defmodule K8s.Resource do
@moduledoc "Kubernetes manifest attribute helpers"
@type yaml_elixir_error_t :: YamlElixir.FileNotFoundError.t() | YamlElixir.ParsingError.t()
defdelegate kind(resource), to: K8s.Resource.FieldAccessors
defdelegate api_version(resource), to: K8s.Resource.FieldAccessors
defdelegate metadata(resource), to: K8s.Resource.FieldAccessors
defdelegate name(resource), to: K8s.Resource.FieldAccessors
defdelegate namespace(resource), to: K8s.Resource.FieldAccessors
defdelegate labels(resource), to: K8s.Resource.FieldAccessors
defdelegate label(resource, name), to: K8s.Resource.FieldAccessors
defdelegate annotations(resource), to: K8s.Resource.FieldAccessors
defdelegate annotation(resource, name), to: K8s.Resource.FieldAccessors
defdelegate has_label?(resource, name), to: K8s.Resource.FieldAccessors
defdelegate has_annotation?(resource, name), to: K8s.Resource.FieldAccessors
defdelegate cpu(value), to: K8s.Resource.Utilization
defdelegate memory(value), to: K8s.Resource.Utilization
@doc """
Helper for building a kubernetes' resource `Map`
## Examples
iex> K8s.Resource.build("v1", "Pod")
%{"apiVersion" => "v1", "kind" => "Pod", "metadata" => %{}}
iex> K8s.Resource.build("v1", "Namespace", "foo")
%{"apiVersion" => "v1", "kind" => "Namespace", "metadata" => %{"name" => "foo"}}
iex> K8s.Resource.build("v1", "Pod", "default", "foo")
%{"apiVersion" => "v1", "kind" => "Pod", "metadata" => %{"namespace" => "default", "name" => "foo"}}
"""
@spec build(binary(), binary()) :: map()
def build(api_version, kind) do
%{
"apiVersion" => api_version,
"kind" => kind,
"metadata" => %{}
}
end
@spec build(binary(), binary(), binary()) :: map()
def build(api_version, kind, name) do
api_version
|> build(kind)
|> put_in(["metadata", "name"], name)
end
@spec build(binary(), binary(), binary(), binary()) :: map()
def build(api_version, kind, namespace, name) do
api_version
|> build(kind, name)
|> put_in(["metadata", "namespace"], namespace)
end
@spec build(binary(), binary(), binary(), binary(), map()) :: map()
def build(api_version, kind, namespace, name, %{} = labels) do
api_version
|> build(kind, name)
|> put_in(["metadata", "namespace"], namespace)
|> put_in(["metadata", "labels"], labels)
end
@doc """
Create a resource `Map` from a YAML file.
## Examples
iex> opts = [namespace: "default", name: "nginx", image: "nginx:nginx:1.7.9"]
...> K8s.Resource.from_file("test/support/deployment.yaml", opts)
{:ok, %{
"apiVersion" => "apps/v1",
"kind" => "Deployment",
"metadata" => %{
"labels" => %{"app" => "nginx"},
"name" => "nginx-deployment",
"namespace" => "default"
},
"spec" => %{
"replicas" => 3,
"selector" => %{"matchLabels" => %{"app" => "nginx"}},
"template" => %{
"metadata" => %{"labels" => %{"app" => "nginx"}},
"spec" => %{
"containers" => [
%{
"image" => "nginx:nginx:1.7.9",
"name" => "nginx",
"ports" => [%{"containerPort" => 80}]
}
]
}
}
}
}}
"""
@spec from_file(binary, keyword | nil) :: {:ok, map} | {:error, :enoent | yaml_elixir_error_t}
def from_file(filepath, assigns \\ []) do
with {:ok, interpolated_template} <- render(filepath, assigns),
{:ok, resource} <- YamlElixir.read_from_string(interpolated_template) do
{:ok, resource}
else
error -> error
end
end
@doc """
Create a resource `Map` from a YAML file.
Raises `File.Error` when the file does not exist.
