Rollout Deployment
Last updated
Last updated
The Rollout Deployment
chart deploys an advanced version of deployment that supports Blue/Green and Canary deployments. For functioning, it requires a rollout controller to run inside the cluster.
You can define application behavior by providing information in the following sections:
Key | Descriptions |
---|---|
| Select the Chart Version using which you want to deploy the application. Refer Chart Version section for more detail. |
| You can perform a basic deployment configuration for your application in the Basic (GUI) section instead of configuring the YAML file. Refer Basic Configuration section for more detail. |
| If you want to do additional configurations, then click Advanced (YAML) for modifications. Refer Advanced (YAML) section for more detail. |
| You can enable |
Super-admins can lock keys in rollout deployment template to prevent non-super-admins from modifying those locked keys. Refer Lock Deployment Configuration to know more.
This defines the ports on which application services will be exposed to other services.
Key | Description |
---|---|
| envoy port for the container. |
| envoy Timeout for the container,envoy supports a wide range of timeouts that may need to be configured depending on the deployment.By default the envoytimeout is 15s. |
| the duration of time that a connection is idle before the connection is terminated. |
| name of the port. |
| port for the container. |
| port of the corresponding kubernetes service. |
| Used for high performance protocols like grpc where timeout needs to be disabled. |
| Envoy container can accept HTTP2 requests. |
EnvVariables
provide run-time information to containers and allow to customize how the application works and the behavior of the applications on the system.
Here we can pass the list of env variables , every record is an object which contain the name
of variable along with value
.
To set environment variables for the containers that run in the Pod.
IMP
Docker image should have env variables, whatever we want to set.
But ConfigMap
and Secret
are the preferred way to inject env variables. You can create this in App Configuration
Section.
It is a centralized storage, specific to k8s namespace where key-value pairs are stored in plain text.
It is a centralized storage, specific to k8s namespace where we can store the key-value pairs in plain text as well as in encrypted(Base64
) form.
IMP
All key-values of Secret
and CofigMap
will reflect to your application.
If this check fails, kubernetes restarts the pod. This should return error code in case of non-recoverable error.
Key | Description |
---|---|
| It define the path where the liveness needs to be checked. |
| It defines the time to wait before a given container is checked for liveliness. |
| It defines how often (in seconds) to perform the liveness probe. |
| It defines the number of successes required before a given container is said to fulfil the liveness probe. |
| The maximum time (in seconds) for the probe to complete. |
| The number of consecutive failures required to consider the probe as failed. |
| The mentioned command is executed to perform the livenessProbe. If the command returns a non-zero value, it's equivalent to a failed probe. |
| Custom headers to set in the request. HTTP allows repeated headers,You can override the default headers by defining .httpHeaders for the probe. |
| Scheme to use for connecting to the host (HTTP or HTTPS). Defaults to HTTP. |
| The kubelet will attempt to open a socket to your container on the specified port. If it can establish a connection, the container is considered healthy. |
The maximum number of pods that can be unavailable during the update process. The value of "MaxUnavailable: " can be an absolute number or percentage of the replicas count. The default value of "MaxUnavailable: " is 25%.
The maximum number of pods that can be created over the desired number of pods. For "MaxSurge: " also, the value can be an absolute number or percentage of the replicas count. The default value of "MaxSurge: " is 25%.
This specifies the minimum number of seconds for which a newly created Pod should be ready without any of its containers crashing, for it to be considered available. This defaults to 0 (the Pod will be considered available as soon as it is ready).
If this check fails, kubernetes stops sending traffic to the application. This should return error code in case of errors which can be recovered from if traffic is stopped.
Key | Description |
---|---|
| It define the path where the readiness needs to be checked. |
| It defines the time to wait before a given container is checked for readiness. |
| It defines how often (in seconds) to perform the readiness probe. |
| It defines the number of successes required before a given container is said to fulfill the readiness probe. |
| The maximum time (in seconds) for the probe to complete. |
| The number of consecutive failures required to consider the probe as failed. |
| The mentioned command is executed to perform the readinessProbe. If the command returns a non-zero value, it's equivalent to a failed probe. |
| Custom headers to set in the request. HTTP allows repeated headers,You can override the default headers by defining .httpHeaders for the probe. |
| Scheme to use for connecting to the host (HTTP or HTTPS). Defaults to HTTP. |
| The kubelet will attempt to open a socket to your container on the specified port. If it can establish a connection, the container is considered healthy. |
Startup Probe in Kubernetes is a type of probe used to determine when a container within a pod is ready to start accepting traffic. It is specifically designed for applications that have a longer startup time.
Key | Description |
---|---|
| It define the path where the startup needs to be checked. |
| It defines the time to wait before a given container is checked for startup. |
| It defines how often (in seconds) to perform the startup probe. |
| The number of consecutive successful probe results required to mark the container as ready. |
| The maximum time (in seconds) for the probe to complete. |
| The number of consecutive failures required to consider the probe as failed. |
| The mentioned command is executed to perform the startup probe. If the command returns a non-zero value, it's equivalent to a failed probe. |
| Custom headers to set in the request. HTTP allows repeated headers,You can override the default headers by defining .httpHeaders for the probe. |
| The kubelet will attempt to open a socket to your container on the specified port. If it can establish a connection, the container is considered healthy. |
This is connected to HPA and controls scaling up and down in response to request load.
