Modules

LambdaStack how-tos - Modules

5 minute read

Modules

Introduction

In version 0.8 of LambdaStack we introduced modules. Modularization of LambdaStack environment will result in:

smaller code bases for separate areas,
simpler and faster test process,
interchangeability of elements providing similar functionality (eg.: different Kubernetes providers),
faster and more focused release cycle.

Those and multiple other factors (eg.: readability, reliability) influence this direction of changes.

User point of view

From a user point of view, there will be no significant changes in the nearest future as it will be still possible to install LambdaStack "classic way" so with a single lambdastack configuration using a whole codebase as a monolith.

For those who want to play with new features, or will need newly introduced possibilities, there will be a short transition period which we consider as a kind of "preview stage". In this period there will be a need to run each module separately by hand in the following order:

moduleA init
moduleA plan
moduleA apply
moduleB init
moduleB plan
moduleB apply
...

Init, plan and apply phases explanation you'll find in next sections of this document. Main point is that dependent modules have to be executed one after another during this what we called "preview stage". Later, with next releases there will be separate mechanism introduced to orchestrate modules dependencies and their consecutive execution.

New scenarios

In 0.8 we offer the possibility to use AKS or EKS as Kubernetes providers. That is introduced with modules mechanism, so we launched the first four modules:

Azure Basic Infrastructure (AzBI) module
Azure AKS (AzKS) module
AWS Basic Infrastructure (AwsBI) module
AWS EKS (AwsKS) module

Those 4 modules together with the classic LambdaStack used with any provider allow replacing of on-prem Kubernetes cluster with managed Kubernetes services.

As it might be already visible there are 2 paths provided:

Azure related, using AzBI and AzKS modules,
AWS related, using AwsBI and AwsKS modules.

Those "... Basic Infrastructure" modules are responsible to provide basic cloud resources (eg.: resource groups, virtual networks, subnets, virtual machines, network security rules, routing, ect.) which will be used by next modules. So in this case, those are "... KS modules" meant to provide managed Kubernetes services. They use resources provided by basic infrastructure modules (eg.: subnets or resource groups) and instantiate managed Kubernetes services provided by cloud providers. The last element in both those cloud provider related paths is classic LambdaStack installed on top of resources provided by those modules using any provider.

Hands-on

In each module, we provided a guide on how to use the module. Please refer:

Azure Basic Infrastructure (AzBI) module
Azure AKS (AzKS) module
AWS Basic Infrastructure (AwsBI) module
AWS EKS (AwsKS) module

After deployment of EKS or AKS, you can perform LambdaStack installation on top of it.

Install LambdaStack on top of AzKS or AwsKS

NOTE - Default OS users:

Azure:
    redhat: ec2-user
    ubuntu: operations
AWS:
    redhat: ec2-user
    ubuntu: ubuntu

Create LambdaStack cluster config file in /tmp/shared/ls.yml Example:

