Pause containers

Every Kubernetes Pod includes an empty pause container, which bootstraps the Pod to establish all of the cgroups, reservations, and namespaces before its individual containers are created. The pause container image is always present, so the pod resource allocation happens instantaneously as containers are created.


To display pause containers:

When using the client bundle, pause containers are hidden by default.

  • To display pause containers when using the client bundle:

    docker ps -a | grep -I pause
    
  • To display pause containers when not using the client bundle:

    1. Log in to a manager or worker node.

    2. Display pause containers:

      docker ps | grep -I pause
      

    Example output on a manager node:

    6d55b40f80ff   mirantis/ucp-pause:3.4.9   "/pause"   4 minutes ago   Up 4 minutes   k8s_POD_ucp-node-feature-discovery-m8552_node-feature-discovery_bd2fd91b-ffb8-426d-b006-0edde0071f44_0
    7f914f75b898   mirantis/ucp-pause:3.4.9   "/pause"   4 minutes ago   Up 4 minutes   k8s_POD_compose-5bd794b958-qgnk8_kube-system_c31fcbe7-29f1-4e7f-9a57-2ca34fb7b42f_0
    4107244c6f8d   mirantis/ucp-pause:3.4.9   "/pause"   4 minutes ago   Up 4 minutes   k8s_POD_compose-api-64d65cc8c8-dgcf9_kube-system_2bb25d91-54bc-4129-869a-5b96a02b2e9e_0
    2afd5515b535   mirantis/ucp-pause:3.4.9   "/pause"   4 minutes ago   Up 4 minutes   k8s_POD_ucp-metrics-2t4tl_kube-system_1c9d6e11-4bc4-41e5-858e-59dc8fb91ef1_0
    14baabbb85c7   mirantis/ucp-pause:3.4.9   "/pause"   4 minutes ago   Up 4 minutes   k8s_POD_coredns-5968d48-hhnwp_kube-system_edda9821-077f-4223-a52f-d72a370506b3_0
    00f73ccd7266   mirantis/ucp-pause:3.4.9   "/pause"   4 minutes ago   Up 4 minutes   k8s_POD_coredns-5968d48-j224d_kube-system_3fc289e0-efca-4ce1-99d1-e70b2c8ae994_0
    8c2c2d5540b3   mirantis/ucp-pause:3.4.9   "/pause"   5 minutes ago   Up 5 minutes   k8s_POD_calico-kube-controllers-7789bcd9cc-jb8kp_kube-system_8ca7f7ef-4500-4164-931b-ff02785f6484_0
    0682011872d1   mirantis/ucp-pause:3.4.9   "/pause"   5 minutes ago   Up 5 minutes   k8s_POD_calico-node-l4cl7_kube-system_02ed0562-f3c5-4724-815a-788ad38ff3c4_0
    

    Example output on a worker node:

    d94e211ae1fe   mirantis/ucp-pause:3.4.9   "/pause"   3 minutes ago   Up 3 minutes   k8s_POD_ucp-node-feature-discovery-58mtc_node-feature-discovery_472be762-14e6-47ba-80b5-c86dce79fbab_2
    80282e0baa43   mirantis/ucp-pause:3.4.9   "/pause"   3 minutes ago   Up 3 minutes   k8s_POD_calico-node-wxk5l_kube-system_030fc501-ec75-4675-a742-d19929818065_0
    

See also

Kubernetes Pods