bug: Fix validator on long strings (#1194)

* 🐛 Fix validator on long strings

Validator was mistakenly identifying a long yaml as a file and trying to
open it, which failed with an error of filename too long.

This was not catched in order to identify that the source is not a file
but a yaml, so it was directly returning the error.

This patch adds that error to the list in order ot identify the source
to validate as yaml. Also adds a couple of tests for this functionality.

Signed-off-by: Itxaka <itxaka.garcia@spectrocloud.com>

* 🐛 Merge initramfs generation between distros

Signed-off-by: Itxaka <itxaka.garcia@spectrocloud.com>

---------

Signed-off-by: Itxaka <itxaka.garcia@spectrocloud.com>

internal/agent/validate_test.go

@@ -24,6 +24,21 @@ var _ = Describe("Validate", func() {
 	Context("Validate", func() {
 		var yaml string
 
+		Context("With a really long config string", func() {
+			BeforeEach(func() {
+				yaml = `#cloud-config
+users:
+  - name: kairos
+    passwd: kairos
+vpn:
+  network_token: "dssdnfjkldashfkjhasdkhfkasjdhfkjhasdjkfhaksjdhfkjashjdkfhioreqwhfuihqweruifhuewrbfhuewrfuyequfhuiehuifheqrihfuiqrehfuirqheiufhreqiuhfuiqheiufhqeuihfuiqrehfiuhqreuifrhiuqehfiuhqeirhfiuewhrfhqwehfriuewhfuihewiuhfruewhrifhwiuehrfiuhweiurfhwueihrfuiwehufhweuihrfuiwerhfuihewruifhewuihfiouwehrfiouhwei"
+`
+			})
+			It("validates", func() {
+				Expect(Validate(yaml)).ToNot(HaveOccurred())
+			})
+		})
+
 		Context("with a valid config", func() {
 			BeforeEach(func() {
 				yaml = `#cloud-config
@@ -32,7 +47,7 @@ users:
     passwd: kairos`
 			})
 
-			It("is successful", func() {
+			It("is successful reading it from file", func() {
 				f, err := ioutil.TempDir("", "tests")
 				Expect(err).ToNot(HaveOccurred())
 				defer os.RemoveAll(f)
@@ -43,6 +58,9 @@ users:
 				err = Validate(path)
 				Expect(err).ToNot(HaveOccurred())
 			})
+			It("is successful reading it from a string", func() {
+				Expect(Validate(yaml)).ToNot(HaveOccurred())
+			})
 		})
 
 		Context("without a header", func() {