Part 5: Importing
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Earthly 0.7
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To copy the files for this example ( Part 5 ) run
earthly --artifact github.com/earthly/earthly/examples/tutorial/go:main+part5/part5 ./part5Examples in Python, JavaScript and Java are at the bottom of this page.
So far we've seen how the FROM command in Earthly has the ability to reference another target's image as its base image, like in the case below where the +build target uses the image from the +deps target.
VERSION 0.7
FROM golang:1.15-alpine3.13
WORKDIR /go-workdir
deps:
COPY go.mod go.sum ./
RUN go mod download
# Output these back in case go mod download changes them.
SAVE ARTIFACT go.mod AS LOCAL go.mod
SAVE ARTIFACT go.sum AS LOCAL go.sum
build:
FROM +deps
COPY main.go .
RUN go build -o output/example main.go
SAVE ARTIFACT output/example AS LOCAL local-output/go-example
But FROM also has the ability to import targets from Earthfiles in different directories. Let's say we have a directory structure like this.
.
├── services
| └── service-one
| ├── Earthfile (containing +deps)
| ├── go.mod
| └── go.sum
├── main.go
└── Earthfile
We can use a target in the Earthfile in /services/service-one from inside the Earthfile in the root of our directory. NOTE: relative paths must use ./ or ../.
./services/service-one/Earthfile
VERSION 0.7
FROM golang:1.15-alpine3.13
WORKDIR /go-workdir
deps:
COPY go.mod go.sum ./
RUN go mod download
# Output these back in case go mod download changes them.
SAVE ARTIFACT go.mod AS LOCAL go.mod
SAVE ARTIFACT go.sum AS LOCAL go.sum./Earthfile
build:
FROM ./services/service-one+deps
COPY main.go .
RUN go build -o output/example main.go
SAVE ARTIFACT output/example AS LOCAL local-output/go-exampleThis code tells FROM that there is another Earthfile in the services/service-one directory and that the Earthfile contains a target called +deps. In this case, if we were to run +build Earthly is smart enough to go into the subdirectory, run the +deps target in that Earthfile, and then use it as the base image for +build.
We can also reference an Earthfile in another repo, which works in a similar way. If the reference does not begin with one of /, ./, or ../, then earthly treats it as a repository. See the reference for details.
build:
FROM github.com/example/project+remote-target
COPY main.go .
RUN go build -o output/example main.go
SAVE ARTIFACT output/example AS LOCAL local-output/go-exampleIn addition to importing single targets from other files, we can also import an entire Earthfile with the IMPORT command. This is helpful if there are several targets in a separate Earthfile that you want access to in your current file. It also allows you to create an alias.
VERSION 0.7
IMPORT ./services/service-one AS my_service
FROM golang:1.15-alpine3.13
WORKDIR /go-workdir
build:
FROM my_service+deps
COPY main.go .
RUN go build -o output/example main.go
SAVE ARTIFACT output/example AS LOCAL local-output/go-exampleIn this example, we assume there is a ./services/service-one directory that contains its own Earthfile. We import it and then use the AS keyword to give it an alias.
Then, in our +build target we can inherit from any target in the imported Earthfile by passing alias+target-name. In this case the Earthfile in the service directory has a target named +deps.