How to mount multiple files / secrets into common directory in kubernetes?

11/27/2019

I've multiple secrets created from different files. I'd like to store all of them in common directory /var/secrets/. Unfortunately, I'm unable to do that because kubernetes throws 'Invalid value: "/var/secret": must be unique error during pod validation step. Below is an example of my pod definition.

apiVersion: v1
kind: Pod
metadata:
  labels:
    run: alpine-secret
  name: alpine-secret
spec:
  containers:
  - command:
    - sleep
    - "3600"
    image: alpine
    name: alpine-secret
    volumeMounts:
    - name: xfile
      mountPath: "/var/secrets/"
      readOnly: true
    - name: yfile
      mountPath: "/var/secrets/"
      readOnly: true
  volumes:
  - name: xfile
    secret:
      secretName: my-secret-one
  - name: yfile
    secret:
      secretName: my-secret-two

How can I store files from multiple secrets in the same directory?

-- Lukasz Dynowski
kubernetes
kubernetes-secrets

3 Answers

11/27/2019

Projected Volume

You can use a projected volume to have two secrets in the same directory

Example

apiVersion: v1
kind: Pod
metadata:
  labels:
    run: alpine-secret
  name: alpine-secret
spec:
  containers:
  - command:
    - sleep
    - "3600"
    image: alpine
    name: alpine-secret
    volumeMounts:
    - name: xyfiles
      mountPath: "/var/secrets/"
      readOnly: true
  volumes:
  - name: xyfiles
    projected:
      sources:
      - secret:
          name: my-secret-one
      - secret:
          name: my-secret-two
-- Jonas
Source: StackOverflow

11/28/2019

(EDIT: Never mind - I just noticed @Jonas gave the same answer earlier. +1 from me)

Starting with Kubernetes v1.11+ it is possible with projected volumes:

A projected volume maps several existing volume sources into the same directory.

Currently, the following types of volume sources can be projected:

  • secret
  • downwardAPI
  • configMap
  • serviceAccountToken

This is an example for "... how to use a projected Volume to mount several existing volume sources into the same directory".

-- apisim
Source: StackOverflow

11/27/2019

Edited: @Jonas answer is correct!

However, if you use volumes as I did in the question then, short answer is you cannot do that, You have to specify mountPath to an unused directory - volumes have to be unique and cannot be mounted to common directory.

Solution: What I did at the end was, instead keeping files in separate secrets, I created one secret with multiple files.

-- Lukasz Dynowski
Source: StackOverflow