reload-instead-of-sync

README

Reload instead of sync example

This example shows you how to develop a go application with devspace with reloading the build & deploy pipeline instead of hot reloading

Step 0: Prerequisites

In order to use this example, make sure you have docker installed and a docker registry where you can push to (hub.docker.com, gcr.io etc.). Make sure you are logged in to the registry via docker login.

Exchange the image name in .devspace/config.yaml under images.default.name with the image name you want to use. Do the same thing in kube/deployment.yaml under spec.template.spec.image. Do not add a tag to those image names, because this will be done at runtime automatically.

Optional: Use self hosted cluster (minikube, GKE etc.) instead of devspace-cloud

If you want to use your own cluster instead of the devspace-cloud as deployment target, make sure kubectl is configured correctly to access your cluster. Then just erase the cluster section in the .devspace/config.yaml and devspace will use your current kubectl context as deployment target.

Step 1: Start the devspace

To deploy the application simply run devspace up. The output of the command should look similar to this:

[INFO]   Loading config .devspace/config.yaml with overwrite config .devspace/overwrite.yaml
[INFO]   Successfully logged into devspace-cloud
[INFO]   Building image 'fabian1991/devspace' with engine 'docker'
[DONE] √ Authentication successful (hub.docker.com)
Sending build context to Docker daemon  14.34kB
Step 1/6 : FROM golang:1.11
 ---> fb7a47d8605b
Step 2/6 : RUN mkdir -p "$GOPATH/src/app" && ln -s $GOPATH/src/app /app
 ---> Using cache
 ---> 9592048b1d0b
Step 3/6 : ADD . $GOPATH/src/app
 ---> Using cache
 ---> c46f025a11b5
Step 4/6 : RUN cd $GOPATH/src/app && go get ./... && go build . && cd /app
 ---> Using cache
 ---> c1ad1a294a4f
Step 5/6 : WORKDIR /app
 ---> Using cache
 ---> 35608cd6e592
Step 6/6 : CMD ["$GOPATH/src/app/app"]
 ---> Using cache
 ---> af6e428fdcef
Successfully built af6e428fdcef
Successfully tagged fabian1991/devspace:mlSwh8F
The push refers to repository [docker.io/fabian1991/devspace]
36ffc46d7733: Pushed
730329ceeb12: Pushed
18f7b628e662: Pushed
cbc3342714a6: Layer already exists
cf2043c0e99a: Layer already exists
84a5f96d6621: Layer already exists
ab016c9ea8f8: Layer already exists
2eb1c9bfc5ea: Layer already exists
0b703c74a09c: Layer already exists
b28ef0b6fef8: Layer already exists
mlSwh8F: digest: sha256:a72aaa06264f9be86da167a78d00f7d1c3a4468f4916ea7dbe26dcdc28f6a697 size: 2422
[INFO]   Image pushed to registry (hub.docker.com)
[DONE] √ Done building and pushing image 'fabian1991/devspace'
[INFO]   Deploying devspace-default with helm
[DONE] √ Tiller started
[DONE] √ Deployed helm chart (Release revision: 1)
[DONE] √ Finished deploying devspace-default
[INFO]   Your DevSpace is now reachable via ingress on this URL: http://fabiankramm-d98142a0.devspace-cloud.com
[INFO]   See https://devspace-cloud.com/domain-guide for more information
Fabians-MBP:reload-instead-of-sync fabiankramm$ devspace up
[INFO]   Loading config .devspace/config.yaml with overwrite config .devspace/overwrite.yaml
[INFO]   Successfully logged into devspace-cloud
[INFO]   Building image 'fabian1991/devspace' with engine 'docker'
[DONE] √ Authentication successful (hub.docker.com)
Sending build context to Docker daemon  10.75kB
Step 1/6 : FROM golang:1.11
 ---> fb7a47d8605b
Step 2/6 : RUN mkdir -p "$GOPATH/src/app" && ln -s $GOPATH/src/app /app
 ---> Using cache
 ---> 9592048b1d0b
Step 3/6 : ADD . $GOPATH/src/app
 ---> a1ee1b4ae832
Step 4/6 : RUN cd $GOPATH/src/app && cd /app
 ---> Running in 72c82ac8c356
 ---> c6895e03655c
Step 5/6 : WORKDIR /app
 ---> Running in 24f6d88d1982
 ---> 49f341db3a9f
Step 6/6 : CMD ["go", "run", "main.go"]
 ---> Running in 6b39765f9e20
 ---> fd3c715ed7f4
Successfully built fd3c715ed7f4
Successfully tagged fabian1991/devspace:aXiK5GW
The push refers to repository [docker.io/fabian1991/devspace]
6791cab63553: Pushed
18f7b628e662: Layer already exists
cbc3342714a6: Layer already exists
cf2043c0e99a: Layer already exists
84a5f96d6621: Layer already exists
ab016c9ea8f8: Layer already exists
2eb1c9bfc5ea: Layer already exists
0b703c74a09c: Layer already exists
b28ef0b6fef8: Layer already exists
aXiK5GW: digest: sha256:c19c53b9f72de998ed8de81bc6591aef91bc23e182ca807d3430ead94ffac3d0 size: 2211
[INFO]   Image pushed to registry (hub.docker.com)
[DONE] √ Done building and pushing image 'fabian1991/devspace'
[INFO]   Deploying devspace-default with kubectl
deployment.extensions/devspace created
[DONE] √ Finished deploying devspace-default
[INFO]   Will now try to attach to a running devspace pod...
[INFO]   Attaching to pod devspace-66c788c9f8-lrtv2/default...
Hello World!
Hello World!

