github.com/containerd/containerd@v22.0.0-20200918172823-438c87b8e050+incompatible/runtime/restart/restart.go (about)

     1  /*
     2     Copyright The containerd Authors.
     3  
     4     Licensed under the Apache License, Version 2.0 (the "License");
     5     you may not use this file except in compliance with the License.
     6     You may obtain a copy of the License at
     7  
     8         http://www.apache.org/licenses/LICENSE-2.0
     9  
    10     Unless required by applicable law or agreed to in writing, software
    11     distributed under the License is distributed on an "AS IS" BASIS,
    12     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13     See the License for the specific language governing permissions and
    14     limitations under the License.
    15  */
    16  
    17  // Package restart enables containers to have labels added and monitored to
    18  // keep the container's task running if it is killed.
    19  //
    20  // Setting the StatusLabel on a container instructs the restart monitor to keep
    21  // that container's task in a specific status.
    22  // Setting the LogPathLabel on a container will setup the task's IO to be redirected
    23  // to a log file when running a task within the restart manager.
    24  //
    25  // The restart labels can be cleared off of a container using the WithNoRestarts Opt.
    26  //
    27  // The restart monitor has one option in the containerd config under the [plugins.restart]
    28  // section.  `interval = "10s" sets the reconcile interval that the restart monitor checks
    29  // for task state and reconciles the desired status for that task.
    30  package restart
    31  
    32  import (
    33  	"context"
    34  
    35  	"github.com/containerd/containerd"
    36  	"github.com/containerd/containerd/cio"
    37  	"github.com/containerd/containerd/containers"
    38  )
    39  
    40  const (
    41  	// StatusLabel sets the restart status label for a container
    42  	StatusLabel = "containerd.io/restart.status"
    43  	// LogURILabel sets the restart log uri label for a container
    44  	LogURILabel = "containerd.io/restart.loguri"
    45  
    46  	// LogPathLabel sets the restart log path label for a container
    47  	//
    48  	// Deprecated(in release 1.5): use LogURILabel
    49  	LogPathLabel = "containerd.io/restart.logpath"
    50  )
    51  
    52  // WithBinaryLogURI sets the binary-type log uri for a container.
    53  func WithBinaryLogURI(binary string, args map[string]string) func(context.Context, *containerd.Client, *containers.Container) error {
    54  	return func(_ context.Context, _ *containerd.Client, c *containers.Container) error {
    55  		uri, err := cio.LogURIGenerator("binary", binary, args)
    56  		if err != nil {
    57  			return err
    58  		}
    59  
    60  		ensureLabels(c)
    61  		c.Labels[LogURILabel] = uri.String()
    62  		return nil
    63  	}
    64  }
    65  
    66  // WithFileLogURI sets the file-type log uri for a container.
    67  func WithFileLogURI(path string) func(context.Context, *containerd.Client, *containers.Container) error {
    68  	return func(_ context.Context, _ *containerd.Client, c *containers.Container) error {
    69  		uri, err := cio.LogURIGenerator("file", path, nil)
    70  		if err != nil {
    71  			return err
    72  		}
    73  
    74  		ensureLabels(c)
    75  		c.Labels[LogURILabel] = uri.String()
    76  		return nil
    77  	}
    78  }
    79  
    80  // WithLogPath sets the log path for a container
    81  //
    82  // Deprecated(in release 1.5): use WithFileLogURI.
    83  func WithLogPath(path string) func(context.Context, *containerd.Client, *containers.Container) error {
    84  	return func(_ context.Context, _ *containerd.Client, c *containers.Container) error {
    85  		ensureLabels(c)
    86  		c.Labels[LogPathLabel] = path
    87  		return nil
    88  	}
    89  }
    90  
    91  // WithStatus sets the status for a container
    92  func WithStatus(status containerd.ProcessStatus) func(context.Context, *containerd.Client, *containers.Container) error {
    93  	return func(_ context.Context, _ *containerd.Client, c *containers.Container) error {
    94  		ensureLabels(c)
    95  		c.Labels[StatusLabel] = string(status)
    96  		return nil
    97  	}
    98  }
    99  
   100  // WithNoRestarts clears any restart information from the container
   101  func WithNoRestarts(_ context.Context, _ *containerd.Client, c *containers.Container) error {
   102  	if c.Labels == nil {
   103  		return nil
   104  	}
   105  	delete(c.Labels, StatusLabel)
   106  	delete(c.Labels, LogPathLabel)
   107  	delete(c.Labels, LogURILabel)
   108  	return nil
   109  }
   110  
   111  func ensureLabels(c *containers.Container) {
   112  	if c.Labels == nil {
   113  		c.Labels = make(map[string]string)
   114  	}
   115  }