implement resolve and apply

Signed-off-by: Jason Hall <jason@chainguard.dev>

tests/testdata/apply_basic.txt

@@ -0,0 +1,32 @@
+# Test basic apply command (requires kubectl)
+
+[!exec:kubectl] skip 'kubectl not available'
+
+-- Cargo.toml --
+[package]
+name = "test-app"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+
+-- src/main.rs --
+fn main() {
+    println!("Hello from test-app!");
+}
+
+-- deployment.yaml --
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: test-config
+data:
+  key: value
+
+# Apply should resolve and apply with kubectl
+# Note: This test only verifies the command runs, not the actual k8s deployment
+# since we don't have a test cluster
+env KRUST_REPO=ttl.sh/test
+! exec ./krust apply -f deployment.yaml
+# kubectl will fail with connection error in test environment, but that's expected
+stderr 'kubectl'

tests/testdata/resolve_basic.txt

@@ -0,0 +1,32 @@
+# Test basic resolve with single YAML file and single krust:// reference
+
+-- Cargo.toml --
+[package]
+name = "test-app"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+
+-- src/main.rs --
+fn main() {
+    println!("Hello from test-app!");
+}
+
+-- deployment.yaml --
+apiVersion: v1
+kind: Pod
+metadata:
+  name: test-pod
+spec:
+  containers:
+  - name: app
+    image: krust://.
+
+# Resolve should build and replace reference
+env KRUST_REPO=ttl.sh/test
+exec ./krust resolve -f deployment.yaml
+stdout 'ttl.sh/test/test-app@sha256:'
+! stdout 'krust://'
+stderr 'Found 1 unique krust:// reference'
+stderr 'Building image for: krust://.'

tests/testdata/resolve_dedup.txt

@@ -0,0 +1,38 @@
+# Test that multiple references to the same path are deduplicated
+
+-- Cargo.toml --
+[package]
+name = "test-app"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+
+-- src/main.rs --
+fn main() {
+    println!("Hello!");
+}
+
+-- deployment.yaml --
+apiVersion: v1
+kind: Pod
+metadata:
+  name: test-pod
+spec:
+  containers:
+  - name: app1
+    image: krust://.
+  - name: app2
+    image: krust://.
+  initContainers:
+  - name: init
+    image: krust://.
+
+# Should find only 1 unique reference and build once
+env KRUST_REPO=ttl.sh/test
+exec ./krust resolve -f deployment.yaml
+stdout 'ttl.sh/test/test-app@sha256:'
+stderr 'Found 1 unique krust:// reference'
+! stderr 'Found 3'
+# All three references should be replaced with same digest
+stdout -count=3 'ttl.sh/test/test-app@sha256:'

tests/testdata/resolve_directory.txt

@@ -0,0 +1,43 @@
+# Test resolving references in a directory of YAML files
+
+-- Cargo.toml --
+[package]
+name = "test-app"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+
+-- src/main.rs --
+fn main() {
+    println!("Hello!");
+}
+
+-- k8s/deployment.yaml --
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: app
+spec:
+  template:
+    spec:
+      containers:
+      - image: krust://.
+
+-- k8s/service.yaml --
+apiVersion: v1
+kind: Service
+metadata:
+  name: app-service
+spec:
+  selector:
+    app: test
+
+# Resolve should process all YAML files in directory
+env KRUST_REPO=ttl.sh/test
+exec ./krust resolve -f k8s
+stdout 'kind: Deployment'
+stdout 'kind: Service'
+stdout 'ttl.sh/test/test-app@sha256:'
+! stdout 'krust://'
+stderr 'Found 1 unique krust:// reference'

tests/testdata/resolve_multi_document.txt

@@ -0,0 +1,47 @@
+# Test YAML file with multiple documents separated by ---
+
+-- Cargo.toml --
+[package]
+name = "test-app"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+
+-- src/main.rs --
+fn main() {
+    println!("Hello!");
+}
+
+-- manifests.yaml --
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: config
+data:
+  key: value
+---
+apiVersion: v1
+kind: Pod
+metadata:
+  name: pod1
+spec:
+  containers:
+  - image: krust://.
+---
+apiVersion: v1
+kind: Pod
+metadata:
+  name: pod2
+spec:
+  containers:
+  - image: krust://.
+
+# Should handle multiple documents and preserve structure
+env KRUST_REPO=ttl.sh/test
+exec ./krust resolve -f manifests.yaml
+stdout 'kind: ConfigMap'
+stdout 'kind: Pod'
+stdout -count=2 'ttl.sh/test/test-app@sha256:'
+stdout -count=2 '---'
+stderr 'Found 1 unique krust:// reference'