Tag Archives: docker
Using tcpdump for k8s pods
You need wireshark to be installed on your local machine — download (more on this below). If you don’t have tcpdump installed inside the pod, you can install it with
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# get pod name kubectl get po -Lversion,cfg,infra-cfg -lapp=<pod-tag> kubectl exec -it <pod-name> sh # inside the pod, alpine apk add tcpdump |
Then, on your local machine:
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kubectl exec <pod-name> -- tcpdump -i eth0 -w - | wireshark -k -i - |
If you want to see packets in grpc/http2, you can add a rule in Wireshark. For this, click …
Datadog in a docker for integration tests and local dev
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DOCKER_CONTENT_TRUST=1 docker run --rm --name dd-agent -p 8126:8126 -v /var/run/docker.sock:/var/run/docker.sock:ro -v /proc/:/host/proc/:ro -v /sys/fs/cgroup/:/host/sys/fs/cgroup:ro -e DD_API_KEY=REPLACE_WITH_NEW_KEY -e DD_SITE=datadoghq.eu datadog/agent |
mmock for mocking microservices
It is a very easy to set up though pretty powerful tool with support for delays and handling query params. It also has a console for checking all the requests and corresponding responses matched. Here it is https://github.com/jmartin82/mmock. Below I describe a way to use it with docker-compose for local development.
XDebug inside a docker container
That’s how you can debug your php app running in a docker container.
Read logs from docker container
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tail -f `docker inspect --format='{{.LogPath}}' [containername]` |
Postgres in docker: random «unique violation» errors
While running postgres in docker (for development, of course), from time to time I just run into errors like «Duplicate Key Value Violates Unique Constraint». I found the solution (thanks to this answer, for sure — https://stackoverflow.com/a/47089825/801426): if you have a table called «[table]», just do this
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SELECT setval('[table]_id_seq', (SELECT MAX(id) FROM [table])); |
Gitlab-ci: build go app with docker as a docker image
Preparations [TO BE UPDATED LATER] My gitlab-ci.yml
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variables: PACKAGE_PATH: /go/src/gitlab.com/[username_for_gitlab]/[project_name] # https://docs.gitlab.com/ee/ci/docker/using_docker_build.html CONTAINER_TEST_IMAGE: $CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG CONTAINER_RELEASE_IMAGE: $CI_REGISTRY_IMAGE:latest stages: - dep - test - build # A hack to make Golang-in-Gitlab happy .anchors: - &inject-gopath mkdir -p $(dirname ${PACKAGE_PATH}) && ln -s ${CI_PROJECT_DIR} ${PACKAGE_PATH} && cd ${PACKAGE_PATH} dep: stage: dep image: golang:1.13.1-alpine before_script: - *inject-gopath script: go mod tidy && go mod vendor artifacts: name: "vendor-$CI_PIPELINE_ID" paths: - vendor/ expire_in: 1 hour test: stage: test dependencies: - dep image: docker:17 services: - docker:dind before_script: - *inject-gopath script: docker build --target=test . lint: stage: test dependencies: - dep image: docker:17 services: - docker:dind before_script: - *inject-gopath script: docker build --target=lint . build: stage: build dependencies: - dep - lint - test image: docker:17 services: - docker:dind before_script: - *inject-gopath - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY registry script: - docker build --target=release --pull -t $CONTAINER_TEST_IMAGE . - docker tag $CONTAINER_TEST_IMAGE $CONTAINER_RELEASE_IMAGE - docker push $CONTAINER_TEST_IMAGE |
My Dockerfile