Key | Description |
---|---|
| Set true to enable autoscaling else set false. |
| Minimum number of replicas allowed for scaling. |
| Maximum number of replicas allowed for scaling. |
| The target CPU utilization that is expected for a container. |
| The target memory utilization that is expected for a container. |
| Used to give external metrics for autoscaling. |
fullnameOverride
replaces the release fullname created by default by devtron, which is used to construct Kubernetes object names. By default, devtron uses {app-name}-{environment-name} as release fullname.
Image is used to access images in kubernetes, pullpolicy is used to define the instances calling the image, here the image is pulled when the image is not present,it can also be set as "Always".
Key | Description |
---|---|
| Determines whether to create a ServiceAccount for pods or not. If set to |
| Specifies the name of the ServiceAccount to use. |
| Specify annotations for the ServiceAccount. |
imagePullSecrets
contains the docker credentials that are used for accessing a registry.
regcred is the secret that contains the docker credentials that are used for accessing a registry. Devtron will not create this secret automatically, you'll have to create this secret using dt-secrets helm chart in the App store or create one using kubectl. You can follow this documentation Pull an Image from a Private Registry https://kubernetes.io/docs/tasks/configure-pod-container/pull-image-private-registry/ .
the hostAliases field is used in a Pod specification to associate additional hostnames with the Pod's IP address. This can be helpful in scenarios where you need to resolve specific hostnames to the Pod's IP within the Pod itself.
This allows public access to the url. Please ensure you are using the right nginx annotation for nginx class. The default value is nginx
.
Legacy deployment-template ingress format
Key | Description |
---|---|
| Enable or disable ingress |
| To configure some options depending on the Ingress controller |
| Host name |
| Path in an Ingress is required to have a corresponding path type. Supported path types are |
| Path name |
| It contains security details |
This allows private access to the url, please ensure you are using right nginx annotation for nginx class, its default value is nginx
Key | Description |
---|---|
| Enable or disable ingress |
| To configure some options depending on the Ingress controller |
| Host name |
| Path in an Ingress is required to have a corresponding path type. Supported path types are |
| Path name |
| Supported path types are |
| It contains security details |
Specialized containers that run before app containers in a Pod. Init containers can contain utilities or setup scripts not present in an app image. One can use base image inside initContainer by setting the reuseContainerImage flag to true
.
To wait for given period of time before switch active the container.
These define minimum and maximum RAM and CPU available to the application.
Resources are required to set CPU and memory usage.
Limits make sure a container never goes above a certain value. The container is only allowed to go up to the limit, and then it is restricted.
Requests are what the container is guaranteed to get.
This defines annotations and the type of service, optionally can define name also.
Key | Description |
---|---|
| Select the type of service, default |
| Annotations are widely used to attach metadata and configs in Kubernetes. |
| Optional field to assign name to service |
| If service type is |
Note - If loadBalancerSourceRanges
is not set, Kubernetes allows traffic from 0.0.0.0/0 to the LoadBalancer / Node Security Group(s).
It is required when some values need to be read from or written to an external disk.
It is used to provide mounts to the volume.
Spec is used to define the desire state of the given container.
Node Affinity allows you to constrain which nodes your pod is eligible to schedule on, based on labels of the node.
Inter-pod affinity allow you to constrain which nodes your pod is eligible to be scheduled based on labels on pods.
Key part of the label for node selection, this should be same as that on node. Please confirm with devops team.
Value part of the label for node selection, this should be same as that on node. Please confirm with devops team.
Taints are the opposite, they allow a node to repel a set of pods.
A given pod can access the given node and avoid the given taint only if the given pod satisfies a given taint.
Taints and tolerations are a mechanism which work together that allows you to ensure that pods are not placed on inappropriate nodes. Taints are added to nodes, while tolerations are defined in the pod specification. When you taint a node, it will repel all the pods except those that have a toleration for that taint. A node can have one or many taints associated with it.
This is used to give arguments to command.
It contains the commands to run inside the container.
Key | Description |
---|---|
| To enable or disable the command. |
| It contains the commands. |
| It is used to specify the working directory where commands will be executed. |
Containers section can be used to run side-car containers along with your main container within same pod. Containers running within same pod can share volumes and IP Address and can address each other @localhost. We can use base image inside container by setting the reuseContainerImage flag to true
.
It is a kubernetes monitoring tool and the name of the file to be monitored as monitoring in the given case.It describes the state of the prometheus.
Accepts an array of Kubernetes objects. You can specify any kubernetes yaml here and it will be applied when your app gets deployed.
Kubernetes waits for the specified time called the termination grace period before terminating the pods. By default, this is 30 seconds. If your pod usually takes longer than 30 seconds to shut down gracefully, make sure you increase the GracePeriod
.
A Graceful termination in practice means that your application needs to handle the SIGTERM message and begin shutting down when it receives it. This means saving all data that needs to be saved, closing down network connections, finishing any work that is left, and other similar tasks.
