Bulao-Héjo Deployment di gajih minimum

Dina artikel ieu kami nganggo bash, ssh, docker и nginx Urang bakal ngatur hiji perenah mulus tina aplikasi wéb. Panyebaran biru-héjo mangrupikeun téknik anu ngamungkinkeun anjeun ngapdet aplikasi sacara instan tanpa nampik hiji pamundut. Éta mangrupikeun salah sahiji strategi panyebaran downtime enol sareng paling cocog pikeun aplikasi sareng hiji conto, tapi kamampuan pikeun ngamuat instansi kadua anu siap dijalankeun caket dieu.

Anggap anjeun gaduh aplikasi wéb anu seueur klien aktip damel, sareng leres pisan henteu aya jalan pikeun ngagolér sababaraha detik. Sareng anjeun leres-leres kedah ngaluncurkeun pembaruan perpustakaan, perbaikan bug, atanapi fitur anu énggal. Dina kaayaan normal, anjeun kedah ngeureunkeun aplikasi, ngagentos sareng ngamimitian deui. Dina kasus docker, anjeun tiasa ngagentos heula, teras ngabalikan deui, tapi masih bakal aya waktos dimana pamundut ka aplikasi moal diolah, sabab biasana aplikasi butuh sababaraha waktos pikeun mimiti dimuat. Kumaha lamun dimimitian, tapi tétéla jadi inoperable? Ieu masalahna, hayu urang ngajawab eta kalawan hartosna minimal na sakumaha elegantly jéntré.

DISCLAIMER: Seuseueurna tulisan dibere dina format ékspérimén - dina bentuk ngarékam sési konsol. Mudah-mudahan ieu moal sesah kahartos sareng kodena bakal ngadokumentasikeun nyalira. Pikeun atmosfir, ngabayangkeun yén ieu teu ngan snippét kode, tapi kertas tina teletype "beusi".

Téhnik anu pikaresepeun anu hésé Google ngan ku maca kodeu dijelaskeun di awal unggal bagian. Upami aya anu teu jelas, google sareng pariksa deui. ngajelaskeun cangkang (untungna tiasa dianggo deui, kusabab ngabuka blokir telegram). Upami anjeun teu tiasa Google nanaon, tanyakeun dina koméntar. Kuring bakal senang pikeun nambahkeun kana bagian pakait "Téknik metot".

Hayu urang ngamimitian.

$ mkdir blue-green-deployment && cd $_

palayanan

Hayu urang ngadamel jasa ékspérimén sareng nempatkeun dina wadah.

Téhnik metot

• cat << EOF > file-name (Di dieu Dokumén + I / O Redirection) nyaéta cara pikeun nyieun file multi-line kalayan hiji paréntah. Sagalana bash maca tina /dev/stdin saatos garis ieu sareng sateuacan garis EOF bakal kacatet dina file-name.
• wget -qO- URL (ngajelaskeun cangkang) - kaluaran hiji dokumen narima via HTTP pikeun /dev/stdout (analog curl URL).

Cetak

Kuring husus megatkeun snippet pikeun Aktipkeun panyorot pikeun Python. Dina tungtungna bakal aya sapotong sejen kawas ieu. Pertimbangkeun yén di tempat-tempat ieu kertas dipotong pikeun dikirim ka departemen panyorot (dimana kodeu diwarnaan ku panyorot), teras potongan-potongan ieu dipasang deui.

$ cat << EOF > uptimer.py

from http.server import BaseHTTPRequestHandler, HTTPServer
from time import monotonic

app_version = 1
app_name = f'Uptimer v{app_version}.0'
loading_seconds = 15 - app_version * 5

class Handler(BaseHTTPRequestHandler):
    def do_GET(self):
        if self.path == '/':
            try:
                t = monotonic() - server_start
                if t < loading_seconds:
                    self.send_error(503)
                else:
                    self.send_response(200)
                    self.send_header('Content-Type', 'text/html')
                    self.end_headers()
                    response = f'<h2>{app_name} is running for {t:3.1f} seconds.</h2>n'
                    self.wfile.write(response.encode('utf-8'))
            except Exception:
                self.send_error(500)
        else:
            self.send_error(404)

httpd = HTTPServer(('', 8080), Handler)
server_start = monotonic()
print(f'{app_name} (loads in {loading_seconds} sec.) started.')
httpd.serve_forever()

