LambdaStack how-tos - Security

How to enable/disable LambdaStack service user

To enable/disable LambdaStack service user you can use tool from our repository. You can find this in directory tools/service_user_disable_enable under name service-user-disable-enable.yml.

To use this you need to have Ansible installed on machine from which you want to execute this.

To disable user you need to run command:

ansible-playbook -i inventory --extra-vars "operation=disable name=your_service_user_name" service-user-disable-enable.yml

To enable user you need to run command:

ansible-playbook -i inventory --extra-vars "operation=enable name=your_service_user_name" service-user-disable-enable.yml

How to add/remove additional users to/from OS

To add/remove users you need to provide additional section to kind: lambdastack-cluster configuration.

You need to add specification.users in the format similar to example that you can find below:

kind: lambdastack-cluster
name: pg-aws-deb
provider: aws
build_path: '' # Dynamically built


    - name: user01 # name of the user
      sudo: true # does user have sudo priviledge, not defined will set to false
      state: present # user will be added if not exist
      public_key: "ssh-rsa ..." # public key to add to .ssh/authorized_keys
    - name: user02
      state: absent # user will deleted if exists
      public_key: "ssh-rsa ..."
    - name: user03
      state: present
      public_key: "ssh-rsa ..."


How to use TLS/SSL certificate with HA Proxy


How to use TLS/SSL with Kafka

Right now LambdaStack supports only self-signed certificates generated and signed by CA self-sign certificate. If you want to provide your own certificates you need to configure Kafka manually according to Kafka documentation.

To use LambdaStack automation and self-signed certificates you need to provide your own configuration for kafka role and enable TLS/SSL as this is disabled by default.

To enable TLS/SSL communication in Kafka you can provide your own configuration of Kafka by adding it to your LambdaStack configuration file and set the enabled flag to true in the security/ssl section.

If in the ssl section you will also set the parameter client_auth parameter as required, you have to also provide configuration of authorization and authentication as this setting enforces checking identity. This option is by default set as required. Values requested and none don't require such setup.

When TLS/SSL is turned on then all communication to Kafka is encrypted and no other option is enabled. If you need different configuration, you need to configure Kafka manually.

When CA certificate and key is created on server it is also downloaded to host from which LambdaStack was executed. By default LambdaStack downloads this package to build output folder to ansible/kafka_certs directory. You can also change this path in LambdaStack configuration.

Sample configuration for Kafka with enabled TLS/SSL:

kind: configuration/kafka
title: "Kafka"
name: default


        enabled: True
        port: 9093 # port on which Kafka will listen for encrypted communication
          local_cert_download_path: kafka-certs # path where generated key and certificate will be downloaded
          keystore_location: /var/private/ssl/kafka.server.keystore.jks # location of keystore on servers
          truststore_location: /var/private/ssl/kafka.server.truststore.jks # location of truststore on servers
          cert_validity: 365 # period of time when certificates are valid
          passwords: # in this section you can define passwords to keystore, truststore and key
            keystore: PasswordToChange
            truststore: PasswordToChange
            key: PasswordToChange

        endpoint_identification_algorithm: HTTPS # this parameter enforces validating of hostname in certificate
        client_auth: required # authentication mode for Kafka - options are: none (no authentication), requested (optional authentication), required (enforce authentication, you need to setup also authentication and authorization then)
      inter_broker_protocol: SSL # must be set to SSL if TLS/SSL is enabled


How to use TLS/SSL certificates for Kafka authentication

To configure Kafka authentication with TLS/SSL, first you need to configure ssl section. Then you need to add authentication section with enabled flag set to true and set authentication_method as certificates. Setting authentication_method as sasl is not described right now in this document.

kind: configuration/kafka
title: "Kafka"
name: default
build_path: '' # Dynamically built




        enabled: True
        authentication_method: certificates


How to use TLS/SSL certificates for Kafka authorization

To configure Kafka authorization with TLS/SSL, first you need to configure ssl and authentication sections. If authentication is disabled, then authorization will be disabled as well.

To enable authorization, you need to provide authorization section and set enabled flag to True.

For authorization you can also provide different than default authorizer_class_name. By default is used.

If allow_everyone_if_no_acl_found parameter is set to False, Kafka will prevent accessing resources everyone except super users and users having permissions granted to access topic.

