Drop dependency on hosted nodes (#12901)

This should hopefully get CI working again.

There are two changes in here:

1. We can no longer change our patched Bazel. I didn’t switch away
   from the current patched version for now (we upload it to gcp bucket
   so it still works fine even if we cannot build it) but if we upgrade,
   we need to go to an unpatched version for now.
2. We need to get `az` from dev-env. I tested the self service compat
   job stuff and it works fine with this but there is a chance other
   parts don’t.

changelog_begin
changelog_end

azure-pipelines.yml

@@ -223,7 +223,8 @@ jobs:
 - job: compat_versions_pr_trigger_daily
   dependsOn: compat_versions_pr
   pool:
-    vmImage: "ubuntu-18.04"
+    name: 'ubuntu_20_04'
+    demands: assignment -equals default
   variables:
     branch: $[ dependencies.compat_versions_pr.outputs['out.branch'] ]
   steps:
@@ -233,6 +234,7 @@ jobs:
       var_name: bash-lib
   - bash: |
       set -euo pipefail
+      eval "$(./dev-env/bin/dade-assist)"
       source $(bash-lib)
       trigger_azure $(System.AccessToken) PRs --branch $(branch)
       trigger_azure $(System.AccessToken) digital-asset.daml-daily-compat --branch $(branch)

ci/build.yml

@@ -150,15 +150,16 @@ jobs:
         trigger_sha: '$(trigger_sha)'
     - template: report-end.yml
 
-- template: patch_bazel_windows/compile.yml
-  parameters:
-    final_job_name: patch_bazel_windows
+# TODO https://github.com/digital-asset/daml/issues/12900
+# - template: patch_bazel_windows/compile.yml
+#  parameters:
+#     final_job_name: patch_bazel_windows
 
 - job: Windows
   dependsOn:
     - da_ghc_lib
     - check_for_release
-    - patch_bazel_windows
+    # - patch_bazel_windows
     - git_sha
   variables:
     - name: release_sha

ci/cron/daily-compat.yml

@@ -500,11 +500,13 @@ jobs:
     condition: and(succeeded(),
                    eq(variables['Build.SourceBranchName'], 'main'))
     pool:
-      vmImage: ubuntu-20.04
+      name: 'ubuntu_20_04'
+      demands: assignment -equals default
     variables:
       need_to_build: $[ dependencies.blackduck_scan.outputs['out.need_to_build'] ]
     steps:
       - bash: |
+          eval "$(./dev-env/bin/dade-assist)"
           if [ "$(need_to_build)" == "true" ]; then
               branch="notices-update-$(Build.BuildId)"
               az extension add --name azure-devops

ci/cron/tuesday.yml

@@ -16,7 +16,8 @@ jobs:
 - job: announce_rotation
   timeoutInMinutes: 60
   pool:
-    vmImage: ubuntu-18.04
+    name: 'ubuntu_20_04'
+    demands: assignment -equals default
   steps:
   - checkout: self
     persistCredentials: true
@@ -25,7 +26,7 @@ jobs:
       var_name: bash_lib
   - bash: |
       set -euo pipefail
-
+      eval "$(./dev-env/bin/dade-assist)"
       source "$(bash_lib)"
 
       RELEASE_MANAGER=$(next_in_rotation_slack)

ci/cron/wednesday.yml

@@ -16,7 +16,8 @@ jobs:
 - job: open_release_pr
   timeoutInMinutes: 60
   pool:
-    vmImage: ubuntu-18.04
+    name: 'ubuntu_20_04'
+    demands: assignment -equals default
   steps:
   - checkout: self
     persistCredentials: true
@@ -25,7 +26,7 @@ jobs:
       var_name: bash_lib
   - bash: |
       set -euo pipefail
-
+      eval "$(./dev-env/bin/dade-assist)"
       source "$(bash_lib)"
 
       AUTH="$(get_gh_auth_header)"

ci/prs.yml

@@ -176,7 +176,8 @@ jobs:
 
 - job: self_service_compat_test
   pool:
-    vmImage: ubuntu-20.04
+    name: 'ubuntu_20_04'
+    demands: assignment -equals default
   condition: eq(variables['Build.Reason'], 'PullRequest')
   steps:
   - checkout: self
@@ -185,6 +186,7 @@ jobs:
       var_name: bash-lib
   - bash: |
       set -euo pipefail
+      eval "$(./dev-env/bin/dade-assist)"
       source $(bash-lib)
       COMMIT=$(git rev-parse HEAD^2)
       REQUEST=$(git log -n1 --format="%(trailers:key=run-full-compat,valueonly)" $COMMIT)

dev-env/bin/az

@@ -0,0 +1 @@
+../lib/dade-exec-nix-tool

nix/default.nix

@@ -199,6 +199,7 @@ in rec {
 
     # Cloud tools
     aws = pkgs.awscli;
+    az = pkgs.azure-cli;
     gcloud = pkgs.google-cloud-sdk;
     bq = gcloud;
     gsutil = gcloud;