# k8s-sidecar

**Repository Path**: mirrors_haf/k8s-sidecar

## Basic Information

- **Project Name**: k8s-sidecar
- **Description**: This is a docker container intended to run inside a kubernetes cluster to collect config maps with a specified label and store the included files in a local folder.
- **Primary Language**: Unknown
- **License**: MIT
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2021-06-29
- **Last Updated**: 2026-02-14

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README



[![CircleCI](https://img.shields.io/circleci/project/github/kiwigrid/k8s-sidecar/master.svg?style=plastic)](https://circleci.com/gh/kiwigrid/k8s-sidecar)
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# What?

This is a docker container intended to run inside a kubernetes cluster to collect config maps with a specified label and store the included files in an local folder. It can also send an HTTP request to a specified URL after a configmap change. The main target is to be run as a sidecar container to supply an application with information from the cluster. The contained Python script is working from Kubernetes API 1.10.

# Why?

Currently (April 2018) there is no simple way to hand files in configmaps to a service and keep them updated during runtime.

# How?

Run the container created by this repo together with your application in an single pod with a shared volume. Specify which label should be monitored and where the files should be stored.
By adding additional env variables the container can send an HTTP request to specified URL.

# Where?

Images are available at:

- [docker.io/kiwigrid/k8s-sidecar](https://hub.docker.com/r/kiwigrid/k8s-sidecar)
- [quay.io/kiwigrid/k8s-sidecar](https://quay.io/repository/kiwigrid/k8s-sidecar)

Both are identical multi-arch images built for `amd64`, `arm64` and `arm/v7`

# Features

- Extract files from config maps
- Filter based on label
- Update/Delete on change of configmap
- Enforce unique filenames

# Usage 

Example for a simple deployment can be found in [`example.yaml`](./example.yaml). Depending on the cluster setup you have to grant yourself admin rights first: `kubectl create clusterrolebinding cluster-admin-binding --clusterrole cluster-admin   --user $(gcloud config get-value account)`

One can override the default directory that files are copied into using a configmap annotation defined by the environment variable "FOLDER_ANNOTATION" (if not present it will default to "k8s-sidecar-target-directory"). The sidecar will attempt to create directories defined by configmaps if they are not present. Example configmap annotation:
  `k8s-sidecar-target-directory: "/path/to/target/directory"`

If the filename ends with `.url` suffix, the content will be processed as an URL the target file will be downloaded and used as the content file.

## Configuration Environment Variables

- `LABEL`
  - description: Label that should be used for filtering
  - required: true
  - type: string

- `LABEL_VALUE`
  - description: The value for the label you want to filter your resources on. Don't set a value to filter by any value
  - required: false
  - type: string

- `FOLDER`
  - description: Folder where the files should be placed
  - required: true
  - type: string

- `FOLDER_ANNOTATION`
  - description: The annotation the sidecar will look for in configmaps to override the destination folder for files, defaults to "k8s-sidecar-target-directory". The annotation _value_ can be either an absolute or a relative path. Relative paths will be relative to `FOLDER`.
  - required: false
  - type: string

- `NAMESPACE`
  - description: If specified, the sidecar will search for config-maps inside this namespace. Otherwise the namespace in which the sidecar is running will be used. It's also possible to specify `ALL` to search in all namespaces.
  - required: false
  - type: string

- `RESOURCE`
  - description: Resource type, which is monitored by the sidecar. Options: configmap (default), secret, both
  - required: false
  - default: configmap
  - type: string

- `METHOD`
  - description: If `METHOD` is set with `LIST`, the sidecar will just list config-maps/secrets and exit. With `SLEEP` it will list all config-maps/secrets, then sleep for `SLEEP_TIME` seconds. Default is watch.
  - required: false
  - type: string

- `SLEEP_TIME`
  - description: How many seconds to wait before updating config-maps/secrets when using `SLEEP` method.
  - required: false
  - default: 60
  - type: integer

- `REQ_URL`
  - description: URL to which send a request after a configmap/secret got reloaded
  - required: false
  - type: URI

- `REQ_USERNAME`
  - description: Username to use for basic authentication
  - required: false
  - type: string

- `REQ_METHOD`
  - description: Request method GET(default) or POST
  - required: false
  - type: string

- `REQ_PAYLOAD`
  - description: If you use POST you can also provide json payload
  - required: false
  - type: json

- `REQ_PASSWORD`
  - description: Password to use for basic authentication
  - required: false
  - type: string

- `REQ_RETRY_TOTAL`
  - description: Total number of retries to allow
  - required: false
  - default: 5
  - type: integer

- `REQ_RETRY_CONNECT`
  - description: How many connection-related errors to retry on
  - required: false
  - default: 5
  - type: integer

- `REQ_RETRY_READ`
  - description: How many times to retry on read errors
  - required: false
  - default: 5
  - type: integer

- `REQ_RETRY_BACKOFF_FACTOR`
  - description: A backoff factor to apply between attempts after the second try
  - required: false
  - default: 0.2
  - type: float

- `REQ_TIMEOUT`
  - description: How many seconds to wait for the server to send data before giving up
  - required: false
  - default: 10
  - type: float

- `SCRIPT`
  - description: Absolute path to shell script to execute after a configmap got reloaded. In runs before REQ
  - required: false
  - type: string

- `ERROR_THROTTLE_SLEEP`
  - description: How many seconds to wait before watching resources again when an error occurs
  - required: false
  - default: 5
  - type: integer

- `SKIP_TLS_VERIFY`
  - description: Set to true to skip tls verification for kube api calls
  - required: false
  - type: boolean

- `UNIQUE_FILENAMES`
  - description: Set to true to produce unique filenames where duplicate data keys exist between ConfigMaps and/or Secrets within the same or multiple Namespaces.
  - required: false
  - default: false
  - type: boolean

- `DEFAULT_FILE_MODE`
  - description: The default file system permission for every file. Use three digits (e.g. '500', '440', ...)
  - required: false
  - type: string

- `KUBECONFIG`
  - description: if this is given and points to a file or `~/.kube/config` is mounted k8s config will be loaded from this file, otherwise "incluster" k8s configuration is tried.
  - required: false
  - type: string

- `ENABLE_5XX`
  - description: Set to true to enable pulling of 5XX response content from config map. Used in case if the filename ends with `.url` suffix (Please refer to the `*.url` feature here.)
  - required: false
  - type: boolean