You can also provide super users that will be added to Kafka configuration. To do this you need to provide list of users, like in the example below, and generate certificate on your own only with CN that matches position that can be found in list (do not set OU, DC or any other of parameters). Then the certificate needs to be signed by CA root certificate for Kafka. CA root certificate will be downloaded automatically by LambdaStack to location set in ssl.server.local_cert_download_path or can be found on first Kafka host in ssl.server.keystore_location directory. To access the certificate key, you need root priviledges.

kind: configuration/kafka
title: "Kafka"
name: default
build_path: '' # Dynamically built




        enabled: True
        allow_everyone_if_no_acl_found: False
          - tester01
          - tester02

How to enable Azure disk encryption

Automatic encryption of storage on Azure is not yet supported by LambdaStack. Guides to encrypt manually can be found:

  • Here for VM storage.
  • Here for storage shares,

How to use TLS/SSL certificate with RabbitMQ

To configure RabbitMQ TLS support in LambdaStack you need to set custom_configurations in the configuration file and manually create certificate with common CA according to documentation on your RabbitMQ machines:


If stop_service parameter in configuration/rabbitmq is set to true, then RabbitMQ will be installed and stopped to allow manual actions that are required to copy or generate TLS certificates.


To complete installation it's required to execute lambdastack apply the second time with stop_service set to false

There is custom_configurations setting in LambdaStack that extends RabbitMQ configuration with the custom one. Also, it can be used to perform TLS configuration of RabbitMQ. To customize RabbitMQ configuration you need to pass a list of parameters in format:

-name: rabbitmq.configuration.parameter value: rabbitmq.configuration.value

These settings are mapping to RabbitMQ TLS parameters configuration from documentation that you can find below the link:

Below you can find example of TLS/SSL configuration.

kind: configuration/rabbitmq
title: "RabbitMQ"
name: default
build_path: '' # Dynamically built


    - name: listeners.tcp # option that disables non-TLS/SSL support
      value: none
    - name: listeners.ssl.default # port on which TLS/SSL RabbitMQ will be listening for connections
      value: 5671
    - name: ssl_options.cacertfile # file with certificate of CA which should sign all certificates
      value: /var/private/ssl/ca/ca_certificate.pem
    - name: ssl_options.certfile # file with certificate of the server that should be signed by CA
      value: /var/private/ssl/server/server_certificate.pem
    - name: ssl_options.keyfile # file with key to the certificate of the server
      value: /var/private/ssl/server/private_key.pem
    - name: ssl_options.password # password to key protecting server certificate
      value: PasswordToChange
    - name: ssl_options.verify # setting of peer verification
      value: verify_peer
    - name: ssl_options.fail_if_no_peer_cert # parameter that configure behaviour if peer cannot present a certificate
      value: "false"


Please be careful about boolean values as they need to be double quoted and written in lowercase form. Otherwise RabbitMQ startup will fail.

How to enable AWS disk encryption

EC2 Root volumes

Encryption at rest for EC2 root volumes is turned on by default. To change this one can modify the encrypted flag for the root disk inside a infrastructure/virtual-machine document:

    volume_type: gp2
    volume_size: 30
    delete_on_termination: true
    encrypted: true

Additional EC2 volumes

Encryption at rest for additional EC2 volumes is turned on by default. To change this one can modify the encrypted flag for each additional_disks inside a infrastructure/virtual-machine document:

    - device_name: "/dev/sdb"
      volume_type: gp2
      volume_size: 60
      delete_on_termination: true
      encrypted: true

EFS storage

Encryption at rest for EFS storage is turned on by default. To change this one can modify the encrypted flag inside the infrastructure/efs-storage document:

kind: infrastructure/efs-storage
title: "Elastic File System Config"
provider: aws
name: default
build_path: '' # Dynamically built
  encrypted: true

Additional information can be found here.

