forked from moby/buildkit
/
caps.go
162 lines (146 loc) · 4.06 KB
/
caps.go
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package apicaps
import (
"fmt"
"sort"
"strings"
pb "github.com/moby/buildkit/util/apicaps/pb"
"github.com/pkg/errors"
)
type PBCap = pb.APICap
// ExportedProduct is the name of the product using this package.
// Users vendoring this library may override it to provide better versioning hints
// for their users (or set it with a flag to buildkitd).
var ExportedProduct string
// CapStatus defines the stability properties of a capability
type CapStatus int
const (
// CapStatusStable refers to a capability that should never be changed in
// backwards incompatible manner unless there is a serious security issue.
CapStatusStable CapStatus = iota
// CapStatusExperimental refers to a capability that may be removed in the future.
// If incompatible changes are made the previous ID is disabled and new is added.
CapStatusExperimental
// CapStatusPrerelease is same as CapStatusExperimental that can be used for new
// features before they move to stable.
CapStatusPrerelease
)
// CapID is type for capability identifier
type CapID string
// Cap describes an API feature
type Cap struct {
ID CapID
Name string // readable name, may contain spaces but keep in one sentence
Status CapStatus
Enabled bool
Deprecated bool
SupportedHint map[string]string
DisabledReason string
DisabledReasonMsg string
DisabledAlternative string
}
// CapList is a collection of capability definitions
type CapList struct {
m map[CapID]Cap
}
// Init initializes definition for a new capability.
// Not safe to be called concurrently with other methods.
func (l *CapList) Init(cc ...Cap) {
if l.m == nil {
l.m = make(map[CapID]Cap, len(cc))
}
for _, c := range cc {
l.m[c.ID] = c
}
}
// All reports the configuration of all known capabilities
func (l *CapList) All() []pb.APICap {
out := make([]pb.APICap, 0, len(l.m))
for _, c := range l.m {
out = append(out, pb.APICap{
ID: string(c.ID),
Enabled: c.Enabled,
Deprecated: c.Deprecated,
DisabledReason: c.DisabledReason,
DisabledReasonMsg: c.DisabledReasonMsg,
DisabledAlternative: c.DisabledAlternative,
})
}
sort.Slice(out, func(i, j int) bool {
return out[i].ID < out[j].ID
})
return out
}
// CapSet returns a CapSet for an capability configuration
func (l *CapList) CapSet(caps []pb.APICap) CapSet {
m := make(map[string]*pb.APICap, len(caps))
for _, c := range caps {
if c.ID != "" {
c := c // capture loop iterator
m[c.ID] = &c
}
}
return CapSet{
list: l,
set: m,
}
}
// CapSet is a configuration for detecting supported capabilities
type CapSet struct {
list *CapList
set map[string]*pb.APICap
}
// Supports returns an error if capability is not supported
func (s *CapSet) Supports(id CapID) error {
err := &CapError{ID: id}
c, ok := s.list.m[id]
if !ok {
return errors.WithStack(err)
}
err.Definition = &c
state, ok := s.set[string(id)]
if !ok {
return errors.WithStack(err)
}
err.State = state
if !state.Enabled {
return errors.WithStack(err)
}
return nil
}
// CapError is an error for unsupported capability
type CapError struct {
ID CapID
Definition *Cap
State *pb.APICap
}
func (e CapError) Error() string {
if e.Definition == nil {
return fmt.Sprintf("unknown API capability %s", e.ID)
}
typ := ""
if e.Definition.Status == CapStatusExperimental {
typ = "experimental "
}
if e.Definition.Status == CapStatusPrerelease {
typ = "prerelease "
}
name := ""
if e.Definition.Name != "" {
name = "(" + e.Definition.Name + ")"
}
b := &strings.Builder{}
fmt.Fprintf(b, "requested %sfeature %s %s", typ, e.ID, name)
if e.State == nil {
fmt.Fprint(b, " is not supported by build server")
if hint, ok := e.Definition.SupportedHint[ExportedProduct]; ok {
fmt.Fprintf(b, " (added in %s)", hint)
}
fmt.Fprintf(b, ", please update %s", ExportedProduct)
} else {
fmt.Fprint(b, " has been disabled on the build server")
if e.State.DisabledReasonMsg != "" {
fmt.Fprintf(b, ": %s", e.State.DisabledReasonMsg)
}
}
return b.String()
}