Ita factum est ut tempore quaestionis proposita, experientiam satis non habui ad hanc solutionem evolvendam et deducendam. Et tunc incepit Google.

Captura nescio quid sit, sed umptendecimo tempore eo sum prae se ferens quod, etiamsi omnia gradatim facio sicut in doceo, eundem ambitum cum auctore praeparet, nihil unquam operatur. Nescio quid rei sit, sed cum hoc iterum offendit, statui me mea scribere, cum omnia operantur. Reprehenderit quis ut labore.

Duces in Internet

Ita accidit ut interreti non patiatur defectus variorum ducum, paedagogorum, gradatim ac similium. Ita factum est ut solutionem enucleandam pensare commodius ordinandi et aedificandi deficiendi postgreSQL botrum, principalia requisita quae a Magistro servo diffusa erant ad omnes replicationes et provisiones latae subsidii in eventu magistri servientis. delictum.

In hac scaena, acervus technologiarum usus definitus est;

• PostgreSQL ut DBMS
• Patroni ut pampineis solution
• etc
• HAproxy ad unum punctum ordinandis applicationes ad usura database

Occasum

Ad animum tuum - aedificandum apprime promptum PostgreSQL botrum utens Patroni, etc., HAProxy.

Все операции выполнялись на виртуальных машинах с установленной ОС Debian 10.

etc

Non commendo inaugurandi etcd in iisdem machinis ubi patroni et postgresql collocabuntur, cum onus orbis magni momenti est pro etc. Sed et finibus enim, id efficitur justo.
Inaugurarimus etc.

#!/bin/bash
apt-get update
apt-get install etcd

Adde contentum fasciculi /etc/default/etcd

[socius]

ETCD_NAME=datanode1 # hostname machinae tuae
ETCD_DATA_DIR = "/var/lib/etcd/default.etcd"

OMNES IP ADDRESSES VALEO. LITERIS PAR, CLIENS etc. AD IP ADSCRIPTIONEM HOSTIAE PONENDAM

ETCD_LISTEN_PEER_URLS="http://192.168.0.143:2380» # electronica currus tui
ETCD_LISTEN_CLIENT_URLS="http://192.168.0.143:2379,http://127.0.0.1:2379» # electronica currus tui

[botrus]

ETCD_INITIAL_ADVERTISE_PEER_URLS="http://192.168.0.143:2380» # electronica currus tui
ETCD_INITIAL_CLUSTER=»datanode1=http://192.168.0.143:2380,datanode2=http://192.168.0.144:2380,datanode3=http://192.168.0.145:2380» # inscriptiones omnium machinarum in botro etc
ETCD_INITIAL_CLUSTER_STATE "novum"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-botrus-1″
ETCD_ADVERTISE_CLIENT_URLS="http://192.168.0.143:2379» # electronica currus tui

Mandatum

systemctl restart etcd

PostgreSQL 9.6 + patroni

Primum, quod debes facere, constituitur tres machinis virtualis, ut instituatur in eis necessariis programmatibus. Inauguratis machinis, si tu me sequeris, hanc simplicem scripturam currere potes quae tibi omnia feret. Fugit ut radix.

Nota quaeso quod scriptor versionis PostgreSQL utitur 9.6, hoc debetur internis exigentiis nostrae societatis. Solutio in aliis versionibus PostgreSQL non probata.

#!/bin/bash
apt-get install gnupg -y
echo "deb http://apt.postgresql.org/pub/repos/apt/ buster-pgdg main" >> /etc/apt/sources.list
wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | apt-key add -
apt-get update
apt-get install postgresql-9.6 python3-pip python3-dev libpq-dev -y
systemctl stop postgresql
pip3 install --upgrade pip
pip install psycopg2
pip install patroni[etcd]
echo "
[Unit]
Description=Runners to orchestrate a high-availability PostgreSQL
After=syslog.target network.target

[Service]
Type=simple

User=postgres
Group=postgres

ExecStart=/usr/local/bin/patroni /etc/patroni.yml

KillMode=process

TimeoutSec=30

Restart=no

[Install]
WantedBy=multi-user.targ
" > /etc/systemd/system/patroni.service
mkdir -p /data/patroni
chown postgres:postgres /data/patroni
chmod 700 /data/patroniпо
touch /etc/patroni.yml

Deinde in lima /etc/patroni.yml quam modo creavit, sequentia ponere debes, utique IP inscriptiones in omnibus locis mutatis ad inscriptiones quas uteris.
Animadverte commentarios in hoc yaml. Muta inscriptiones tuas in utraque machina in botro.

