Introduction
When deploying an ASP.NET Core application on Kubernetes (K8S), it is essential to handle sensitive information such as database connection strings, API keys, and other configurations securely. K8S provides two essential resources for managing such data: Secrets and ConfigMaps. In this blog post, we will explore how to leverage Secrets and ConfigMaps to store and retrieve sensitive configuration data in an ASP.NET Core application running on K8S.
What are Secrets?
Secrets in K8S are a way to store sensitive information, such as passwords, API keys, and certificates, securely. Secrets are stored as Base64 encoded strings within K8S and can be mounted as files or accessed as environment variables by the containers running in the K8S cluster. By using Secrets, we can avoid hardcoding these sensitive values directly into the application code or configuration files.
Creating a Secret
To create a Secret, we can run the following command in the K8S cluster:
kubectl create secret generic my-secret --from-literal=database-connection-string=<connection_string> --from-literal=api-key=<api_key>
In the above command, we create a Secret called "my-secret" and provide two key-value pairs: "database-connection-string" and "api-key". The values for these keys are specified using the --from-literal flag.
Mounting a Secret in ASP.NET Core
Once the Secret is created, we can mount it in our ASP.NET Core application running on K8S. To do this, we need to modify the deployment file for our application. An example of how to mount a Secret as environment variables is shown below:
...
spec:
containers:
- name: my-app
image: my-app-image
env:
- name: DB_CONNECTION_STRING
valueFrom:
secretKeyRef:
name: my-secret
key: database-connection-string
- name: API_KEY
valueFrom:
secretKeyRef:
name: my-secret
key: api-key
...
In the above YAML configuration, we specify the environment variable names (DB_CONNECTION_STRING and API_KEY) and link them to the corresponding keys in the Secret (database-connection-string and api-key).
What are ConfigMaps?
ConfigMaps in K8S are used to store non-sensitive configuration data, such as application settings, environment variables, and file contents. These configurations can be mounted as environment variables or files in the containers running in the K8S cluster. ConfigMaps are especially useful in scenarios where we want to separate the configuration data from the application code.
Creating a ConfigMap
To create a ConfigMap, we can use the following command:
kubectl create configmap my-config --from-literal=app-setting-1=<setting_1> --from-literal=app-setting-2=<setting_2>
In the above command, we create a ConfigMap called "my-config" and provide two key-value pairs: "app-setting-1" and "app-setting-2". The values for these keys are specified using the --from-literal flag.
Mounting a ConfigMap in ASP.NET Core
To mount a ConfigMap in an ASP.NET Core application, we need to modify the deployment file similarly to how we did for the Secret. Below is an example of how to mount a ConfigMap as environment variables:
...
spec:
containers:
- name: my-app
image: my-app-image
envFrom:
- configMapRef:
name: my-config
...
In the above YAML configuration, we specify the name of the ConfigMap (my-config) in the envFrom field. This will mount all the key-value pairs in the ConfigMap as environment variables in the container.
Conclusion
In this blog post, we explored how to leverage Secrets and ConfigMaps in K8S to store and retrieve sensitive configuration data in an ASP.NET Core application. By using these resources, we can ensure that our application's sensitive information is securely managed and decoupled from the application code. Incorporating Secrets and ConfigMaps in our K8S deployments enables us to easily scale and manage our ASP.NET Core applications in a more secure and maintainable way.
本文来自极简博客，作者：蓝色幻想，转载请注明原文链接：ASP.NET Core on K8S: Secret
