OAuth 2.0  authorization flow
-type AuthFlowInfo struct {
+type AuthFlowInfo struct { //nolint:revive
 	DeviceCode              string `json:"device_code"`
 	UserCode                string `json:"user_code"`
 	VerificationURI         string `json:"verification_uri"`

iface/netstack/tun.go

@@ -8,7 +8,7 @@ import (
 	"golang.zx2c4.com/wireguard/tun/netstack"
 )
 
-type NetStackTun struct {
+type NetStackTun struct { //nolint:revive
 	address       string
 	mtu           int
 	listenAddress string

management/server/activity/event.go

@@ -9,7 +9,7 @@ const (
 )
 
 // ActivityDescriber is an interface that describes an activity
-type ActivityDescriber interface {
+type ActivityDescriber interface { //nolint:revive
 	StringCode() string
 	Message() string
 }

management/server/peer/peer.go

@@ -46,7 +46,7 @@ type Peer struct {
 	Location Location `gorm:"embedded;embeddedPrefix:location_"`
 }
 
-type PeerStatus struct {
+type PeerStatus struct { //nolint:revive
 	// LastSeen is the last time peer was connected to the management service
 	LastSeen time.Time
 	// Connected indicates whether peer is connected to the management service or not
@@ -72,7 +72,7 @@ type NetworkAddress struct {
 }
 
 // PeerSystemMeta is a metadata of a Peer machine system
-type PeerSystemMeta struct {
+type PeerSystemMeta struct { //nolint:revive
 	Hostname           string
 	GoOS               string
 	Kernel             string