Container Logs¶

$ cat Dockerfile
FROM pubrepo.guance.com/base/ubuntu:18.04 AS base
RUN mkdir -p /opt
RUN echo 'i=0; \n\
while true; \n\
do \n\
    echo "$(date +"%Y-%m-%d %H:%M:%S")  [$i]  Bash For Loop Examples. Hello, world! Testing output."; \n\
    i=$((i+1)); \n\
    sleep 1; \n\
done \n'\
>> /opt/s.sh
CMD ["/bin/bash", "/opt/s.sh"]

## Build the image
$ docker build -t testing/log-output:v1 .

## Start the container, add the environment variable DATAKIT_LOGS_CONFIG (note the character escaping)
$ docker run --name log-output -env DATAKIT_LOGS_CONFIG='[{"disable":false,"source":"log-source","service":"log-service"}]' -d testing/log-output:v1

apiVersion: apps/v1
kind: Deployment
metadata:
  name: log-demo-deployment
  labels:
    app: log-demo
spec:
  replicas: 1
  selector:
    matchLabels:
      app: log-demo
  template:
    metadata:
      labels:
        app: log-demo
      annotations:
        ## Add the configuration and specify the container as log-output
        datakit/log-output.logs: |
          [{
              "disable": false,
              "source":  "log-output-source",
              "service": "log-output-service",
              "tags" : {
                "some_tag": "some_value"
              }
          }]
    spec:
      containers:
      - name: log-output
        image: pubrepo.guance.com/base/ubuntu:18.04
        args:
        - /bin/sh
        - -c
        - >
          i=0;
          while true;
          do
            echo "$(date +'%F %H:%M:%S')  [$i]  Bash For Loop Examples. Hello, world! Testing output.";
            i=$((i+1));
            sleep 1;
          done

$ kubectl apply -f log-output.yaml
...

$ cat Dockerfile
FROM pubrepo.guance.com/base/ubuntu:18.04 AS base
RUN mkdir -p /opt
RUN echo 'i=0; \n\
while true; \n\
do \n\
    echo "$(date +"%Y-%m-%d %H:%M:%S")  [$i]  Bash For Loop Examples. Hello, world! Testing output." >> /tmp/opt/log; \n\
    i=$((i+1)); \n\
    sleep 1; \n\
done \n'\
>> /opt/s.sh
CMD ["/bin/bash", "/opt/s.sh"]

## Build the image
$ docker build -t testing/log-to-file:v1 .

## Start the container, add the environment variable DATAKIT_LOGS_CONFIG (note the character escaping).
## Unlike configuring stdout, "type" and "path" are mandatory fields, and add the path volume.
## Path `/tmp/opt/log` add the `/tmp/opt` anonymous volumes.
$ docker run --env DATAKIT_LOGS_CONFIG="[{\"disable\":false,\"type\":\"file\",\"path\":\"/tmp/opt/log\",\"source\":\"log-source\",\"service\":\"log-service\"}]" -v /tmp/opt -d testing/log-to-file:v1

apiVersion: apps/v1
kind: Deployment
metadata:
  name: log-demo-deployment
  labels:
    app: log-demo
spec:
  replicas: 1
  selector:
    matchLabels:
      app: log-demo
  template:
    metadata:
      labels:
        app: log-demo
      annotations:
        ## Add the configuration and specify the container as logging-demo.
        ## Configure both file and stdout collection, need to add the emptyDir volume to "/tmp/opt" first.
        datakit/logging-demo.logs: |
          [
            {
              "disable": false,
              "type": "file",
              "path":"/tmp/opt/log",
              "source":  "logging-file",
              "tags" : {
                "some_tag": "some_value"
              }
            },
            {
              "disable": false,
              "source":  "logging-output"
            }
          ]
    spec:
      containers:
      - name: logging-demo
        image: pubrepo.guance.com/base/ubuntu:18.04
        args:
        - /bin/sh
        - -c
        - >
          i=0;
          while true;
          do
            echo "$(date +'%F %H:%M:%S')  [$i]  Bash For Loop Examples. Hello, world! Testing output.";
            echo "$(date +'%F %H:%M:%S')  [$i]  Bash For Loop Examples. Hello, world! Testing output." >> /tmp/opt/log;
            i=$((i+1));
            sleep 1;
          done
        volumeMounts:
        - mountPath: /tmp/opt
          name: datakit-vol-opt
      volumes:
      - name: datakit-vol-opt
        emptyDir: {}

$ kubectl apply -f logging.yaml

## Take image for example.
## Capture a container's log when its image matches `datakit`.
container_include_log = ["image:datakit"]
## Ignore all kodo containers
container_exclude_log = ["image:kodo"]

## This causes all containers to be filtered. If there is a container ``datakit`` that satisfies both ``include`` and ``exclude``, then it will be filtered out of log collection; if there is a container ``nginx`` that does not satisfy ``include`` in the first place, it will be filtered out of log collection.

container_include_log = ["image_name:datakit"]
container_exclude_log = ["image_name:*"]

## The container only needs to match either `image_name` and `namespace` to stop collecting logs.

container_include_log = []
container_exclude_log = ["image_name:datakit", "namespace:datakit-ns"]

- env:
  - name: ENV_INPUT_CONTAINER_CONTAINER_INCLUDE_LOG
    value: image:hello*  # Specify the image name or its wildcard

- env:
  - name: ENV_INPUT_CONTAINER_CONTAINER_INCLUDE_LOG
    value: namespace:foo  # Specify the namespace or its wildcard