EOF

$ cat << EOF > Dockerfile
FROM python:alpine
EXPOSE 8080
COPY uptimer.py app.py
CMD [ "python", "-u", "./app.py" ]
EOF

$ docker build --tag uptimer .
Sending build context to Docker daemon  39.42kB
Step 1/4 : FROM python:alpine
 ---> 8ecf5a48c789
Step 2/4 : EXPOSE 8080
 ---> Using cache
 ---> cf92d174c9d3
Step 3/4 : COPY uptimer.py app.py
 ---> a7fbb33d6b7e
Step 4/4 : CMD [ "python", "-u", "./app.py" ]
 ---> Running in 1906b4bd9fdf
Removing intermediate container 1906b4bd9fdf
 ---> c1655b996fe8
Successfully built c1655b996fe8
Successfully tagged uptimer:latest

$ docker run --rm --detach --name uptimer --publish 8080:8080 uptimer
8f88c944b8bf78974a5727070a94c76aa0b9bb2b3ecf6324b784e782614b2fbf

$ docker ps
CONTAINER ID        IMAGE               COMMAND                CREATED             STATUS              PORTS                    NAMES
8f88c944b8bf        uptimer             "python -u ./app.py"   3 seconds ago       Up 5 seconds        0.0.0.0:8080->8080/tcp   uptimer

$ docker logs uptimer
Uptimer v1.0 (loads in 10 sec.) started.

$ wget -qSO- http://localhost:8080
  HTTP/1.0 503 Service Unavailable
  Server: BaseHTTP/0.6 Python/3.8.3
  Date: Sat, 22 Aug 2020 19:52:40 GMT
  Connection: close
  Content-Type: text/html;charset=utf-8
  Content-Length: 484

$ wget -qSO- http://localhost:8080
  HTTP/1.0 200 OK
  Server: BaseHTTP/0.6 Python/3.8.3
  Date: Sat, 22 Aug 2020 19:52:45 GMT
  Content-Type: text/html
<h2>Uptimer v1.0 is running for 15.4 seconds.</h2>

$ docker rm --force uptimer
uptimer

Ngabalikeun proxy

Supados aplikasi urang bisa ngarobah unnoticed, perlu aya sababaraha éntitas séjén di hareup eta anu bakal nyumputkeun ngagantian na. Éta tiasa janten pangladén wéb nginx в modeu proxy sabalikna. A proxy sabalikna diadegkeun antara klien tur aplikasi. Éta nampi pamundut ti klien sareng diteruskeun kana aplikasi sareng neraskeun réspon aplikasi ka klien.

Aplikasi sareng proxy sabalikna tiasa dikaitkeun di jero docker nganggo jaringan docker. Ku kituna, wadahna kalawan aplikasi nu malah teu kedah neraskeun port dina sistem host; hal ieu ngamungkinkeun aplikasi pikeun maksimal diasingkeun tina ancaman éksternal.

Upami proxy sabalikna hirup dina host anu sanés, anjeun kedah ngantunkeun jaringan docker sareng sambungkeun aplikasi ka proxy sabalikna ngalangkungan jaringan host, teraskeun palabuhan. aktip parameter --publish, sakumaha dina mimiti mimiti jeung salaku proxy sabalikna.

Kami bakal ngajalankeun proxy sabalikna dina port 80, sabab ieu mangrupikeun éntitas anu kedah ngadangukeun jaringan éksternal. Mun port 80 sibuk on host test Anjeun, ngarobah parameter --publish 80:80 dina --publish ANY_FREE_PORT:80.

Téhnik metot

• "Dina jaringan Docker anu diciptakeun ku pangguna, anjeun tiasa komunikasi sareng wadah henteu ngan ukur ku alamat IP. Ngaran wadahna ogé direngsekeun kana alamat IP na" (artikel "Jaringan sareng wadah mandiri", bagian "Paké jaringan sasak anu ditetepkeun ku pangguna", titik 5 tina kode docker).

