forkjo/services/context/quota.go
Gergely Nagy 67fa52dedb
feat(quota): Quota enforcement
The previous commit laid out the foundation of the quota engine, this
one builds on top of it, and implements the actual enforcement.

Enforcement happens at the route decoration level, whenever possible. In
case of the API, when over quota, a 413 error is returned, with an
appropriate JSON payload. In case of web routes, a 413 HTML page is
rendered with similar information.

This implementation is for a **soft quota**: quota usage is checked
before an operation is to be performed, and the operation is *only*
denied if the user is already over quota. This makes it possible to go
over quota, but has the significant advantage of being practically
implementable within the current Forgejo architecture.

The goal of enforcement is to deny actions that can make the user go
over quota, and allow the rest. As such, deleting things should - in
almost all cases - be possible. A prime exemption is deleting files via
the web ui: that creates a new commit, which in turn increases repo
size, thus, is denied if the user is over quota.

Limitations
-----------

Because we generally work at a route decorator level, and rarely
look *into* the operation itself, `size:repos:public` and
`size:repos:private` are not enforced at this level, the engine enforces
against `size:repos:all`. This will be improved in the future.

AGit does not play very well with this system, because AGit PRs count
toward the repo they're opened against, while in the GitHub-style fork +
pull model, it counts against the fork. This too, can be improved in the
future.

There's very little done on the UI side to guard against going over
quota. What this patch implements, is enforcement, not prevention. The
UI will still let you *try* operations that *will* result in a denial.

Signed-off-by: Gergely Nagy <forgejo@gergo.csillger.hu>
2024-08-02 11:10:34 +02:00