## Examples
iex> opts = [namespace: "default", name: "nginx", image: "nginx:nginx:1.7.9"]
...> K8s.Resource.from_file!("test/support/deployment.yaml", opts)
%{
"apiVersion" => "apps/v1",
"kind" => "Deployment",
"metadata" => %{
"labels" => %{"app" => "nginx"},
"name" => "nginx-deployment",
"namespace" => "default"
},
"spec" => %{
"replicas" => 3,
"selector" => %{"matchLabels" => %{"app" => "nginx"}},
"template" => %{
"metadata" => %{"labels" => %{"app" => "nginx"}},
"spec" => %{
"containers" => [
%{
"image" => "nginx:nginx:1.7.9",
"name" => "nginx",
"ports" => [%{"containerPort" => 80}]
}
]
}
}
}
}
"""
@spec from_file!(binary, keyword | nil) :: map | no_return
def from_file!(path, assigns \\ []) do
case from_file(path, assigns) do
{:ok, resource} -> resource
{:error, error} -> raise error
end
end
@doc """
Create a list of resource `Map`s from a YAML file containing a YAML stream.
## Examples
iex> opts = [namespace: "default", name: "nginx", image: "nginx:nginx:1.7.9"]
...> K8s.Resource.all_from_file("test/support/helm-chart.yaml", opts)
{:ok, [
%{
"apiVersion" => "v1",
"kind" => "Namespace",
"metadata" => %{"name" => "default"}
},
%{
"apiVersion" => "apps/v1",
"kind" => "Deployment",
"metadata" => %{
"labels" => %{"app" => "nginx"},
"name" => "nginx-deployment",
"namespace" => "default"
},
"spec" => %{
"replicas" => 3,
"selector" => %{"matchLabels" => %{"app" => "nginx"}},
"template" => %{
"metadata" => %{"labels" => %{"app" => "nginx"}},
"spec" => %{
"containers" => [
%{
"image" => "nginx:nginx:1.7.9",
"name" => "nginx",
"ports" => [%{"containerPort" => 80}]
}
]
}
}
}
}
]}
"""
@spec all_from_file(binary, keyword) ::
{:ok, list(map)} | {:error, :enoent | yaml_elixir_error_t}
def all_from_file(filepath, assigns \\ []) do
with {:ok, interpolated_template} <- render(filepath, assigns),
{:ok, resources} <- YamlElixir.read_all_from_string(interpolated_template),
no_empty_maps <- Enum.filter(resources, &(&1 != %{})) do
{:ok, no_empty_maps}
end
end
@doc """
Create a list of resource `Map`s from a YAML file containing a YAML stream.
Raises `File.Error` when the file does not exist.
## Examples
iex> opts = [namespace: "default", name: "nginx", image: "nginx:nginx:1.7.9"]
...> K8s.Resource.all_from_file!("test/support/helm-chart.yaml", opts)
[
%{
"apiVersion" => "v1",
"kind" => "Namespace",
"metadata" => %{"name" => "default"}
},
%{
"apiVersion" => "apps/v1",
"kind" => "Deployment",
"metadata" => %{
"labels" => %{"app" => "nginx"},
"name" => "nginx-deployment",
"namespace" => "default"
},
"spec" => %{
"replicas" => 3,
"selector" => %{"matchLabels" => %{"app" => "nginx"}},
"template" => %{
"metadata" => %{"labels" => %{"app" => "nginx"}},
"spec" => %{
"containers" => [
%{
"image" => "nginx:nginx:1.7.9",
"name" => "nginx",
"ports" => [%{"containerPort" => 80}]
}
]
}
}
}
}
]
"""
@spec all_from_file!(String.t(), keyword()) :: list(map) | no_return
def all_from_file!(path, assigns \\ []) do
case all_from_file(path, assigns) do
{:ok, resources} -> resources
{:error, error} -> raise error
end
end
@spec render(binary, keyword) :: {:ok, binary} | {:error, :enoent}
defp render(filepath, assigns) do
case File.read(filepath) do
{:ok, template} ->
rendered = EEx.eval_string(template, assigns)
{:ok, rendered}
error ->
error
end
end
end