How to use Kubernetes Secrets

Prerequisites: LambdaStack Kubernetes cluster

  1. SSH into the Kubernetes master.

  2. Run echo -n 'admin' > ./username.txt, echo -n 'VeryStrongPassword!!1' > ./password.txt and kubectl create secret generic mysecret --from-file=./username.txt --from-file=./password.txt

  3. Copy over secrets-sample.yaml file from the example folder and run it with kubectl apply -f secrets-sample.yaml

  4. Run kubectl get pods, copy the name of one of the ubuntu pods and run kubectl exec -it POD_NAME -- /bin/bash with it.

  5. In the pods bash run printenv | grep SECRET - Kubernetes secret created in point 2 was attached to pods during creation (take a look at secrets-sample.yaml) and are availiable inside of them as an environmental variables.

How to authenticate to Azure AD app

  1. Register you application. Go to Azure portal to Azure Active Directory => App registrations tab.

  2. Click button New application registration fill the data and confirm.

  3. Deploy app from examples/dotnet/LambdaStack.SampleApps/LambdaStack.SampleApps.AuthService.

    This is a test service for verification Azure AD authentication of registered app. (How to deploy app)

  4. Create secret key for your app settings => keys. Remember to copy value of key after creation.

  5. Try to authenticate (e.g. using postman) calling service api <service-url>/api/auth/ with following Body application/json type parameters :

      "TenantId": "<tenant-id>",
      "ClientId": "<client-id>",
      "Resource": "",
      "ClientSecret": "<client-secret>"
    • TenantId - Directory ID, which you find in Azure active Directory => Properties tab.

    • ClientId - Application ID, which you find in details of previously registered app Azure Active Directory => App registrations => your app

    • Resource - is the service root of Azure AD Graph API. The Azure Active Directory (AD) Graph API provides programmatic access to Azure AD through OData REST API endpoints. You can construct your own Graph API URL. (How to construct a Graph API URL)

    • ClientSecret - Created secret key from 4. point.

  6. The service should return Access Token.

How to run lambdastack with password

LambdaStack encrypts Kubernetes artifacts (access tokens) stored in LambdaStack build directory. In order to achieve it, user is asked for password which will be used for encryption and decryption of artifacts. Remember to enter the same password for the same cluster - if password will not be the same, lambdastack will not be able to decrypt secrets.

Standard way of executing lambdastack has not been changed:

lambdastack apply -f demo.yaml

But you will be asked to enter a password:

Provide password to encrypt vault:

When running lambdastack from CI pipeline you can use new parameter for lambdastack:

lambdastack apply -f build/demo/demo.yaml --vault-password MYPWD

How to make kubectl work for non-root user on master node

For security reasons, the access to the admin credentials is limited to the root user. To make a non-root user the cluster administrator, run these commands (as the non-root user):

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

See more options in Troubleshooting

How to turn on Hashicorp Vault functionality

In LambdaStack beside storing secrets in Kubernetes secrets there is also a possibility of using secrets stored in Vault from Hashicorp. This can provide much more sophisticated solution for using secrets and also higher level of security than standard Kubernetes secrets implementation. Also LambdaStack provides transparent method to access Hashicorp Vault secrets with applications running on Kubernetes. You can read in the more about it in How to turn on Hashicorp Vault integration with k8s section. In the future we want also to provide additional features that right now can be configured manually according to Hashicorp Vault documentation.

At the moment only installation on Kubernetes Control Plane is supported, but we are also planning separate installation with no other components. Also at this moment we are not providing clustered option for Vault deployment, but this will be part of the future releases. For multi-master (HA) Kubernetes, Vault is installed only on the first master defined in Ansible inventory.

Below you can find sample configuration for Vault with description of all options.

