// insertEnvAfterFrom inserts an ENV instruction with the environment variables
// from env after every FROM instruction in node.
func insertEnvAfterFrom(node *parser.Node, env []kapi.EnvVar) error {
if node == nil || len(env) == 0 {
return nil
}
// Build ENV instruction.
var m []dockerfile.KeyValue
for _, e := range env {
m = append(m, dockerfile.KeyValue{Key: e.Name, Value: e.Value})
}
buildEnv, err := dockerfile.Env(m)
if err != nil {
return err
}
// Insert the buildEnv after every FROM instruction.
// We iterate in reverse order, otherwise indices would have to be
// recomputed after each step, because we're changing node in-place.
indices := dockerfile.FindAll(node, dockercmd.From)
for i := len(indices) - 1; i >= 0; i-- {
err := dockerfile.InsertInstructions(node, indices[i]+1, buildEnv)
if err != nil {
return err
}
}
return nil
}
// appendKeyValueInstruction is a primitive used to avoid code duplication.
// Callers should use a derivative of this such as appendEnv or appendLabel.
// appendKeyValueInstruction appends a Dockerfile instruction with key-value
// syntax created by f as the last child of node with keys and values from m.
func appendKeyValueInstruction(f func([]dockerfile.KeyValue) (string, error), node *parser.Node, m []dockerfile.KeyValue) error {
if node == nil {
return nil
}
instruction, err := f(m)
if err != nil {
return err
}
return dockerfile.InsertInstructions(node, len(node.Children), instruction)
}