defmodule K8s.Operation.Path do
@moduledoc "Generates Kubernetes REST API Paths"
alias K8s.Operation.Error
@path_params [:namespace, :name, :path, :logpath]
@doc false
@spec path_params() :: list(atom)
def path_params, do: @path_params
@doc """
Generates the API path for a `K8s.Operation`.
## Examples
Generate a path for a cluster scoped resource:
iex> resource = K8s.Resource.build("apps/v1", "CertificateSigningRequest", "foo")
...> operation = %K8s.Operation{
...> method: :put,
...> verb: :update,
...> data: resource,
...> path_params: [name: "foo"],
...> api_version: "apps/v1",
...> name: "certificatesigningrequests"
...> }
...> K8s.Operation.Path.build(operation)
{:ok, "/apis/apps/v1/certificatesigningrequests/foo"}
iex> resource = K8s.Resource.build("apps/v1", "CertificateSigningRequest", "foo")
...> operation = %K8s.Operation{
...> method: :put,
...> verb: :update,
...> data: resource,
...> path_params: [name: "foo", namespace: nil],
...> api_version: "apps/v1",
...> name: "certificatesigningrequests"
...> }
...> K8s.Operation.Path.build(operation)
{:ok, "/apis/apps/v1/certificatesigningrequests/foo"}
Generate a path for a namespace scoped resource:
iex> resource = K8s.Resource.build("v1", "Pod", "default", "foo")
...> operation = %K8s.Operation{
...> method: :put,
...> verb: :update,
...> data: resource,
...> path_params: [namespace: "default", name: "foo"],
...> api_version: "v1",
...> name: "pods"
...> }
...> K8s.Operation.Path.build(operation)
{:ok, "/api/v1/namespaces/default/pods/foo"}
Generate a path for a namespace scoped resource on the collection: (ie create, list)
iex> resource = K8s.Resource.build("v1", "Pod", "default", "foo")
...> operation = %K8s.Operation{
...> method: :post,
...> verb: :create,
...> data: resource,
...> path_params: [namespace: "default", name: "foo"],
...> api_version: "v1",
...> name: "pods"
...> }
...> K8s.Operation.Path.build(operation)
{:ok, "/api/v1/namespaces/default/pods"}
Generating a listing path for a namespace:
iex> operation = %K8s.Operation{
...> method: :get,
...> verb: :list,
...> data: nil,
...> path_params: [namespace: "default"],
...> api_version: "v1",
...> name: "pods"
...> }
...> K8s.Operation.Path.build(operation)
{:ok, "/api/v1/namespaces/default/pods"}
Generating a listing path for a all namespaces:
iex> operation = %K8s.Operation{
...> method: :get,
...> verb: :list_all_namespaces,
...> data: nil,
...> path_params: [namespace: "default"],
...> api_version: "v1",
...> name: "pods"
...> }
...> K8s.Operation.Path.build(operation)
{:ok, "/api/v1/pods"}
Generating a listing path for a watching all namespaces:
iex> operation = %K8s.Operation{
...> method: :get,
...> verb: :watch_all_namespaces,
...> data: nil,
...> path_params: [namespace: "default"],
...> api_version: "v1",
...> name: "pods"
...> }
...> K8s.Operation.Path.build(operation)
{:ok, "/api/v1/pods"}
Generating a path for a subresource:
iex> operation = %K8s.Operation{
...> method: :get,
...> verb: :get,
...> data: nil,
...> path_params: [namespace: "default", name: "foo"],
...> api_version: "v1",
...> name: "pods/status"
...> }
...> K8s.Operation.Path.build(operation)
{:ok, "/api/v1/namespaces/default/pods/foo/status"}
Deleting a collection:
iex> operation = %K8s.Operation{
...> method: :delete,
...> verb: :deletecollection,
...> data: nil,
...> path_params: [namespace: "default"],
...> api_version: "v1",
...> name: "pods"
...> }
...> K8s.Operation.Path.build(operation)
{:ok, "/api/v1/namespaces/default/pods"}
"""
@spec build(K8s.Operation.t()) :: {:ok, binary} | {:error, Error.t()}
def build(%K8s.Operation{} = operation) do
path_template = to_path(operation)
required_params = K8s.Operation.Path.find_params(path_template)
provided_params = Keyword.keys(operation.path_params)
case required_params -- provided_params do
[] ->
{:ok, replace_path_vars(path_template, operation.path_params)}
missing_params ->
msg = "Missing required params: #{inspect(missing_params)}"
{:error, %Error{message: msg}}
end
end
@doc """
Replaces path variables with options.
## Examples
iex> K8s.Operation.Path.replace_path_vars("/foo/{name}", name: "bar")
"/foo/bar"
"""
@spec replace_path_vars(binary(), keyword()) :: binary()
def replace_path_vars(path_template, opts) do
Regex.replace(~r/\{(\w+?)\}/, path_template, fn _, var ->
opts[String.to_existing_atom(var)]
end)
end
@doc """
Find valid path params in a URL path.
## Examples
iex> K8s.Operation.Path.find_params("/foo/{name}")
[:name]
iex> K8s.Operation.Path.find_params("/foo/{namespace}/bar/{name}")
[:namespace, :name]
iex> K8s.Operation.Path.find_params("/foo/bar")
[]
"""
@spec find_params(binary()) :: list(atom())
def find_params(path_with_args) do
~r/{([a-z]+)}/
|> Regex.scan(path_with_args)
|> Enum.map(fn match -> match |> List.last() |> String.to_existing_atom() end)
end
@spec to_path(K8s.Operation.t()) :: binary
defp to_path(%K8s.Operation{path_params: params} = operation) do
has_namespace = !is_nil(params[:namespace])
namespaced = has_namespace && params[:namespace] != :all
prefix =
case String.contains?(operation.api_version, "/") do
true -> "/apis/#{operation.api_version}"
false -> "/api/#{operation.api_version}"
end
suffix =
operation.name
|> String.split("/")
|> resource_path_suffix(operation.verb)
build_path(prefix, suffix, namespaced, operation.verb)
end
@spec resource_path_suffix(list(binary), atom) :: binary
defp resource_path_suffix([name], verb), do: name_param(name, verb)
defp resource_path_suffix([name, subresource], verb),
do: name_with_subresource_param(name, subresource, verb)
@spec name_param(binary, atom) :: binary
defp name_param(resource_name, :create), do: resource_name
defp name_param(resource_name, :list_all_namespaces), do: resource_name
defp name_param(resource_name, :list), do: resource_name
defp name_param(resource_name, :deletecollection), do: resource_name
defp name_param(resource_name, :watch_all_namespaces), do: resource_name
defp name_param(resource_name, _), do: "#{resource_name}/{name}"
@spec name_with_subresource_param(binary, binary, atom) :: binary
defp name_with_subresource_param(resource_name, subresource, _),
do: "#{resource_name}/{name}/#{subresource}"
@spec build_path(binary, binary, boolean, atom) :: binary
defp build_path(prefix, suffix, true, :watch_all_namespaces), do: "#{prefix}/#{suffix}"
defp build_path(prefix, suffix, true, :list_all_namespaces), do: "#{prefix}/#{suffix}"
defp build_path(prefix, suffix, true, _), do: "#{prefix}/namespaces/{namespace}/#{suffix}"
defp build_path(prefix, suffix, false, _), do: "#{prefix}/#{suffix}"
end