/etc/patroni.yml

scope: pgsql # должно быть одинаковым на всех нодах
namespace: /cluster/ # должно быть одинаковым на всех нодах
name: postgres1 # должно быть разным на всех нодах

restapi:
    listen: 192.168.0.143:8008 # адрес той ноды, в которой находится этот файл
    connect_address: 192.168.0.143:8008 # адрес той ноды, в которой находится этот файл

etcd:
    hosts: 192.168.0.143:2379,192.168.0.144:2379,192.168.0.145:2379 # перечислите здесь все ваши ноды, в случае если вы устанавливаете etcd на них же

# this section (bootstrap) will be written into Etcd:/<namespace>/<scope>/config after initializing new cluster
# and all other cluster members will use it as a `global configuration`
bootstrap:
    dcs:
        ttl: 100
        loop_wait: 10
        retry_timeout: 10
        maximum_lag_on_failover: 1048576
        postgresql:
            use_pg_rewind: true
            use_slots: true
            parameters:
                    wal_level: replica
                    hot_standby: "on"
                    wal_keep_segments: 5120
                    max_wal_senders: 5
                    max_replication_slots: 5
                    checkpoint_timeout: 30

    initdb:
    - encoding: UTF8
    - data-checksums
    - locale: en_US.UTF8
    # init pg_hba.conf должен содержать адреса ВСЕХ машин, используемых в кластере
    pg_hba:
    - host replication postgres ::1/128 md5
    - host replication postgres 127.0.0.1/8 md5
    - host replication postgres 192.168.0.143/24 md5
    - host replication postgres 192.168.0.144/24 md5
    - host replication postgres 192.168.0.145/24 md5
    - host all all 0.0.0.0/0 md5

    users:
        admin:
            password: admin
            options:
                - createrole
                - createdb

postgresql:
    listen: 192.168.0.143:5432 # адрес той ноды, в которой находится этот файл
    connect_address: 192.168.0.143:5432 # адрес той ноды, в которой находится этот файл
    data_dir: /data/patroni # эту директорию создаст скрипт, описанный выше и установит нужные права
    bin_dir:  /usr/lib/postgresql/9.6/bin # укажите путь до вашей директории с postgresql
    pgpass: /tmp/pgpass
    authentication:
        replication:
            username: postgres
            password: postgres
        superuser:
            username: postgres
            password: postgres
    create_replica_methods:
        basebackup:
            checkpoint: 'fast'
    parameters:
        unix_socket_directories: '.'

tags:
    nofailover: false
    noloadbalance: false
    clonefrom: false
    nosync: false

Scriptum debet currere in omnibus tribus machinis botri, et schematismum in omnibus machinis /etc/patroni.yml supra lineam etiam collocari debet.

Postquam has operationes in omnibus machinis in botro perfecisti, praeceptum tuum ad aliquem excurre

systemctl start patroni
systemctl start postgresql

Exspecta circiter 30 secundis, hoc praeceptum currite in reliquis machinis in botro.

HAproxy

HAproxy mirabilis utimur ad unum punctum ingressum. Dominus servo semper praesto erit inscriptione machinae qua HAproxy explicatur.

Ut machinam cum HAproxy non efficiat unum punctum defectionis, eam in vas Docker mittemus, in futurum in botrum K8 deduci potest et nostrum labrum etiam certius facere.

Facere directorium ubi duas tabulas condere potes - Dockerfile et haproxy.cfg. Hoc agite.

Dockerfile

FROM ubuntu:latest

RUN apt-get update 
    && apt-get install -y haproxy rsyslog 
    && rm -rf /var/lib/apt/lists/*

RUN mkdir /run/haproxy

COPY haproxy.cfg /etc/haproxy/haproxy.cfg

CMD haproxy -f /etc/haproxy/haproxy.cfg && tail -F /var/log/haproxy.log

Cave, tres ultimi lineae fasciculi haproxy.cfg inscriptiones machinarum tuarum recenseant. HAproxy Patroni contactum erit, in capite HTTP capitis servo 200 semper reddet, et imago semper 503 reddet.

haproxy.cfg

global
    maxconn 100

defaults
    log global
    mode tcp
    retries 2
    timeout client 30m
    timeout connect 4s
    timeout server 30m
    timeout check 5s

listen stats
    mode http
    bind *:7000
    stats enable
    stats uri /

listen postgres
    bind *:5000
    option httpchk
    http-check expect status 200
    default-server inter 3s fall 3 rise 2 on-marked-down shutdown-sessions
    server postgresql1 192.168.0.143:5432 maxconn 100 check port 8008
    server postgresql2 192.168.0.144:5432 maxconn 100 check port 8008
    server postgresql3 192.168.0.145:5432 maxconn 100 check port 8008

Cum in indicem in quo tum scrinii nostri "mendacium" exequantur, mandata sequentia continentis comportant, tum deductis portubus necessariis promovendis:

docker build -t my-haproxy .
docker run -d -p5000:5000 -p7000:7000 my-haproxy 

Nunc, inscriptione machinae tuae cum HAproxy in navigatro aperiens et portum 7000 denotans, statisticam in botro videbis.

Servus, qui est dominus, in UP statu erit, et replicationes in civitate erunt. Hoc rectum est, re vera laborant, sed hoc modo apparent, quia redeunt 503 petitiones ab HAproxy. Hoc nobis permittit ut semper exacte cognoscatur quis trium servientium dominus sit praesens.

conclusio,

Pulcherrima es! In tantum XXX momentis egregium mendum tolerantem et altae operationis datorum racemum cum effusis replicationibus et latis fallback direxisti. Si hac solutione uti paras, reprehendo sicco cum officialis Patroni documentaet maxime cum parte sua de utilitate patronictl, quae opportunum praebet aditum ad botrum disponendum.

Macte!

Source: www.habr.com