[ci] Simplify tmpnet monitoring action

.github/actions/install-nix/action.yml

@@ -0,0 +1,17 @@
+name: 'Install nix'
+description: 'Install nix and populate the store for the repo flake'
+
+inputs:
+  github_token:
+    description: "github token to authenticate with to avoid being rate-limited"
+    default: ${{ github.token }}
+    required: false
+
+runs:
+  using: composite
+  steps:
+    - uses: cachix/install-nix-action@v30
+      with:
+        github_access_token: ${{ inputs.github_token }}
+    - run: nix develop --command echo "dependencies installed"
+      shell: bash

.github/actions/run-monitored-tmpnet-cmd/action.yml

@@ -3,10 +3,15 @@ description: 'Run the provided command in an environment configured to monitor t
 
 inputs:
   run:
-    description: "the bash command to run"
+    description: "the bash script to run e.g. ./scripts/my-script.sh"
     required: true
+  run_env:
+    description: 'a string containing env vars for the command e.g. "MY_VAR1=foo MY_VAR2=bar"'
+    default: ''
   filter_by_owner:
     default: ''
+  artifact_prefix:
+    default: ''
   prometheus_username:
     required: true
   prometheus_password:
@@ -36,6 +41,9 @@ inputs:
 runs:
   using: composite
   steps:
+    # Ensure promtail and prometheus are available
+    - name: Install nix
+      uses: ./.github/actions/install-nix
     - name: Start prometheus
       # Only run for the original repo; a forked repo won't have access to the monitoring credentials
       if: (inputs.prometheus_username != '')
@@ -63,11 +71,17 @@ runs:
         FILTER_BY_OWNER: ${{ inputs.filter_by_owner }}
     - name: Run command
       shell: bash
-      run: ${{ inputs.run }}
+      run: ${{ inputs.run_env }} ${{ inputs.run }}
       env:
+        TMPNET_DELAY_NETWORK_SHUTDOWN: true # Ensure shutdown waits for a final metrics scrape
         GH_REPO: ${{ inputs.repository_owner }}/${{ inputs.repository_name }}
         GH_WORKFLOW: ${{ inputs.workflow }}
         GH_RUN_ID: ${{ inputs.run_id }}
         GH_RUN_NUMBER: ${{ inputs.run_number }}
         GH_RUN_ATTEMPT: ${{ inputs.run_attempt }}
         GH_JOB_ID: ${{ inputs.job }}
+    - name: Upload tmpnet network dir
+      uses: ./.github/actions/upload-tmpnet-artifact
+      if: always()
+      with:
+        name: ${{ inputs.artifact_prefix }}-tmpnet-data

