Skip to main content

Kubernetes: 17. Application Logs

Docker Logs

  • docker run will shows the logs on the terminal
  • docker run when executed in detached mode "-d" will not show the logs on the terminal
  • To view the logs of container running in the detached mode we use docker logs command. Add "-f" flag to follow the live logs
Kubernetes Logs
  • Kubernetes pod logs can be viewed using kubectl logs command
  • If there are multiple containers running in the pod, provide the container name as input to the command
  • Use "-f" flag to "follow" the logs similar to docker
  • When using "-f" flag with kubectl create, it indicates create from the file specified in the command

docker run nginx 
-> Run a container on the terminal, logs will be be displayed

docker run -d nginx 
-> Run the container in the detached mode, logs will no more be displayed

docker logs -f nginx
-> display the logs of the container, -f (follows) will shows the live logs

kubectl logs -f <pod-name>
-> Shows the logs of the <pod-name> in the default namespace

kubectl logs -f <pod-name> -c <container-name>
-> Shows the logs of the <container-name> running in the <pod-name> in the default namespace



Labels:

Comments

Post a Comment

Popular posts from this blog

Azure Active Directory

Azure Active directory (AAD) is a Identity as a Service. This is a smaller subset of Active directory. This is not a replacement to active directory at all. Azure active directory provides the identity services to the mobile apps and web apps in Private cloud. These apps may be connected to on-premise applications. So an SSO is enabled for these apps. So Azure active directory has very simple functionality. Create Users, Groups. Map groups to network security groups and provide the authentication to the resources. When you login to Azure portal, right upper corner of the screen has username along with the domain. Domain or tenant or organization are used interchangeably. Management of Users and Groups: Cloud identity (create users manually)  Directory synchronized identifiers (users are synchronized)  Add users Adding a cloud identity users makes the user as Guest When you do directory synchronization on Premise AD Groups are synched up wi...
Post a Comment
Read more

Kubernetes: 18. Rollout and Rollback

Deployment When a deployment is created, it triggers a rollout Rollout creates a new revision (version) In the future when new deployment is created,  a new rollout is created The new rollout creates one more "new" version These versions help to keep track of the changes and rollback if necessary Deployment Strategy First strategy is delete and recreate strategy.  Delete all the existing pods and deploy the new updated pods But this comes with application downtime Second strategy and default strategy is Rolling update strategy Kubernetes deletes one pod at a time in the older version and in its place creates a one pod at a time in the newer version Update Strategy Updates can be many things like updating the labels, docker image, replicas etc These are directly updated into the deployment file and the changes are applied When the changes are applied using kubectl apply command, a new rollout and a new revision is created Another way to update the image name is to use the kube...
Post a Comment
Read more

Kubernetes: 19. Configure Application

Configuring application consists of Configuring commands and arguments on applications Configuring environment variables Configuring secrets Docker Commands docker run ubuntu  -> Runs ubuntu container and exit, container CMD is set to [bash], so the container quitely exits docker run ubuntu echo "Hello World" -> Runs ubuntu container, prints "Hello World" exits quitely. To update the default settings, create your own image from the base image lets call this ubuntu-sleeper image FROM ubuntu CMD sleep 5 CMD can also be mentioned in the JSON format like CMD ["sleep", "5"] Note that with JSON format the first element should always be the command to execute,  for eg, it CANNOT be ["sleep 5"] Run build the new ubuntu-sleeper image and run the new image docker build -t ubuntu-sleeper .  -> Build the image docker run ubuntu-sleeper -> Run the new image So the new image will launch ubuntu container, sleep for 5 seconds and quitely ex...
Post a Comment
Read more