Docker Log use

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foreword

Viewing docker logs usually uses the docker log command, and you can view the functions provided by the docker log by commanding docker help logs :

Options (optional parameters):
--details Display more detailed information
-f, --follow Track real-time logs --since string Display logs after
a certain (time) timestamp
, or relative time, such as 42m (ie 42 minutes) –tail string display N lines after the end of the log, the default is to display all -t, --timestamps add timestamp (timestamp)
before each line of log –until string display the log before a certain timestamp of the log, or relative time, such as 42m (ie 42 minutes)

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1. Common commands of Docker logs

docker log provides the function of querying logs according to time or time period, and querying logs according to a certain keyword. The following will give examples of commonly used log viewing commands:

1. View the docker container:

docker ps: List container
OPTIONS description:
-a: Display all containers, including those that are not running.
-f : Filter the displayed content according to the condition.
--format : Specifies the template file for the return value.
-l : Show recently created containers.
-n : List the last n containers created.
--no-trunc : Do not truncate output.
-q : Quiet mode, only display the container number.
-s : Display the total file size.

2. View container logs (all):

docker logs -f container ID

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3. View the container log, only the last 100 lines are displayed:

docker logs --tail 100 container ID

4. View the logs of the last 30 minutes of the container:

docker logs --since 30m container ID

5. View the logs of the container after a certain time:

The demonstration here is to query the logs docker logs --since 2023-03-03T10:13:58.655 container ID after 10:13:58 am on March 3, 2023

6. View the logs of the container for a certain period of time:

docker logs --since 2023-03-03T10:13:58.655 --until 2023-03-03T10:13:58.880 container id

7. View the container log and display the timestamp:

docker logs -t container ID

8. View the latest log of a certain time in the container log:

The demonstration here is the latest ten lines of log information within ten days
docker logs --tail 10 --since 240h container

9. Write container logs to a file:

The demonstration here is to write the last 100 logs of the specified container to the error file
docker logs --tail 100 container ID>>error.log

9. Query logs based on a certain keyword:

The demonstration here is to query logs according to the error keyword
docker logs container ID | grep error

10. Query the logs of the container for a certain period of time, and query based on keywords:

Here is a demonstration to view the logs of the container from 665 to 880 at 10:13:58 AM on March 3, 2023, and filter
docker logs according to the keyword 'Tomcat started on port' --since 2023-03-03T10:13:58.655 --until 2023-03-03T10:13:58.880 Container ID | grep 'Tomcat started on port'