200 lines
5.4 KiB
Go

// Copyright 2024 The Forgejo Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package context
import (
"context"
"net/http"
"strings"
quota_model "code.gitea.io/gitea/models/quota"
"code.gitea.io/gitea/modules/base"
)
type QuotaTargetType int
const (
QuotaTargetUser QuotaTargetType = iota
QuotaTargetRepo
QuotaTargetOrg
)
// QuotaExceeded
// swagger:response quotaExceeded
type APIQuotaExceeded struct {
Message string `json:"message"`
UserID int64 `json:"user_id"`
UserName string `json:"username,omitempty"`
}
// QuotaGroupAssignmentAPI returns a middleware to handle context-quota-group assignment for api routes
func QuotaGroupAssignmentAPI() func(ctx *APIContext) {
return func(ctx *APIContext) {
groupName := ctx.Params("quotagroup")
group, err := quota_model.GetGroupByName(ctx, groupName)
if err != nil {
ctx.Error(http.StatusInternalServerError, "quota_model.GetGroupByName", err)
return
}
if group == nil {
ctx.NotFound()
return
}
ctx.QuotaGroup = group
}
}
// QuotaRuleAssignmentAPI returns a middleware to handle context-quota-rule assignment for api routes
func QuotaRuleAssignmentAPI() func(ctx *APIContext) {
return func(ctx *APIContext) {
ruleName := ctx.Params("quotarule")
rule, err := quota_model.GetRuleByName(ctx, ruleName)
if err != nil {
ctx.Error(http.StatusInternalServerError, "quota_model.GetRuleByName", err)
return
}
if rule == nil {
ctx.NotFound()
return
}
ctx.QuotaRule = rule
}
}
// ctx.CheckQuota checks whether the user in question is within quota limits (web context)
func (ctx *Context) CheckQuota(subject quota_model.LimitSubject, userID int64, username string) bool {
ok, err := checkQuota(ctx.Base.originCtx, subject, userID, username, func(userID int64, username string) {
showHTML := false
for _, part := range ctx.Req.Header["Accept"] {
if strings.Contains(part, "text/html") {
showHTML = true
break
}
}
if !showHTML {
ctx.plainTextInternal(3, http.StatusRequestEntityTooLarge, []byte("Quota exceeded.\n"))
return
}
ctx.Data["IsRepo"] = ctx.Repo.Repository != nil
ctx.Data["Title"] = "Quota Exceeded"
ctx.HTML(http.StatusRequestEntityTooLarge, base.TplName("status/413"))
}, func(err error) {
ctx.Error(http.StatusInternalServerError, "quota_model.EvaluateForUser")
})
if err != nil {
return false
}
return ok
}
// ctx.CheckQuota checks whether the user in question is within quota limits (API context)
func (ctx *APIContext) CheckQuota(subject quota_model.LimitSubject, userID int64, username string) bool {
ok, err := checkQuota(ctx.Base.originCtx, subject, userID, username, func(userID int64, username string) {
ctx.JSON(http.StatusRequestEntityTooLarge, APIQuotaExceeded{
Message: "quota exceeded",
UserID: userID,
UserName: username,
})
}, func(err error) {
ctx.InternalServerError(err)
})
if err != nil {
return false
}
return ok
}
// EnforceQuotaWeb returns a middleware that enforces quota limits on the given web route.
func EnforceQuotaWeb(subject quota_model.LimitSubject, target QuotaTargetType) func(ctx *Context) {
return func(ctx *Context) {
ctx.CheckQuota(subject, target.UserID(ctx), target.UserName(ctx))
}
}
// EnforceQuotaWeb returns a middleware that enforces quota limits on the given API route.
func EnforceQuotaAPI(subject quota_model.LimitSubject, target QuotaTargetType) func(ctx *APIContext) {
return func(ctx *APIContext) {
ctx.CheckQuota(subject, target.UserID(ctx), target.UserName(ctx))
}
}
// checkQuota wraps quota checking into a single function
func checkQuota(ctx context.Context, subject quota_model.LimitSubject, userID int64, username string, quotaExceededHandler func(userID int64, username string), errorHandler func(err error)) (bool, error) {
ok, err := quota_model.EvaluateForUser(ctx, userID, subject)
if err != nil {
errorHandler(err)
return false, err
}
if !ok {
quotaExceededHandler(userID, username)
return false, nil
}
return true, nil
}
type QuotaContext interface {
GetQuotaTargetUserID(target QuotaTargetType) int64
GetQuotaTargetUserName(target QuotaTargetType) string
}
func (ctx *Context) GetQuotaTargetUserID(target QuotaTargetType) int64 {
switch target {
case QuotaTargetUser:
return ctx.Doer.ID
case QuotaTargetRepo:
return ctx.Repo.Repository.OwnerID
case QuotaTargetOrg:
return ctx.Org.Organization.ID
default:
return 0
}
}
func (ctx *Context) GetQuotaTargetUserName(target QuotaTargetType) string {
switch target {
case QuotaTargetUser:
return ctx.Doer.Name
case QuotaTargetRepo:
return ctx.Repo.Repository.Owner.Name
case QuotaTargetOrg:
return ctx.Org.Organization.Name
default:
return ""
}
}
func (ctx *APIContext) GetQuotaTargetUserID(target QuotaTargetType) int64 {
switch target {
case QuotaTargetUser:
return ctx.Doer.ID
case QuotaTargetRepo:
return ctx.Repo.Repository.OwnerID
case QuotaTargetOrg:
return ctx.Org.Organization.ID
default:
return 0
}
}
func (ctx *APIContext) GetQuotaTargetUserName(target QuotaTargetType) string {
switch target {
case QuotaTargetUser:
return ctx.Doer.Name
case QuotaTargetRepo:
return ctx.Repo.Repository.Owner.Name
case QuotaTargetOrg:
return ctx.Org.Organization.Name
default:
return ""
}
}
func (target QuotaTargetType) UserID(ctx QuotaContext) int64 {
return ctx.GetQuotaTargetUserID(target)
}
func (target QuotaTargetType) UserName(ctx QuotaContext) string {
return ctx.GetQuotaTargetUserName(target)
}