Alfred Sabitzer - K8s Applications mit MicroK8S auf Raspberry PI

alfred@monitoring:~/GetInfo$ go build GetInfo.go

go: downloading github.com/shirou/gopsutil v3.21.9+incompatible

go: extracting github.com/shirou/gopsutil v3.21.9+incompatible

go: downloading golang.org/x/sys v0.0.0-20211007075335-d3039528d8ac

go: extracting golang.org/x/sys v0.0.0-20211007075335-d3039528d8ac

go: finding github.com/shirou/gopsutil v3.21.9+incompatible

go: finding golang.org/x/sys v0.0.0-20211007075335-d3039528d8ac

alfred@monitoring:~/GetInfo$ ll

total 7716

drwxrwxr-x 2 alfred alfred 4096 Oct 15 20:30 ./

drwxr-xr-x 22 alfred alfred 4096 Oct 11 07:30 ../

-rwxrwxr-x 1 alfred alfred 8009715 Oct 15 20:30 GetInfo*

-rw------- 1 alfred alfred 4473 Oct 10 21:34 GetInfo.go

-rw------- 1 alfred alfred 81 Oct 10 21:48 dockerfile

-rw------- 1 alfred alfred 1434 Oct 10 21:19 error.html

-rw-rw-r-- 1 alfred alfred 0 Oct 11 07:28 getinfo.tar

-rw------- 1 alfred alfred 263 Oct 10 10:04 go.mod

-rw------- 1 alfred alfred 1314 Oct 10 10:04 go.sum

-rw------- 1 alfred alfred 3180 Oct 10 21:32 hello.html

alfred@monitoring:~/GetInfo$ ./GetInfo

Ein kurzer Test auf http://monitoring:8080/view/helloergibt

Abbildung 20: GetInfo Ausgabe

Das heist das Programm funktioniert. Die Logausgabe sieht aus wie folgt:

alfred@monitoring:~/GetInfo$ ./GetInfo

2021/10/10 21:42:01 Main Started

2021/10/10 21:42:16 hello.html

^C

alfred@monitoring:~/GetInfo$

Jetzt brauchen wir noch ein Docker-File

alfred@monitoring:~/GetInfo$ cat dockerfile

# syntax=docker/dockerfile:1

# Alpine is chosen for its small footprint

# compared to Ubuntu

FROM golang:1.16-alpine

WORKDIR /app

# Download necessary Go modules

COPY go.mod ./

COPY go.sum ./

RUN go mod download

COPY *.go ./

COPY hello.html ./

COPY error.html ./

RUN go build -o /GetInfo

EXPOSE 8080

CMD [ "/GetInfo" ]

alfred@monitoring:~/GetInfo$

um den Container zu bauen.

alfred@monitoring:~/GetInfo$ docker build . -t docker.registry:5000/getinfo:20211015

Sending build context to Docker daemon 16.38kB

Step 1/11 : FROM golang:1.16-alpine

1.16-alpine: Pulling from library/golang

552d1f2373af: Pull complete

eb74239f2a0c: Pull complete

2a8ec004bf6b: Pull complete

12f1fa1a3b20: Pull complete

5c12166b7f9d: Pull complete

Digest: sha256:05df7ff684a2cb06aa207be14a78918cbc3285ed3b965974979e575d59de1c11

Status: Downloaded newer image for golang:1.16-alpine

---> d2f4346f5656

Step 2/11 : WORKDIR /app

---> Running in 9b6c3b098321

Removing intermediate container 9b6c3b098321

---> 738bd59f63db

Step 3/11 : COPY go.mod ./

---> cb6306d5fdf2

Step 4/11 : COPY go.sum ./

---> f7eeef9ebda2

Step 5/11 : RUN go mod download

---> Running in efbe89b22883

Removing intermediate container efbe89b22883

---> cb738e90d4d7

Step 6/11 : COPY *.go ./

---> c5ab2f4e9e5c

Step 7/11 : COPY hello.html ./

---> 8e6738e25799

Step 8/11 : COPY error.html ./

---> 5c9506b2dc3f

Step 9/11 : RUN go build -o /GetInfo.go

---> Running in 3ad675aeb626

Removing intermediate container 3ad675aeb626

---> 0abfe5a9d849

Step 10/11 : EXPOSE 8080

---> Running in 80f728420378

Removing intermediate container 80f728420378

---> b9c5a76c55d2

Step 11/11 : CMD [ "/GetInfo" ]

---> Running in 71d6f27934d2

Removing intermediate container 71d6f27934d2

---> 4fae231152c2

Successfully built 4fae231152c2

Successfully tagged docker.registry:5000/getinfo:20211015

alfred@monitoring:~/GetInfo$

alfred@monitoring:~/GetInfo$ docker images

REPOSITORY TAG IMAGE ID CREATED SIZE

docker.registry:5000/getinfo 20211015 4fae231152c2 39 seconds ago 317MB

golang 1.16-alpine d2f4346f5656 2 days ago 296MB

alfred@monitoring:~/GetInfo$

Nun starten wir den Container im Vordergrund um den Output zu testen.

alfred@monitoring:~/GetInfo$ docker run --publish 8080:8080 docker.registry:5000/getinfo:20211015

2021/10/15 19:22:13 Main Started

2021/10/15 19:22:40 hello.html

Der Output im Browser ist wie folgt:

Abbildung 21: Docker Test Output

Der Container ist am erwarteten Port erreichbar. Die Anzeige der Werte sind jetzt aus Sicht des Containers, wie man an den Variablen und am Environment sehen kann.