There are many reasons why Kubernetes might terminate a perfectly healthy container. If you update your deployment with a rolling update, Kubernetes slowly terminates old pods while spinning up new ones. If you drain a node, Kubernetes terminates all pods on that node. If a node runs out of resources, Kubernetes terminates pods to free those resources. It’s important that your application handle termination gracefully so that there is minimal impact on the end user and the time-to-recovery is as fast as possible.
It is used for providing server configurations.
It gives the details for deployment.
Key | Description |
---|---|
| It is the image tag |
| It is the URL of the image |
It gives the set of targets to be monitored.
It is used to configure database migration.
These Istio configurations collectively provide a comprehensive set of tools for controlling access, authenticating requests, enforcing security policies, and configuring traffic behavior within a microservices architecture. The specific settings you choose would depend on your security and traffic management requirements.
These Istio configurations collectively provide a comprehensive set of tools for controlling access, authenticating requests, enforcing security policies, and configuring traffic behavior within a microservices architecture. The specific settings you choose would depend on your security and traffic management requirements.
Key | Description |
---|---|
| Istio enablement. When |
| It allows you to define access control policies for service-to-service communication. |
| Determines whether to ALLOW or DENY the request based on the defined rules. |
| Authorization providers are external systems or mechanisms used to make access control decisions. |
| List of rules defining the authorization policy. Each rule can specify conditions and requirements for allowing or denying access. |
| It allows for the fine-tuning of traffic policies and load balancing for specific services. You can define subsets of a service and apply different traffic policies to each subset. |
| Specifies subsets within the service for routing and load balancing. |
| Policies related to connection pool size, outlier detection, and load balancing. |
| Allowing external traffic to enter the service mesh through the specified configurations. |
| The external domain through which traffic will be routed into the service mesh. |
| Traffic to and from the gateway should be encrypted using TLS. |
| Specifies the name of the Kubernetes secret that contains the TLS certificate and private key. The TLS certificate is used for securing the communication between clients and the Istio gateway. |
| It allows you to enforce mutual TLS and control the authentication between services. |
| Mutual TLS. Mutual TLS is a security protocol that requires both client and server, to authenticate each other using digital certificates for secure communication. |
| Mutual TLS mode, specifying how mutual TLS should be applied. Modes include STRICT, PERMISSIVE, and DISABLE. |
| Configures port-specific mTLS settings. Allows for fine-grained control over the application of mutual TLS on specific ports. |
| Configuration for selecting workloads to apply PeerAuthentication. |
| Defines rules for authenticating incoming requests. |
| Rules for validating JWTs (JSON Web Tokens). It defines how incoming JWTs should be validated for authentication purposes. |
| Specifies the conditions under which the RequestAuthentication rules should be applied. |
| Enables the definition of rules for how traffic should be routed to different services within the service mesh. |
| Specifies the gateways to which the rules defined in the VirtualService apply. |
| List of hosts (domains) to which this VirtualService is applied. |
| Configuration for HTTP routes within the VirtualService. It define routing rules based on HTTP attributes such as URI prefixes, headers, timeouts, and retry policies. |
Application metrics can be enabled to see your application's metrics-CPU Service Monitor usage, Memory Usage, Status, Throughput and Latency.
It gives the realtime metrics of the deployed applications
Key | Description |
---|---|
| It shows how often this app is deployed to production |
| It shows how often the respective pipeline fails. |
| It shows the average time taken to deliver a change to production. |
| It shows the average time taken to fix a failed pipeline. |
A service account provides an identity for the processes that run in a Pod.
When you access the cluster, you are authenticated by the API server as a particular User Account. Processes in containers inside pod can also contact the API server. When you are authenticated as a particular Service Account.
When you create a pod, if you do not create a service account, it is automatically assigned the default service account in the namespace.
You can create PodDisruptionBudget
for each application. A PDB limits the number of pods of a replicated application that are down simultaneously from voluntary disruptions. For example, an application would like to ensure the number of replicas running is never brought below the certain number.
or
You can specify either maxUnavailable
or minAvailable
in a PodDisruptionBudget and it can be expressed as integers or as a percentage.
Key | Description |
---|---|
| Evictions are allowed as long as they leave behind 1 or more healthy pods of the total number of desired replicas. |
| Evictions are allowed as long as at most 1 unhealthy replica among the total number of desired replicas. |
Envoy is attached as a sidecar to the application container to collect metrics like 4XX, 5XX, Throughput and latency. You can now configure the envoy settings such as idleTimeout, resources etc.
Alerting rules allow you to define alert conditions based on Prometheus expressions and to send notifications about firing alerts to an external service.
In this case, Prometheus will check that the alert continues to be active during each evaluation for 1 minute before firing the alert. Elements that are active, but not firing yet, are in the pending state.
Labels are key/value pairs that are attached to pods. Labels are intended to be used to specify identifying attributes of objects that are meaningful and relevant to users, but do not directly imply semantics to the core system. Labels can be used to organize and to select subsets of objects.
Pod Annotations are widely used to attach metadata and configs in Kubernetes.