Merge ~ubuntu-docker-images/ubuntu-docker-images/+git/prometheus:update-21.04 into ~ubuntu-docker-images/ubuntu-docker-images/+git/prometheus:update-20.04-snap

[Sergio Durigan Junior]

This is the 21.04 branch for prometheus. It's worth mentioning a few things:

- This MP is based on https://code.launchpad.net/~canonical-server/ubuntu-docker-images/+git/prometheus/+merge/400420.

- This MP's target branch is update-20.04-snap, but that's just to simplify the review. Obviously the intention is to create a new M.N-21.04 branch when this MP is approved.

- Although the prometheus version listed here is 2.25.2, the prometheus snap on the 21.04 track hasn't been updated yet (it will be soon, though).

Having said all that, once the 20.04 MP has been approved, this one will should be breeze to review.

[Bryce Harrington (bryce)]

Straightforward, essentially just updating the release number.

Build worked fine:

Step 14/15 : ENTRYPOINT [ "/usr/bin/prometheus" ]
 ---> Running in ce42ca5d50f6
Removing intermediate container ce42ca5d50f6
 ---> 14fa37a23267
Step 15/15 : CMD [ "--config.file=/etc/prometheus/prometheus.yml", "--storage.tsdb.path=/prometheus" ]
 ---> Running in 10e0503c49b4
Removing intermediate container 10e0503c49b4
 ---> 29f3294a9577
Successfully built 29f3294a9577

LGTM, +1

[Bryce Harrington (bryce)]

review: Approve

diff --git a/Dockerfile b/Dockerfile
index 51f175d..c810437 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:focal AS snap-installer
+FROM ubuntu:hirsute AS snap-installer
 
 RUN set -eux; \
 	apt-get update; \
@@ -7,11 +7,11 @@ RUN set -eux; \
 		jq curl ca-certificates squashfs-tools; \
 # taken from https://snapcraft.io/docs/build-on-docker
 # Alternatively, we can install snapd, and issue `snap download prometheus`
-	curl -L $(curl -H 'X-Ubuntu-Series: 16' 'https://api.snapcraft.io/api/v1/snaps/details/prometheus?channel=20.04/edge' | jq '.download_url' -r) --output prometheus.snap; \
+	curl -L $(curl -H 'X-Ubuntu-Series: 16' 'https://api.snapcraft.io/api/v1/snaps/details/prometheus?channel=21.04/edge' | jq '.download_url' -r) --output prometheus.snap; \
 	mkdir -p /snap; \
 	unsquashfs -d /snap/prometheus prometheus.snap
 
-FROM ubuntu:focal
+FROM ubuntu:hirsute
 
 ENV TZ UTC
 
diff --git a/README.md b/README.md
index a1e5136..9c98e64 100644
--- a/README.md
+++ b/README.md
@@ -19,7 +19,7 @@ _Tags in italics are not available in ubuntu/prometheus but are shown here for c
 
 | Channel Tag | | | Currently | Architectures |
 |---|---|---|---|---|
-| **`2.20-20.04_beta`**    | | | Prometheus 2.20.1 on Ubuntu 20.04 LTS | `amd64`, `arm64`, `ppc64el`, `s390x` |
+| **`2.25-21.04_beta`**    | | | Prometheus 2.25.2 on Ubuntu 21.04 | `amd64`, `arm64`, `ppc64el`, `s390x` |
 | _`track_risk`_ |
 
 Channel tag shows the most stable channel for that track ordered `stable`, `candidate`, `beta`, `edge`. More risky channels are always implicitly available. So if `beta` is listed, you can also pull `edge`. If `candidate` is listed, you can pull `beta` and `edge`. When `stable` is listed, all four are available. Images are guaranteed to progress through the sequence `edge`, `beta`, `candidate` before `stable`.
@@ -30,7 +30,7 @@ Channel tag shows the most stable channel for that track ordered `stable`, `cand
 Launch this image locally:
 
 ```sh
-docker run -d --name prometheus-container -e TZ=UTC -p 30090:9090 ubuntu/prometheus:2.20-20.04_beta
+docker run -d --name prometheus-container -e TZ=UTC -p 30090:9090 ubuntu/prometheus:2.25-21.04_beta
 ```
 Access your Prometheus server at `localhost:30090`.
 
@@ -40,8 +40,8 @@ Access your Prometheus server at `localhost:30090`.
 |---|---|
 | `-e TZ=UTC` | Timezone. |
 | `-p 30090:9090` | Expose Prometheus server on `localhost:30090`. |
-| `-v /path/to/prometheus.yml:/etc/prometheus/prometheus.yml` | Local [configuration file](https://prometheus.io/docs/prometheus/2.20/configuration/configuration/) `prometheus.yml` (try [this example](https://git.launchpad.net/~canonical-server/ubuntu-docker-images/+git/prometheus/plain/examples/config/prometheus.yml?h=2.20-20.04)). |
-| `-v /path/to/alerts.yml:/etc/prometheus/alerts.yml` | Local [alert configuration file](https://prometheus.io/docs/prometheus/2.20/configuration/configuration/) `alerts.yml` (try [this example](https://git.launchpad.net/~canonical-server/ubuntu-docker-images/+git/prometheus/plain/examples/config/alerts.yml?h=2.20-20.04)). |
+| `-v /path/to/prometheus.yml:/etc/prometheus/prometheus.yml` | Local [configuration file](https://prometheus.io/docs/prometheus/2.25/configuration/configuration/) `prometheus.yml` (try [this example](https://git.launchpad.net/~canonical-server/ubuntu-docker-images/+git/prometheus/plain/examples/config/prometheus.yml?h=2.25-21.04)). |
+| `-v /path/to/alerts.yml:/etc/prometheus/alerts.yml` | Local [alert configuration file](https://prometheus.io/docs/prometheus/2.25/configuration/configuration/) `alerts.yml` (try [this example](https://git.launchpad.net/~canonical-server/ubuntu-docker-images/+git/prometheus/plain/examples/config/alerts.yml?h=2.25-21.04)). |
 
 
 #### Testing/Debugging
@@ -64,8 +64,8 @@ docker exec -it prometheus-container /bin/bash
 Works with any Kubernetes; if you don't have one, we recommend you [install MicroK8s](https://microk8s.io/) and `microk8s.enable dns storage` then `snap alias microk8s.kubectl kubectl`.
 
