When writing the haproxy.cfg file, a `TypeError: write() argument must be str, not bytes` is thrown.

Subscribed ~field-critical since this is blocking the cloud handover and the last known charm revision is not available on charmstore

There is a workaround: deploying the haproxy revision 66.

That could be done adding this to an overlay:
```
  landscape-server-proxy:
    charm: haproxy
    channel: stable
    revision: 66
```

Removing ~field-critical and subscribing ~field-high

I believe this is the fix, but I'm still trying to reproduce the bug:

```
$ bzr di
=== modified file 'hooks/hooks.py'
--- old/hooks/hooks.py 2023-08-09 07:20:52 +0000
+++ new/hooks/hooks.py 2023-08-27 13:13:08 +0000
@@ -833,7 +833,7 @@
             full_path = os.path.join(
                 path, "%s.http" % errorfile["http_status"])
             with open(full_path, 'w') as f:
- f.write(base64.b64decode(errorfile["content"]))
+ f.write(base64.b64decode(errorfile["content"]).decode('utf-8'))

         # Write to disk the content of the given SSL certificates
         crts = service_config.get('crts', [])

```

I've tried recreating the issue with the following bundle, but have so far been unable to do so:
```
# Create certs as follows:
# openssl req -x509 -newkey rsa:4096 -keyout key.pem -out cert.pem -sha256 -days 3650 -nodes -subj "/C=XX/ST=StateName/L=CityName/O=CompanyName/OU=CompanySectionName/CN=CommonNameOrHostname"
#
applications:
  haproxy:
    charm: haproxy
    num_units: 1
    series: jammy
    options:
      default_timeouts: queue 60000, connect 5000, client 120000, server 120000
      global_default_bind_options: no-tlsv10
      services: ''
      ssl_cert: include-base64://cert.pem
      ssl_key: include-base64://key.pem
  pollen:
    charm: pollen
    channel: latest/edge
    series: jammy
    num_units: 1
relations:
  - - haproxy
    - pollen
```
Can you confirm if the options mentioned in the bug report are the full list of options to reproduce the bug? Or can you provide a reproducer?

Hello Tom,

Yes, those are the options used for the deployment.

The script used for generating the certs is:
```
#!/bin/bash

# Directory to store certificates
CERTIFICATES_DIR=tls/landscape

# Validity duration in days
DURATION=3560

SUBJECT="/C=BR/ST=Sao Paulo/L=Sao Paulo/O=Customer/CN=landscapeha-1.maas"

mkdir -p ${CERTIFICATES_DIR}

# Generate landscape self-signed certificate
openssl req -x509 -newkey rsa:4096 -nodes \
  -keyout ${CERTIFICATES_DIR}/landscape.key \
  -out ${CERTIFICATES_DIR}/landscape.crt \
  -subj "${SUBJECT}" \
  -days ${DURATION}

echo -n "base64:" > ${CERTIFICATES_DIR}/landscape.crt.b64
base64 ${CERTIFICATES_DIR}/landscape.crt >> ${CERTIFICATES_DIR}/landscape.crt.b64
```

Ok, can you help with providing a reproducer? Which charm is related to this, can you give me a bundle that I can use to reproduce the issue?

Hi Tom,

haproxy is related to landscape-server:

```
- ['landscape-server-haproxy:reverseproxy', 'landscape-server:website']
```

The full bundle: https://pastebin.canonical.com/p/TjmYPDTrbm/

Ok, I've been able to reproduce the issue with the following bundle:
```
# Create certs as follows:
# openssl req -x509 -newkey rsa:4096 -keyout key.pem -out cert.pem -sha256 -days 3650 -nodes -subj "/C=XX/ST=StateName/L=CityName/O=CompanyName/OU=CompanySectionName/CN=CommonNameOrHostname"
#
applications:
  haproxy:
    charm: haproxy
    num_units: 1
    series: jammy
    options:
      default_timeouts: queue 60000, connect 5000, client 120000, server 120000
      global_default_bind_options: no-tlsv10
      services: ''
      ssl_cert: include-base64://cert.pem
      ssl_key: include-base64://key.pem
  landscape-server:
    charm: landscape-server
    series: bionic
    num_units: 1
    options:
      ssl-cert: include-base64://cert.pem
      ssl-key: include-base64://key.pem
  postgresql:
    charm: postgresql
    channel: latest/stable
    series: jammy
    num_units: 1
relations:
  - - haproxy
    - landscape-server
  - - landscape-server:db
    - postgresql:db-admin
```
I've got a fix (not the one I was proposing), but am running into another problem, which I think is related to the version of HAProxy I'm using. I'll test again tomorrow with the same series as in the bundle above to confirm.

The fix I think will be:
```
$ bzr di
=== modified file 'hooks/hooks.py'
--- old/hooks/hooks.py 2023-08-09 07:20:52 +0000
+++ new/hooks/hooks.py 2023-08-29 16:30:45 +0000
@@ -832,7 +832,7 @@
             path = get_service_lib_path(service_name)
             full_path = os.path.join(
                 path, "%s.http" % errorfile["http_status"])
- with open(full_path, 'w') as f:
+ with open(full_path, 'wb') as f:
                 f.write(base64.b64decode(errorfile["content"]))

         # Write to disk the content of the given SSL certificates

```

This has been fixed in revision 75