The command built your Dockerfile and pushed it to the target docker registry. Afterwards, it created a new kubernetes namespace for you and deployed the kube/deployment.yaml to that namespace. It also created a new kubectl context for you. You can check the running pods via kubectl get po.

Furthermore it watches all files in the example for changes, which will trigger on change an automatic rebuild & redeploy.

Step 2: Start developing

You should see a "Hello World!" printed every second in the console. Try changing main.go so that it prints "Hello DevSpace!" instead of "Hello World!". In the console window a similar output should be shown:

[INFO]   Change detected, will reload in 2 seconds
Hello World!
Hello World!
[INFO]   Building image 'fabian1991/devspace' with engine 'docker'
[DONE] √ Authentication successful (hub.docker.com)
Sending build context to Docker daemon  10.75kB
Step 1/6 : FROM golang:1.11
 ---> fb7a47d8605b
Step 2/6 : RUN mkdir -p "$GOPATH/src/app" && ln -s $GOPATH/src/app /app
 ---> Using cache
 ---> 9592048b1d0b
Step 3/6 : ADD . $GOPATH/src/app
 ---> 52e10ca4c98e
Step 4/6 : RUN cd $GOPATH/src/app && cd /app
 ---> Running in d14db7b806d5
 ---> 2cfa70fd538d
Step 5/6 : WORKDIR /app
 ---> Running in 29a9f491dff8
 ---> 4ba94b76c2fd
Step 6/6 : CMD ["go", "run", "main.go"]
 ---> Running in a479f87f252c
 ---> 98c5aac29268
Successfully built 98c5aac29268
Successfully tagged fabian1991/devspace:9LCpwdd
The push refers to repository [docker.io/fabian1991/devspace]
d3666866ac6e: Pushed
18f7b628e662: Layer already exists
cbc3342714a6: Layer already exists
cf2043c0e99a: Layer already exists
84a5f96d6621: Layer already exists
ab016c9ea8f8: Layer already exists
2eb1c9bfc5ea: Layer already exists
0b703c74a09c: Layer already exists
b28ef0b6fef8: Layer already exists
9LCpwdd: digest: sha256:f6bba6e00c42d099d08d415d794ae3202f64bd70589a4e189e1062890e894440 size: 2211
[INFO]   Image pushed to registry (hub.docker.com)
[DONE] √ Done building and pushing image 'fabian1991/devspace'
[INFO]   Deploying devspace-default with kubectl
deployment.extensions/devspace configured
[DONE] √ Finished deploying devspace-default
[INFO]   Will now try to attach to a running devspace pod...
[INFO]   Attaching to pod devspace-859d5ccbd7-x77hc/default...
Hello DevSpace!
Hello DevSpace!
Hello DevSpace!

Now you can just change any files and devspace will rebuild and redeploy your changes immediately.