Cetak

$ docker network create web-gateway
5dba128fb3b255b02ac012ded1906b7b4970b728fb7db3dbbeccc9a77a5dd7bd

$ docker run --detach --rm --name uptimer --network web-gateway uptimer
a1105f1b583dead9415e99864718cc807cc1db1c763870f40ea38bc026e2d67f

$ docker run --rm --network web-gateway alpine wget -qO- http://uptimer:8080
<h2>Uptimer v1.0 is running for 11.5 seconds.</h2>

$ docker run --detach --publish 80:80 --network web-gateway --name reverse-proxy nginx:alpine
80695a822c19051260c66bf60605dcb4ea66802c754037704968bc42527bf120

$ docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED              STATUS              PORTS                NAMES
80695a822c19        nginx:alpine        "/docker-entrypoint.…"   27 seconds ago       Up 25 seconds       0.0.0.0:80->80/tcp   reverse-proxy
a1105f1b583d        uptimer             "python -u ./app.py"     About a minute ago   Up About a minute   8080/tcp             uptimer

$ cat << EOF > uptimer.conf
server {
    listen 80;
    location / {
        proxy_pass http://uptimer:8080;
    }
}
EOF

$ docker cp ./uptimer.conf reverse-proxy:/etc/nginx/conf.d/default.conf

$ docker exec reverse-proxy nginx -s reload
2020/06/23 20:51:03 [notice] 31#31: signal process started

$ wget -qSO- http://localhost
  HTTP/1.1 200 OK
  Server: nginx/1.19.0
  Date: Sat, 22 Aug 2020 19:56:24 GMT
  Content-Type: text/html
  Transfer-Encoding: chunked
  Connection: keep-alive
<h2>Uptimer v1.0 is running for 104.1 seconds.</h2>

Seamless deployment

Hayu urang gulung kaluar versi anyar tina aplikasi (kalawan dorongan kinerja ngamimitian dua kali) jeung cobaan pikeun nyebarkeun eta seamlessly.

Téhnik metot

• echo 'my text' | docker exec -i my-container sh -c 'cat > /my-file.txt' - Tulis téks my text pikeun berkas /my-file.txt jero wadah my-container.
• cat > /my-file.txt - Tulis eusi input standar kana file /dev/stdin.

Cetak

$ sed -i "s/app_version = 1/app_version = 2/" uptimer.py

$ docker build --tag uptimer .
Sending build context to Docker daemon  39.94kB
Step 1/4 : FROM python:alpine
 ---> 8ecf5a48c789
Step 2/4 : EXPOSE 8080
 ---> Using cache
 ---> cf92d174c9d3
Step 3/4 : COPY uptimer.py app.py
 ---> 3eca6a51cb2d
Step 4/4 : CMD [ "python", "-u", "./app.py" ]
 ---> Running in 8f13c6d3d9e7
Removing intermediate container 8f13c6d3d9e7
 ---> 1d56897841ec
Successfully built 1d56897841ec
Successfully tagged uptimer:latest

$ docker run --detach --rm --name uptimer_BLUE --network web-gateway uptimer
96932d4ca97a25b1b42d1b5f0ede993b43f95fac3c064262c5c527e16c119e02

$ docker logs uptimer_BLUE
Uptimer v2.0 (loads in 5 sec.) started.

$ docker run --rm --network web-gateway alpine wget -qO- http://uptimer_BLUE:8080
<h2>Uptimer v2.0 is running for 23.9 seconds.</h2>

$ sed s/uptimer/uptimer_BLUE/ uptimer.conf | docker exec --interactive reverse-proxy sh -c 'cat > /etc/nginx/conf.d/default.conf'

$ docker exec reverse-proxy cat /etc/nginx/conf.d/default.conf
server {
    listen 80;
    location / {
        proxy_pass http://uptimer_BLUE:8080;
    }
}

$ docker exec reverse-proxy nginx -s reload
2020/06/25 21:22:23 [notice] 68#68: signal process started