 Download
-[prometheus.yml](https://git.launchpad.net/~canonical-server/ubuntu-docker-images/+git/prometheus/plain/examples/config/prometheus.yml?h=2.20-20.04), [alerts.yml](https://git.launchpad.net/~canonical-server/ubuntu-docker-images/+git/prometheus/plain/examples/config/alerts.yml?h=2.20-20.04) and
-[prometheus-deployment.yml](https://git.launchpad.net/~canonical-server/ubuntu-docker-images/+git/prometheus/plain/examples/prometheus-deployment.yml?h=2.20-20.04) and set `containers.prometheus.image` in `prometheus-deployment.yml` to your chosen channel tag (e.g. `ubuntu/prometheus:2.20-20.04_beta`), then:
+[prometheus.yml](https://git.launchpad.net/~canonical-server/ubuntu-docker-images/+git/prometheus/plain/examples/config/prometheus.yml?h=2.25-21.04), [alerts.yml](https://git.launchpad.net/~canonical-server/ubuntu-docker-images/+git/prometheus/plain/examples/config/alerts.yml?h=2.25-21.04) and
+[prometheus-deployment.yml](https://git.launchpad.net/~canonical-server/ubuntu-docker-images/+git/prometheus/plain/examples/prometheus-deployment.yml?h=2.25-21.04) and set `containers.prometheus.image` in `prometheus-deployment.yml` to your chosen channel tag (e.g. `ubuntu/prometheus:2.25-21.04_beta`), then:
 
 ```sh
 kubectl create configmap prometheus-config --from-file=prometheus=prometheus.yml --from-file=prometheus-alerts=alerts.yml
diff --git a/data/prometheus.yaml b/data/prometheus.yaml
index a766c44..e01e1c9 100644
--- a/data/prometheus.yaml
+++ b/data/prometheus.yaml
@@ -3,8 +3,8 @@ main: false
 repo: prometheus
 description: >
   Prometheus is a systems and service monitoring system. It collects metrics from configured targets at given intervals, evaluates rule expressions, displays the results, and can trigger alerts if some condition is observed to be true. Read more on the [Prometheus website](https://prometheus.io/).
-version: 2.20.1
-base: Ubuntu 20.04 LTS
+version: 2.25.2
+base: Ubuntu 21.04
 architectures:
   - amd64
   - arm64
@@ -23,10 +23,10 @@ parameters:
     description: Expose Prometheus server on `localhost:30090`.
   - type: -v
     value: /path/to/prometheus.yml:/etc/prometheus/prometheus.yml
-    description: Local [configuration file](https://prometheus.io/docs/prometheus/2.20/configuration/configuration/) `prometheus.yml` (try [this example](https://git.launchpad.net/~canonical-server/ubuntu-docker-images/+git/prometheus/plain/examples/config/prometheus.yml?h=2.20-20.04)).
+    description: Local [configuration file](https://prometheus.io/docs/prometheus/2.25/configuration/configuration/) `prometheus.yml` (try [this example](https://git.launchpad.net/~canonical-server/ubuntu-docker-images/+git/prometheus/plain/examples/config/prometheus.yml?h=2.25-21.04)).
   - type: -v
     value: /path/to/alerts.yml:/etc/prometheus/alerts.yml
-    description: Local [alert configuration file](https://prometheus.io/docs/prometheus/2.20/configuration/configuration/) `alerts.yml` (try [this example](https://git.launchpad.net/~canonical-server/ubuntu-docker-images/+git/prometheus/plain/examples/config/alerts.yml?h=2.20-20.04)).
+    description: Local [alert configuration file](https://prometheus.io/docs/prometheus/2.25/configuration/configuration/) `alerts.yml` (try [this example](https://git.launchpad.net/~canonical-server/ubuntu-docker-images/+git/prometheus/plain/examples/config/alerts.yml?h=2.25-21.04)).
 debug:
   - nothing
 microk8s:
@@ -34,10 +34,10 @@ microk8s:
     files:
       - key: prometheus
         name: prometheus.yml
-        link: https://git.launchpad.net/~canonical-server/ubuntu-docker-images/+git/prometheus/plain/examples/config/prometheus.yml?h=2.20-20.04
+        link: https://git.launchpad.net/~canonical-server/ubuntu-docker-images/+git/prometheus/plain/examples/config/prometheus.yml?h=2.25-21.04
       - key: prometheus-alerts
         name: alerts.yml
-        link: https://git.launchpad.net/~canonical-server/ubuntu-docker-images/+git/prometheus/plain/examples/config/alerts.yml?h=2.20-20.04
+        link: https://git.launchpad.net/~canonical-server/ubuntu-docker-images/+git/prometheus/plain/examples/config/alerts.yml?h=2.25-21.04
   deploy:
-    link: https://git.launchpad.net/~canonical-server/ubuntu-docker-images/+git/prometheus/plain/examples/prometheus-deployment.yml?h=2.20-20.04
+    link: https://git.launchpad.net/~canonical-server/ubuntu-docker-images/+git/prometheus/plain/examples/prometheus-deployment.yml?h=2.25-21.04
     access: You will now be able to connect to the Prometheus on `http://localhost:30090`.