Add terminals to the Kubernetes deployment service

1 files changed, 80 insertions, 0 deletions

diff --git a/lib/gitlab/kubernetes.rb b/lib/gitlab/kubernetes.rb
new file mode 100644
index 00000000000..288771c1c12
--- /dev/null
+++ b/lib/gitlab/kubernetes.rb
@@ -0,0 +1,80 @@
+module Gitlab
+  # Helper methods to do with Kubernetes network services & resources
+  module Kubernetes
+    # This is the comand that is run to start a terminal session. Kubernetes
+    # expects `command=foo&command=bar, not `command[]=foo&command[]=bar`
+    EXEC_COMMAND = URI.encode_www_form(
+      ['sh', '-c', 'bash || sh'].map { |value| ['command', value] }
+    )
+
+    # Filters an array of pods (as returned by the kubernetes API) by their labels
+    def filter_pods(pods, labels = {})
+      pods.select do |pod|
+        metadata = pod.fetch("metadata", {})
+        pod_labels = metadata.fetch("labels", nil)
+        next unless pod_labels
+
+        labels.all? { |k, v| pod_labels[k.to_s] == v }
+      end
+    end
+
+    # Converts a pod (as returned by the kubernetes API) into a terminal
+    def terminals_for_pod(api_url, namespace, pod)
+      metadata = pod.fetch("metadata", {})
+      status   = pod.fetch("status", {})
+      spec     = pod.fetch("spec", {})
+
+      containers = spec["containers"]
+      pod_name   = metadata["name"]
+      phase      = status["phase"]
+
+      return unless containers.present? && pod_name.present? && phase == "Running"
+
+      created_at = DateTime.parse(metadata["creationTimestamp"]) rescue nil
+
+      containers.map do |container|
+        {
+          selectors:    { pod: pod_name, container: container["name"] },
+          url:          container_exec_url(api_url, namespace, pod_name, container["name"]),
+          subprotocols: ['channel.k8s.io'],
+          headers:      Hash.new { |h, k| h[k] = [] },
+          created_at:   created_at,
+        }
+      end
+    end
+
+    def add_terminal_auth(terminal, token, ca_pem = nil)
+      terminal[:headers]['Authorization'] << "Bearer #{token}"
+      terminal[:ca_pem] = ca_pem if ca_pem.present?
+      terminal
+    end
+
+    def container_exec_url(api_url, namespace, pod_name, container_name)
+      url = URI.parse(api_url)
+      url.path = [
+        url.path.sub(%r{/+\z}, ''),
+        'api', 'v1',
+        'namespaces', ERB::Util.url_encode(namespace),
+        'pods', ERB::Util.url_encode(pod_name),
+        'exec'
+      ].join('/')
+
+      url.query = {
+        container: container_name,
+        tty: true,
+        stdin: true,
+        stdout: true,
+        stderr: true,
+      }.to_query + '&' + EXEC_COMMAND
+
+      case url.scheme
+      when 'http'
+        url.scheme = 'ws'
+      when 'https'
+        url.scheme = 'wss'
+      end
+
+      url.to_s
+    end
+  end
+end