kind: lambdastack-cluster
title: LambdaStack Cluster Config
name: your-cluster-name # <----- make unified with other places and build directory name
build_path: # Dynamically built
provider: any # <----- use "any" provider
specification:
  name: your-cluster-name # <----- make unified with other places and build directory name
  admin_user:
    name: operations # <----- make sure os-user is correct
    key_path: /tmp/shared/vms_rsa # <----- use generated key file
    path: # Dynamically built
  cloud:
    k8s_as_cloud_service: true # <----- make sure that flag is set, as it indicates usage of a managed Kubernetes service
  components:
    repository:
      count: 1
      machines:
        - default-lambdastack-modules-test-all-0 # <----- make sure that it is correct VM name
    kubernetes_master:
      count: 0
    kubernetes_node:
      count: 0
    logging:
      count: 0
    monitoring:
      count: 0
    kafka:
      count: 0
    postgresql:
      count: 1
      machines:
        - default-lambdastack-modules-test-all-1 # <----- make sure that it is correct VM name
    load_balancer:
      count: 0
    rabbitmq:
      count: 0
---
kind: configuration/feature-mapping
title: Feature mapping to roles
name: your-cluster-name # <----- make unified with other places and build directory name
provider: any
specification:
  roles_mapping:
    repository:
      - repository
      - image-registry
      - firewall
      - filebeat
      - node-exporter
      - applications
---
kind: infrastructure/machine
name: default-lambdastack-modules-test-all-0
provider: any
specification:
  hostname: lambdastack-modules-test-all-0
  ip: 12.34.56.78 # <----- put here public IP attached to machine
---
kind: infrastructure/machine
name: default-lambdastack-modules-test-all-1
provider: any
specification:
  hostname: lambdastack-modules-test-all-1
  ip: 12.34.56.78 # <----- put here public IP attached to machine
---
kind: configuration/repository
title: "LambdaStack requirements repository"
name: default
specification:
  description: "Local repository of binaries required to install LambdaStack"
  download_done_flag_expire_minutes: 120
  apache_lsrepo_path: "/var/www/html/lsrepo"
  teardown:
    disable_http_server: true
    remove:
      files: false
      helm_charts: false
      images: false
      packages: false
provider: any
---
kind: configuration/postgresql
title: PostgreSQL
name: default
specification:
  config_file:
    parameter_groups:
      - name: CONNECTIONS AND AUTHENTICATION
        subgroups:
          - name: Connection Settings
            parameters:
              - name: listen_addresses
                value: "'*'"
                comment: listen on all addresses
          - name: Security and Authentication
            parameters:
              - name: ssl
                value: 'off'
                comment: to have the default value also on Ubuntu
      - name: RESOURCE USAGE (except WAL)
        subgroups:
          - name: Kernel Resource Usage
            parameters:
              - name: shared_preload_libraries
                value: AUTOCONFIGURED
                comment: set by automation
      - name: ERROR REPORTING AND LOGGING
        subgroups:
          - name: Where to Log
            parameters:
              - name: log_directory
                value: "'/var/log/postgresql'"
                comment: to have standard location for Filebeat and logrotate
              - name: log_filename
                value: "'postgresql.log'"
                comment: to use logrotate with common configuration
      - name: WRITE AHEAD LOG
        subgroups:
          - name: Settings
            parameters:
              - name: wal_level
                value: replica
                when: replication
          - name: Archiving
            parameters:
              - name: archive_mode
                value: 'on'
                when: replication
              - name: archive_command
                value: "'test ! -f /dbbackup/{{ inventory_hostname }}/backup/%f &&\
                    \ gzip -c < %p > /dbbackup/{{ inventory_hostname }}/backup/%f'"
                when: replication
      - name: REPLICATION
        subgroups:
          - name: Sending Server(s)
            parameters:
              - name: max_wal_senders
                value: 10
                comment: maximum number of simultaneously running WAL sender processes
                when: replication
              - name: wal_keep_segments
                value: 34
                comment: number of WAL files held for standby servers
                when: replication
  extensions:
    pgaudit:
      enabled: false
      shared_preload_libraries:
        - pgaudit
      config_file_parameters:
        log_connections: 'off'
        log_disconnections: 'off'
        log_statement: 'none'
        log_line_prefix: "'%m [%p] %q%u@%d,host=%h '"
        pgaudit.log: "'write, function, role, ddl' # 'misc_set' is not supported for\
            \ PG 10"
        pgaudit.log_catalog: 'off # to reduce overhead of logging'
        pgaudit.log_relation: 'on # separate log entry for each relation'
        pgaudit.log_statement_once: 'off'
        pgaudit.log_parameter: 'on'
    pgbouncer:
      enabled: false
    replication:
      enabled: false
      replication_user_name: ls_repmgr
      replication_user_password: PASSWORD_TO_CHANGE
      privileged_user_name: ls_repmgr_admin
      privileged_user_password: PASSWORD_TO_CHANGE
      repmgr_database: ls_repmgr
      shared_preload_libraries:
        - repmgr
  logrotate:
    config: |-
      /var/log/postgresql/postgresql*.log {
          maxsize 10M
          daily
          rotate 6
          copytruncate
      # delaycompress is for Filebeat
          delaycompress