.github/workflows/ci.yml

@@ -51,78 +51,55 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: ./.github/actions/setup-go-for-project
-      - uses: cachix/install-nix-action@v30
-        with:
-          github_access_token: ${{ secrets.GITHUB_TOKEN }}
-      # TODO(marun) Maybe figure out how to use `nix build` somehow i.e. make the default shell double as the default package
-      - run: nix develop --command echo "dependencies installed"
       - name: Build AvalancheGo Binary
         shell: bash
         run: ./scripts/build.sh -r
       - name: Run e2e tests
         uses: ./.github/actions/run-monitored-tmpnet-cmd
         with:
-          run: E2E_SERIAL=1 ./scripts/tests.e2e.sh --delay-network-shutdown
+          run: ./scripts/tests.e2e.sh
+          run_env: E2E_SERIAL=1
+          artifact_prefix: e2e
           filter_by_owner: avalanchego-e2e
           prometheus_username: ${{ secrets.PROMETHEUS_ID || '' }}
           prometheus_password: ${{ secrets.PROMETHEUS_PASSWORD || '' }}
           loki_username: ${{ secrets.LOKI_ID || '' }}
           loki_password: ${{ secrets.LOKI_PASSWORD || '' }}
-      - name: Upload tmpnet network dir
-        uses: ./.github/actions/upload-tmpnet-artifact
-        if: always()
-        with:
-          name: e2e-tmpnet-data
   e2e_existing_network:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
       - uses: ./.github/actions/setup-go-for-project
-      - uses: cachix/install-nix-action@v30
-        with:
-          github_access_token: ${{ secrets.GITHUB_TOKEN }}
-      - run: nix develop --command echo "dependencies installed"
       - name: Build AvalancheGo Binary
         shell: bash
         run: ./scripts/build.sh -r
       - name: Run e2e tests with existing network
         uses: ./.github/actions/run-monitored-tmpnet-cmd
         with:
-          run: E2E_SERIAL=1 ./scripts/tests.e2e.existing.sh --delay-network-shutdown
+          run: ./scripts/tests.e2e.existing.sh
+          run_env: E2E_SERIAL=1
+          artifact_prefix: e2e-existing-network
           prometheus_username: ${{ secrets.PROMETHEUS_ID || '' }}
           prometheus_password: ${{ secrets.PROMETHEUS_PASSWORD || '' }}
           loki_username: ${{ secrets.LOKI_ID || '' }}
           loki_password: ${{ secrets.LOKI_PASSWORD || '' }}
-      - name: Upload tmpnet network dir
-        uses: ./.github/actions/upload-tmpnet-artifact
-        if: always()
-        with:
-          name: e2e-existing-network-tmpnet-data
   Upgrade:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
       - uses: ./.github/actions/setup-go-for-project
-      - uses: cachix/install-nix-action@v30
-        with:
-          github_access_token: ${{ secrets.GITHUB_TOKEN }}
-      - run: nix develop --command echo "dependencies installed"
       - name: Build AvalancheGo Binary
         shell: bash
         run: ./scripts/build.sh
       - name: Run e2e tests
         uses: ./.github/actions/run-monitored-tmpnet-cmd
         with:
           run: ./scripts/tests.upgrade.sh
+          artifact_prefix: upgrade
           prometheus_username: ${{ secrets.PROMETHEUS_ID || '' }}
           prometheus_password: ${{ secrets.PROMETHEUS_PASSWORD || '' }}
           loki_username: ${{ secrets.LOKI_ID || '' }}
           loki_password: ${{ secrets.LOKI_PASSWORD || '' }}
-      - name: Upload tmpnet network dir
-        uses: ./.github/actions/upload-tmpnet-artifact
-        if: always()
-        with:
-          name: upgrade-tmpnet-data
   Lint:
     runs-on: ubuntu-latest
     steps:
@@ -243,9 +220,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: ./.github/actions/setup-go-for-project
-      - uses: cachix/install-nix-action@v30
-        with:
-          github_access_token: ${{ secrets.GITHUB_TOKEN }}
+      - uses: ./.github/actions/install-nix
       - run: nix develop --command echo "dependencies installed"
       - name: Run e2e tests
         shell: bash

tests/fixture/e2e/flags.go

@@ -10,12 +10,18 @@ import (
 	"path/filepath"
 	"time"
 
+	"github.com/spf13/cast"
+
 	"github.com/ava-labs/avalanchego/tests/fixture/tmpnet"
 )
 
-// Ensure that this value takes into account the scrape_interval
-// defined in scripts/run_prometheus.sh.
-const networkShutdownDelay = 12 * time.Second
+const (
+	// Ensure that this value takes into account the scrape_interval
+	// defined in scripts/run_prometheus.sh.
+	networkShutdownDelay = 12 * time.Second
+
+	delayNetworkShutdownEnvName = "TMPNET_DELAY_NETWORK_SHUTDOWN"
+)
 
 type FlagVars struct {
 	avalancheGoExecPath  string
@@ -143,7 +149,7 @@ func RegisterFlags() *FlagVars {
 	flag.BoolVar(
 		&vars.delayNetworkShutdown,
 		"delay-network-shutdown",
-		false,
+		cast.ToBool(GetEnvWithDefault(delayNetworkShutdownEnvName, "false")),
 		"[optional] whether to delay network shutdown to allow a final metrics scrape.",
 	)
 	flag.BoolVar(