$ wget -qO- http://localhost
<h2>Uptimer v2.0 is running for 63.4 seconds.</h2>

$ docker rm -f uptimer
uptimer

$ wget -qO- http://localhost
<h2>Uptimer v2.0 is running for 84.8 seconds.</h2>

$ docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED              STATUS              PORTS                NAMES
96932d4ca97a        uptimer             "python -u ./app.py"     About a minute ago   Up About a minute   8080/tcp             uptimer_BLUE
80695a822c19        nginx:alpine        "/docker-entrypoint.…"   8 minutes ago        Up 8 minutes        0.0.0.0:80->80/tcp   reverse-proxy

Dina tahap ieu, gambar diwangun langsung dina server, anu merlukeun sumber aplikasi pikeun aya, sarta ogé beban server kalawan karya teu perlu. Lengkah saterusna nyaéta alokasi assembly gambar ka mesin misah (contona, ka sistem CI) lajeng mindahkeun ka server.

Mindahkeun gambar

Hanjakalna, teu asup akal pikeun nransferkeun gambar tina localhost ka localhost, janten bagian ieu ngan ukur tiasa dijelajah upami anjeun gaduh dua host sareng Docker. Sahenteuna sigana sapertos kieu:

$ ssh production-server docker image ls
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE

$ docker image save uptimer | ssh production-server 'docker image load'
Loaded image: uptimer:latest

$ ssh production-server docker image ls
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
uptimer             latest              1d56897841ec        5 minutes ago       78.9MB

regu docker save nyimpen data gambar dina arsip .tar, hartina eta weighs ngeunaan 1.5 kali leuwih ti eta bakal beuratna dina formulir dikomprés. Janten hayu urang goyangkeun dina nami ngahémat waktos sareng lalu lintas:

$ docker image save uptimer | gzip | ssh production-server 'zcat | docker image load'
Loaded image: uptimer:latest

Anjeun ogé tiasa ngawas prosés unduhan (sanaos peryogi utilitas pihak katilu):

$ docker image save uptimer | gzip | pv | ssh production-server 'zcat | docker image load'
25,7MiB 0:01:01 [ 425KiB/s] [                   <=>    ]
Loaded image: uptimer:latest

Tip: Upami anjeun peryogi seueur parameter pikeun nyambung ka server liwat SSH, anjeun panginten henteu nganggo file éta ~/.ssh/config.

Mindahkeun gambar via docker image save/load - Ieu métode paling minimalistic, tapi teu ngan hiji. Aya batur:

1. Registry Wadahna (standar industri).
2. Sambungkeun ka server daemon docker ti host anu sanés:
   1. variabel lingkungan DOCKER_HOST.
   2. Pilihan garis paréntah -H atawa --host Instrumén docker-compose.
   3. docker context

Metodeu kadua (kalawan tilu pilihan pikeun palaksanaan na) ogé dijelaskeun dina artikel Kumaha cara nyebarkeun host Docker jauh sareng docker-compose.

deploy.sh

Ayeuna hayu urang kumpulkeun sadayana anu urang laksanakeun sacara manual kana hiji naskah. Hayu urang mimitian ku fungsi tingkat luhur, lajeng kasampak di séjén dipaké di dinya.

Téhnik metot

• ${parameter?err_msg} - salah sahiji mantra sihir bash (alias substitusi parameter). Upami parameter teu dieusian, kaluaran err_msg sareng kaluar sareng kode 1.
• docker --log-driver journald - sacara standar, supir logging docker mangrupikeun file téks tanpa rotasi. Kalayan pendekatan ieu, log gancang ngeusian sakumna disk, janten pikeun lingkungan produksi kedah ngagentos supir ka anu langkung pinter.

Aksara deployment

deploy() {
    local usage_msg="Usage: ${FUNCNAME[0]} image_name"
    local image_name=${1?$usage_msg}