          compress
          notifempty
          missingok
          su root root
          nomail
      # to have multiple unique filenames per day when dateext option is set
          dateformat -%Y%m%dH%H
      }      
provider: any
---
kind: configuration/applications
title: "Kubernetes Applications Config"
name: default
specification:
  applications:
    - name: ignite-stateless
      enabled: false
      image_path: "lambdastack/ignite:2.9.1"
      use_local_image_registry: false
      namespace: ignite
      service:
        rest_nodeport: 32300
        sql_nodeport: 32301
        thinclients_nodeport: 32302
      replicas: 1
      enabled_plugins:
        - ignite-kubernetes
        - ignite-rest-http
    - name: rabbitmq
      enabled: false
      image_path: rabbitmq:3.8.3
      use_local_image_registry: false
      service:
        name: rabbitmq-cluster
        port: 30672
        management_port: 31672
        replicas: 2
        namespace: queue
      rabbitmq:
        plugins:
          - rabbitmq_management
          - rabbitmq_management_agent
        policies:
          - name: ha-policy2
            pattern: ".*"
            definitions:
              ha-mode: all
        custom_configurations:
          - name: vm_memory_high_watermark.relative
            value: 0.5
        cluster:
    - name: auth-service
      enabled: false
      image_path: jboss/keycloak:9.0.0
      use_local_image_registry: false
      service:
        name: as-testauthdb
        port: 30104
        replicas: 2
        namespace: namespace-for-auth
        admin_user: auth-service-username
        admin_password: PASSWORD_TO_CHANGE
      database:
        name: auth-database-name
        user: auth-db-user
        password: PASSWORD_TO_CHANGE
    - name: pgpool
      enabled: true
      image:
        path: bitnami/pgpool:4.1.1-debian-10-r29
        debug: false
      use_local_image_registry: false
      namespace: postgres-pool
      service:
        name: pgpool
        port: 5432
      replicas: 3
      pod_spec:
        affinity:
          podAntiAffinity:
            preferredDuringSchedulingIgnoredDuringExecution:
              - weight: 100
                podAffinityTerm:
                  labelSelector:
                    matchExpressions:
                      - key: app
                        operator: In
                        values:
                          - pgpool
                  topologyKey: kubernetes.io/hostname
        nodeSelector: {}
        tolerations: {}
      resources:
        limits:
          memory: 176Mi
        requests:
          cpu: 250m
          memory: 176Mi
      pgpool:
        env:
          PGPOOL_BACKEND_NODES: autoconfigured
          PGPOOL_POSTGRES_USERNAME: ls_pgpool_postgres_admin
          PGPOOL_SR_CHECK_USER: ls_pgpool_sr_check
          PGPOOL_ADMIN_USERNAME: ls_pgpool_admin
          PGPOOL_ENABLE_LOAD_BALANCING: true
          PGPOOL_MAX_POOL: 4
          PGPOOL_POSTGRES_PASSWORD_FILE: /opt/bitnami/pgpool/secrets/pgpool_postgres_password
          PGPOOL_SR_CHECK_PASSWORD_FILE: /opt/bitnami/pgpool/secrets/pgpool_sr_check_password
          PGPOOL_ADMIN_PASSWORD_FILE: /opt/bitnami/pgpool/secrets/pgpool_admin_password
        secrets:
          pgpool_postgres_password: PASSWORD_TO_CHANGE
          pgpool_sr_check_password: PASSWORD_TO_CHANGE
          pgpool_admin_password: PASSWORD_TO_CHANGE
        pgpool_conf_content_to_append: |
          #------------------------------------------------------------------------------
          # CUSTOM SETTINGS (appended by LambdaStack to override defaults)
          #------------------------------------------------------------------------------
          # num_init_children = 32
          connection_life_time = 900
          reserved_connections = 1          
        pool_hba_conf: autoconfigured
    - name: pgbouncer
      enabled: true
      image_path: brainsam/pgbouncer:1.12
      init_image_path: bitnami/pgpool:4.1.1-debian-10-r29
      use_local_image_registry: false
      namespace: postgres-pool
      service:
        name: pgbouncer
        port: 5432
      replicas: 2
      resources:
        requests:
          cpu: 250m
          memory: 128Mi
        limits:
          cpu: 500m
          memory: 128Mi
      pgbouncer:
        env:
          DB_HOST: pgpool.postgres-pool.svc.cluster.local
          DB_LISTEN_PORT: 5432
          LISTEN_ADDR: "*"
          LISTEN_PORT: 5432
          AUTH_FILE: "/etc/pgbouncer/auth/users.txt"
          AUTH_TYPE: md5
          MAX_CLIENT_CONN: 150
          DEFAULT_POOL_SIZE: 25
          RESERVE_POOL_SIZE: 25
          POOL_MODE: transaction
provider: any

Run lambdastack tool to install LambdaStack:
```
lambdastack --auto-approve apply --file='/tmp/shared/ls.yml' --vault-password='secret'
```
This will install PostgreSQL on one of the machines and configure PgBouncer, Pgpool and additional services to manage database connections.

Please make sure you disable applications that you don't need. Also, you can enable standard LambdaStack services like Kafka or RabbitMQ, by increasing the number of virtual machines in the basic infrastructure config and assigning them to LambdaStack components you want to use.

If you would like to deploy custom resources into managed Kubernetes, then the standard kubeconfig yaml document can be found inside the shared state file (you should be able to use vendor tools as well to get it).

We highly recommend using the Ingress resource in Kubernetes to allow access to web applications inside the cluster. Since it's managed Kubernetes and fully supported by the cloud platform, the classic HAProxy load-balancer solution seems to be deprecated here.

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