Wir überprüfen die Struktur des gebauten docker-files.

alfred@monitoring:~/GetInfo$ docker save docker.registry:5000/getinfo:20211015 > getinfo.tar

alfred@monitoring:~/GetInfo$ tar -tvf getinfo.tar

-rw-r--r-- 0/0 7059 2021-10-15 21:22 0fca605bf404203fe0e1d41e306687bf70b8cdb4392c41363af0f6712ae28959.json

drwxr-xr-x 0/0 0 2021-10-15 21:22 11ada22ca4865de4368da5b2cdea81c34f3fc62b60e62f00329f839e1e51a431/

-rw-r--r-- 0/0 3 2021-10-15 21:22 11ada22ca4865de4368da5b2cdea81c34f3fc62b60e62f00329f839e1e51a431/VERSION

-rw-r--r-- 0/0 406 2021-10-15 21:22 11ada22ca4865de4368da5b2cdea81c34f3fc62b60e62f00329f839e1e51a431/json

-rw-r--r-- 0/0 5605376 2021-10-15 21:22 11ada22ca4865de4368da5b2cdea81c34f3fc62b60e62f00329f839e1e51a431/layer.tar

drwxr-xr-x 0/0 0 2021-10-15 21:22 1a41da37655e1ae130db0ff268801f26989f408ad4e24fee81b18252883fe835/

-rw-r--r-- 0/0 3 2021-10-15 21:22 1a41da37655e1ae130db0ff268801f26989f408ad4e24fee81b18252883fe835/VERSION

-rw-r--r-- 0/0 482 2021-10-15 21:22 1a41da37655e1ae130db0ff268801f26989f408ad4e24fee81b18252883fe835/json

-rw-r--r-- 0/0 2560 2021-10-15 21:22 1a41da37655e1ae130db0ff268801f26989f408ad4e24fee81b18252883fe835/layer.tar

drwxr-xr-x 0/0 0 2021-10-15 21:22 278bc14dbdd9bd52e524b98375e76f5b0f975f02167b6a7e8168184e577a8d17/

-rw-r--r-- 0/0 3 2021-10-15 21:22 278bc14dbdd9bd52e524b98375e76f5b0f975f02167b6a7e8168184e577a8d17/VERSION

-rw-r--r-- 0/0 482 2021-10-15 21:22 278bc14dbdd9bd52e524b98375e76f5b0f975f02167b6a7e8168184e577a8d17/json

-rw-r--r-- 0/0 5632 2021-10-15 21:22 278bc14dbdd9bd52e524b98375e76f5b0f975f02167b6a7e8168184e577a8d17/layer.tar

drwxr-xr-x 0/0 0 2021-10-15 21:22 37df72a20bd40f12a164a419626ffb20b4554c96983ec36b78024136e65f15c2/

-rw-r--r-- 0/0 3 2021-10-15 21:22 37df72a20bd40f12a164a419626ffb20b4554c96983ec36b78024136e65f15c2/VERSION

-rw-r--r-- 0/0 482 2021-10-15 21:22 37df72a20bd40f12a164a419626ffb20b4554c96983ec36b78024136e65f15c2/json

-rw-r--r-- 0/0 2560 2021-10-15 21:22 37df72a20bd40f12a164a419626ffb20b4554c96983ec36b78024136e65f15c2/layer.tar

drwxr-xr-x 0/0 0 2021-10-15 21:22 55a816cb614fc0754c9af49269934861de9251688789bc4a3e9f304ac1059e10/

-rw-r--r-- 0/0 3 2021-10-15 21:22 55a816cb614fc0754c9af49269934861de9251688789bc4a3e9f304ac1059e10/VERSION

-rw-r--r-- 0/0 482 2021-10-15 21:22 55a816cb614fc0754c9af49269934861de9251688789bc4a3e9f304ac1059e10/json

-rw-r--r-- 0/0 3584 2021-10-15 21:22 55a816cb614fc0754c9af49269934861de9251688789bc4a3e9f304ac1059e10/layer.tar

drwxr-xr-x 0/0 0 2021-10-15 21:22 5fe6d80a697427a6b315445103e12f8e5e14a6f9f071e119d9da5aa7787dedf0/

-rw-r--r-- 0/0 3 2021-10-15 21:22 5fe6d80a697427a6b315445103e12f8e5e14a6f9f071e119d9da5aa7787dedf0/VERSION

-rw-r--r-- 0/0 1432 2021-10-15 21:22 5fe6d80a697427a6b315445103e12f8e5e14a6f9f071e119d9da5aa7787dedf0/json

-rw-r--r-- 0/0 10244608 2021-10-15 21:22 5fe6d80a697427a6b315445103e12f8e5e14a6f9f071e119d9da5aa7787dedf0/layer.tar