    ensure-reverse-proxy || return 2
    if get-active-slot $image_name
    then
        local OLD=${image_name}_BLUE
        local new_slot=GREEN
    else
        local OLD=${image_name}_GREEN
        local new_slot=BLUE
    fi
    local NEW=${image_name}_${new_slot}
    echo "Deploying '$NEW' in place of '$OLD'..."
    docker run 
        --detach 
        --restart always 
        --log-driver journald 
        --name $NEW 
        --network web-gateway 
        $image_name || return 3
    echo "Container started. Checking health..."
    for i in {1..20}
    do
        sleep 1
        if get-service-status $image_name $new_slot
        then
            echo "New '$NEW' service seems OK. Switching heads..."
            sleep 2  # Ensure service is ready
            set-active-slot $image_name $new_slot || return 4
            echo "'$NEW' service is live!"
            sleep 2  # Ensure all requests were processed
            echo "Killing '$OLD'..."
            docker rm -f $OLD
            docker image prune -f
            echo "Deployment successful!"
            return 0
        fi
        echo "New '$NEW' service is not ready yet. Waiting ($i)..."
    done
    echo "New '$NEW' service did not raise, killing it. Failed to deploy T_T"
    docker rm -f $NEW
    return 5
}

Fitur anu dianggo:

• ensure-reverse-proxy - Pastikeun proxy sabalikna jalan (mangpaat pikeun panyebaran munggaran)
• get-active-slot service_name - Nangtukeun slot mana anu ayeuna aktip pikeun layanan anu dipasihkeun (BLUE atawa GREEN)
• get-service-status service_name deployment_slot - Nangtukeun naha jasa parantos siap ngolah pamundut anu datang
• set-active-slot service_name deployment_slot - Ngarobah konfigurasi nginx dina wadah proxy sabalikna

Dina pilihan:

ensure-reverse-proxy() {
    is-container-up reverse-proxy && return 0
    echo "Deploying reverse-proxy..."
    docker network create web-gateway
    docker run 
        --detach 
        --restart always 
        --log-driver journald 
        --name reverse-proxy 
        --network web-gateway 
        --publish 80:80 
        nginx:alpine || return 1
    docker exec --interactive reverse-proxy sh -c "> /etc/nginx/conf.d/default.conf"
    docker exec reverse-proxy nginx -s reload
}

is-container-up() {
    local container=${1?"Usage: ${FUNCNAME[0]} container_name"}

    [ -n "$(docker ps -f name=${container} -q)" ]
    return $?
}

get-active-slot() {
    local service=${1?"Usage: ${FUNCNAME[0]} service_name"}

    if is-container-up ${service}_BLUE && is-container-up ${service}_GREEN; then
        echo "Collision detected! Stopping ${service}_GREEN..."
        docker rm -f ${service}_GREEN
        return 0  # BLUE
    fi
    if is-container-up ${service}_BLUE && ! is-container-up ${service}_GREEN; then
        return 0  # BLUE
    fi
    if ! is-container-up ${service}_BLUE; then
        return 1  # GREEN
    fi
}

get-service-status() {
    local usage_msg="Usage: ${FUNCNAME[0]} service_name deployment_slot"
    local service=${1?usage_msg}
    local slot=${2?$usage_msg}

    case $service in
        # Add specific healthcheck paths for your services here
        *) local health_check_port_path=":8080/" ;;
    esac
    local health_check_address="http://${service}_${slot}${health_check_port_path}"
    echo "Requesting '$health_check_address' within the 'web-gateway' docker network:"
    docker run --rm --network web-gateway alpine 
        wget --timeout=1 --quiet --server-response $health_check_address
    return $?
}

set-active-slot() {
    local usage_msg="Usage: ${FUNCNAME[0]} service_name deployment_slot"
    local service=${1?$usage_msg}
    local slot=${2?$usage_msg}
    [ "$slot" == BLUE ] || [ "$slot" == GREEN ] || return 1

    get-nginx-config $service $slot | docker exec --interactive reverse-proxy sh -c "cat > /etc/nginx/conf.d/$service.conf"
    docker exec reverse-proxy nginx -t || return 2
    docker exec reverse-proxy nginx -s reload
}

fungsi get-active-slot peryogi katerangan sakedik:

Naha éta ngabalikeun nomer sareng henteu ngaluarkeun senar?

Atoh, dina fungsi nélépon urang pariksa hasil karyana, sarta mariksa kode kaluar maké bash loba gampang ti mariksa string a. Salaku tambahan, kéngingkeun senar tina éta saderhana pisan:
get-active-slot service && echo BLUE || echo GREEN.

Dupi tilu kaayaan bener cukup keur ngabedakeun sakabeh nagara?

Malah dua bakal cukup, hiji panungtungan dieu ngan pikeun completeness, ambéh teu nulis else.

