SimpleApp — KrakenD API Gateway Templates (Part II)

Previous part, we added a simple Krakend config. You can see it from here.

What are KrakenD Templates?

A template system gives you full flexibility to work with the configuration file. It comes in handy to: Split a large krakend. json file into several pieces. Inject variables, like environment settings, into the configuration.

create a config folder and add some files

• settings

service.json

We keep our application url in service.json

• templates

We have sample.json which includes category api endpoint. If I add my all endpoints here, It would be bigger and not readable. I divide my endpoints for each apis to templates. So I have more files but it is more readable now.

CategoryApiEndpoint.tmpl

.tmpl is special file extension for KrakenD. CategoryApiEndpoint.tmpl includes just our category api endpoints.

Note: I use docker on windows. So if I want to access my local network, I need to use host.docker.internal instead of localhost

ProductApiEndpoint.tmpl

Endpoint.tmpl

This file has the sum of all templates. We just call api templates we just created. We also say which service will be used by which template.

sample.json

Now, we don’t need to add anymore all endpoints here. We just include our Endpoint template.

update Dockerfile

FROM devopsfaith/krakend
COPY . /etc/krakend/
RUN FC_ENABLE=1 \
FC_SETTINGS="config/settings" \
FC_TEMPLATES="config/templates" \
krakend check -t -d -c "config/sample.json"
ENTRYPOINT FC_ENABLE=1 \
FC_SETTINGS="/etc/krakend/config/settings"\
FC_TEMPLATES="/etc/krakend/config/templates" \
krakend run -c "/etc/krakend/config/sample.json"

Now run following these commands.

docker build -t simplekrakend .
docker run -d -p 8080:8080 simplekrakend

When we call POST localhost:8080/category, they route our categoryapi (http://localhost:5000/category/insert) behind

Next Post, we will talk about Containerization

References

KrakenD - Open source API Gateway