Add docker test target which can be easily run in concourse

Author: SuperSandro2000

internal/core/config.go

@@ -242,6 +242,7 @@ type DockerfileConfig struct {
 	ExtraDirectives      []string `yaml:"extraDirectives"`
 	ExtraIgnores         []string `yaml:"extraIgnores"`
 	ExtraPackages        []string `yaml:"extraPackages"`
+	ExtraTestPackages    []string `yaml:"extraTestPackages"`
 	RunAsRoot            bool     `yaml:"runAsRoot"`
 	UseBuildKit          bool     `yaml:"useBuildKit"`
 	WithLinkerdAwait     bool     `yaml:"withLinkerdAwait"`

internal/dockerfile/Dockerfile.tmpl

@@ -26,6 +26,41 @@ RUN {{ if .UseBuildKit }}--mount=type=cache,target=/go/pkg/mod \
 {{ end -}}
 ################################################################################
 
+# To only build the tests run: docker build . --target test
+# We can't do `FROM builder AS test` here, as than make prepare-static-check would not be cached during interactive use when developing
+# and caching all the tools, especially golangci-lint, takes a few minutes.
+FROM {{ .DockerHubMirror }}golang:{{ .Constants.DefaultGoVersion }}-alpine{{ .Constants.DefaultAlpineImage }} AS test
+
+COPY Makefile /src/Makefile
+
+# used below by USER
+RUN addgroup -g 4200 appgroup \
+  && adduser -h /home/appuser -s /sbin/nologin -G appgroup -D -u 4200 appuser
+
+RUN apk add --no-cache --no-progress git make {{- range .ExtraTestPackages }} {{.}}{{ end }} \
+{{- if .ReuseEnabled }}
+  && pip3 install --break-system-packages reuse \
+{{- end }}
+  && make -C /src prepare-static-check
+
+
+# We only copy here because we want the "prepare-static-check" to be cacheable.
+# It is not a problem that we are overwriting the go cache from the earlier steps because we do not need to rebuild those tools.
+COPY --from=builder /go /go
+COPY --from=builder /src /src
+
+RUN make -C /src static-check
+
+# Some things like postgres do not like to run as root. For simplicity, just always run as a unprivileged user,
+# but for it to be able to read the go cache, we need to allow it.
+RUN chmod 777 -R /src/
+USER 4200:4200
+RUN cd /src \
+  && git config --global --add safe.directory /src \
+  && make build/cover.out
+
+################################################################################
+
 FROM {{ .DockerHubMirror }}alpine:{{ .Constants.DefaultAlpineImage }}
 
 {{ if not $dcfg.RunAsRoot -}}

internal/dockerfile/docker.go

@@ -12,6 +12,7 @@ import (
 	"github.com/sapcc/go-bits/must"
 
 	"github.com/sapcc/go-makefile-maker/internal/core"
+	"github.com/sapcc/go-makefile-maker/internal/golang"
 	"github.com/sapcc/go-makefile-maker/internal/util"
 )
 
@@ -22,7 +23,7 @@ var (
 	dockerignoreTemplate string
 )
 
-func RenderConfig(cfg core.Configuration) {
+func RenderConfig(cfg core.Configuration, sr golang.ScanResult) {
 	// if there is an entrypoint configured use that otherwise fallback to the first binary name
 	var entrypoint string
 	if len(cfg.Dockerfile.Entrypoint) > 0 {
@@ -70,14 +71,25 @@ func RenderConfig(cfg core.Configuration) {
 		dockerHubMirror = "keppel.eu-de-1.cloud.sap/ccloud-dockerhub-mirror/library/"
 	}
 
+	var extraTestPackages []string
+	reuseEnabled := cfg.Reuse.Enabled.UnwrapOr(true)
+	if reuseEnabled {
+		extraTestPackages = append(extraTestPackages, "py3-pip")
+	}
+	if sr.UsesPostgres {
+		extraTestPackages = append(extraTestPackages, "postgresql")
+	}
+
 	must.Succeed(util.WriteFileFromTemplate("Dockerfile", dockerfileTemplate, map[string]any{
 		"Config": cfg,
 		"Constants": map[string]any{
 			"DefaultGoVersion":   core.DefaultGoVersion,
 			"DefaultAlpineImage": core.DefaultAlpineImage,
 		},
 		"DockerHubMirror":    dockerHubMirror,
+		"ExtraTestPackages":  extraTestPackages,
 		"Entrypoint":         entrypoint,
+		"ReuseEnabled":       reuseEnabled,
 		"RunCommands":        strings.Join(commands, " \\\n  && "),
 		"RunVersionCommands": strings.Join(runVersionCommands, " \\\n  && "),
 		"UseBuildKit":        cfg.Dockerfile.UseBuildKit,

internal/dockerfile/dockerignore.tmpl

@@ -7,13 +7,10 @@
 # TODO: uncomment when applications no longer use git to get version information
 #.git/
 /.github/
-/.gitignore
-/.golangci.yaml
 /.goreleaser.yml
 /.vscode/
 /CONTRIBUTING.md
 /Dockerfile
-/LICENSE*
 /Makefile.maker.yaml
 /README.md
 /build/

main.go

@@ -94,7 +94,7 @@ func main() {
 	// Render Dockerfile
 	if cfg.Dockerfile.Enabled {
 		logg.Debug("rendering Dockerfile")
-		dockerfile.RenderConfig(cfg)
+		dockerfile.RenderConfig(cfg, sr)
 	}
 
 	// Render golangci-lint config file