Ngan fungsi anu mulangkeun konfigurasi nginx tetep teu ditangtukeun: get-nginx-config service_name deployment_slot. Ku analogi sareng pamariksaan kaséhatan, di dieu anjeun tiasa nyetél konfigurasi naon waé pikeun jasa naon waé. Tina hal metot - hijina cat <<- EOF, anu ngamungkinkeun anjeun mupus sadaya tab di awal. Leres, harga pormat anu saé dicampurkeun tab sareng rohangan, anu ayeuna dianggap bentuk anu goréng. Tapi bash maksakeun tab, sareng éta ogé bakal saé gaduh pormat normal dina config nginx. Pondokna, nyampur tab sareng rohangan di dieu sigana mangrupikeun solusi anu pangsaéna tina anu paling awon. Najan kitu, anjeun moal ningali ieu dina snippet handap, saprak Habr "ngalakukeun eta ogé" ku ngarobah sakabeh tab kana 4 spasi tur nyieun EOF teu valid. Sarta di dieu éta noticeable.

Sangkan teu gugah dua kali, abdi bakal ngabejaan Anjeun langsung ngeunaan cat << 'EOF', nu bakal kapanggih engké. Lamun nulis saukur cat << EOF, teras di jero heredoc string diinterpolasi (variabel dilegaan ($foo), paréntah panggero ($(bar)) jeung sajabana), sareng upami anjeun ngalampirkeun tungtung dokumen dina tanda petik tunggal, maka interpolasi ditumpurkeun sareng simbolna. $ dipintonkeun sakumaha anu kasebut. Naon anu anjeun kedah nyelapkeun naskah dina naskah anu sanés.

get-nginx-config() {
    local usage_msg="Usage: ${FUNCNAME[0]} service_name deployment_slot"
    local service=${1?$usage_msg}
    local slot=${2?$usage_msg}
    [ "$slot" == BLUE ] || [ "$slot" == GREEN ] || return 1

    local container_name=${service}_${slot}
    case $service in
        # Add specific nginx configs for your services here
        *) nginx-config-simple-service $container_name:8080 ;;
    esac
}

nginx-config-simple-service() {
    local usage_msg="Usage: ${FUNCNAME[0]} proxy_pass"
    local proxy_pass=${1?$usage_msg}

cat << EOF
server {
    listen 80;
    location / {
        proxy_pass http://$proxy_pass;
    }
}
EOF
}

Ieu sakabéh naskah. Teras kumaha inti jeung naskah ieu pikeun ngundeur via wget atanapi curl.

Ngaéksekusi Aksara parameterized dina server jauh

Ieu waktu pikeun sambel on server target. Waktos ayeuna localhost cukup cocog:

$ ssh-copy-id localhost
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
himura@localhost's password: 

Number of key(s) added: 1

Now try logging into the machine, with:   "ssh 'localhost'"
and check to make sure that only the key(s) you wanted were added.

Kami parantos nyerat naskah panyebaran anu ngaunduh gambar anu tos diwangun ka server target sareng sacara lancar ngagentos wadah jasa, tapi kumaha urang tiasa ngaéksekusi dina mesin jauh? Skripna ngagaduhan alesan, sabab éta universal sareng tiasa nyebarkeun sababaraha jasa sakaligus dina hiji proxy sabalikna (anjeun tiasa nganggo nginx configs pikeun nangtukeun url mana anu janten jasa). Skrip teu tiasa disimpen dina server, sabab dina hal ieu urang moal tiasa ngapdet sacara otomatis (pikeun perbaikan bug sareng nambihan jasa énggal), sareng sacara umum, kaayaan = jahat.

Solusi 1: Masih nyimpen naskah dina server, tapi nyalin eta unggal waktu ngaliwatan scp. Teras sambungkeun via ssh jeung ngajalankeun naskah kalawan argumen diperlukeun.

kontra:

• Dua lampah tinimbang hiji
• Bisa jadi teu aya tempat dimana anjeun nyalin, atawa meureun aya aksés ka dinya, atawa naskah bisa dieksekusi dina waktu substitusi.
• Disarankeun pikeun ngabersihan diri saatosna (ngahapus naskah).
• Geus tilu lampah.

