containerd/oci/spec_opts.go
Paul Knopf b4c3cd7640
Add WithEnv and WithMount oci options
Signed-off-by: Paul Knopf <pauldotknopf@gmail.com>
2018-01-22 16:35:31 -05:00

93 lines
2.5 KiB
Go

package oci
import (
"context"
"strings"
"github.com/containerd/containerd/containers"
specs "github.com/opencontainers/runtime-spec/specs-go"
)
// SpecOpts sets spec specific information to a newly generated OCI spec
type SpecOpts func(context.Context, Client, *containers.Container, *specs.Spec) error
// WithProcessArgs replaces the args on the generated spec
func WithProcessArgs(args ...string) SpecOpts {
return func(_ context.Context, _ Client, _ *containers.Container, s *specs.Spec) error {
s.Process.Args = args
return nil
}
}
// WithProcessCwd replaces the current working directory on the generated spec
func WithProcessCwd(cwd string) SpecOpts {
return func(_ context.Context, _ Client, _ *containers.Container, s *specs.Spec) error {
s.Process.Cwd = cwd
return nil
}
}
// WithHostname sets the container's hostname
func WithHostname(name string) SpecOpts {
return func(_ context.Context, _ Client, _ *containers.Container, s *specs.Spec) error {
s.Hostname = name
return nil
}
}
// WithEnv appends environment variables
func WithEnv(environmnetVariables []string) SpecOpts {
return func(_ context.Context, _ Client, _ *containers.Container, s *specs.Spec) error {
if len(environmnetVariables) > 0 {
s.Process.Env = replaceOrAppendEnvValues(s.Process.Env, environmnetVariables)
}
return nil
}
}
// WithMounts appends mounts
func WithMounts(mounts []specs.Mount) SpecOpts {
return func(_ context.Context, _ Client, _ *containers.Container, s *specs.Spec) error {
s.Mounts = append(s.Mounts, mounts...)
return nil
}
}
// replaceOrAppendEnvValues returns the defaults with the overrides either
// replaced by env key or appended to the list
func replaceOrAppendEnvValues(defaults, overrides []string) []string {
cache := make(map[string]int, len(defaults))
for i, e := range defaults {
parts := strings.SplitN(e, "=", 2)
cache[parts[0]] = i
}
for _, value := range overrides {
// Values w/o = means they want this env to be removed/unset.
if !strings.Contains(value, "=") {
if i, exists := cache[value]; exists {
defaults[i] = "" // Used to indicate it should be removed
}
continue
}
// Just do a normal set/update
parts := strings.SplitN(value, "=", 2)
if i, exists := cache[parts[0]]; exists {
defaults[i] = value
} else {
defaults = append(defaults, value)
}
}
// Now remove all entries that we want to "unset"
for i := 0; i < len(defaults); i++ {
if defaults[i] == "" {
defaults = append(defaults[:i], defaults[i+1:]...)
i--
}
}
return defaults
}