kind: configuration/vault
title: Vault Config
name: default
  vault_enabled: true # enable Vault install
  vault_system_user: vault # user name under which Vault service will be running
  vault_system_group: vault # group name under which Vault service will be running
  enable_vault_audit_logs: false # turn on audit logs that can be found at /opt/vault/logs/vault_audit.log
  enable_vault_ui: false # enable Vault UI, shouldn't be used at production
  vault_script_autounseal: true # enable automatic unseal vault at the start of the service, shouldn't be used at production
  vault_script_autoconfiguration: true # enable automatic configuration of Hashicorp Vault. It sets the UNSEAL_VAULT variable in script.config
  app_secret_path: devwebapp # application specific path where application secrets will be mounted
  revoke_root_token: false # not implemented yet (more about in section Root token revocation)
  secret_mount_path: secret # start of the path that where secrets will be mounted
  vault_token_cleanup: true # should configuration script clean token
  vault_install_dir: /opt/vault # directory where vault will be installed
  vault_log_level: info # logging level that will be set for Vault service
  override_existing_vault_users: false # should user from vault_users ovverride existing user and generate new password
  vault_users: # users that will be created with vault
    - name: admin # name of the user that will be created in Vault
      policy: admin # name of the policy that will be assigned to user (descrption bellow)
    - name: provisioner
      policy: provisioner
  vault_helm_chart_values: # helm chart values overwriting the default package (to be able to use internal registry for offline purposes)
      externalVaultAddr: https://your-external-address:8200 # external vault address (only if you want to setup address to provide full name to use with signed certificate) [IMPORTANT: switch https->http if tls_disable parameter is set to true]
        repository: "{{ image_registry_address }}/hashicorp/vault-k8s" # docker image used by vault injector in kubernetes
        repository: "{{ image_registry_address }}/vault" # docker image used by vault injector in kubernetes
        repository: "{{ image_registry_address }}/vault" # docker image used by vault injector in kubernetes
  # TLS part
  tls_disable: false # enable TLS support, should be used always in production
  certificate_name: fullchain.pem # certificate file name
  private_key_name: privkey.pem # private key file name for certificate
  vault_tls_valid_days: 365 # certificate valid time in days
  selfsigned_certificate: # selfsigned certificate information
    country: US # selfexplanatory
    state: state # selfexplanatory
    city: city # selfexplanatory
    company: company # selfexplanatory
    common_name: "*" # selfexplanatory

More information about configuration of Vault in LambdaStack and some guidance how to start working with Vault with LambdaStack you can find below.

To get more familiarity with Vault usage you can reffer to official getting started guide.

Creation of user using LambdaStack in Vault

To create user by LambdaStack please provide list of users with name of policy that should be assigned to user. You can use predefined policy delivered by LambdaStack, default Vault policies or your own policy. Remember that if you have written your own policy it must exist before user creation.

Password for user will be generated automatically and can be found in directory /opt/vault in files matching tokens-*.csv pattern. If user password will be generated or changed you will see corresponding line in csv file with username, policy and password. If password won't be updated you will see ALREADY_EXISTS in password place.

Predefined Vault policies

Vault policies are used to define Role-Based Access Control that can be assigned to clients, applications and other components that are using Vault. You can find more information about policies here.

LambdaStack besides two already included in vault policies (root and default) provides two additional predefined policies:

  • admin - policy granting administration privileges, have sudo permission on Vault system endpoints
  • provisioner - policy granting permissions to create user secrets, adding secrets, enable authentication methods, but without access to Vault system endpoints

Manual unsealing of the Vault

By design Hashicorp Vault starts in sealed mode. It means that Vault data is encrypted and operator needs to provide unsealing key to be able to access data.

Vault can be unsealed manually using command:

vault operator unseal

and passing three unseal keys from /opt/vault/init.txt file. Number of keys will be defined from the level of LambdaStack configuration in the future releases. Right now we are using default Hashicorp Vault settings.

For development purposes you can also use vault_script_autounseal option in LambdaStack configuration.

More information about unseal you can find in documentation for CLI and about concepts here.

Configuration with manual unsealing

If you are using option with manual unseal or want to perform manual configuration you can run script later on manually from the command line:

        -c /opt/vault/script.config
        -a ip_address_of_vault
        -p http | https
        -v helm_chart_values_be_override

Values for script configuration in script.config are automatically generated by LambdaStack and can be later on used to perform configuration.

Log into Vault with token

To log into Vault with token you just need to pass token. You can do this using command:

vault login

Only root token has no expiration date, so be aware that all other tokens can expire. To avoid such situations you need to renew the token. You can assign policy to token to define access.

More information about login with tokens you can find here and about tokens here.

Log into Vault with user and password

Other option to log into Vault is to use user/password pair. This method doesn't have disadvantage of login each time with different token after expire. To login with user/password pair you need to have userpass method and login with command:

vault login -method=userpass username=your-username

More information about login with tokens you can find here and about userpass authentication here.

Token Helpers

Vault provide option to use token helper. By default Vault is creating a file .vault-token in home directory of user running command vault login, which let to user perform automatically commands without providing a token. This token will be removed by default after LambdaStack configuration, but this can be changed using vault_token_cleanup flag.