Solusi 2:

• Tetep ngan definisi fungsi dina naskah jeung ngajalankeun nanaon pisan
• jeung sed tambahkeun panggero fungsi ka tungtung
• Kirimkeun sadayana langsung ka shh via pipa (|)

pro:

• Leres stateless
• Taya éntitas boilerplate
• Ngarasa tiis

Hayu urang ngalakukeun tanpa Ansible. Sumuhun, sagalana geus nimukeun. Enya, sapédah. Tingali kumaha basajan, elegan sareng minimalis sapédah éta:

$ cat << 'EOF' > deploy.sh

#!/bin/bash

usage_msg="Usage: $0 ssh_address local_image_tag"
ssh_address=${1?$usage_msg}
image_name=${2?$usage_msg}

echo "Connecting to '$ssh_address' via ssh to seamlessly deploy '$image_name'..."
( sed "$a deploy $image_name" | ssh -T $ssh_address ) << 'END_OF_SCRIPT'
deploy() {
    echo "Yay! The '${FUNCNAME[0]}' function is executing on '$(hostname)' with argument '$1'"
}
END_OF_SCRIPT

EOF

$ chmod +x deploy.sh

$ ./deploy.sh localhost magic-porridge-pot
Connecting to localhost...
Yay! The 'deploy' function is executing on 'hut' with argument 'magic-porridge-pot'

Najan kitu, urang teu bisa yakin yén host jauh boga bash nyukupan, jadi urang bakal nambahan cek leutik di awal (ieu tinimbang cangkang):

if [ "$SHELL" != "/bin/bash" ]
then
    echo "The '$SHELL' shell is not supported by 'deploy.sh'. Set a '/bin/bash' shell for '$USER@$HOSTNAME'."
    exit 1
fi

Sareng ayeuna éta nyata:

$ docker exec reverse-proxy rm /etc/nginx/conf.d/default.conf

$ wget -qO deploy.sh https://git.io/JUURc

$ chmod +x deploy.sh

$ ./deploy.sh localhost uptimer
Sending gzipped image 'uptimer' to 'localhost' via ssh...
Loaded image: uptimer:latest
Connecting to 'localhost' via ssh to seamlessly deploy 'uptimer'...
Deploying 'uptimer_GREEN' in place of 'uptimer_BLUE'...
06f5bc70e9c4f930e7b1f826ae2ca2f536023cc01e82c2b97b2c84d68048b18a
Container started. Checking health...
Requesting 'http://uptimer_GREEN:8080/' within the 'web-gateway' docker network:
  HTTP/1.0 503 Service Unavailable
wget: server returned error: HTTP/1.0 503 Service Unavailable
New 'uptimer_GREEN' service is not ready yet. Waiting (1)...
Requesting 'http://uptimer_GREEN:8080/' within the 'web-gateway' docker network:
  HTTP/1.0 503 Service Unavailable
wget: server returned error: HTTP/1.0 503 Service Unavailable
New 'uptimer_GREEN' service is not ready yet. Waiting (2)...
Requesting 'http://uptimer_GREEN:8080/' within the 'web-gateway' docker network:
  HTTP/1.0 200 OK
  Server: BaseHTTP/0.6 Python/3.8.3
  Date: Sat, 22 Aug 2020 20:15:50 GMT
  Content-Type: text/html

New 'uptimer_GREEN' service seems OK. Switching heads...
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful
2020/08/22 20:15:54 [notice] 97#97: signal process started
The 'uptimer_GREEN' service is live!
Killing 'uptimer_BLUE'...
uptimer_BLUE
Total reclaimed space: 0B
Deployment successful!

Ayeuna anjeun tiasa muka http://localhost/ dina browser nu, ngajalankeun deployment deui tur pastikeun yén éta ngajalankeun seamlessly ku ngamutahirkeun kaca nurutkeun kana CD salila perenah nu.

Tong hilap beberesih saatos damel :3

$ docker rm -f uptimer_GREEN reverse-proxy 
uptimer_GREEN
reverse-proxy

$ docker network rm web-gateway 
web-gateway

$ cd ..

$ rm -r blue-green-deployment

sumber: www.habr.com