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FROM golang:1.13.1-alpine AS build WORKDIR /go/src/gitlab.com/[username_for_gitlab]/[project_name] COPY . . RUN go get -u github.com/jessevdk/go-assets-builder RUN apk add --no-cache make RUN make build #some pareparations and after that: go build -i -o ./[path_to_bin] ./cmd/[...] FROM alpine:3.10 AS release COPY --from=build /go/src/gitlab.com/[username_for_gitlab]/[project_name]/[path_to_bin] /usr/local/bin/[appname] RUN apk add --no-cache make bash curl tzdata EXPOSE 3000 3001 ENTRYPOINT ["/usr/local/bin/[appname]"] FROM golang:1.13.1-alpine AS test ENV CGO_ENABLED=0 WORKDIR /go/src/gitlab.com/[username_for_gitlab]/[project_name] COPY . . RUN apk add --no-cache make bash RUN make test FROM golangci/golangci-lint:v1.20 AS lint WORKDIR /go/src/gitlab.com/[username_for_gitlab]/[project_name] COPY . . RUN make lint-full # to check things locally # docker build --target=check_container . # docker images # docker run -it <hash> /bin/bash FROM golang:1.13.1-alpine AS check_container WORKDIR /go/src/gitlab.com/[username_for_gitlab]/[project_name] COPY . . RUN apk add --no-cache make bash RUN /bin/bash FROM release |
Pulling from your private registry Create deploy token as described here. After that, you can do this:
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docker login -u [deploy_username] -p [deploy_token] registry.gitlab.com docker pull registry.gitlab.com/[username_for_gitlab]/[project_name]:master docker run -d --name [container_name_you_like] --env-file [path-to-.env] --net host --rm registry.gitlab.com/[username_for_gitlab]/[project_name]:master |
Useful links: https://dev.to/hypnoglow/how-to-make-friends-with-golang-docker-and-gitlab-ci-4bil https://docs.gitlab.com/ee/ci/docker/using_docker_build.html https://medium.com/@tonistiigi/advanced-multi-stage-build-patterns-6f741b852fae https://docs.gitlab.com/ee/ci/yaml/ (full description of gitlab-ci.yml) https://about.gitlab.com/blog/2017/11/27/go-tools-and-gitlab-how-to-do-continuous-integration-like-a-boss/ https://gitlab.com/hypnoglow/example-go-docker-gitlab/blob/master/.gitlab-ci.yml Somewhat useful: https://blog.lwolf.org/post/how-to-build-tiny-golang-docker-images-with-gitlab-ci/ https://angristan.xyz/build-push-docker-images-gitlab-ci/ https://docs.gitlab.com/ee/user/packages/container_registry/#use-images-from-gitlab-container-registry https://www.digitalocean.com/community/tutorials/how-to-install-and-use-docker-on-centos-7 (it says to do sudo usermod -aG docker …
docker-compose example for ceph, kafka, postgres cluster
That is how it can be done:
docker simple starter
Build and run (on linux do not forget sudo):
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docker image build -t <image-name> . docker container run --env "DOCKER=true" --env "NODE_ENV=test" --env "NODE_PORT=8000" --mount "type=bind,source=/etc/nginx/sites-enabled,target=/sites-enabled" --env "PATH_CONF=/sites-enabled" -p 8000:8000 --rm --name <container-name> --network=host <image-name> |
Login into container
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docker container exec -it <container-name> bash |
docker-compose for starting aerospike and memcache
Place this config wherever you like (in your project) — for instance, ~/myproj/docker/docker-compose.yml:
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version: "2" services: #aerspike as: image: aerospike/aerospike-server volumes: - ./aerospike/etc:/opt/aerospike/etc ports: - 3000:3000 command: [asd, --config-file, /opt/aerospike/etc/docker.conf] memcached: image: memcached ports: - 11211:11211 volumes: #volume for etcd dicovery-data: driver: local #volume for database db-data: driver: local |
And this config for aerospike should be placed in a directory ~/myproj/docker/aerospike/etc/docker.conf After that you should run it like that:
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cd ~/myproj/docker docker-compose up -d |
When you finished, just run:
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cd ~/myproj/docker docker-compose down |
https://docs.docker.com/compose/reference/up/