More information about token helper you can find here.

Creating your own policy

In order to create your own policy using CLI please refer to CLI documentation and documentation.

Creating your own user

In order to create your own user with user and password login please refer to documentation. If you have configured any user using LambdaStack authentication userpass will be enabled, if not needs to be enabled manually.

Root token revocation

In production is a good practice to revoke root token. This option is not implemented yet, by LambdaStack, but will be implemented in the future releases.

Be aware that after revoking root token you won't be able to use configuration script without generating new token and replace old token with the new one in /opt/vault/init.txt (field Initial Root Token). For new root token generation please refer to documentation accessible here.

TLS support

By default tls_disable is set to false which means that certificates are used by vault. There are 2 ways of certificate configuration:

  1. selfsigned

Vault selfsigned certificates are generated automatically during vault setup if no custom certificates are present in dedicated location.

  1. certificate provided by user

In dedicated location user can add certificate (and private key). File names are important and have to be the same as provided in configuration and .pem file extensions are required.

Dedicated location of custom certificates: core/src/lambdastack/data/common/ansible/playbooks/roles/vault/files/tls-certs

Certificate files names configuration:

kind: configuration/vault
title: Vault Config
name: default
  certificate_name: fullchain.pem # certificate file name
  private_key_name: privkey.pem # private key file name for certificate

Production hardening for Vault

In LambdaStack we have performed a lot of things to improve Vault security, e.g.:

  • End-to-End TLS
  • Disable Swap (when running on Kubernetes machine)
  • Don't Run as Root
  • Turn Off Core
  • Enable Auditing
  • Restrict Storage Access
  • Tweak ulimits

However if you want to provide more security please refer to this guide.


To perform troubleshooting of vault and find the root cause of the problem please enable audit logs and set vault_log_level to debug. Please be aware that audit logs can contain sensitive data.

How to turn on Hashicorp Vault integration with k8s

In LambdaStack there is also an option to configure automatically integration with Kubernetes. This is achieved with applying additional settings to Vault configuration. Sample config with description you can find below.

kind: configuration/vault
title: Vault Config
name: default
  vault_enabled: true
  vault_script_autounseal: true
  vault_script_autoconfiguration: true
  kubernetes_integration: true # enable setup kubernetes integration on vault side
  kubernetes_configuration: true # enable setup kubernetes integration on vault side
  enable_vault_kubernetes_authentication: true # enable kubernetes authentication on vault side
  kubernetes_namespace: default # namespace where your application will be deployed

Vault and Kubernetes integration in LambdaStack relies on vault-k8s tool. Thit tool enables sidecar injection of secret into pod with usage of Kubernetes Mutating Admission Webhook. This is transparent for your application and you do not need to perform any binding to Hashicorp libaries to use secret stored in Vault.

You can also configure Vault manually on your own enabling by LambdaStack only options that are necessary for you.

More about Kubernetes sidecar integration you can find at the link.

Vault Kubernetes authentication

To work with sidecar integration with Vault you need to enable Kubernetes authentication. Without that sidecar won't be able to access secret stored in Vault.

If you don't want to use sidecar integration, but you want to access automatically Vault secrets you can use Kubernetes authentication. To find more information about capabilities of Kubernetes authentication please refer to documentation.

Create your secret in Vault

In LambdaStack you can use integration of key value secrets to inject them into container. To do this you need to create them using vault CLI.

You can do this running command similar to sample below:

vault kv put secret/yourpath/to/secret username='some_user' password='some_password'

LambdaStack as backend for Vault secrets is using kv secrets engine. More information about kv secrets engine you can find here.

Kubernetes namespace

In LambdaStack we are creating additional Kubernetes objects to inject secrets automatically using sidecar. Those objects to have access to your application pods needs to be deployed in the same namespace.


Below you can find sample of deployment configuration excerpt with annotations. For this moment cannot be changed, but this will change in future release.

        app: yourapp
      annotations: "true" "devweb-app" "secret/data/yourpath/to/secret" "true" If true, configures the Vault Agent to skip verification of Vault's TLS certificate. It's mandatory for selfsigned certificates and not recommended to set this value to true in a production environment.

More information about annotations you can find here.